| IntroductionPancreatic cancer is a common malignant tumor of gastrointestinal tract. Even though pancreatic cancer accounts for only 2%of all cancer diagnoses in the world, it is the fourth-leading cause of cancer death and one of the most difficult malignancies to manage. Because of the usually late onset of symptoms, only 15%-20%or less of patients present with resectable disease. Despite a lack of consistent evidence from previous clinical trials, surgical resection provides the best chance for cure or long-term survival, and chemotherapy is the most commonly used approach in treating locally advanced pancreatic cancer. Gemcitabine is the first-line drug for patients with advanced pancreatic cancer, but there's not so much effect on the patients'life survival using gemcitabine alone. Now drug combinations are often used on the clinical treatment, such as gemcitabine in combination with 5-fluorouracil, cisplatin, taxotere and the molecular tagarted drug like erlotinib. Compared with the use of single drug, drug combinations chemotherapy can improve overall survival, objective response rate and progression-free survival period, and achieved statistical significance. However, the 5-year survival rate shows little improvement of the therapy with drug combination.Mesothelin is a differentiation antigen whose expression in normal human tissues is limited to masothelial cells lining the pleura, pericardium and peritoneum. However, mesothelin is highly expressed in several human cancers, including virtually all mesotheliomas and pancreatic adenocarcinomas, and approximately 70%of ovarian cancers and 50%of lung adenocarcinomas. Argani and colleagues were the first to show mesothelin expression in pancreatic ductal adenocarcinoma. Using SAGE database they found the tag for mesothelin to be consistently present in pancreatic cancer libraries but not in normal pancreas. In addition, mesothelin mRNA expression was present in 4 of 4 resected primary pancreatic cancers and by immunohistochemistry all 60 resected primary adenocarcinomas were mesothelin positive. These results were confirmed by Hassan and colleagues who showed that mesothelin was expressed in all 18 cases of pancreatic adenocarcinomas examined but absent in normal pancreas and in chronic pancreatitis. Ordanez also showed mesothelin was expressed in majority of pancreatic adenocarcinomas, but was absent in islet cell tumors of the pancreas. In addition to pancreas cancer mesothelin is also highly expressed in other adenocarcinomas of the biliary tree such as gallbaadder cancer, and tumors of the common bile duct.Although the functions of mesothelin remain largely unknown, recent studies have shed light on the possible role of mesothelin in cancer biology. Recent studies provide evidence that mesothelin and MUC 16 binding to mesothelin could therefore be a potentially useful strategy to treat ovarian cancer. A small amount of the membrane-bound mesothelin is shed into the serum and is usefull for the diagnosis of ovarian cancer and masothelioma. Li M and his college found that forced expression of mesothelin significantly increased tumor cell proliferation and migration by 90%and 300%in vitro, respectively, and increased tumor volume by 4-fold in the nude mice xenograft model when compared with the vector control cell line. Silencing of mesothelin inhibited cell proliferation and migration in pancreatic cancer cells and ablated tumor progression in vivo.Materials and methodsPANC-1 cells were treated with transicent transfection of small RNA of MSLN. Flow cytometry and fluorescent microscopy were used to detect the effect of the transfection. The expression of MSLN was evaluated by Western blot analysis. Then the cells were treated with different concentration of gencitabine, cisplatin, cucurbitacin E and doxorubicin. Cell proliferation were tested by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results was analysed by the SPSS 16.0 software.Results1,Flow cytometry showed that a fluorescent labeled cells accounted for 77.4%of the total and proved the successful transfection.2,Fluorescence microscopy showed that the green flrorescent cells accounted for 80%of the total cell number under the visible light in the same field.3,Westen blot analysis showed that silencing of MSLN genes suppressed the expression of the MSLN.4,The proliferation of PANC-1 were significantly inhibited after the gene silencing of MSLN. (P<0.05 vs. control).5,Gemcitabine could inhibit tumor cell proliferation dose depedently. After MSLN silencing, the growth inhibition rate with 0.1μM gemcitabine was 60.47%. (P< 0.01 vs. gemcitabine).6,Cisplatin could inhibit tumor cell proliferation dose depedently. After MSLN silencing, the growth inhibition rate with 1μM cisplatin was 59.82%. (P< 0.01 vs. cisplatin).7,Cucurbitacin E could inhibit tumor cell proliferation dose depedently. After MSLN silencing, the growth inhibition rate with 1μM cucurbitacin E was 38.32%. (P< 0.01 vs. cucurbitacin E).8,Doxorubicin could inhibit tumor cell proliferation dose depedently. After MSLN silencing, the growth inhibition rate with 1μM doxorubicin was 80.82%. (P< 0.01 vs. doxorubicin).Conclusion1,Gene silencing of MSLN inhibits the growth of pancreatic cancer PANC-1 in vitro.2,Silencing of mesothelin in combination of chemotherapic drug result in marked inhibition of pancreatic cancer cells.
|
PDF Full Text Request