Cheung Hoi Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 151-166). / Abstracts in English and Chinese. / ACKNOWLEDGEMENT --- p.I / ABSTRACT --- p.II / ABBREVIATIONS --- p.IV / LIST OF FIGURES --- p.VII / LIST OF TABLES --- p.IX / CONTENTS --- p.X / Chapter CHAPTER ONE: --- GENERAL INTRODUCTION / Chapter 1.1 --- Non-coding RNAs in transcriptional output --- p.2 / Chapter 1.2 --- Diverse functions of non-coding RNAs --- p.5 / Chapter 1.3 --- HI9: imprinted non-coding RNA --- p.6 / Chapter 1.4 --- Objective --- p.7 / Chapter CHAPTER TWO: --- The ROLE OF H19 RNA IN MDR1 EXPRESSION OF HUMAN HEPATOCELLULAR CARCINOMA HepG2 CELLS / Chapter 2.1 --- Introduction / Chapter 2.1.1 --- H19-Igf2 locus as a model for genomic imprinting --- p.10 / Chapter 2.1.2 --- HI9 as a non-protein coding regulatory RNA --- p.12 / Chapter 2.1.3 --- Controversial roles of H19 RNA --- p.13 / Chapter 2.1.4 --- Novel role of H19 RNA in drug resistance --- p.15 / Chapter 2.2 --- Materials and methods / Chapter 2.2.1 --- Materials --- p.17 / Chapter 2.2.2 --- Methods / Chapter 2.2.2.1 --- Cell culture --- p.19 / Chapter 2.2.2.2 --- Plasmid construction and stable cell transfection --- p.19 / Chapter 2.2.2.3 --- Transient gene transfection --- p.20 / Chapter 2.2.2.4 --- RNA isolation and RT-PCR --- p.21 / Chapter 2.2.2.5 --- MTT drug sensitivity assay --- p.22 / Chapter 2.2.2.6 --- Western blot analysis --- p.22 / Chapter 2.3 --- Results / Chapter 2.3.1 --- Differential expression of H19 RNA in different human cancer cell lines --- p.24 / Chapter 2.3.2 --- R-HepG2 cells over-expressed P-glycoprotein and H19 RNA --- p.24 / Chapter 2.3.3 --- Development of H19-silenced cell lines in HepG2 cells by RNA interference --- p.26 / Chapter 2.3.4 --- Altered drug sensitivity in H19-silenced cells --- p.28 / Chapter 2.3.5 --- Expression of P-glycoprotein in H19-silenced cells --- p.31 / Chapter 2.3.6 --- Overexpression of H19 RNA in HepG2 cells --- p.34 / Chapter 2.3.7 --- Induction of H19 RNA and MDR1 in HepG2 cells --- p.34 / Chapter 2.4 --- Discussion / Chapter 2.4.1 --- H19 regulation of MDR1 associated drug resistance --- p.38 / Chapter 2.4.2 --- The puzzle of riboregulation in drug resistance --- p.40 / Chapter CHAPTER THREE: --- The ROLES OF PTB AND IMP1 IN H19-RELATED MDR1 EXPRESSION OF HUMAN HEPATOCELLULAR CARCINOMA HepG2 CELLS / Chapter 3.1 --- Introduction / Chapter 3.1.1 --- H19 RNA binding proteins --- p.43 / Chapter 3.2 --- Materials and methods / Chapter 3.2.1 --- Materials --- p.46 / Chapter 3.2.2 --- Methods / Chapter 3.2.2.1 --- Cell culture --- p.48 / Chapter 3.2.2.2 --- Plasmid construction and stable cell transfection --- p.48 / Chapter 3.2.2.3 --- RNA extraction and RT-PCR --- p.48 / Chapter 3.2.2.4 --- MTT drug sensitivity assay --- p.48 / Chapter 3.2.2.5 --- Western blot analysis --- p.48 / Chapter 3.2.2.6 --- Real-time PCR analysis of gene expression --- p.49 / Chapter 3.2.2.7 --- DOX efflux assay --- p.49 / Chapter 3.3 --- Results / Chapter 3.3.1 --- PTB knockdown increased P-glycoprotein expression --- p.51 / Chapter 3.3.2 --- IMP1 knockdown decreased MDR1 /P-glycoprotein expression --- p.54 / Chapter 3.3.3 --- Altered drug sensitivity in IMP 1 -knockdown cells --- p.60 / Chapter 3.4 --- Discussion / Chapter 3.4.1 --- Antagonistic effect of PTB and IMP1 on H19/MDR1 expressions --- p.64 / Chapter 3.4.2 --- Complexity of riboregulation --- p.65 / Chapter CHAPTER FOUR: --- IDENTIFICATION OF H19 RNA BINDING PROTEINS FROM HUMAN HEPATOCELLULAR CARCINOMA HepG2 CELLS / Chapter 4.1 --- Introduction / Chapter 4.1.1 --- Overview of RNA-protein interactions --- p.69 / Chapter 4.1.2 --- Methodology in the study of RNA-protein interactions --- p.71 / Chapter 4.1.3 --- Identification of RNA-binding proteins --- p.72 / Chapter 4.2 --- Materials and methods / Chapter 4.2.1 --- Materials --- p.75 / Chapter 4.2.2 --- Methods / Chapter 4.2.2.1 --- Screening of H19 cDNA from human placenta cDNA library --- p.78 / Chapter 4.2.2.2 --- Preparation of nuclear and cytoplasmic extracts from HepG2 cells / Chapter 4.2.2.3 --- In vitro RNA transcription and RNA