Dissertations / Theses on the topic 'Tumor pathogenesis'

NK cell lymphoma is one of the cellular malignancies that arise from lymphocytes. Due to its rarity and aggressiveness the detailed molecular pathogenesis of NK cell lymphoma remains to be discovered. There are recent studies showing that the master regulator of B-cell differentiation into plasma cells, the Positive Regulatory Domain containing 1, with ZNF domain(PRDM1) has tumor suppressive function not only in diffuse large B-cell lymphoma (DLBCL), but also in NK cell lymphoma. The PRDM1 has two isoforms, αand β, where the former one is a functional isoform and the latter is a defective isoform with shortened and disrupted positive regulatory domain formed from transcription of internal promoter. By semi -quantitative RT-PCR, PRDM1-αexpression was found to be absent in 80% (4/5) NK cell lines while present in the normal NK cells. Loss of PRDM1 expression suggests its role as tumor suppressor. In order to study the tumor suppressive role of the αisoform of PRDM1, short-hairpin RNA (shRNA) with isoform specific sequence is used to knockdown the expression of PRDM1-αin NK cell lines. Western blot result showed about 40% decrease of PRDM1-αprotein after knockdown. Retroviral infection of the NK cell lines, NKYS and YT which have endogenous α-isoforms of expression, for the delivery of the shRNA was done and were subsequently subjected to in vitro functional analyses including MTS assay, colony formation assay, cell viability test and cell cycle analysis to determine potential effect of the loss of PRDM1-αon the NK cell lines. The PRDM1-αprotein isoform is expected to be able to repress excessive growth of NK cell line. When this isoform is inactivated, the NK cell lines are expected to proliferate significantly than the negative control counterpart in functional analyses. However in this study only YTcell line showed significant proliferation advantage in MTS and colony formation assay after the knockdown of PRDM1-α by shRNA. Cell viability assays and cell cycle analyses failed to show significant changes in both NK cell lines and yet even showed inhibitory effect after the knockdown of the gene. Ectopic expression of PRDM1-αby retroviral infection was done in KHYG cell line to further evaluate its tumor suppressive function. Apoptotic assay on the KHYG cells with ectopic expression of PRDM1-αwas performed and percentage of cells with late apoptosis was found to be significantly higher in this cell line. This suggests that one of the mechanisms for PRDM1-αto act as tumor suppressor is via the apoptosis pathway which in turn promotes the cell death. Future studies will be made to further investigate the effects of knockdown of PRDM-1αby designing another shRNA sequence which knockdown the expression of gene by at least 50% and to further investigate the role of PRDM1-αinthe pathogenesis NK cell lymphomaby proliferation assays, colony formation assay and cell cycle analysis.
published_or_final_version
Pathology
Master
Master of Medical Sciences

Metastasis suppressors regulate multiple steps during the process of dissemination of tumor cells from primary sites to distant organs, while they do not affect the growth of the primary tumor. Previously, we identified NDRG1 (N-myc downstream regulated gene 1) as a tumor metastasis suppressor gene and found that it is negatively involved in metastatic progression of prostate and breast cancers. To elucidate the molecular mechanism of NDRG1 function, we used the yeast two-hybrid system to identify proteins interacting with NDRG1. In the first part of this project, we demonstrate that NDRG1, interacts with the Wnt receptor, LRP6, followed by blocking of the Wnt signaling, and therefore, orchestrates a cellular network that impairs the metastatic progression of tumor cells in vitro and in animal model. We also found that restoring NDRG1 expression by a small molecule compound significantly suppressed the capability of otherwise highly metastatic tumor cells to thrive in circulation and distant organs in animal models. In addition, our analysis of clinical cohorts data indicate that Wnt+/NDRG-/LRP+ signature has a strong predictable value for recurrence-free survival of cancer patients. Collectively, we have identified NDRG1 as a negative master regulator of Wnt signaling during the metastatic progression, and therefore revealed a novel control mechanism of Wnt signaling in tumor progression. Previously, we identified the metastasis promoting transcription factor, ATF3, as a downstream target of NDRG1. Further analysis revealed that the KAI1 promoter contained a consensus binding motif of ATF3, suggesting a possibility that NDRG1 suppresses metastasis through inhibition of ATF3 expression followed by activation of KAI1 gene. In the second part of this project, we examine a possible link between two metastasis suppressor genes, NDRG1 and KAI1, through ATF3. We demonstrated that ectopic expression of NDRG1 was able to augment endogenous KAI1gene expression in prostate cancer cell lines, while silencing NDRG1 accompanied with significant decrease in KAI1 expression in vitro and in vivo. In addition, our results of ChIP analysis indicate that ATF3 indeed bound to the promoter of KAI1 gene. Importantly, our promoter-based analysis revealed that ATF3 modulated KAI1 transcription through cooperation with other endogenous transcription factor as co-activator (ATF3-JunB) or co-repressor (ATF3-NFêB). Moreover, loss of KAI1 expression significantly abrogated NDRG1-mediated metastatic suppression in vitro as well as in a spontaneous metastasis animal model, indicating that KA11 is a functional down-stream target of NDRG1 pathway. Our result of immunohistochemical analysis showed that loss of NDRG1 and KAI1 occurs in parallel as prostate cancer progresses. We also found that a combined expression status of these two genes serves as a strong independent prognostic marker to predict metastasis-free survival of prostate cancer patients. Taken together, our result revealed a novel regulatory network of two metastasis suppressor genes, NDRG1 and KAI1, which together concerted metastasis-suppressive activities through intrinsic transcriptional cascade.

ING4 was identified as a tumor suppressor in 2003 and shown to diminish colony-forming efficiency, induce p53-dependent apoptosis, and arrest cell cycle at G2/M phase. To investigate the role of ING4 in human cutaneous melanoma, we examined ING4 expression using tissue microarray and found that ING4 expression was significantly decreased in malignant melanoma compared with dysplastic nevi and reduced ING4 expression was correlated with melanoma thickness, ulceration and poor 5-year survival of melanoma patients. Multivariate analysis revealed that ING4 expression is an independent prognostic marker in melanoma patients. In melanoma cells, we found that overexpression of ING4 suppressed melanoma cell migration through RhoA-ROCK pathway and cell invasion by inhibiting MMP-2 and MMP-9 activity. We also demonstrated that ING4 inhibits endothelial cell growth and tube formation in vitro through suppressing NF- κB/IL-6 pathway. In vivo model revealed that ING4 inhibited blood vessel formation and recruitment of endothelial cells in matrigel plugs. Strikingly, we found that ING4 is induced by BRMS1. Further experiments showed that BRMS1 expression was significantly decreased in metastatic melanoma compared with primary melanoma or dysplastic nevi, and reduced BRMS1 staining was correlated with AJCC stages and worse 5-year survival of melanoma patients. Moreover, we demonstrated that BRMS1 overexpression inhibited endothelial cell growth and tube formation in vitro through suppressing NF-κB/IL-6 pathway and this BRMS1-mediated IL-6 expression is dependent on NF-κB. In vivo studies indicated that BRMS1 inhibited supportive blood vessel formation in matrigel plugs. Furthermore, we demonstrated that ING4 knockdown abrogated the suppressive effect of BRMS1 on HUVECs growth, while ING4 overexpression inhibited BRMS1 knockdown-induced angiogenesis, indicating BRMS1 as upstream regulator of ING4 in regulating tumor angiogenesis. Finally, we found that the integrate score of six-biomarker system, including ING4, BRMS1 together with other four biomarkers, showed higher variations between melanoma with and without metastasis, and predicted melanoma patients outcome more accurately than individual biomarker. In summary, reduced ING4 expression in melanoma results in deficient suppression of melanoma cell migration and invasion. With BRMS1 as the upstream regulator, ING4 inhibits NF-κB/IL-6 to modulate melanoma angiogenesis. ING4 expression can be a prognostic marker and novel target for human melanoma treatment.

Tumor-like proliferative vascular lesions manifest in several diseases such as peripheral arterial disease (PAD) and atherosclerosis (AS) after arterial injury. The cause of the vascular cell dysfunction in PAD patients is not known. Our recent novel discovery shows that inhibitor of differentiation 3 (ID3) is highly expressed in intimal lesions of clinical vascular disease samples. The central hypothesis of our study is: estrogenic chemical induced dysregulation of ID3 target genes is involved in the development of vascular disease. NHANES data analysis demonstrated higher geometric levels of all 6 PCB congeners in both PAD diagnosed participants and participants at risk of AS when compared to the rest of the population. Adjusted models showed association between higher exposure of PCBs, phthalates, BPA, and increased risk of PAD. Furthermore PCB153 was shown to have the highest geometric mean amongst all PCB congeners in both participants diagnosed with PAD and at risk of AS. Gene expression of ID3 & ID3 candidate targets in blood & tissue studies identified ID3 & ID3 candidate target genes as a driver of vascular disease. Overlapping ID3 & ID3 candidate target genes included: ABCB6, ACP1, BYSL, CAD, CDH15, DCBLD2, DHRS3, DNMT1, ID3, MCM4, and NDUFA7. The ID3 target genes involved in the: focal adhesion pathway were ACTN1, COL1A2, COL3A1, COL6A1, CTNNB1, IBSP, ID3, ITGA8, and MYL2; ECM-receptor interaction were COL1A2, COL3A1, COL6A1, IBSP, ID3, and ITGA8; oxidative phosphorylation pathway ATP5D, ATP5H, ATP6V0B, ATP6V0D1, ATP6V1B2, COX5A, COX7C, COX8A, CYC1, ID3, NDUFA1, NDUFA7, NDUFS4, NDUFV1, NDUFV2; and cell cycle pathway ANAPC10, ATM, CDKN2B, E2F5, MCM3, and MCM4. In summary our results showed an association between exposure to PCBs, phthalates, BPA, and increased risk of PAD and AS, and possible molecular mechanisms of interaction of ID3 target genes and estrogenic chemicals involved in PAD and AS.

