With the recent advances in the knowledge of hepato-carcinogenesis, there has been encouraging development in the molecular targeted therapy for patients with advanced hepatocellular carcinoma (HCC). Sorafenib, an anti-angiogenic multi-targeted receptor tyrosine kinase inhibitor, has become the standard of treatment in HCC patients with Child-Pugh A cirrhosis. Nevertheless, the benefits and safety profile of sorafenib in the majority of the unselected advanced HCC patients and other patient subgroups are still unclear. More importantly, the survival benefit associated with sorafenib use is generally modest in Asian population. Therefore, an unmet medical need remains for more effective therapeutic agents. This thesis studied the impact of molecular targeted therapy in the treatment of advanced HCC patients and it contains 10 original studies divided into six sections. The first section provides a concise overview of the epidemiology, risk factors, and current treatment options for HCC patients. Also, the molecular biology and opportunity for the use of targeted therapy in advanced HCC were discussed. The second section is about a new prognostic score system that we developed — Advanced Liver Cancer Prognostic System (ALCPS). Our study results showed that ALCPS was able to objectively estimate the 3-month survival probability of advanced HCC patients and thus could enhance patient selection for targeted therapy or clinical trials. The third section is about the use of sorafenib in the treatment of advanced HCC patients. The results of our single centre phase II study showed that sorafenib had good efficacy and acceptable tolerability in treating advanced HCC patients in hepatitis B endemic area. Furthermore, our retrospective study results confirmed that the overall survival benefits and overall treatment-related adverse events of sorafenib were comparable in elderly and young advanced HCC patients. More importantly, our other retrospective analysis showed that Child-Pugh (CP) A and CP B patients tolerated sorafenib similarly and derived similar clinical and progression-free survival benefit. Among CP B patients, most benefits were observed in patients with score 7. Nevertheless, CP B patients were more susceptible to developing cirrhotic complications. Last but not least, our study also demonstrated that drop in serum alpha-fetoprotein level > 20% in the first 6 weeks of sorafenib treatment was a useful early surrogate endpoint for evaluating antitumor response and survival benefits. All these results are instrumental in guiding future rational use of sorafenib in advanced HCC population. The fourth section is about the role of targeted therapies in treating sorafenib-refractory advanced HCC patients. In a single arm phase II study, we showed that bevacizumab and erlotinib combination was not effective in treating advanced HCC patients who had failed prior sorafenib treatment. The fifth section of the thesis comprises results of four early phase novel clinical trials that may potentially improve the therapeutic outcomes in advanced HCC patients. First, our phase I/II study demonstrated that another anti-angiogenic agent — PTK787 had encouraging and possible synergistic activity when combined with intravenous doxorubicin in treating advanced HCC patients. Second, our multi-center phase II study results demonstrated promising activity with good tolerability of a novel combination — sorafenib together with capecitabine and oxaliplatin (SECOX) in the treatment of advanced HCC patients. Third, in a phase I study, we showed that pazopanib, a novel anti-angiogenic agent, had a manageable safety profile and preliminary activity in advanced HCC patients. Moreover, pazopanib reduced tumor vessel leakage, as shown by contrast-enhanced magnetic resonance imaging indicating a direct effect on HCC vasculature that might be associated with its antitumor activity. Lastly, in another phase I study, we evaluated safety, pharmacological parameters, and potential antitumor activity of pegylated recombinant human arginase 1 (peg-rhArg1) in advanced HCC patients. Our results illustrated that arginine depletion in humans can be achieved safely with peg-rhAgr1 in a dose-response manner and peg-rhArg1 had manageable safety profile and preliminary evidence of activity in advanced HCC patients. In the last section, the future perspectives about the use of molecular targeted therapy in the treatment of advanced HCC patients were discussed. / published_or_final_version / Medicine / Master / Doctor of Medicine