labeling --- p.80 / Chapter 4.2.2.4 --- RNA electrophoretic mobility shift assay --- p.81 / Chapter 4.2.2.5 --- In vitro UV-crosslinking assay --- p.82 / Chapter 4.2.2.6 --- Preparation of RNA-affinity column and isolation of RNA binding proteins --- p.83 / Chapter 4.2.2.7 --- In-gel digestion and MALDI-TOF mass spectrometry --- p.84 / Chapter 4.3 --- Results / Chapter 4.3.1 --- Screening of H19 cDNA and preparation ofH19 RNA --- p.86 / Chapter 4.3.2 --- Electrophoretic mobility shift analysis of H19 RNA with HepG2 cytoplasmic extract --- p.87 / Chapter 4.3.3 --- UV-crosslinking of H19 RNA with HepG2 nuclear and cytoplasmic extract --- p.90 / Chapter 4.3.4 --- Isolation of H19 RNA binding proteins by RNA-affmity chromatography --- p.94 / Chapter 4.3.5 --- Confirmation of PTB and IMP1 as H19 RNA binding protein --- p.96 / Chapter 4.3.6 --- MALDI-TOF mass spectrometric analysis of isolated H19 RNA binding proteins --- p.96 / Chapter 4.4 --- Discussion / Chapter 4.4.1 --- RNA-protein interactions: an initial step for mechanistic study --- p.99 / Chapter 4.4.2 --- In vitro and in vivo methods for isolation of RNA binding proteins --- p.101 / Chapter 4.4.3 --- Novel role of hnRNP M protein in H19 RNA binding --- p.103 / Chapter CHAPTER FIVE: --- THE ROLE OF PTB IN APOPTOSIS / Chapter 5.1 --- Introduction / Chapter 5.1.1 --- Overview of polypyrimidine tract-binding protein in RNA processing and post-transcriptional gene regulation --- p.106 / Chapter 5.1.2 --- Evidences of polyrimidine-tract binding protein in the regulation of apoptosis --- p.108 / Chapter 5.2 --- Materials and methods / Chapter 5.2.1 --- Materials --- p.111 / Chapter 5.2.2 --- Methods / Chapter 5.2.2.1 --- Cell culture --- p.114 / Chapter 5.2.2.2 --- Stable cell transfection in A431 cells --- p.114 / Chapter 5.2.2.3 --- Western Blot analysis --- p.114 / Chapter 5.2.2.4 --- MTT drug sensitivity assay --- p.114 / Chapter 5.2.2.5 --- DNA fragmentation assay --- p.115 / Chapter 5.2.2.6 --- Flow cytometry analysis of apoptosis --- p.115 / Chapter 5.2.2.7 --- Caspase activity assay --- p.116 / Chapter 5.3 --- Results / Chapter 5.3.1 --- Taxol as an apoptosis inducer in HepG2 cells --- p.117 / Chapter 5.3.2 --- PTB was cleaved during Taxol-induced apoptosis --- p.118 / Chapter 5.3.3 --- PTB knockdown increased Taxol cytotoxicity and apoptosis --- p.118 / Chapter 5.3.4 --- Effect of PTB knockdown on drug sensitivity of cells --- p.121 / Chapter 5.3.5 --- Effect of PTB knockdown on other drug-induced apoptosis --- p.121 / Chapter 5.3.6 --- Effect of PTB knockdown on the basal expressions of genes in apoptosis pathway --- p.126 / Chapter 5.3.7 --- The role of caspase-9 activation in PTB-regulated apoptosis --- p.129 / Chapter 5.3.8 --- The effect of PTB knockdown on pro-caspase-9 expression and Taxol-induced apoptosis in A431 cells --- p.133 / Chapter 5.3.9 --- The role of PTB in the regulation of intrinsic apoptosis pathway --- p.136 / Chapter 5.4 --- Discussion / Chapter 5.4.1 --- The role of PTB in intrinsic apoptosis pathway --- p.138 / Chapter 5.4.2 --- PTB in regulation of pro-caspase-9 expression --- p.139 / Chapter CHAPTER SIX: --- GENERAL DISCUSSION AND CONCLUSION / Chapter 6.1 --- H19 as a potential target in anti-cancer gene therapy --- p.143 / Chapter 6.2 --- Conclusion --- p.144 / Chapter 6.3 --- Unanswered questions and future work --- p.145 / Chapter 6.4 --- A proposed model for H19 pathway --- p.148 / REFERENCES --- p.151

INTRODUÇÃO: O transplante hepático (TxH) vem mudando o curso de doenças graves, incapacitantes e potencialmente fatais, se tornando o tratamento de escolha quando há falência do órgão. OBJETIVO: Comparar as taxas de TxH, exclusão e sobrevida entre candidatos com cirrose descompensada (CIR), situações especiais (SPE) e carcinoma hepatocelular (HCC). MÉTODOS:Foram realizados dois estudos em 358 pacientes: uma coorte retrospectiva (agosto de 2008 - julho de 2009, incluindo 189 pacientes listados) e uma prospectiva (de novembro de 2012 a maio de 2014, com um período de acompanhamento até novembro de 2015, incluindo 169 candidatos a transplante