Vitiligo is an autoimmune skin disease in which the pigment producing cells of the epidermis, melanocytes, are targeted for destruction by CD8+ T cells specific for melanocyte/melanoma-shared antigens. Previous work has identified IFNg as the central cytokine driving disease pathogenesis in both human patients and in our mouse model of vitiligo. IFNg signaling induces production of the chemokines CXCL9 and CXCL10, which trigger autoreactive T cell migration into the epidermis where effector T cells can target and destroy melanocytes. However, both IFNg and type I IFN signaling through activation of STAT1 proteins can induce transcription of the chemokines CXCL9 and CXCL10. Therefore, it seems reasonable that type I IFN signaling may also contribute to disease pathogenesis. The role of type I IFN in vitiligo is still unclear. Genome wide association studies identified multiple genes within the type I IFN pathway including TICAM1 and IFIH1 as susceptibility loci in vitiligo. One additional study reported increased epidermal staining of CD123, a marker expressed by pDCs, and the type I IFN induced gene MX1 in vitiligo patient skin. However, this study did not show any functional data to support the role of type I IFN signaling in vitiligo pathogenesis. Since the role of type I IFN in vitiligo is ill-defined, we used two different mouse models of vitiligo to functionally determine the role of type I IFN in disease by inducing vitiligo in hosts which lack the type I IFN receptor (IFNaR). In the first model, we induced vitiligo by adoptive transfer of melanocyte-specific CD8 T cells, which are activated in vivo by infection with recombinant vaccinia virus (VACV) expressing their cognate antigen. Vitiligo induction in IFNaR-deficient mice led to the development of severe disease compared to wild type mice. Acceleration and severity of disease was characterized by increased early recruitment of melanocyte-specific CD8 T cells to the skin, increased production of effector cytokines TNFa and IFNg, and reduced PD-1 expression. Increased production of IFNg by CD8 T cells in the skin of IFNaR-deficient mice led to increased expression of the chemokines CXCL9 and CXCL10 driving disease progression. IFNaR-deficient mice also displayed significantly increased VACV titters compared to wild type hosts. This data reveals a role of type I IFN in the clearance of recombinant VACV. This data also suggests that persistent VACV infection and prolonged antigen exposure in IFNaR deficient hosts is likely driving enhanced activation of melanocyte specific CD8 T cells and the subsequent development of severe vitiligo. Since melanocytes and melanoma cells express shared antigens that can be recognized by CD8 T cells, and because the development of vitiligo after melanoma immunotherapy is a positive prognostic factor for patients, we asked whether VACV vaccine therapy in IFNaR deficient mice would enhance the anti-tumor response to melanoma. B16-F10 inoculated wild type and IFNaR-deficient mice received adoptive transfer of melanocyte-specific CD8 T cells in combination with vaccinia virus expressing their cognate antigen to activate the cells in vivo. Treatment of adoptive T cell transfer and infection with VACV in IFNaR-deficient mice revealed significantly reduced tumor burden compared to wild type mice. Improved tumor regression in IFNaR-deficient hosts was characterized by increased infiltrating cytotoxic T lymphocytes and reduced PD-1 expression. These results further demonstrate that in the absence of type I IFN, hosts mount a robust cytotoxic CD8 T cell response against melanocyte/melanoma antigens and this is likely a result of persistent VACV that leads to prolonged CD8 T cell priming. As a result, IFNaR deficient hosts kill tumor cells more efficiently. To determine whether type I IFN regulates disease pathogenesis in the absence of virus infection, we generated a model of vitiligo in which bone marrow derived dendritic cells (BMDCs) pulsed with the cognate antigen were used to prime melanocyte-specific T cells in place of the viral vector. Induction of vitiligo in IFNaR-deficient hosts using BMDCs revealed no significant differences in disease score compared to wild type hosts. This data clearly demonstrates that type I IFN, in contrast to IFNg, is not required during the effector stage of vitiligo pathogenesis in mice. However, since we intentionally activate transferred melanocyte-specific CD8 T cells with VACV or BMDCs expressing their cognate antigen, our mouse models may circumvent the role of type I IFNs in initiating activation of autoreactive cells and driving autoimmunity. Type I IFN is critical for providing innate immune signals that drive the priming of autoreactive T cells through maturation of DCs by inducing antigen presentation, co-stimulatory molecule expression, and migration to the lymph nodes to encounter naïve T cells. Our mouse models of vitiligo may not capture this process. We have addressed this question by using a TLR ligand to activate BMDCs before transfer into hosts. In fact, activation of BMDCs before transfer leads to significantly enhanced vitiligo in mice and this is partially a result of type I IFN signaling on host cells. Thus, we provide evidence that type I IFNs can enhance the activation of melanocyte-specific CD8 T cells and drive autoimmunity. Collectively, our results show that type I IFN signaling has disparate effects on autoreactive T cell priming in a context dependent manner. We reveal that although type I IFN is not required for the effector phase of vitiligo in mice, maturation of DCs and subsequent type I IFN production can enhance the priming of autoreactive T cells and enhance vitiligo severity. Our studies also reveal that type I IFN is required to clear recombinant attenuated VACV infection and vaccine administration in IFNaR deficient hosts led to a robust autoreactive and anti-tumor response. These insights describing the role of type I IFN in autoimmunity and tumor immunology could have important implications for T cell dependent tumor immunotherapy.

