Colorectal cancer is a serious health problem that has concerned people for decades. In Hong Kong, it is the most common cancer and the second leading cause of death. Among colorectal cancer patients, around 40-50% of them will develop metastatic disease. Chemotherapy is playing an important role all the time in the treatment of advanced colorectal cancer. In the past decade, the application of targeted therapies in treatment has largely improved efficacy and prolonged survival. Bevacizumab and cetuximab are two commonly used targeted agents in daily clinical practice of Hong Kong. Since multiple clinical trials have studied bevacizumab and cetuximab in combination with other chemotherapies, limited data is available in Asian patients. Therefore, we conduct three 5-year retrospective analyses based on patients received treatment in Hong Kong Queen Mary Hospital, to investigate the clinical efficacy and toxicity of those two drugs. The first study examined the use of bevacizumab in treating KRAS mutated type patients. We found the efficacy and results were consistent with historical data. In the next analysis of cetuximab, comparable data were shown which suggested the consistency with previous studies. The last study is aim to compare bevacizumab and cetuximab in previously untreated wild-type KRAS patients. Identical response rates, progression-free survival and overall survival were finally reported. / published_or_final_version / Medicine / Master / Master of Philosophy

Indiana University-Purdue University Indianapolis (IUPUI) / Signal Transducer and Activator of Transcription 4 (STAT4) is an important transcription factor activated by IL-12 signaling. Activated STAT4 is essential for Th1 cell differentiation, a process characterized by increased potential for interferon (IFN)-γ production. Defective IFN-γ production due to STAT4 deficiency occurs after autologous stem cell transplantation for lymphoma. We have investigated the mechanisms of post-transplant STAT4 deficiency. The tumor-bearing state is ruled out to be the cause because STAT4 levels were not significantly different in peripheral blood mononuclear cells (PBMCs) obtained from lymphoma patients prior to treatment and healthy control subjects. The magnitude of the decrease in STAT4 levels corresponded with increasing intensity of chemotherapeutic treatment in vivo. Furthermore, treatment of normal PBMC cultures or a natural killer (NK) cell line with chemotherapy drugs in vitro also resulted in reduced STAT4 protein and reduced IL-12-induced IFN-γ production. Chemotherapy drugs are shown to have no impact on the stability of STAT4 mRNA, while steady-state levels of STAT4 transcripts are decreased in lymphoma patients. Our findings demonstrated that chemotherapeutic drugs up-regulate the ubiquitination rates of the STAT4 protein, which in turn promotes its degradation via the proteasome-mediated pathway. Treatment with the proteasome inhibitor bortezomib largely reversed the chemotherapy-induced STAT4 deficiency. Thus, acquired STAT4 deficiency in lymphoma patients is a consequence of treatment with chemotherapy. These results have important implications for design of optimal immunotherapy for lymphoma.

published_or_final_version / abstract / Surgery / Master / Master of Philosophy

published_or_final_version / Microbiology / Master / Master of Medical Sciences

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.