hepático, comparando CIR, HCC e SPE. Foram avaliadas as seguintes variáveis: K-in (taxas de entrada da lista de espera: K-1in se CIR, K-2in se HCC e K-3in se SPE); K-out (taxa de TxH); K-1out (drop out no grupo CIR); K-2out (drop out no grupo HCC) e K-3out(drop out no grupo SPE). RESULTADOS: Na coorte retrospectiva, 112 casos (59,3%) tinham CIR, 63 (33,3%) com HCC e 14 (7,4%) se enquadraram em SPE. Os tempos médios de avaliação até a inscrição em lista para TxH foram 194 dias (IC 95% 152-236), 36 dias (IC95% 21-50) e 98 dias (IC95% 0-308) para CIR, HCC e SPE, respectivamente (P <0,001). Dos 86 pacientes transplantados (K-out = 45,5%), 31 tinham CIR (K-1in = 27,7%), 44 HCC (K-2in = 69,8%) e 11 SPE (K-3in = 88,6%) (P <0,001). As taxas de drop out foram maiores em CIR (K-1out = 64,3%, K-2out = 30,2%, K-3out = 21,4%, P <0,001). O hazar ratio (HR) para TxH foi 85% (IC95% 1,35-2,55) maior em HCC do que CIR. Na coorte prospectiva, 110 dos 167 pacientes avaliados foram listados (K-in = 65,9%). Os tempos médios de avaliação foram de 783 dias (IC95% 330-1236), 52 dias (IC95% 17-87) e 184 dias (IC95% 19-349) para CIR, HCC e SPE, respectivamente (P <0,001). Em relação ao TxH, o K1-in foi 21,7%, K2-in, 76,4% e K3-in, 92,3 % (P <0,001). K-out foi 57,3% (63/110), K1-out = 50%, K2-out = 21,1% e K3-out = 3,84% (P <0,001). HR para TxH foi 329% superior em HCC do que CIR (HR = 4,29; IC95%: 2,74-6,72). CONCLUSÃO: Neste estudo, os pacientes com cirrose descompensada tiveram um tempo de avaliação para transplante significativamente maior que os outros grupos avaliados, bem como maior taxa de drop out em lista. A taxa de transplante foi significativamente menor nos pacientes com cirrose descompensada, demonstrando que as políticas de alocação de órgãos merecem ser revistas. / INTRODUCTION: Liver transplantation (LT) has been changing the course of serious, incapacitating and potentially fatal diseases becoming the treatment of choice when there is organ failure. AIM: To compare transplant, delisting, and survival rates between candidates with decompensated cirrhosis (CIR), special conditions (SPE), and hepatocellular carcinoma (HCC). METHODS: We carried out two studies with 358 patientes: a retrospective one (Aug 2008-Jul 2009, including 189 enlisted patients) and another prospective (Nov 2012-May 2014, with a follow-up period up to Nov 2015, including 169 LT candidates), comparing CIR, HCC, and SPE. The following variables were assessed: K-in (rates of waitlist entry – K-1in if CIR, K-2in if HCC, and K-3in if SPE); K-out (rate of LT); K-1out (drop-out in CIR); K-2out (drop-out in HCC); and K-3 out (drop-out in SPE). RESULTS: In the retrospective study, 112 cases (59.3%) were due to CIR, 63 (33.3%) to HCC, and 14 (7.4%) to SPE. The average time from selection to enlisting was 194 days (CI95% 152-236), 36 days (CI95% 21-50), and 98 days (CI95% 0-308) for CIR, HCC, and SPE, respectively (P<0.001). Of the 86 transplanted patients (K-out = 45.5%), 31 had CIR (K-1in = 27.7%), 44 HCC (K-2in = 69.8%), and 11 SPE (K-3in = 88.6%) (P<0.001). Drop-out rates were higher in CIR (K-1out = 64.3%, K-2out = 30.2%, K-3out = 21.4%, P<0.001). The hazar ratio (HR) for LT was 85% (CI95% 1.35-2.55) higher in HCC than CIR. In the prospective study, 110 out of 167 evaluated patients were enlisted (K-in = 65.9%). The average time from selection to enlisting was 783 days (CI95% 330-1236), 52 days (CI95% 17-87), and 184 days (CI95% 19-349) for CIR, HCC, and SPE, respectively (P<0.001). Regarding LT, K1-in was 21.7%, K2-in, 76.4%, and K3-in, 92.3% (P<0.001). K-out was 57.3% (63/110), K1-out = 50%, K2-out = 21.1%, and K3-out = 3.84% (P<0.001). HR for LT was 329% times higher in HCC than CIR (HR = 4.29; CI95% 2.74–6.72).CONCLUSION: In this study, patients with decompensated cirrhosis had a time evaluation for transplantation significantly higher than other evaluated groups as well as a higher rate of waiting list drop out. Transplant rate was significantly lower in patients with decompensated cirrhosis, demonstrating that organ allocation policies deserve to be reviewed.