Introducció: La malaltia pulmonar obstructiva crònica (MPOC) és un factor de risc independent per el desenvolupament de càncer de pulmó (CP) en els pacients. Els mecanismes encara s’han de dilucidar per a comprendre les relacions entre MPOC i CP. Hipòtesi: Els components del microambient tumoral poden diferir en els tumors de pacients amb CP amb i sense MPOC. La immunoteràpia també pot reduir la càrrega tumoral a través de diversos mecanismes biològics. Objectius: 1) Pacients: estudiar el paper del microambient tumoral, les cèl·lules immunitàries, les característiques de l’estroma i la sobreactivació de PARP en el procés de tumorigènesi en pacients amb CP amb i sense MPOC. 2) Ratolins: avaluar els efectes de la immunoteràpia en la grandària tumoral mitjançant l’anàlisi de diversos mecanismes biològics com l’estrès oxidatiu, l’apoptosi i l’autofàgia. Mètodes: 1) Pacients: es van reclutar 90 pacients amb MPOC-CP i 43 pacients només amb CP procedents de la cohort Càncer de Pulmó Mar (Barcelona) des de l’any 2008 fins al 2019. Es van obtenir mostres pulmonars tumorals i no tumorals en els pacients mitjançant toracotomia/cirurgia toracoscòpica assistida per vídeo (VATS), sempre previ a la quimioteràpia i/o radioteràpia. 2) Ratolins: dos grups de ratolins Balb/c amb CP induït mitjançant la inoculació subcutània de cèl·lules d’adenocarcinoma pulmonar LP07: ratolins tractats i no tractats, n = 9/grup. Al grup tractat se li va administrar un còctel d’anticossos monoclonals (anti-PD-L1, anti-CTLA-4, anti-CD19 i anti-CD137) i una solució tampó (PBS) als ratolins control. Es van obtenir els tumors en tots els ratolins per dur a terme l’estudi (30 dies). Anàlisi biològic: es van utilitzar Western-blot, immunohistoquímica, ELISA, cultius cel·lulars, i immunofluorescència per avaluar els marcadors biològics objecte d’estudi en cada model i tipus de mostres. Resultats: 1) Pacients: els tumors pulmonars de pacients amb MPOC van mostrar nivells més baixos d’estructures limfoides terciàries (ETLs) i centres germinals (CG) respecte dels pacients sense MPOC. Els nivells més baixos de ETLs i cèl·lules B en els tumors pulmonars es van associar amb una pitjor supervivència a 10 anys, especialment en aquells amb MPOC. En l’estroma tumoral, la presència de MPOC no es va associar a diferències en els components de l’estroma com ara la matriu extracel·lular, els fibroblasts associats al càncer o les cèl·lules endotelials. A més, els nivells de dany de l’ADN i la consegüent activació de PARP estaven més elevats només en els tumors pulmonars dels pacients amb MPOC, mentre que l’expressió dels enzims PARP-1 i PARP-2 estaven disminuïdes en els tumors pulmonars respecte de les no tumorals, independentment de la presència de MPOC. 2) Ratolins: la immunoteràpia va reduir la càrrega tumoral a través de l’augment dels nivells de l’estrès oxidatiu, apoptosi, autofàgia i de vies de senyalització com NF-kB i sirtuin-1 en tumors dels ratolins tractats comparant amb els ratolins amb CP sense immunoteràpia. Conclusions: El microambient immunològic tumoral, els components de l’estroma i l’activitat de PARP s’expressen de forma clarament diferenciada en els tumors pulmonars de pacients amb CP amb MPOC respecte dels pacients sense MPOC. La reducció en la formació de ELTs i CGs, l’augment en el dany de l’ADN i la sobreactivació de PARP probablement contribueixin a la major susceptibilitat per desenvolupar CP en pacients amb MPOC. En ratolins tractats amb la immunoteràpia, l’augment dels nivells d’estrès oxidatiu juntament amb l’activació d’apoptosi i autofàgia poden ser part dels mecanismes mitjançant els quals la immunoteràpia redueix la càrrega tumoral. En resum, la presència de MPOC s’ha de tenir en compte en el disseny de teràpies per al CP, incloses la immunoteràpia i la inhibició de l’activació de PARP.
Introducción: La enfermedad pulmonar obstructiva crónica (EPOC) es un factor de riesgo independiente para el desarrollo de cáncer de pulmón (CP) en los pacientes. Los mecanismos aún se quedan por dilucidar a comprender las relaciones entre EPOC y CP. Hipótesis: Los componentes del microambiente tumoral pueden diferir en los tumores de pacientes con CP con y sin EPOC. La inmunoterapia también puede reducir la carga tumoral a través de varios mecanismos biológicos. Objetivos: 1) Pacientes: estudiar el papel del microambiente tumoral, las células inmunes, las características del estroma y la sobreactivación de PARP en el proceso de tumorigénesis en pacientes con CP con y sin EPOC. 2) Ratones: evaluar los efectos de la inmunoterapia en el tamaño tumoral mediante el análisis de varios mecanismos biológicos como el estrés oxidativo, la apoptosis y la autofagia. Métodos: 1) Pacientes: se reclutaron 90 pacientes con EPOC-CP y 43 pacientes solo con CP procedentes de la Cohorte Cáncer de Pulmón Mar, Barcelona, desde el año 2008 hasta el 2019. Se obtuvieron muestras pulmonares tumorales y no tumorales en los pacientes mediante toracotomía/cirugía toracoscópica asistida por video (VATS), siempre previo a la quimioterapia y/o radioterapia. 2) Ratones: dos grupos de ratones BALB /c con CP inducido mediante la inoculación subcutánea de células de adenocarcinoma pulmonar LP07: ratones tratados y no tratados, n= 9/grupo. Al grupo tratado se le administró un cóctel de anticuerpos monoclonales (anti-PD-L1, anti-CTLA-4, anti-CD19 y anti-CD137) y una solución tampón (PBS) a los ratones control. Se obtuvieron los tumores en todos los ratones al final del estudio (30 días). Análisis biológico: se utilizaron Western-blot, inmunohistoquímica, ELISA, cultivos celulares, y inmunofluorescencia para evaluar los marcadores biológicos objeto de estudio en cada modelo y tipos de muestras. Resultados: 1) Pacientes: los tumores pulmonares de pacientes con EPOC mostraron niveles más bajos de estructuras linfoides terciarias (ETLs) y centros germinales (CG) respecto de los pacientes sin EPOC. Los niveles más bajos de ELTs y células B en los tumores pulmonares se asociaron con una peor supervivencia a 10 años, especialmente en aquéllos con EPOC. En el estroma tumoral, la presencia de EPOC no se asoció a diferencias en los componentes del estroma tales como la matriz extracelular, los fibroblastos asociados al cáncer o las células endoteliales. Además, los niveles de daño del ADN y la consiguiente activación de PARP estaban más elevados solamente en los tumores pulmonares de los pacientes con EPOC, mientras que la expresión de las enzimas PARP-1 y PARP-2 estaban disminuidas en los tumores pulmonares respecto de las no tumorales, independientemente de la presencia de EPOC. 2) Ratones: la inmunoterapia redujo la carga tumoral a través del aumento de los niveles del estrés oxidativo, apoptosis, autofagia y de vías de señalización como NF-kB y sirtuin-1 en tumores de los ratones tratados comparando con los ratones con CP sin inmunoterapia. Conclusiones: El microambiente inmunológico tumoral, los componentes del estroma y la actividad de PARP se expresan de forma claramente diferenciada en los tumores pulmonares de pacientes con CP con EPOC respecto de los pacientes sin EPOC. La reducción en la formación de ELTs y CGs, el aumento en el daño del ADN y la sobreactivación de PARP probablemente contribuyan a la mayor susceptibilidad para desarrollar CP en pacientes con EPOC. En ratones tratados con la inmunoterapia, el aumento de los niveles de estrés oxidativo junto con la activación de apoptosis y autofagia pueden ser parte de los mecanismos mediante los cuales la inmunoterapia reduce la carga tumoral. En resumen, la presencia de EPOC debe tenerse en cuenta en el diseño de terapias para el CP, incluidas la inmunoterapia y la inhibición de la activación de PARP.
Background: Lung cancer (LC) is a leading cause of death worldwide. Chronic obstructive pulmonary disease (COPD) is a highly prevalent lung disease. COPD has been well established as an independent risk factor for lung tumorigenesis in patients. However, the biological mechanisms that explain the possible associations between lung cancer and COPD remain to be fully elucidated. Hypothesis: The tumor microenvironment components (immune profile, stroma, cytokines, and PARP activation) may differ in tumors of lung cancer patients with and without COPD. Immunotherapy may also reduce tumor burden through several biological events. Objectives: 1) Studies in patients: to elucidate the role of the biological events: tumor microenvironment, immune cell composition, stroma characteristics, and PARP overactivation in the process of tumorigenesis in tumors of patients with and without underlying COPD; 2) Mouse study: to evaluate the effects of immunotherapy on tumor burden through the analyses of several biological mechanisms such as oxidative stress, apoptosis, and autophagy. Methods: Two models were used: 1) Studies in patients: 90 LC patients with underlying COPD and 43 LC-only patients were recruited from 2008 to 2019 from the Lung Cancer Mar Cohort, Barcelona. Lung tumor and the surrounding non-tumor lung specimens were obtained from all study patients through thoracotomy or video-assisted thoracoscopic surgery (VATS) prior to chemotherapy and/or radiotherapy; 2) Mouse study: Two groups of wild-type BALB/C mice with experimental lung cancer (subcutaneous inoculation of LP07 adenocarcinoma cells in the left flank of mice) were established: treated and non-treated mice, n=9/group. In the treatment group, lung cancer mice were treated with a cocktail of monoclonal antibodies (intraperitoneal injection, anti-PD-L1, anti-CTLA-4, anti-CD19, and anti-CD137). Lung tumors were obtained from all mice. Biological analysis: laboratory techniques such as western-blot, immunohistochemistry, ELISA, cell culture, and immunofluorescence were used to assess the target biological markers in each study. Results: 1) Studies in patients: lung tumors of patients with underlying COPD showed lower levels of tertiary lymphoid structures (TLSs) compared to lung cancer only patients. Moreover, lower levels of TLS and B cells in lung tumors were associated with poorer 10-year overall survival rates of patients, especially in those with underlying COPD. In tumor stroma, the presence of COPD did not elicit any significant difference in levels of extracellular matrix, cancer-associated fibroblasts or endothelial cells. In addition, DNA damage and PARP activation levels were higher only in lung tumors of patients with underlying COPD, while PARP-1 and PARP-2 enzyme expression levels were lower in lung tumors compared to non-tumor specimens irrespective of the presence of COPD. 2) Mouse study: treatment with immunotherapy reduced tumor burden through increased levels of oxidative stress, apoptosis, autophagy, and signaling pathways such as NF-kB and sirtuin-1 in tumors of the treated mice compared to tumors of non-treated animals. Conclusions: Tumor immune microenvironment, stroma components, and PARP are differentially expressed in lung tumors of lung cancer patients with underlying COPD. The reduction in TLS and GC formation, the rise in DNA damage, and PARP overactivation probably contribute to the greater susceptibility of COPD patients to develop lung tumors. In mice treated with the combination of monoclonal antibodies, increased levels of oxidative stress along with activated apoptosis and autophagy may be part of the mechanisms whereby immunotherapy may reduce tumor burden. In conclusion, the presence of COPD should be considered when designing therapeutic strategies of lung cancer including immunotherapy as well as PARP activity inhibition.
Universitat Autònoma de Barcelona. Programa de Doctorat en Medicina

