Project 1：Roles of RCN1 and XRCC3 in Doxorubicin-Resistant Uterine Project 2：Role of SCaMC-1 in metastatic oral cancer cell line

• Main Authors: Chi-Lun Feng, 馮啟倫
• Other Authors: Hsiu-Chuan Chou
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/61945728074054348171

碩士 === 國立新竹教育大學 === 應用科學系碩士班 === 103 === Project 1 Abstract According to Taiwan's Ministry of Health and Welfare Statistics of top ten cancer causes of death in 2013, the cervix and uterine related cancers is the seventh leading cause for females. Therefore, the risk of the cervix and uterine related cancers to women’s health is an issue worthy of our attention. Current treatments of uterine sarcoma manner are surgery, radiation therapy, chemotherapy, and hormone therapy. In recent studies of chemotherapy, the causes and burden of drug resistance have been in-depth discussed. In the treatment of uterine sarcoma, the most commonly used drug is doxorubicin. Although the biological mechanisms associated with doxorubicin resistance has been widely reported, the precise mechanism of resistance remains unclear. Therefore, doxorubicin resistance forming mechanisms still deserves to be explored. Previous studies have known that RCN1 and XRCC3 protein expression in MES-SA/DxR-8μM cells are higher 2.06 times and 2.13 times than MES-SA cells, respectively. Unexpectedly, RCN1_T5G and XRCC3_T241C point mutations were found in MES-SA/DxR-8μM cells that we decide to reverse the mutation sites back. Therefore, the purpose of the study is to transfect four different overexpression plasmids (RCN1, RCN1_T5G, XRCC3, XRCC3_T241C) in MES-SA cells to investigate the role of mutation sites in drug resistance by means of cells proliferation and cell apoptosis. My experimental results showed that resistant ability of MES-SAXRCC3_T241C cell to doxorubicin has significantly increased, and cell apoptosis mediated has decreased. This result explains that XRCC3 Thr241Met polymorphism significant association with doxorubicin-resistance in uterine sarcoma. However, the RCN1_T5G and RCN1 plasmids are still underway to be transfected into MES-SA cells. I will continue to optimize G418 concentration to select cells that can stably express transfected DNA. I wish that this study can provide a useful reference to doxorubicin resistance in future. Project 2 Abstract According to Taiwan's Ministry of Health and Welfare Statistics in 2013, oral cancer is the fifth leading cause of death in cancer. The incidence rates of oral cancer in males are 2~3 times higher than in females. Since approximately nine in ten of cancer deaths are attributable to cancer metastasis, cancer metastasis is a main cause of failure treatment. When patients present with oral cancer, over 60% of them have spreaded cancer cells in regional lymph nodes or distant organs at their first medical care. The five-year survival rates of these patients compared with cancer cells confined to primary site (localized) decrease as high as 50%. Recently, the comprehensive gene expression analysis showed that SCaMC-1 overexpression is a general feature of transformed cancer cells. In this study, we used a pair of oral squamous cell carcinoma lines, OC3, and invasive OC3-I5 as a model system to examine invasive mechanism and to identify whether SCaMC-1 protein is a therapeutic target. We used RNA interference technique to monitor the influence of SCaMC-1 protein in cell proliferation, migration and invasion ability. Our results show that siSCaMC-1 can reduce invasive OC3-I5 cells cell proliferation, migration and invasion. We also used western blotting to examine SCaMC-1 protein’s role in Epithelial-mesenchymal transition (EMT) pathway. The experimental results showed that after siSCaMC-1, reducing epithelial-mesenchymal transition factor Snail, Twist, SIP1, and further, increasing E-cadherin, reducing Vimentin, MMP3, MMP7 protein expression, leading to decreased cell motility, EMT and cell survival. Therefore, we infer in oral cancer cells, SCaMC-1 overexpression may likely to contribute to epithelial-mesenchymal transition (EMT). Taken together, our preliminary results demonstrate that SCaMC-1 protein is a useful diagnostic marker and therapeutic target for reducing oral cancer metastasis.