O presente estudo teve por objetivo estudar a participação da apoptose na carcinogênese hepatocelular, quantificando os corpos apoptóticos imunomarcados por caspase-3 clivada em amostras de carcinoma hepatocelular (CHC) em pacientes com ou sem cirrose, comparando também estes achados com amostras correspondentes de fígado não tumoral. Visou também à análise semi-quantitativa da imuno-expressão da proteína p53, Bax e Citocromo-C, relacionadas à via mitocondrial da apoptose em busca de eventuais relações com as variáveis clínicopatológicas dos carcinomas hepatocelulares. A análise comparativa da distribuição das diversas proteínas aqui estudadas foi ainda efetuada, com vistas à possível demonstração de sua interação no processo de apoptose em CHC. Amostras selecionadas de 79 casos de CHC foram distribuídas em micromatriz tecidual e submetidas a pesquisa imuno-histoquímica com amplificação por polímeros curtos de dextran ligados a peroxidase. IA foi maior nos CHC que nas amostras não-neoplásicas, mostrando ainda tendência a associação com o grau histológico do CHC .A imuno-expressão de p53 foi maior nos CHC em fígado cirrótico (CHC-C), em casos com invasão vascular, e nos graus histológicos altos. Houve maior imunoexpressão de citocromo c em CHC-C, sendo importante sua associação com p53. Bax mostrou apenas tendência a associação com o tamanho do CHC. Essas evidências contribuem para a compreensão da importância da via mitocondrial da apoptose mediada pela proteína p53 no CHC, destacando também prováveis diferenças do mecanismo carcinogenético na presença ou não de cirrose / This study aimed at the assesment of aspects of the role of apoptosis in hepatocellular carcinogenesis, quantifying apoptotic bodies immunomarked by cleaved caspase-3 in samples of hepatocellular carcinoma (HCC) in patients with or without cirrhosis, further comparing these findings to those from samples in non-tumoral areas of these livers. We also aimed herein to semiquantitate the immunoexpression of p53, Bax, Cytochrome-C, participants of the mitochondrial pathway of apoptosis, searching for possible relations with clinico-pathological variables in HCC. Samples from 79 cases of HCC were arranged in tissue microarrays were and submitted to immunohistochemical reaction with signal amplification achieved by the short-polymer-peroxidase system. Apoptotic index measured by immunoexpression of cleaved-caspase 3 was higher in HCC than in samples from non-neoplastic areas. p53 immunoexpression was higher in HCC occurring in cirrhotic livers, (HCC-C), in cases with vascular invasion and in higher histological grades. Cytochrome-c immunoexpression was also higher in HCC-C and, interestingly, was directly related to p53. Bax immunoreactivity showed only a trend for a relation with the size of HCC. The evidences from the present study further demonstrate the importance of p53-mediated pathway of apoptosis in HCC, and also point for possible differences in carcinogenesis in cirrhotic versus non-cirrhotic livers

A combinação de agentes quimiopreventivos com diferentes mecanismos de ação tem sido considerada uma estratégia promissora para a prevenção do câncer. Dentre os diversos compostos bioativos em alimentos, destacam-se a tributirina, um pró-fármaco do ácido butírico presente em laticínios e produzido pela fermentação de fibras dietéticas, e o óleo de linhaça, fonte de ácido alfa linolênico. Nesse contexto, foi avaliada a atividade quimiopreventiva de lipídios estruturados obtidos a partir da interesterificação enzimática de tributirina e óleo de linhaça durante a fase de promoção inicial da hepatocarcinogênese experimental. Ratos Wistar machos submetidos ao modelo do hepatócito resistente receberam diariamente, por via intragástrica (i.g), maltodextrina, óleo de linhaça, tributirina, a mistura não esterificada ou lipídios estruturados durante a fase de promoção inicial. O tratamento com lipídios estruturados demonstrou atividade quimiopreventiva comparável à da tributirina, mesmo resultando em menor concentração hepática de ácido butírico. Tanto a tributirina quanto os lipídios estruturados não inibiram a proliferação celular em lesões preneoplásicas, mas induziram a apoptose naquelas em remodelação. Os efeitos inibitórios da tributirina em fases iniciais da hepatocarcinogênese experimental estão relacionados ao aumento da acetilação de histonas e à modulação de processos de translocação nuclear da p53. No presente estudo, foi observado aumento substancial da razão nuclear/citoplasmática de p53 e importina-alfa em fígados de animais submetidos ao modelo e tratados com tributirina, mas não nos tratados com lipídios estruturados. Por outro lado, o tratamento com lipídios estruturados reduziu a expressão dos oncogenes Bcl2, Ccnd2, Pdgfa, Vegfa e aumentou a expressão dos genes supressores de tumor Cdh13, Fhit e Socs3. Assim, embora o potencial quimiopreventivo dos lipídios estruturados seja comparável ao da tributirina, os resultados sugerem que o novo composto não exibe atividade de HDACi, e que seus efeitos inibitórios na hepatocarcinogênese possam ser atribuídos à modulação da expressão de oncogenes e genes supressores de tumor. / Combination of chemopreventive agents with different mechanisms of action has been considered a promising strategy to cancer prevention. Among several bioactive food compounds, tributyrin, a butyric acid prodrug obtained from dairy products and dietetic fiber fermentation, and flax seed oil, a rich source of alpha linolenic acid have shown chemopreventive potential. Here, we evaluated the chemopreventive activity of structured lipids obtained by enzymatic interesterification of tributyrin and flax seed oil during the early promotion phase of experimental hepatocarcinogenesis. Male Wistar rats subjected to the resistant hepatocyte model were treated daily, i.g, with maltodextrin, flax seed oil, tributyrin, non-sterified blend, or structured lipids. Treatment structured lipids showed similar chemopreventive activity compared to tributyrin, even when structured lipids yielded lower concentrations of butyric in the liver. Tributyrin and structured lipids did not inhibit cell proliferation in preneoplastic lesions, but both of them induced apoptosis in remodeling preneoplastic lesions. In addition, histone acetylation and p21 restored expression tributyrin molecular mechanisms were related to modulation of p53 nuclear shuttling mechanisms. In the present study, it was observed a substantial increase in p53 nuclear/cytoplasmic ratio and importin-alpha in preneoplastic livers of tributyrin treated rats, but not in those treated with structured lipids. In contrast, treatment structured lipids downregulated expression of major oncogenes Bcl2, Ccnd2, Pdgfa, and Vegfa; and upregulated expression of critical tumor suppressor genes, Cdh13, Socs3 and Fhit. Hence, although structured lipids and tributyrin show similar chemopreventive potential, the results suggest that the new compound does not exhibit HDACi activity, and that its inhibitory effects may be attributed to the modulation of oncogenes and tumor suppressor genes expression.