EBAG9 (estrogen receptor-binding fragment-associated gene 9) hat als unabhängiger prognostischer Marker viel Aufmerksamkeit erregt, da in einigen Tumoren hohe Expressionsraten und Tumorentwicklung korrelieren. In diesen Fällen ist eine hohe EBAG9 Expression häufig mit einer schlechten klinischen Prognose verbunden. EBAG9 ist ein ubiquitär exprimiertes Golgi Protein. Aktuelle Daten demonstrieren, dass es in sekretorischen Zellen an der regulierten Exozytose und an der zytotoxischen Funktion von Lymphozyten beteiligt ist. In epithelialen Zellen führt es zur Generierung von Tumor-assoziierten O-Glykanen, welche ein Erkennungsmerkmal vieler Krebsarten sind. In dieser Arbeit wurde der pathogenetische Zusammenhang zwischen EBAG9 Expression und der Veränderung des zellulären Glykoms untersucht. Um einen tieferen Einblick in die zelluläre Funktion von EBAG9 in epithelialen Zellen zu gewinnen, wurden Zellen mit tumorähnlicher EBAG9 Expression verwendet. Innerhalb dieser Arbeit wurde demonstriert, dass EBAG9 mit anterograden COPI Vesikeln assoziiert und zwischen dem ER-Golgi intermediären Kompartiment und cis-Golgi pendelt. EBAG9 verursacht eine Verzögerung des anterograden Transportes vom ER zum Golgi und verändert die Lokalisation von Komponenten der ER Qualitätskontrolle und des Glycosylierungsapparates. Auf der anderen Seite beschleunigt die verminderte Expression von EBAG9 den Proteintransport durch den Golgi und verstärkt die Aktivität von Mannosidase II. Mechanistisch betrachtet verhindert EBAG9 die Rekrutierung von ArfGAP1 an die Membran. Dies beeinträchtigt das Auflösen der COPI Vesikelhülle und somit die Fusion von Vesikeln am cis-Golgi. Damit agiert EBAG9 in epithelialen Zellen als negativer Regulator des COPI-abhängigen ERGolgi Transportes und stellt damit ein neues phatogenetisches Prinzip dar, bei dem die Beeinflussung des intrazellulären Transportes zu der Entstehung von Tumor-assoziierten Glykanen führt.
The estrogen receptor-binding fragment-associated gene 9 (EBAG9) has received increased attention as an independent prognostic marker for disease-specific survival since in some human tumor entities high expression levels correlate with tumor progression and poor clinical prognosis. Interestingly, EBAG9 was identified as an ubiquitously expressed Golgi protein. Recent data demonstrate an involvement in regulated exocytosis in secretory cells and the cytotoxic functions of lymphocytes. However, EBAG9 is expressed in essentially all mammalian tissues, and in epithelial cells it has been identified as a modulator of tumorassociated O-linked glycan expression, a hallmark of many carcinomas. This thesis addresses the pathogenetic link between EBAG9 expression and the alteration of the cellular glycome. To gain further insights into the cellular functions of EBAG9 in epithelial cells, tumor-associated EBAG9 overexpression was mimicked in living cells. It was demonstrated that EBAG9 associates with anterograde COPI-coated carriers and shuttles between the ER-Golgi intermediate compartment and cis-Golgi stacks. EBAG9 overexpression imposes a delay in anterograde ER-to-Golgi transport and mislocalizes components of the ER quality-control and glycosylation machinery. Conversely, EBAG9 downregulation accelerates glycoprotein transport through the Golgi and enhances mannosidase activity. Functionally, EBAG9 impairs ArfGAP1 recruitment to membranes and consequently, interferes with the disassembly of the coat lattice at the cis-Golgi prior to fusion. Thus, EBAG9 acts as a negative regulator of a COPI-dependent ER-to-Golgi transport pathway in epithelial cells and represents a novel pathogenetic principle in which interference with intracellular membrane trafficking results in the emergence of a tumor-associated glycome.

Die Expression homöostatischer Chemokinrezeptoren auf hämatopoetischen Neoplasien wird zunehmend mit tumorpathogenen Funktionen in Zusammenhang gebracht. In der Arbeit wurden Funktionen der Rezeptoren CXCR7 und CCR7 in der Pathogenese lymphatischer Erkrankungen anhand von Mausmodellen charakterisiert. Für CXCR7 konnte in der normalen Differenzierung von T-Zellen eine schwache Expression in murinen Thymozyten, dagegen eine verstärkte, vor allem intrazellulär lokalisierte Expression in peripheren aktivierten T-Zellen identifiziert werden. Eine aberrante Überexpression lag in humanen Zelllinien, aber auch in primären Fällen von T-ALL und klassischen Hodgkin-Lymphomen vor. Die Analyse eines retroviralen Überexpressionsmodells ergab für CXCR7 die Funktion als anti-apoptotischer Kostimulator während der thymischen beta-Selektion. Im Signaltransduktionskomplex mit CXCR4 und dem präTCR vermittelte CXCR7 einen effizienteren DN3-zu-DN4 Übergang. Unreife Thymozyten waren durch eine verstärkte Apoptoseresistenz und Expression von anti-apoptotischen Bcl2-Molekülen charakterisiert. Dies könnte CXCR7 überexprimierende Thymozyten putativ empfänglicher für die Entwicklung von T-ALLs machen. Für CCR7 konnten in der Arbeit bedeutende Funktionen in der organspezifischen Dissemination von B-Zelllymphomen identifiziert werden. Unter Verwendung des Eµ-Myc-Mausmodells wurde gezeigt, dass Eµ-Myc Lymphomzellen CCR7-abhängig in die T-Zellzone von Milz und Lymphknoten einwandern und dort durch reziproke Interaktionen mit gp38+ FRCs und DCs entscheidende Überlebenfaktoren, darunter Ihh, Igf-1 und VCAM-1, erhalten. Die Lymphomzellen vermittelten darüber hinaus eine aktive Veränderung der Stromazellzusammensetzung, welche durch ein expandiertes FRC-Netzwerk, durch die Induktion putativ immunsupprimierender DCs und durch ein inflammatorisches Milieu charakterisiert war. Eine Inhibition der Lymphom-Stroma-Interaktionen könnte daher eine neue Strategie der Lymphomtherapie darstellen.
In recent years the expression of homeostatic chemokine receptors on hematological tumors was increasingly associated with tumor pathogenic functions. Within this thesis, functions of the chemokine receptors CXCR7 und CCR7 in the pathogenesis of lymphoid diseases were characterized using different mouse models. For CXCR7, low expression levels were detected in murine thymocytes during normal T cell development. Enhanced expression was found mainly intracellularly in peripheral activated T cells. An aberrant overexpression was identified in human cell lines and primary cases of T-ALL and classical Hodgkin lymphoma. The analysis of a retroviral overexpression model suggested a function of CXCR7 as an anti-apoptotic costimulator during thymic beta-selection. In a functional complex with CXCR4 and the preTCR CXCR7 mediated a more efficient DN3-to-DN4 transition. CXCR7 expressing thymocytes were characterized by enhanced apoptosis resistance and expression of anti-apoptotic Bcl2-family genes. Thus, CXCR7 could putatively make immature thymocytes more susceptible to develop T-ALL. In addition, new insights into the function of CCR7 in the context B cell lymphoma dissemination were gained within this thesis. Applying the Eµ-Myc mouse model, CCR7 was shown to mediate the specific homing of Eµ-Myc lymphoma cells into the T cell zone of spleen and lymph nodes. Here, lymphoma cells received pivotal survival signals following reciprocal interactions with gp38+ FRCs and DCs, amongst them Ihh, Igf-1 and VCAM-1. Moreover, the lymphoma cells induced a survival promoting active remodelling of the T cell zone stroma, which was characterized by the expansion of the FRC network, by the induction of putatively immune suppressive DCs and by the induction of a pro-inflammatory milieu. Therefore, an inhibition of lymphoma-stroma interactions could provide a new strategy in lymphoma therapy.

The type II tumour suppressor ING3 has been shown to modulate transcription, cell cycle control, and apoptosis. To investigate the putative role of ING3 in melanoma development, we examined the expression of ING3 in 58 dysplastic nevi, 114 primary melanomas, and 50 metastatic melanomas with tissue microarray and immunohistochemistry. Overall ING3 was reduced in metastatic melanomas compared with dyslastic nevi and primary melanomas. Reduced nuclear ING3 staining also correlated with melanoma progression, increased cytoplasmic ING3 level, tumour location at sun-exposed sites, and a poorer disease-specific 5-year survival of patients with primary melanoma. Multivariate analysis revealed that nuclear ING3 staining can independently predict patient outcome in primary melanomas. In melanoma cells, ING3 expression was rapidly induced by UV irradiation. Using stable clones of melanoma cells overexpressing ING3, we showed that ING3 significantly promoted UV-induced apoptosis. Unlike its homologues ING1b and ING2, ING3-enhanced apoptosis upon UV irradiation was independent of functional p53. Furthermore, ING3 did not affect the expression of mitochondrial proteins but increased the cleavage of Bid and caspases. Moreover, ING3 upregulated Fas expression and ING3-mediated apoptosis was blocked by inhibiting caspase-8 or Fas activation. Knockdown of ING3 expression decreased UV-induced apoptosis remarkably, suggesting that ING3 plays a crucial role in cellular response to UV radiation. To explore how ING3 is deregulated in advanced melanomas, we examined ING3 expression in metastatic melanoma cells and found that ING3 was downregulated due to a rapid protein turnover in these cells. Further studies demonstrated that ING3 undergoes degradation via the ubiquitin-proteasome pathway. We also demonstrate that ING3 interacts with the SCF (Skp1/Cul1/Roc1/Skp2) E3 ligase complex. Knockdown of Cul1 or Skp2 significantly stabilized ING3 in melanoma cells. In addition, lysine residue 96 is essential for ING3 ubiquitination as its mutation to arginine completely abrogated ING3 turnover and enhanced ING3-stimulatd apoptosis upon UV irradiation. Taken together, ING3 is deregulated in melanomas as a result of both nucleus-to-cytoplasm shift and rapid degradation. The level of ING3 in the nucleus may be an important marker for human melanoma progression and prognosis. Restoration of ING3 expression significantly sensitizes melanoma cells to UV radiation through the activation of Fas/caspase-8 pathway.