Hepatocellular Carcinoma (HCC) the fifth most common cancer and the third leading cause of death among cancer worldwide. Curative treatments such as liver resection and liver transplantation are generally used in treating early-stage HCC patients. However, only 10% to 30% of HCC patients are eligible for the surgery, which is due to the asymptomatic characteristic of HCC, most HCC patients are diagnosed at late stage. Palliative treatment such as TAE, TACE and Sorafenib provide them options to maintain their quality of life and extend their survival. Nevertheless, current treatments provides limited benefits to them as efficacy remains unsatisfactory. Therefore, there is a great need to develop new palliative treatments and explore new agents for the treatment of HCC. The aim of this study is to investigate the efficacy of a new therapeutic agent, Ombrabulin, in the treatment of HCC. Angiogenesis in HCC has been well-studied for many years as many studies proved that angiogeneisis plays an important role in the progression and development of HCC. Angiogenesis can also affect the prognosis and efficacy of treatments in HCC. As a result, antiangiogenesis and vascular disrupting agents have become new target in the therapaies of HCC. Ombrabulin is a synthetic vascular disrupting agent, which can inhibit tubulin polymerization in endothelial cells, causing cytoskeleton disorganization in endothelial cells. Endothelial cells will then detach from the basement membrane and eventually lead to vascular shutdown. This study demonstrated for the first time that Ombrabulin could selectively inhibit human umbilical vein endothelial cell (HUVEC) growth in vitro; particularly the early-form of HUVEC, which represent immature endothelial cell in neovasculature. Furthermore, this study also demonstrated the antiangiogenic effect of Ombrabulin on endothelial cells. By F-actin staining, it was shown that Ombrabulin caused changes in HUVECs morphology, which supported that Ombrabulin could lead to distortion in cytoskeleton. In vivo study demonstrated the early effect and long term effect of Ombrabulin. For the first part of the in vivo study, Nude mice were treated with single-dose of Ombrabulin for one week. Hoechst 33342, anti-CD34 staining and PCNA staining were carried out to study the functional effect of Ombrabulin and the combination effect with Sorafenib in vivo. Mice treated with Ombrabulin resulted in decreased blood perfusion, microvessel density and tumor cell proliferation, and tumor necrosis was also observed. In the combination with Sorafenib, it did not show synergistic effect in both tumor cell proliferation and microvessel density. For the second part of the in vivo study, nod scid mice were treated with multiple doses of Ombrabulin for three weeks to study the long term effect of Ombrabulin. Mice treated with Ombrabulin resulted in significantly smaller tumor size, demonstrating its antitumor efficacy in HCC. Furthermore, combination treatment of Sorafenib and Ombrabulin in vivo could enhance the efficacy of the treatment of HCC. In conclusion, Ombrabulin has vascular disrupting and antitumor effects, which could efficiently suppress HCC tumor growth in vivo. These results suggest that Ombrabulin could be a promising vascular disrupting agent in treating HCC. Combination with sorafenib should be further explored in clinical studies to demonstrate the synergistic antitumor effects in HCC patients. / published_or_final_version / Surgery / Master / Master of Philosophy

abstract / Anatomy / Doctoral / Doctor of Philosophy

published_or_final_version / Pathology / Master / Master of Philosophy

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the second leading cause of cancer-related deaths in the world. It is a disease with poor prognosis with unsatisfactory long-term survival of patients, and thus new strategies to control this disease are warranted. T helper (Th) 17 cells and IL-17 have recently been detected with increased frequency in a number of tumors including HCC. Its role in tumor remains controversial but its presence in HCC has been linked to disease progression, possibly involving angiogenesis. Th17 cells could be homed to inflammatory sites such as tumor microenvironment via CCR6/CCL20 axis and expand locally, and studies from other inflammatory diseases such as autoimmune disease has shown that the gut is the potential source of Th17, where its induction is affected by signals from gut microbiota. Yet this link is not yet shown in extra-intestinal tumors. Probiotics are living microorganisms, which when administered in adequate amounts confer a health benefit on the host. They have been reported to relieve chronic inflammatory diseases in animal and in human intervention studies. It is believed that probiotics regulate signals to gut antigen-presenting cells, which act as the pivot in modulating the systemic immune responses and inactivated bacteria also exhibited immunomodulatory effects in this regard. Accordingly, it was hypothesized that oral feeding of probiotics to HCCbearing animals may affect Th17 polarization and distribution and thereby modulate tumor microenvironment, which may have beneficial effect in tumor development, possibly via affecting angiogenesis. To address this hypothesis, wild-type C57BL/6 mice were fed with different heat-inactivated or viable probiotics– Lactobacillus rhamnosus GG (LGG), Escherichia coli Nissle 1917 (EcN), VSL#3 or mixture of probiotics − Prohep (heat-inactivated LGG, heatinactivated VSL#3 and viable EcN) either one week in advance or at the time of subcutaneous tumor inoculation. Probiotic feeding had improved survival in tumor-bearing mice, slowed down tumor growth and reduced tumor burden when monitored for 38 days. Probiotics showed better efficacy when feeding was given in advance. The anti-tumor effect was related to reduced angiogenesis and reduced IL-17 serum and gene expression within tumor. The mechanistic link between IL-17 modulation and tumor development was further studied in animals by IL-17 neutralization. The anti-tumor efficacy of probiotics, in relation to tumor growth and angiogenesis, was lost after IL-17 neutralization, which was linked to recruitment of myeloid suppressor cells. Since cells from both adaptive and innate immune systems could secrete IL-17, the source of IL-17 production was then identified, and found that Th17 was the major IL-17 secretor being modulated by probiotic feeding. Reduced homing of Th17 to tumor via circulation, with a tendency being recruited from gut was observed. Probiotics-mediated Th17 cell modulation in the gut by inducing the skewing of IL-10 secreting type1 regulatory T cells via dendritic cells may link to limited IL-17 mediated angiogenesis in the tumor microenvironment. With better understanding of the immunomodulation properties of probiotics, prophylactic or therapeutic efficacy in management of other inflammation-associated cancer can be availed. / published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