Both mRNA and protein expression levels of P-glycoprotein, one of the major factors involved in drug resistance, was decreased in Pa-treated R-HepG2 cells. The chemo-sensitivity of these MDR cells towards doxorubicin would be enhanced by pretreatment of Pa. / In the study, 35 TCMs with historical background in treating liver diseases were screened. S. barbata was chosen for intensive studies based on its significant anti-hepatoma activity. Using bioassay-guided purification approach, an active component, pheophorbide a (Pa) - a chlorophyll derivative, was isolated from Scutellaria barbata. / Motivated by the severe health hazards worldwide caused by liver cancer, and the pronounced side effects of some recent anti-hepatoma agents in clinical treatment, we have initiated a research project in screening safe and effective agents from Traditional Chinese Medicine (TCM) for the treatment of hepatoma. The main objective of this research is to define the in vitro and in vivo anti-proliferative activities and to identify the action mechanisms of a TCM, the aerial part of Scutellaria barbata , in human hepatoma cells (HepG2 and Hep3B cells). / Pa exhibited anti-proliferative effects on HepG2 and Hep3B cells, through cell-cycle arrest and apoptosis, with IC50 values being 12.5 and 25.7 muM respectively. However, Pa produced insignificant cytotoxic effect on WRL-68 cells, a normal hepatic cell line. Pa also caused cell death in R-HepG2 cells, a multi-drug resistant (MDR) cell line developed from HepG2 cells. Microarray analysis indicated that a hypothetical protein FLJ10803 was found to be down-regulated upon the treatment of Pa on HepG2 cells. The sub-cellular localization of FLJ10803 was demonstrated by over-expression of the GFP fusion protein in HepG2 cells. / The anti-tumor effects of Pa could be enhanced by photodynamic therapy (PDT) approach, presumably due to the rapid generation of reactive oxygen species in the drug-binding site. Pa-PDT showed potent cytotoxicity on hepatoma cell lines, HepG2 and Hep3B, with IC50 values being 0.4 and 1.5 muM, respectively. The antitumor effects were confirmed by studies using animal model, where Pa treatment (300mug/kg/day, s.c.) could significantly inhibit the growth of Hep3B cells in nude mice after PDT treatment in vivo. Fluorescent imaging showed that Pa was located at the mitochondria, and the induction of cell death was found to be initiated by the mitochondrial dependent apoptotic pathway. Results of 2D-gel analysis suggested that Pa-PDT activated an immune-marker expression pathway that results in an over expression of HLA class I proteinsin Pa-PDT treated HepG2 cells. / To conclude, Pa may be a candidate for further development into an anti-hepatomic agent for clinical application. / Tang, Ming Kuen. / "September 2007." / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4742. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 227-243). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

By means of reverse-transcription polymerase chain reaction, overexpression of ZNF146 was detected in two human HCC cell lines HepG2 and Hep3B and a clear relationship between HCC and overexpression of ZNF146 has been established. Subcellular localization of ZNF146 protein in liver cells was studied by generation and expression of a green fluorescent protein (GFP) fusion protein. The nuclear localization and the reported DNA binding ability of ZNF146 protein provided a hint that ZNF146 may carry out its function in the cell system by interacting with specific genomic DNA sequences. Recombinant ZNF146 protein was expressed using bacterial and yeast system for the genomic DNA pull down assay in the identification of potential interacting genomic DNA sequences. Several potential genomic DNA sequences that interact with ZNF146 were identified and the gene MDM2 is the one of the candidates that is directly related to human carcinogenesis. MDM2 is a negative regulator of the tumor suppresser protein p53. Deregulation of MDM2 will impair the cell's ability in cell cycle arrest, DNA repair and apoptosis upon induced DNA damage. / Hepatocellular carcinoma (HCC) is a type of primary malignant liver tumor. And is one of the most frequent malignancies worldwide. The focus of this research project is the characterization of a Kruppel zinc finger protein, zinc Finger Protein 146 (ZNF146) using HCC as a disease model. The aim of this project is to understand the functional role ZNF146 and try to explore the mechanism of how ZNF146 might be involved in the carcinogenesis of HCC. / In order to have a better understanding with the protein ZNF146, SUMOylation properties of this protein has been studied. SUMO1 modification on ZNF146 has already been reported. And in our study, experimental result demonstrated that ZNF146 is also modified by SUMO2 and SUMO3 in liver cells. Other than the SUMOylation sites for SUMO1 protein which has been reported, modification sites for SUMO2 at the K247 and K275 positions were mapped, while K191R, K219R, K247R, K256R and K275R, five positions were mapped for SUMO3 modification. A more complete picture of the SUMOylation properties of ZNF146 has been revealed. Since we hypothesized that ZNF146 is related to the p53 tumor suppressor, cell cycle control and DNA repair pathway, a cell cycle study using flow cytometry was performed for the investigation of the effect on cell cycle regulation by ZNF146 overexpression. In our study, ZNF146 overexpression promoted the G1/S transition in the cell division cycle, which indicated that liver cells were more active for the progression of cell cycle. / On the other hand, using cDNA microarray technology expression profiles of ZNF146 overexpressing and non-overexpressing liver cell lines were compared and with real-time polymerase chain reaction, six candidate genes CRLF1, IFI44, ST6GAL1, LOC441601, IL18 and RAD17 were confirmed with their deregulation induced by the overexpression of ZNF146. Four of the candidates, IFI44, LOC441601, IL18 and RAD17 were found to be related to the p53 tumor suppressor activity or DNA damage, repair response and control. This observation, together with the result of genomic DNA pull down assay, gives us a hint that ZNF146 is possibly involved in liver carcinogenesis by affecting DNA repair and cell cycle control upon induced DNA damage. / The gene ZNF146 codes for a member of the Kruppel zinc finger proteins, however ZNF146 protein is different from most members of the Kruppel zinc finger proteins subfamily. It encodes a 33 kDa protein solely composed of 10 zinc finger motifs and is devoid of any non-zinc finger regulatory domain for interactions with other proteins. ZNF146 overexpression has been reported in a number of cancers including colon cancer and pancreatic carcinoma. However, the functional role of ZNF146 overexpression in tumorigenesis is yet to be solved and not much research on how ZNF146 might be invovled in the establishment of HCC was published. / To conclude, the experimental results of this study support the hypothesis that ZNF146 overexpression may deregulating the cell division cycle and some genes differentially regulated upon over-expression of ZNF146 are related to the regulations of DNA damage response. Future research on ZNF146 can be focused on the detail regulatory pathway of ZNF146 overexpression and its interaction between the p53 tumor suppressor, DNA damage response and cell cycle regulation, and a fuller picture of how ZNF146 overexpression might induce hepatocarcinogenesis can be revealed. / Yeung, Tsz Lun. / Adviser: Miu Yee (Mary) Waye. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3329. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 287-304). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Wu Xiujuan. / "May 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 294-314). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