Canine Transmissible Venereal Tumour (CTVT) is a neoplastic disease occurring naturally in dogs. CTVT is usually sexually transmitted, but transmission may occur by licking, biting, or scratching tumour-affected areas. Cytogenetic studies directed to verify the cell transmissibility of the CTVT showed that the tumour cells are characterized by a rearranged karyotype, which is similar in tumours from in different parts of the world. Thus it was postulated that that the transmissible agent causing the CTVT is the tumour cell itself and that all worldwide CTVT have a clonal origin. Given the lack of a definitive proof of the cellular transmission and clonal origin of CTVT, in this PhD project, I tested this hypothesis by analysing the genetic distance between host and tumour and between tumours, using molecular genetic markers including major histocompatibility (MHC) genes, microsatellite loci, and mitochondrial (mt) DNA in matched tumour and normal tissues from naturally occurring tumours collected worldwide. Here I demonstrate that tumours are genetically distinct from their hosts and that the tumours obtained from 5 different continents are derived from a single neoplastic clone. During its evolution CTVT has diverged into two distinct phylogenetic subclades. Although naturally occurring CTVTs are observed only in dogs, CTVT has been reported to be experimentally transmitted by inoculation of tumour cells in other species of the Canidae family such as foxes, coyotes and jackals, thus raising questions about its capacity to grow as an allograft or xenograft and its phylogenetic origin of CTVT. I therefore examined MHC gene transcription in a progressive growing tumour and observed MHC class I and II downregulation. In this study phylogenetic analyses indicate that CTVT most likely originated from a wolf or an East Asian breed of dog. CTVT has been described for the first time in 1876 by Novinsky, thus arguing for an age of at least 130 years old. Here phylogenetic analysis based on microsatellites suggests that CTVT originated between 250 and 2500 years ago.

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of haematological stem cell malignancies characterised by proliferation of one or more cells of the myeloid lineage. The molecular investigation of MPN was revolutionized in 2005 by the finding that approximately 95% of cases with polycythaemia vera (PV) and 50-60% of cases of essential thrombocythaemia (ET) and primary myelofibrosis (PMF) are characterised by a single acquired mutation, JAK2 V617F. My study has focused on four principal areas: (i) Involvement of V617F in other myeloid disorders. After developing sensitive methods to detect and quantify V617F, this mutation was identified in 17% of cases of atypical chronic myeloid leukaemia (17/99) as well as other atypical MPN, thus demonstrating that it was more widely involved in myeloid disorders that initially thought. Homozygosity of V617F was shown to have arisen by acquired uniparental disomy (UPD) and examination of two cases with V617F plus either KIT D816V or BCR-ABL demonstrated that the mutations had arisen in independent clones. (ii) In vitro assays to predict imatinib sensitivity. Haemopoietic colony and liquid cultures were used to determine if peripheral blood or bone marrow cells from atypical MPN cases (n=200) were sensitive to imatinib. Of those that responded in one or both cultures (n=185) some had known abnormalities of PDGFRA or PDGFRB, but a significant minority proved negative for all molecular tests suggesting the presence of uncharacterised imatinib-sensitive mutations. (iii) V617F as a marker of response to therapy. JAK2 V617F was used as a molecular marker to monitor the response of PV patients (n=21) to therapy with imatinib and interferon-α. Neither therapy eradicated V617F but there was a modest reduction in %V617F which correlated with haematological response. By contrast, in those patients that did not respond (n=13) the %V617F marginally increased. (iv) Genetic predisposition to MPN. Whilst investigating the possible contribution of JAK2 single nucleotide polymorphisms to the phenotypic diversity associated with V617F, marked skewing of alleles associated with the mutation was observed. Further investigation revealed that V617Fassociated disease is strongly associated with a specific constitutional JAK2 haplotype, designated 46/1, in all three disease entities compared to healthy controls (PV, n=192, P=2.9x10-16; ET, n=78, P=8.2x10-9 and MF, n=41, P=8.0x10-5). Furthermore, allele-specific PCR demonstrated that V617F specifically arises on the 46/1 allele in most cases. The 46/1 JAK2 haplotype thus predisposes to the development of V617F associated MPNs (OR=3.7; 95% CI 3.1-4.3) and provides a model whereby a constitutional genetic factor is associated with an increased risk of acquiring a specific somatic mutation.

Le cancer du poumon est un probleme de sante publique majeur et il represente la premiere cause de mort par cancer chez l'homme dans le monde. Nous nous sommes interesses a l'analyse des desequilibres genetiques dans les tumeurs bronchiques dans le but d'etablir une cartographie precise des zones du genome associees a cette pathologie. Nous avons utilise la technique d'hybridation genomique comparative in situ (cgh) qui met en evidence de maniere rapide et globale l'ensemble des desequilibres genetiques presents dans une tumeur. Nous avons mis au point un protocole permettant d'obtenir des preparations de chromosomes metaphasiques adaptees a l'hybridation de type cgh et determine les conditions optimales requises pour une analyse cgh fiable et reproductible. Nous avons realise une etude cgh sur 11 tumeurs neuroendocrines de haut garde de malignite et 11 tumeurs non neuroendocrines. Nous avons montre que ces deux phenotypes partagent des anomalies communes et que certaines anomalies sont retrouvees specifiquement dans un phenotype. Ces resultats renforcent la notion qu'il existerait deux voies differentes de tumorgenese conduisant a la formation de ces deux classes de cancers bronchiques. Nous avons analyse un ensemble de 74 tumeurs bronchiques incluant tous les types histologiques. Notre but etant d'une part, d'identifier les regions chromosomiques specifiques pour chaque type histologique et d'autre part, d'etablir des correlations entre les anomalies chromosomiques mises en evidence par cgh, le type de cancer (ne, non ne), le type histologique et le degre de malignite de la tumeur. Les resultats ont montre des anomalies chromosomiques communes et differentes dans les differents types histologiques et nous avons etabli un patron d'anomalies chromosomiques pour chaque type histologique. Le nombre, le type et la distribution des anomalies permet de distinguer les carcinomes de haut grade et de bas grade de malignite. De plus, certaines anomalies semblent etre plus particulierement impliquees dans le caractere agressif des tumeurs. Ces resultats permettront ainsi d'orienter les recherches moleculaires visant a caracteriser les genes impliques dans le processus de cancerogenese.

Epstein-Barr virus (EBV) is strongly associated with rare but aggressive lymphoproliferative diseases of NK and T cell origin. The finding of clonal and episomal forms of the virus in tumour cells from these clinically diverse diseases indicates involvement of EBV at an early stage of lymphomagenesis. However, many fundamental questions about EBV’s contribution to pathogenesis remain unanswered. In vivo analyses herein found that infection of tonsillar (but not peripheral blood) T cells occasionally occurred in primary and persistent infection, whilst infection of NK cells was a rare event. By contrast, a high EBV load was found in peripheral blood NK cells from 3 adult patients with EBV-associated haemophagocytic-lymphohistiocytosis, a disease previously associated with CD8+ T cell infection in children. Complementary studies examined EBV latent gene expression in EBV+ T/NK malignancies. Notwithstanding an apparent absence of latent membrane protein 2A and 2B (LMP2A/B), these tumour cells were recognised and killed by LMP2-specific cytotoxic T lymphocytes. This paradox was resolved by identifying a novel LMP2 mRNA, initiated from within the terminal repeat (TR) region of the viral genome and containing downstream epitope-encoding exons. Expression of LMP2-TR in T/NK cell lines and primary tissue implicates this truncated viral protein in T/NK lymphomagenesis.

Mutations in the ATM gene have previously been identified in CLL tumours. In this project, I have demonstrated that their detection would have prognostic value. With a prevalence of 12%, ATM mutations represent the commonest single gene defect to be detected in CLL tumours and they identified a subgroup of CLL patients that had a significant reduction in both treatment free and overall survival. Furthermore, ATM mutations provided prognostic information that was independent of age, clinical stage, the mutation status of the IGVH genes and TP53 mutations. The temporal acquisition of the ATM mutations and their relationship with loss of an ATM allele via a chromosomal 11q deletion provides clues into their mechanism of action. There was only a partial correlation between CLL tumours with mutations in the ATM gene and those with a chromosome 11q deletion. In certain cases, the ATM mutations represented germ-line changes and in others were acquired very early in the disease course raising the possibility that they might contribute to the initial clonal transformation process. However, in some CLL tumours, the ATM mutations had been acquired after the development of the tumour clone during disease progression indicating that there may be a step-wise acquisition of ATM allelic defects during the ontogeny of CLL. The ATM protein is the key coordinator of the cellular response to DNA double strand breaks. In this study, I showed that bi-allelic defects in the ATM gene lead to deficient ATM dependent responses, including the up regulation of p53, following both ionising irradiation and also treatment with the chemotherapeutic drug, Fludarabine. Thus an important mechanism accounting for the poor outcome in CLL patients with ATM mutations is likely to relate to chemo-resistance. Interestingly, there were differential responses to DNA damage with both irradiation and fludarabine amongst the category of tumours with an 11q deletion according to the status of the remaining ATM allele. Therefore, ATM mutations can stratify tumours with a chromosome 11q deletion into two functional subgroups. The identification of CLL tumours with ATM mutations would therefore predict those patients that will have a poor clinical outcome and be both more likely to require early treatment for their disease. Patients whose tumours had bi-allelic ATM defects will be expected to have deficient responses to DNA damaging chemotherapeutic drugs, while those with mono-allelic ATM defects might identify a group in whom the use of DNA damaging agents could provide selective pressure for the emergence of sub-clones that have subsequently acquired bi-allelic ATM defects.