No description available.

Hepatocellular carcinoma (HCC) is one of the most devastating malignancies worldwide with increasing incidences in both developed and developing countries. Survival rates have not been significantly improved over the past decades in spite of advances in detection and therapies for this disease, suggesting that current treatments may target the wrong cells, and miss the cancer stem cells (CSCs). The cancer stem cell hypothesis presents that tumor formation, proliferation and propagation are driven by a rare subpopulation of chemoresistant CSCs that are not killed by conventional therapies and go on to cause disease relapse. The objective of this study was to identify and characterize CSCs in HCC cell lines and human liver tumor specimens using CD90 as a potential marker. The number of CD90+ cells present in HCC cell lines was found to positively correlate with tumorigenicity potentials. Injection of as few as 2,000 sorted CD90+ cells from HCC cell lines resulted in the formation of tumor nodules in nude mice, whereas no tumors formed for CD90ˉcells in the same model. The tumor xenograft generated by injection of CD90+ cells sorted from previous xenograft in a serial xenotransplantation assay exhibited recapitulation of tumor heterogeneity to original primary tumor and consistent proportion of CD90+ and CD90ˉ cells which demonstrated self-renewal and differentiation capacities of CD90+CSCs. CD45ˉCD90+ cells were detected (0.03%–6.2%) in human liver tumor specimens, but were only present in minute quantities in normal, cirrhotic and non-tumorous tissues. More importantly, CD45ˉCD90+ cells sorted from primary HCC tumor also displayed tumorigenicity, self-renewal and lineage differentiation capacities. CD90+CSCs were found to be more resistant to therapeutic drugs compared to CD90- cells, as reflected by the results of enrichment of the CD90+ CSCs and longer survival rates after chemotherapeutic treatment. The high expression of genes, such as OCT4, MRP3, ABCG2, AKT1, BirC5, BCL2, HA and CD44, in CD90+CSCs may mediate chemoresistance. The majority of CD90+ cells co-expressed CD44, another stem cell marker. Blocking CD44 activities by anti-CD44 antibody increased apoptosis of CD90+ CSCs, sensitized CD90+CSCs to chemotherapeutic drugs in vitro, and decreased tumorigenic and metastatic potentials of CD90+CSCs in vivo, indicating that a therapeutic potential of targeting CD44. However side effects may be problematic due to the endogenous expression of CD44 in healthy tissues and normal lymphocytes. To identify novel gene targets specific to liver CSCs, a sensitive RNA-sequencing (RNA-Seq) technique was used to compare the gene expression profiles between CD90+CSCs sorted from HCC primary tumors and CD90+cells from adjacent non-tumorous tissue (CD90+NTSCs). The up-regulated genes in CD90+CSCs were associated with lipid metabolism, inflammation, and drug resistance. Among the differentially expressed genes, glypican-3 (GPC3) was specifically elevated in CD90+CSCs but not in CD90+NTSCs. Therefore, GPC3 could be a promising gene candidate for HCC therapy as targeting GPC3 should not induce damage to normal liver stem cells. In summary, CD90 is a liver CSCs marker. Identification of CD90+ CSCs in HCC provides new insight into cellular basis of hepatocarcinogenesis, recurrence and metastasis, which opens new avenues for the design of future CSC-targeted therapies. / published_or_final_version / Surgery / Doctoral / Doctor of Philosophy