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No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) PERFIL CLÍNICO E EPIDEMIOLÓGICO DOS PACIENTES PORTADORES DE CARCINOMA HEPATOCELULAR ATENDIDOS EM UM HOSPITAL FEDERAL NO M-1.pdf: 1579277 bytes, checksum: 961daf0e2b566d24ce96c3664d1f90b5 (MD5) Previous issue date: 2016 / Instituto Nacional de Câncer, Coordenação de Assistência Técnica, Centro de Transplante de Medúla Óssea / O câncer é responsável por mais de 12% de todas as mortes no mundo: mais de sete milhões de pessoas morrem anualmente dessa doença. Dentre as neoplasias primárias do fígado, o carcinoma hepatocelular (CHC) ou hepatocarcinoma é a mais frequente. No Brasil, este tipo de câncer foi a sexta causa de morte por neoplasia nos últimos 10 anos. Este estudo teve como objetivo determinar as características clínicas e epidemiológicas dos pacientes portadores de CHC atendidos de janeiro de 2011 a dezembro de 2015 no ambulatório de Hepatologia de um Hospital Federal na Cidade do Rio de Janeiro. Foram coletados os dados referentes ao perfil clínico e epidemiológico, ao tratamento e à evolução clínica da doença. O processamento e a análise dos dados foram feitos através dos programas Excel e SPSS 20.0. Dos 326 pacientes, 231 eram homens (70,9%) e 212 de cor branca (65%). O Índice de Massa Corporal (IMC) médio foi de 25,96 (± 4,37). A média de idade ao diagnóstico foi de 62,8 anos. A causa mais frequente de CHC foi a infecção pelo Vírus da Hepatite C (65,6%) seguida por alcoolismo (9,2%), por doença hepática não alcoólica (DHGNA) (9,2%) e pela infecção pelo Vírus da Hepatite B (8,9%). A cirrose já estava presente em 94,5% dos pacientes. De acordo com a função hepática, a maior parte dos pacientes foi classificada como Child A (62,6%) ou B (33,4%). Em relação à classificação pelo Barcelona-Clinic Liver Cancer (BCLC), 135 tiveram seu diagnóstico de CHC ainda na fase inicial da doença: 21 pacientes foram classificados como BCLC 0 e 114 como BCLC A. Cento e quatro pacientes foram classificados como BCLC B e 73 como BCLC C. Quatorze pacientes estavam em estágio terminal (BCLC D) quando o CHC foi diagnosticado. Oitenta pacientes (24,5%) apresentavam cinco ou mais lesões tumorais e em 109 pacientes a lesão de maior tamanho tinha mais que 5 cm de diâmetro. A maior parte dos pacientes foi submetida a pelo menos um tipo de intervenção terapêutica, sendo a TACE (53%) e o sorafenibe (40,2%) as mais frequentes. De 114 pacientes com indicação de transplante hepático (35%), dentro do Critério de Milão, 44 já tinham sido transplantados ao final do estudo. Das 180 mortes registradas, 154 foram por progressão da doença, 12 ocorreram por intercorrências causadas por algum dos tratamentos para o CHC, e 14 não tiveram qualquer relação com o CHC. Concluímos que os pacientes com CHC atendidos no hospital estudado são, em sua maioria, homens, brancos, com sobrepeso, maiores de 60 anos e cirróticos por infecção pelo VHC. A maior parte dos pacientes chegou ao centro de referência em estágio inicial (BCLC A), com uma função hepática ainda preservada (Child A) no momento do diagnóstico, possibilitando a escolha do tratamento mais adequado. Apesar de a maior parte dos pacientes ter sido submetida a TACE e/ou tratamento com sorafenibe, aproximadamente 1/3 dos pacientes puderam ter opções curativas como tratamento inicial / Over 12% of all deaths in the world are due to cancer: more than seven million people die of this disease each year. Among primary liver cancers, hepatocellular carcinoma (HCC) is the most common. In Brazil, this type of cancer was the sixth leading cause of cancer death in the last 10 years. This study aimed to describe the clinical and epidemiological characteristics of HCC patients treated from January 2011 to December 2015 at the hepatology outpatient clinic of a federal hospital in the city of Rio de Janeiro. Data concerning the epidemiological and clinic profile, treatment, and clinical course were gathered. Data processing and analysis of variables were performed using the Excel and SPSS 20.0 software. Among the 326 patients, 231 were men (70.9%) and 212 were white (65%). The average BMI was 25.96 (± 4.37). The median age at diagnosis was 62.8 years, ranging from 18.0 to 92 years. The most frequent cause of HCC was Hepatitis C Virus infection (65.6%), followed by alcohol abuse (9.2%), non-alcoholic steatohepatitis (NASH) (9.2 %) and Hepatitis B Virus infection (8.9%). Cirrhosis was already present in 94.5% of patients. According to liver function, most patients were classified as Child A (62.6%) or B (33.4%). Regarding to the Barcelona-Clinic Liver Cancer (BCLC) classification, 135 patients had their HCC diagnosed in an early phase: 21 patients were classified as BCLC 0 and 114 as BCLC A. One hundred four patients were classified as BCLC B, and 73 as BCLC C. Fourteen patients had end-stage disease (BCLC D) when their HCC was diagnosed. Eighty patients (24.5%) had five or more tumor lesions and in 109 patients the largest lesion had a diameter of more than 5 cm. Most patients underwent at least one kind of therapeutic intervention, being transarterial chemoembolization (TACE) (52.1%) and sorafenib (40.2%) the most frequent. We had 114 (35%) of patients diagnosed within the Milan criteria and thus eligible to liver transplantation, of whom 44 had already been transplanted by the end of the study. Of the 180 deaths recorded, 154 were due to disease progression, 12 were due to complications caused by the treatment employed, and 14 had no relationship with the HCC. We conclude that patients with HCC treated at the hospital studied are mostly men, white, overweight, over 60 and cirrhotic HCV infection. Most patients reached the reference center at an initial stage of disease (BCLC A), with a liver function still preserved (Child-Pugh A) at diagnosis, enabling the choice of the most appropriate treatment. Although most patients having undergone TACE and/or treatment with sorafenib, approximately 1/3 of the patients could be curative options as an initial treatment.