Collagen is the ligand for the discoidin domain receptor-1 (DDR1), a receptor tyrosine kinase that is over-expressed in Hodgkin lymphoma. However, the role of DDR1 in diffuse large B cell lymphoma (DLBCL) is not known. I showed that DDR1 is over-expressed in a subset of DLBCL where it positively correlates with expression of its collagen ligands, and negatively correlates with expression of mitotic spindle genes. DDR1 correlated genes also overlapped with three aneuploidy signatures and DDR1 expression correlated significantly with autosomal aneuploidy index. RNAseq analysis revealed that over-expression of DDR1 in primary germinal centre B cells down-regulated expression of CENPE, an essential component of the mitotic spindle checkpoint that when inactivated leads to chromosome mis-segregation and aneuploidy. CENPE expression was also significantly reduced in primary DLBCL. Moreover, I showed that the constitutive activation of DDR1 in an in vitro lymphoma model led to aneuploidy. Finally, I showed that DDR1 can be inhibited by three small molecules and established the basis for in vivo model to test these inhibitors in DLBCL xenograft. My data provide evidence that DDR1 can induce aneuploidy in B cells, and as such identify a mechanism to potentially explain the link between chronic inflammation and lymphomagenesis.

Central chondroid bone tumours are one of the most common primary bone tumours. Benign central chondroid tumours are termed enchondromas and its malignant counterpart are called chondrosarcomas. Enchondromas are frequently observed on routine imaging. Similarly, chondrosarcomas are the second most common primary bone tumour after osteosarcoma. Imaging is crucial in the diagnosis of central chondroid tumours and in the differentiation of enchondromas from chondrosarcomas. Furthermore, imaging plays a vital role in the staging of chondrosarcomas. In this thesis, the published scientific literature on the role of imaging in the diagnosis of benign chondroid tumours and chondrosarcomas and the role of imaging in the staging of chondrosarcomas is reviewed and summarised. Furthermore, the contribution of the authors’ published work is highlighted in the thesis. The first two articles are review articles which discuss the clinical and imaging features of benign and malignant chondrogenic tumours and the significance of imaging in the diagnosis of these tumours. The third article is an original article which investigates the theory of the pathogenesis of enchondromas. It is widely believed that enchondromas arise from cartilage islands which are displaced from the growth plate during the process of skeletal maturation. However, this theory is unproven, and the origin of this theory was forgotten prior to the authors’ study. Based on the incidental prevalence of enchondromas of the knee in the adult population of 2.9%, the study assesses the prevalence of cartilage islands/enchondromas in skeletally immature patients. In this study, no cartilage islands/enchondromas in skeletally immature patients were identified. The study therefore shows the rarity of enchondromas in skeletally immature individuals which is in contrast to the adult population. Furthermore, in view of the absence of cartilage islands in this study, the study raises doubts about the validity of the unproven theory. Lastly, the very origin of this theory is rediscovered in this thesis which has been forgotten in modern medicine. The fourth article is an original article which evaluates the role of diffusion-weighted MRI (DWI) in the diagnosis of central cartilage tumours. Prior to the authors’ study the role of DWI in the diagnosis of central cartilage tumours was uncertain. The authors’ study demonstrates that DWI cannot be used to differentiate between enchondromas and chondrosarcomas and that DWI does not aid in the distinction of low-grade chondroid tumours from high-grade chondrosarcomas. This is a finding which was not known prior to the study. The fifth article is an original article which assesses the utility of conventional MRI in the differentiation of low-grade from high-grade chondrosarcomas of long bone. Prior to the authors’ study the role of conventional MRI in the differentiation of low- grade from high-grade chondrosarcomas of long bone was unknown. The authors’ study shows that bone expansion, active periostitis, soft tissue mass and tumour length can be used to differentiate high-grade from low-grade chondral lesions of long bone on conventional MRI. Furthermore, the presence of these four MRI features shows a diagnostic accuracy of 95.6%. These findings were not known prior to the study and have significantly furthered the knowledge about the role of conventional MRI in the grading of chondrosarcoma of long bone. The sixth article is an original article which evaluates the role of bone scintigraphy and Computed Tomography of the chest in the staging of chondrosarcoma of bone. Whilst guidelines regarding the staging of bone sarcomas state that bone scintigraphy should be performed to assess for the presence of skeletal metastases and that Computed Tomography (CT) of the chest should be performed to evaluate for possible pulmonary metastases, there has been no research on the utility of bone scintigraphy in chondrosarcoma of bone and on the role of CT-chest in the staging of chondrosarcomas. Furthermore, the prevalence of skeletal and pulmonary metastases of chondrosarcoma at presentation was unknown prior to this study. The authors’ study demonstrated no skeletal metastases on bone scintigraphy in chondrosarcoma of bone at presentation. In contrast, pulmonary metastases were observed in approximately 5% of all patients with chondrosarcoma at presentation on CT-chest. The finding therefore demonstrates the rarity of skeletal metastases in chondrosarcoma of bone at presentation which is in contrast to osteosarcoma and Ewing sarcoma. The study therefore concludes that there is little role for skeletal scintigraphy in the surgical staging of chondrosarcoma. In contrast, the study shows that there is a role for CT-chest in the staging of chondrosarcoma. These above described findings are important new findings and represent a significant contribution to the knowledge base regarding metastatic behaviour of chondrosarcomas at presentation and regarding the staging of chondrosarcoma of bone. In summary, the authors’ publications have significantly enhanced and furthered the understanding of the pathogenesis of enchondromas, the role of functional MRI in the differentiation of enchondromas from chondrosarcomas, the utility of MRI in the grading of chondrosarcomas and the role of skeletal scintigraphy in the staging of chondrosarcomas.

Introduction: COPD (Chronic Obstructive Pulmonary Disease) and lung cancer are related conditions associated with inflammation. Relatively little focus has been given to the endothelium, through which inflammatory cells transmigrate to reach the lung. We sought to determine if coding and non-coding alterations in pulmonary endothelium exist in COPD and lung cancer. Methods: Patients with and without COPD undergoing thoracic surgery were recruited. Pulmonary Endothelial Cells were isolated from lung and tumour and extracted RNA (ribonucleic acid) used for miRNA (micro-RNA) and mRNA (messenger RNA) microarrays. Ingenuity pathway analysis (IPA) was also carried out. Results: 2071 genes and 43 miRNAs were significantly upregulated in COPD. 4 targets were validated by quantitative polymerase chain reaction, of which miR-181b-3p was chosen for functional validation. Another target, miR-429, was also increased in lung tumour. Several cancer-related pathways such as transforming growth factor- β were altered in the IPA. There was significantly reduced tube formation and endothelial sprouting in Human umbilical vein endothelial cells transfected with miR-181b-3p, consistent with an effect on angiogenesis. Conclusions: Upregulation of miR-181b-3p reduces tube formation and sprouting by endothelial cells. This might be significant in the development of emphysema as lung vasculature is important in the structural maintenance of alveoli.

The complexity of melanoma is pronounced at many levels, whereby both environmental influences and genetic predisposition are involved and interact. Embedded within this complexity is heterogeneity, a defining characteristic of this malignancy. The rearrangement of genomic material on chromosomes 1p, 6q, 9p or 10q, 11q and 17q has been frequently reported during the development and progression of cutaneous malignant melanoma (CMM), suggesting several putative tumour suppressor genes and oncogenes in these regions. The genomic complexity of chromosome 9p21 in melanoma development is well documented. This region encodes a potent cyclin-dependent kinase inhibitor CDKN2/INK4A/p16 as a tumour suppressor gene (TSG) that is frequently inactivated in melanomas. Functional evidence suggested the presence of additional TSG loci in the 9p21-22 chromosome region (Parris et al., 1999). In pursuit of identifying novel TSG(s), our previous group’s collaborative research provided experimental evidence that suggests IFNA1 as a candidate TSG for melanoma development. Therefore, the aim of this work was to provide a further functional validation of such tumour-suppressive activity in CMM. Firstly, I have successfully subcloned IFNA1 cDNA into pcDNA3 expression vector and established a panel of stably IFNA1-expressing clones. Subsequently, I have assessed their tumourigenicity in soft agar by measuring the colony-forming ability of each transfected clone. Expression analyses of IFNA1, at both post-transcriptional and translational levels, were also carried out. I have also demonstrated a strong correlation between anchorage-independent growth in soft agar and IFNA1 expression in qRT-PCR. The antiproliferative and pro-apoptotic effects of IFNα have been widely documented, however, the precise mechanisms that trigger and potentiate this behaviour are not completely known. Based on previous findings, I have investigated whether IFNA1 exerts its antitumoural activity through apoptosis. I was able to demonstrate a moderate relationship between anchorage-independent growth in soft agar and the apoptotic levels in the transfected clones. Although unpersuasive and inconclusive, the results seemed encouraging since this study was carried out using only the highly tumourigenic malignant melanoma UACC903 cell line.