Yip, Ka Yan. / "August 2011." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 87-113). / Abstracts in English and Chinese. / Acknowledgement --- p.III / Abstract --- p.V / 論文摘要 --- p.VI / Table of Contents --- p.VII / List of Figures --- p.IX / List of Abbreviations --- p.XI / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Hepatocellular carcinoma --- p.1 / Chapter 1.1.1 --- Overview --- p.1 / Chapter 1.1.2 --- Risk factors --- p.3 / Chapter 1.1.3 --- Treatment ofHCC --- p.12 / Chapter 1.2 --- Berberine - a compound derived from Traditional Chinese Medicine --- p.15 / Chapter 1.2.1 --- Traditional Chinese Medicine --- p.15 / Chapter 1.2.2 --- Berberine --- p.16 / Chapter 1.3 --- Cell cycle --- p.18 / Chapter 1.3.1 --- An Overview of cell cycle --- p.18 / Chapter 1.3.2 --- Cell cycle and carcinogenesis --- p.18 / Chapter 1.4 --- Molecular mechanism of apoptosis --- p.20 / Chapter 1.4.1 --- Overview of apoptosis --- p.20 / Chapter 1.4.2 --- Caspases cascade --- p.22 / Chapter 1.4.3 --- Bcl-2 family --- p.24 / Chapter 1.5 --- Apoptosis as a target of cancer therapy --- p.26 / Chapter 1.6 --- Aims of study --- p.27 / Chapter Chapter 2 --- Materials and Methods --- p.28 / Chapter 2.1 --- Cell culture and treatment --- p.28 / Chapter 2.1.1 --- Cell lines --- p.28 / Chapter 2.1.2 --- Berberine --- p.29 / Chapter 2.1.3 --- Chemicals and reagents --- p.29 / Chapter 2.1.4 --- Preparation of solutions --- p.29 / Chapter 2.1.5 --- Procedures --- p.31 / Chapter 2.2 --- Apoptosis detection by FITC Annexin V and PI co-staining --- p.33 / Chapter 2.2.1 --- Chemicals and reagents --- p.33 / Chapter 2.2.2 --- Procedures --- p.33 / Chapter 2.3 --- Gene expression in Berberine-induced apoptotic cells --- p.35 / Chapter 2.3.1 --- Chemicals and Reagents --- p.35 / Chapter 2.3.2 --- Procedures --- p.35 / Chapter 2.4 --- Protein expression in Berberine-induced apoptotic cells --- p.38 / Chapter 2.4.1 --- Chemicals and Reagents --- p.38 / Chapter 2.4.2 --- Preparation of solution --- p.39 / Chapter 2.4.3 --- Procedures --- p.41 / Chapter 2.5 --- Caspase cascade studies in berberine-induced apoptosis --- p.43 / Chapter 2.5.1 --- Chemicals and reagents --- p.43 / Chapter 2.5.2 --- Procedures --- p.43 / Chapter 2.6 --- Cell cycle study in berberine-induced apoptotic cells --- p.44 / Chapter 2.6.1 --- Chemicals and Reagents --- p.44 / Chapter 2.6.2 --- Preparation of solutions --- p.44 / Chapter 2.6.3 --- Procedures --- p.44 / Chapter Chapter 3 --- Results --- p.46 / Chapter 3.1 --- Berberine induces apoptosis in hepatocellular cells --- p.46 / Chapter 3.2 --- Gene expression in Berberine-induced apoptotic cells --- p.53 / Chapter 3.3 --- Caspase cascade studies in berberine-induced apoptosis --- p.58 / Chapter 3.4 --- Protein expression in Berberine-induced apoptotic cells --- p.62 / Chapter 3.5 --- Berberine caused G1 cell cycle arrest in HCC cell lines --- p.65 / Chapter Chapter 4 --- Discussion --- p.76 / References --- p.87

published_or_final_version / Surgery / Master / Master of Philosophy

published_or_final_version / Surgery / Doctoral / Doctor of Philosophy