Ces dernières années des études ont montré le rôle de la méthylation dans la régulation transcriptionnelle. Au cours de cette thèse, nous avons exposé des cellules hépatiques à plusieurs stimuli pour en évaluer l'effet au niveau du méthylome. Nous avons précisément étudié des facteurs clés dans le carcinome hépatocellulaire que sont le virus de l'hépatite B, le TGFbeta et au cours de la différenciation des hépatocytes. Au cours de ces expositions, nous avons observé que la méthylation était remanié spécifiquement dans certaines régions. En effet nous n'avons pas observé de nombreux changements dans les régions promotrices mais dans les régions intragéniques. Nous avons ensuite identifié l'impact des changements de méthylation dans ces régions. Nous avons ainsi pu observer qu'au cours de la différenciation hépatique une déméthylation du corps du gène HNF4A au sein d'un promoteur alternatif était corrélé à l'expression d'un autre isoforme de ce gène sous le contrôle de ce promoteur alternatif. Enfin nous avons utilisé l'outil d'édition CRISPR pour modifier les régions intragéniques. Nous avons ainsi inséré des mutations au sein d'un enhancer intronique du gène TRRAP. Nous avons alors observé que cette région semblait être nécessaire à la surexpression du gène au cours du traitement mais également au niveau de la réponse au TGFbeta. En conclusion nous avons identifié les régions intragéniques comme des régions épigénétiquement dynamiques en réponse aux facteurs environnementaux tels que l'inflammation et l'infection par HBV. Nous avons également identifié pour ces régions un potentiel rôle dans la régulation transcriptionnelle ainsi que dans les événements d'épissage alternatif / Hepatitis B virus (HBV) and chronic inflammation are well known risk factors for several chronic liver pathologies and cancer. We firstly studied the ability of HBV to modify the host methylome, using naturally infected primary human hepatocytes, and bead array. As a result, we identified non- random changes in gene expression and DNA methylation occurring specifically upon HBV infection. Moreover, a set of differentially methylated sites appeared early and were stable. These HBV-induced DNA methylation changes were defined by a specific chromatin context characterized by CpG-poor regions outside of gene promoters. During liver inJury, hepatic progenitor cells (HPC) are essential for tissue regeneration. Because of its role in determining cellular fate, DNA methylation may have an important role during the process of HPC differentiation. We therefore assessed DNA methylation during HPC differentiation. We found a progressive demethylation of HNF4A alternative promoter strongly associated with higher expression of another isoforms of HNF4A. Finally, TGFbeta is linked to a change in DNA methylation profiles. Using genome-wide strategy we observed a specific pattern of DNA methylation changes in response to TGFbeta treatment. Indeed, the observed changes were, as for HBV-induced changes, enriched in intragenic regions. In order to study the role of these regions, we used CRISPR/Cas 9 strategy on the intragenic enhancer of the TRRAP gene. This disruption was likely to suppress TGFbeta response at TRRAP expression level as well as the complete response to this cytokine. These data support a higher dynamicity of intragenic regions in response to the different stimuli we used at methylation level in liver cells. Moreover, these results support a role of intragenic methylation in cellular

INTRODUÇÃO O câncer é uma das principais causas de morte no mundo, sendo responsável por cerca de 8 milhões de mortes por ano, segundo dados da OMS. As mortes por câncer são provocadas por tumores que se originam em órgãos como pulmão, fígado, estômago, intestino, mama e esôfago. As células-tronco mesenquimais (CTM) foram identificadas em vários órgãos e estudos da sua interação com células tumorais têm apresentado resultados indicando ação inibitória sobre alguns tipos de tumores. Para explorar essa questão foram analisados os efeitos sobre células tumorais de carcinoma hepatocelular humano (HepG-2) do meio condicionado (MC) obtido do cultivo de CTM isoladas de tecido adiposo (TA), líquido amniótico (LA) e geleia de Wharton (GW). MÉTODOS Os MCs foram coletados após 24 horas de incubação das CTM sub-confluentes com ?