There is an increasing body of evidence indicating an important role for the bioactive signalling lipid S1P (sphingosine 1-phosphate) in cancer. Sphingosine kinase-1 (SPHK1), one of the enzymes responsible for the synthesis of S1P, is reported to be overexpressed in many cancer types; in many cases correlating with increased tumour grade and reduced patient survival. However, the expression of SPHK1, and how it might contribute to lymphomagenesis, has not previously been explored in diffuse large B-cell lymphoma (DLBCL). In chapter 3, I show that SPHK1 overexpression in DLBCL correlates with the expression of known tumour-angiogenic genes. I also describe the characterisation of human umbilical vein endothelial cells (HUVEC) as an in vitro model with which to study the impact of S1P on the endothelial cell transcriptome and to explore the extent to which these changes can be observed in primary DLBCL. In chapter 4, I explore the effects of S1P on the transcription of endothelial cells with a focus on genes associated with leukocyte recruitment. I confirm the S1P-induced upregulation of chemokines and adhesion molecules in HUVEC and show that SPHK1 expression correlates with the expression of stromal cell gene signatures in primary DLBCL. Finally, in chapter 5, I show that I can inhibit S1P-induced signalling in HUVEC with Sphingomab, a monoclonal antibody against S1P. Additionally, I validate the A20 syngeneic model of lymphoma as a relevant system which could be used to study the potential therapeutic targeting of SPHK1-S1P signalling in DLBCL.

Latent membrane protein 1 (LMP1) is an oncogene expressed in a subset of germinal centre (GC)-derived lymphomas including Hodgkin’s lymphoma (HL) and diffuse large B cell lymphoma (DLBCL). However, LMP1 shares functional homology with CD40, a receptor required for normal GC B cell development. Dissecting how LMP1 functions differently from CD40 in GC cells is central to a better understanding of lymphomagenesis and is the subject of this thesis. In Chapter 3, I show that GC B cells can be successfully isolated from normal human tonsils and that these cells retain a GC phenotype upon short-term culture. In Chapter 4 I explore how the transcriptional programmes of LMP1 and CD40 differ in GC B cells and identify a subgroup of genes regulated by LMP1 but not by CD40, which are also concordantly regulated in primary HL cells from which I focus on sphingosine-1-phosphate receptor 2 (S1PR2). I confirm that S1PR2 is an LMP1 target in GC B cells and show that it is not expressed in the tumour cells of the majority of cases of HL and DLBCL. In DLBCL, S1PR2 loss is associated with LMP1 expression. I also provide preliminary evidence that the over-expression of S1PR2 can inhibit the HL cell migration. In Chapter 5, I report my initial attempts to optimise a method for the measurement of the activity of transcription factors in GC B cells which can be used to delineate those pathways activated by LMP1, but not by CD40, in GC B cells.

The Best PhD Thesis in the Faculties of Dentistry, Engineering, Medicine and Science (University of Hong Kong), Li Ka Shing Prize,1997-1999
published_or_final_version
abstract
Pathology
Doctoral
Doctor of Philosophy

Nasopharyngeal carcinoma (NPC) is endemic in Southern China and South East Asia, causally linked to Epstein-Barr virus (EBV) infection, and frequently shows dysregulation in a number of stem cell maintenance signalling pathways. This thesis has endeavoured to investigate the status of one of these pathways; the Hedgehog (HH) signalling pathway, in NPC tumours, and reveals the novel finding that EBV is able to active the HH signalling pathway through autocrine induction of the SHH ligand in the C666.1 authentic EBV-positive NPC-derived cell line and latently infected epithelial carcinoma cell lines. This study demonstrates that constitutive engagement of the HH pathway in EBV-infected epithelial cells in vitro induces the expression of a number of stemness-associated genes and imposes stem-like characteristics. Using epithelial cells expressing individual EBV latent genes, this study also investigates the viral protein responsible for HH dysregulation demonstrating that EBNA1, LMP1 and LMP2A are all capable of inducing SHH ligand and activating the HH pathway, but only LMP1 and LMP2A are able to induce expression of stemness-associated marker genes. These findings not only identify a role for dysregulated HH signalling in NPC oncogenesis but also provide a novel rationale for therapeutic intervention.

In this thesis I have explored different components of the pathogenesis of several related EBV associated cancers. In the first part of the thesis I focus on the microenvironment of two of these cancers, nasopharyngeal carcinoma (NPC) and diffuse large B cell lymphoma (DLBCL). Our group has developed a therapeutic vaccine against EBV which has already been shown to be safe in patients with NPC. Therefore, in the first results chapter (chapter 3), I present a description of the phenotyping of expression of the immune microenvironment including immune checkpoint (ICP) genes and MHC class I and class II genes in NPC tissues. I showed for the first time in NPC tissue samples, two types of PD-L1 expressing tumours: diffuse and marginal. In re-analysis of published data, I found co-expression of immune checkpoint genes and their receptors in EBV positive NPC samples; information which is likely to inform the design of combination immunotherapy in NPC patients. I have shown in my re-analysis of EBV positive NPC that PD-L1 is not up-regulated by LMP-1. In chapter 4, I show the results of studies of the expression of collagen and collagen receptors in DLBCL in which I have identified the over-expression of a potentially novel immune checkpoint receptor, LAIR-1, on the macrophages infiltrating this tumour. In the second part of the thesis I switch my line of inquiry to the tumour cells of EBV-associated cancers, this time focussing on Hodgkin lymphoma (HL), another EBV-associated lymphoma. During the course of the work presented in this chapter I was able to define a role for aberrant sphingosine-1-phosphate (S1P) signalling in driving PI3-K activation mediated through up-regulation of S1PR1 and downregulation of S1PR2 receptors in HL. I also showed that in turn, PI3-K signalling increases the expression of potentially oncogenic downstream transcription factors, such as BATF3 which I have shown to be overexpressed in HL. These data suggest that antagonists of S1P could be considered for the treatment of patients with HL.

Tese de Doutoramento em Ciências Veterinárias, especialidade de Sanidade Animal
Bovine Enzootic Hematuria (BEH) is a disease that affects cattle and water buffalos in specific regions of the globe, mainly associated with the chronic ingestion of bracken fern (Pteridium aquilinum) whose major characteristic is the development of urinary bladder tumors. One of the regions where this disease is endemic is the Azores Archipelago, Portugal. In these Atlantic islands bracken fern finds the appropriate conditions for continuous growth in the farmlands, and thus this toxic plant is frequently available for cattle consumption. The involvement of the Bovine papillomavirus type 2 (BPV2) in the genesis of this disease has been pointed out to be paramount, but some aspects involving the association between bracken fern and Papillomavirus remain unclear. This work aimed to study the role of this infectious agent in the oncological process observed in BEH, and is divided into seven chapters. In the first chapter, the major features, the implications and the etiology of this disease, with a special focus on ptaquiloside and BPV2, are reviewed. Additionally, urinary bladder tumors in man, and the genetic alterations associated to the disease, are briefly revised. The second chapter contains the specific objectives that were sought with the present work, and that resulted in the four experimental chapters that follow. In the third chapter, a detailed histopathological characterization of the urinary bladder lesions found in BEH-affected cattle from the Azores Archipelago which were used in the experimental work, is presented. Furthermore, an immunohistochemical study of the expression of cytokeratins in the epithelial neoplasms is also presented. Our results support previous findings that most urinary bladder BEH-associated lesions are neoplastic, and have epithelial origin. The decrease in the number of neoplastic cells expressing cytokeratin 7 in urinary bladder urothelial tumors was associated with increasing pathological grade and stage, whereas the decrease in the expression of cytokeratin 20 was only associated with increasing stage. The fourth chapter is dedicated to the prevalence and transcriptional activity of BPV2 in the urinary bladder lesions of BEH-affected cattle from the Azores Archipelago. The results obtained show that, though BPV2 is widely distributed within the bovine vii population of the Azores, the viral loads determined are very low, suggesting that BPV2 could be inactive, since no transcriptional activity was detected. In the fifth chapter a quantitative and qualitative gene expression study is presented, comparing the expression levels of cell cycle controlling genes and of a growth factor receptor gene in BPV2 positive and negative epithelial and endothelial bovine urinary bladder tumors of BEH-affected cattle. The expression of TP53, MDM2 and CCND1 genes was above normal, but no differences between BPV2 positive and negative epithelial and endothelial tumors were found. The expression of the EGFR gene was lower both in BPV2 positive epithelial and endothelial tumors when compared with BPV2 negative ones. This possible association between BPV2 infection and lower EGFR should be further investigated in future studies. The sixth chapter presents the preliminary in vitro study through which the effects of BPV2’s oncoproteins in a bovine cell line were assessed. Neoplastic transformation was not achieved, but changes in the cellular growth rate and gene expression patterns were observed, suggesting viral oncoprotein activities yet unknown. The main conclusions of this work are pointed out and discussed in the seventh chapter. The oncological process found BEH and its association with BPV2 are still a matter for further research. The results presented within this thesis provide a better insight into this subject but also open and support new questions worth investigating in future research.
RESUMO - Infeção por Papilomavírus Bovino tipo 2 na patogenia do processo oncológico associado à Hematúria Enzoótica Bovina - A Hematúria Enzoótica Bovina (HEB) é uma doença que afeta bovinos e búfalos em regiões específicas do Globo particularmente relacionada com a ingestão do feto comum (Pteridium aquilinum), sendo um dos aspetos mais relevantes o desenvolvimento de tumores na bexiga dos animais afetados. Uma dessas regiões onde a HEB é endémica é o Arquipélago dos Açores, Portugal. O feto comum encontra nestas ilhas Atlânticas as condições apropriadas para o crescimento constante nas pastagens, fazendo com que esta planta tóxica esteja facilmente acessível aos animais criados em regime extensivo. A participação do Papilomavírus bovino tipo 2 (BPV2) também tem sido apontada como crucial na génese da HEB. Porém, alguns dos aspetos relacionados com a associação entre o feto comum e o Papilomavírus permanecem por esclarecer. O presente trabalho teve como objetivo estudar o papel deste agente infecioso no processo oncológico associado à HEB, estando dividido em sete capítulos...

碩士
國立中山大學
生物醫學科學研究所
91
The annexin-7 (ANX7) gene is located on human chromosome 10q21, a site long been hypothesized to harbor a tumor suppressor gene (TSG) associated with brain, prostate, breast and other cancers. To test whether ANX7 might be a candidate TSG, and its role in the molecular pathogenesis of malignant glioma. We examined the ANX7 expression levels in several kinds of cell lines, 139 glioma specimens and 84 gastric cancer specimences. Consistently, analysis of ANX7 protein expression in human glioma tumor a significantly higher rate (2.14 times) of loss of ANX7 expression in glioblastoma multiformes (GBM) as compared with low grade astrocytoma (p=0.04). The striking correlation ANX7 expression and the differentiation of gastric carcinoma (p = 0.001). ANX7 may play an important role in the tumor progression. Loss or reduced expression of ANX7 is possibly a biomarker for tumor cell progression

博士
國立臺灣大學
漁業科學研究所
99
The infectious pancreatic necrosis virus (IPNV) belongs to the Birnaviridae family of viruses and causes acute contagious diseases in a number of economically important freshwater and marine fish. Previous studies have shown that IPNV induces both atypical apoptosis and secondary necrosis in fish cells. The expression of the survival factor Mcl-1 has been shown to be down-regulated and that of the pro-apoptotic bcl-2 family gene Bad has been shown to be up-regulated by IPNV. IPNV infection can trigger the tyrosine kinase-mediated death pathway and cause the activation of caspase-8 and -3 in virus-infected cells. IPNV can induce Bad-mediated apoptosis followed by secondary necrosis in fish cells, but it is not known how these two types of cell death are regulated by IPNV. Using DNA microarray and quantitative RT-PCR analyses, two major subsets of differentially expressed genes were characterized, including the innate immune response gene TNFα and the pro-apoptotic genes Bad and Bid. In the early replication stage, we observed that the pro-inflammatory cytokine TNFα underwent a rapid six-fold induction. Then during the early-middle replication stages, the TNFα level was eight-fold higher, and the pro-apoptotic Bcl-2 family members Bad and Bid were also up-regulated. Specific inhibitors of TNFα expression (AG-126 or TNFα-specific siRNA) were used to block apoptotic and necrotic death signaling during the early or early-middle stages of IPNV infection. Inhibition of TNFα expression dramatically reduced the activity of the Bad/Bid-mediated apoptotic and Rip1/ROS-mediated necrotic cell death pathways and rescued host cell viability. The Rip1/ROS-mediated secondary necrotic pathway appeared to be reduced in IPNV-infected fish cells during the middle-late stage of infection. We also infected zebrafish embryonic (ZF4) cells with IPNV and analyzed the gene expression patterns of normal and infected cells using quantitative real-time PCR. We identified a number of immune response genes, including ifna, ifng, mx, irf1, irf2, irf4, tnfa, tnfb, il-1b, il-15, il-26, ccl4 and mmp family genes, that are induced after viral infection. Transcriptional regulators, including cebpb, junb, nfkb and stat1, stat4 and stat5, were also up-regulated in IPNV-infected cells. In addition, we used Pathway Studio software to identify TNFα as the factor with the greatest downstream influence among these altered genes. Treating virus-infected cells with an siRNA targeting TNFα inhibited NF-κB expression. To further interrupt the TNFα/NF-κB-mediated pathway, the expression levels of cytokines and metalloproteinases were inhibited in IPNV-infected cells. Using microRNA array and real-time quantitative PCR assays, the expression patterns of microRNAs in IPNV-infected fish cells were characterized during different replication stages of IPNV. We found that the gene transcription levels of miR-132, miR-146a and miR-155 were up-regulated, and miR-125b was down-regulated. Previous studies have shown that the 3’-untranslated regions of TNFα transcripts can be targeted by miR-125b. A miR-125b mimic or a TNFα-specific siRNA was able to down-regulate the expression of TNFα in IPNV-infected cells. Following miR-125b mimic treatment, the viability of IPNV-infected cells was increased. The percentages of apoptotic and necrotic IPNV-infected ZF4 cells that were pretreated with a miR-125b mimic or a TNFα-specific siRNA were decreased, as shown by fluorescence images of Annexin V-fluorescein and PI staining. The activation of caspase-3, -8, and -9 and the formation of ROS were inhibited following miR-125b mimic or TNFα-specific siRNA treatment of ZF4 cells infected with IPNV. Therefore, this work indicates that miR-125b is suppressed in response to IPNV and acts as a negative regulator of TNFα-mediated apoptosis and secondary necrosis induced by IPNV. Taken together, our results indicate that IPNV triggers two death pathways via upstream induction of the pro-inflammatory cytokine TNFα and that the expression of cytokines and metalloproteinases might be initiated through the TNFα/NF-κB-mediated pathway. TNFα plays important roles in cell death and immune responses during IPNV infection. These results may provide new insights into the pathogenesis of RNA viruses.

博士
國立陽明大學
臨床醫學研究所
93
Cirrhotic patients frequently suffer from loss of skeletal muscle mass and alterations of glucose metabolism. This thesis was aimed to investigate the pathological role of tumor necrosis factor-alpha (TNF-alpha) in skeletal muscle wasting and insulin resistance in liver cirrhosis. In cirrhotic patients, it was shown that circulating soluble TNF-alpha receptor levels correlated positively with blood leptin and homeostasis assessment model-insulin resistance (HOMA-IR) index, respectively. In experimental studies, the bile duct ligation (BDL)-induced cirrhotic rats demonstrated significantly lower body weight and peripheral skeletal muscle mass with increased protein degradation rate and expression of various components of the ubiquitin-proteasome pathway. The TNF-alpha, TNF-alpha receptor I levels and activity of nuclear factor kappa B in skeletal muscle of cirrhotic rats were all elevated, and the addition of anti-TNF-alpha antibodies into the cultured skeletal muscle reduced protein degradation rate significantly. The BDL-induced cirrhotic rats also showed less insulin sensitivity as measured by continuously intravenous infusion of insulin and glucose. The adipose TNF-alpha levels were increased and positively correlated with blood insulin levels. mRNA and protein levels of another adipocytokine, namely resistin, were also increased in the cirrhotic rats, and TNF-alpha stimulated resistin mRNA expression of cultured adipose explants significantly. Overall, with the results of the clinical and experimental studies, it is concluded that TNF-alpha�� plays an important role in the pathogenesis of skeletal muscle wasting and insulin resistance in liver cirrhosis.

We recently discovered a high-level amplicon spanning the chr19q13.41 microRNA cluster in CNS Primitive Neuroectodermal Tumour, which results in striking upregulation of miR-520g. Constitutive over-expression of miR-520g in untransformed human neural stem cells enhanced cell growth, restricted differentiation down the neuronal lineage, and promoted expression of neural stem/progenitor cell markers. We thus hypothesize that ectopic miR-520g expression promotes tumourigenesis in part by inhibiting cellular differentiation. Consistent with this proposition, miR-520g is silenced upon embryonic stem cell differentiation and its expression is absent from most adult tissues. Moreover, expression analysis of miR-520g overexpressing cells revealed significant dysregulation of developmental signalling pathways. Further efforts focused on elucidating mechanisms of miR-520g function led to the identification of a cell cycle inhibitor, p21, as an important candidate target. These findings collectively suggest that miR-520g may modulate differentiation by regulating developmental signalling pathways and cell cycle exit of neural stem/progenitor cells.