-MEM contendo 20% de soro fetal bovino (SFB). Os MCs foram centrifugados e passados através de filtros de 0,22 ?M e armazenadas a -20 °C. O MC da própria célula HepG-2 foi utilizado como controle. Os efeitos dos MCs sobre a proliferação de células HepG-2 foram testados por ensaio MTT, em várias concentrações após 24 h de incubação. O ciclo celular de células HepG-2 tratadas com MC a 25%, 50% ou 75% foi analisado por citometria de fluxo (coloração IP) utilizando o software Modfit LT. A expressão dos genes bcl-2, bcl-6, CCND1 foi analisada por RT-PCR. A proliferação celular foi avaliada pela expressão das proteínas survivina, Bcl-2, PCNA e Ki-67 e pela quantificação de mitocôndrias com corante MitoTracker, assim como pelo potencial de membrana mitocondrial por corante JC-1 Mitoscreen utilizando equipamento de high content analysis. RESULTADOS Os meios condicionados de células-tronco de tecido adiposo (MC-TA) não alteraram a proliferação de células tumorais HepG-2 e os meios condicionados de células-tronco de líquido amniótico (MC-LA) e de geleia de Wharton (MC-GW) provocam aumento da proliferação, confirmada pela contagem de células com núcleos corados com Hoescht 33342. A análise de alterações do ciclo celular demonstrou que a exposição de células HepG-2 aos meios MC-LA diminuem as células na fase G0/G1 e aumentam na fase G2/M do ciclo celular. A expressão dos genes CCND1, Bcl2 e Bcl6 que estão relacionados à proliferação e morte celular não apresentaram alteração. A quantificação das proteínas PCNA e survivina não apresentou alteração sob efeito dos MC, porém a comparação direta entre células tratadas com MC-LA e MC-TA indicou a tendência das células tratadas com MC-LA proliferarem. O percentual de células HepG-2 expressando a proteína Ki-67 foi significativamente menor em relação ao controle quando tratadas com MC-TA, não apresentando diferenças quando tratadas com MC-LA e MC-GW. A contagem de mitocôndrias evidenciou aumento de mitocôndrias nas células HepG-2 tratadas com MC-LA e efeito não significativo dos tratamentos com MC-TA e MC-GW. A diferença do potencial de membrana mitocondrial por JC-1 apresentou aumento da polarização nas células HepG-2 cultivadas com MC-TA. CONCLUSÃO Os resultados confirmam que as células-tronco mesenquimais diferem de acordo com a sua origem tecidual em sua ação na proliferação das células HepG-2. Mais estudos são necessários para estabelecer a causa destas ações, que não parecem ser devido a mediadores mais comuns na proliferação e morte celular / INTRODUCTION Cancer is a leading cause of death worldwide, accounting for about 8 million deaths per year, according to WHO data. Cancer deaths are caused by tumors that originate in organs such as lung, liver, stomach, bowel, breast and esophagus. The mesenchymal stem cells (MSCs) have been identified in many organs and studies of their interaction with tumor cells have shown results indicating an inhibitory effect on some types of tumors. To explore this question the effects of the conditioned medium (CM) obtained from mesenchymal stem cell isolated from adipose tissue (AT), amniotic fluid (AF) and Wharton jelly (WJ) on tumor cells of human hepatocellular carcinoma (HepG-2) were analyzed. METHODS The MSC CM was collected after 24 hours incubation of sub confluent MSC with ?-MEM containing 20% fetal bovine serum (FBS). The MSC CM were centrifuged and passed through 0.22 ?M filter and stored at -20° C. The CM of HepG-2 cell itself was used as control. The effects of contrast media on proliferation of HepG-2 cells were tested by MTT assay at various concentrations after 24 h of incubation. The cell cycle HepG-2 cells treated with CM at 25%, 50% or 75% was analyzed by flow cytometry (PI staining) using Modfit software LT. The expression of the genes Bcl-2, Bcl-6, CCND1 was analyzed by RT-PCR. Cell proliferation was assessed by the expression of survivin, Bcl-2, Ki-67 and PCNA proteins, and the quantization of mitochondrial by MitoTracker dye, as well as the mitochondrial membrane potential by JC-1 Mitoscreen dye using high content analysis equipment. RESULTS The conditioned media of mesenchymal stem cells (MSC) from adipose tissue (AT-CM) did not alter the proliferation of tumor HepG-2 cells and conditioned media of MSC cells from amniotic fluid (AF-CM) and Wharton jelly (WJ-CM) caused increased proliferation, confirmed by counting cells with nuclei stained with Hoechst 33342. The cell cycle analysis showed that exposure of HepG-2 cells to AF-CM means decrease the cells in G0 / G1 cell cycle phase and increase in phase G2 / M. The expression of Bcl2, Bcl6 and CCND1 genes that are related to proliferation and cell death did not change. The quantization of PCNA and survivin protein did not change under the effect of conditioned media, but a direct comparison between cells treated with AF-CM and AT-CM indicated the tendency of cells treated with AF-CM proliferate. The percentage of HepG-2 cells expressing the protein Ki-67 was significantly lower than the control when treated with AT-CM and no differences when treated with AF-CM and WJ-CM. The counting of mitochondria showed increased mitochondria in HepG-2 cells treated with AF-CM and no significant effect of treatment with WJ-CM and AT-CM. The difference in mitochondrial membrane potential by JC-1 showed an increase in polarization in HepG-2 cells cultured with AT-CM. CONCLUSION The results confirm that mesenchymal stem cells differ according to their tissue origin in its action on the proliferation of HepG-2 cells. More studies are needed to establish the cause of these actions, which seem to be not related to the most common mediators in cell proliferation and death