The Role And Mechanism Research Of RARα In The Development Of Cholangiocarcinoma

Clinically cholangiocarcinoma has increasingly higher incidence, cancer cells grow fast and attack power. Surgery plus radiotherapy and combined therapy for the treatment of chemotherapy has become the main method. Cholangiocarcinoma possesses low sensitivity to chemotherapy, which showed strong resistance and side effects. Aforementioned characteristics severely limit the clinical use of chemotherapy drugs. Therefore, in-depth study of the development of cholangiocarcinoma is significant. In this context, three human cholangiocarcinoma QBC939, SK-ChA-1and HCcc9810cell strains cultured in vitro act as test subjects. The present attempt was made to elucidate the molecular mechanism of RARa involved in the development of bile duct cancer, providing new strategies for early diagnosis device of cholangiocarcinoma.Firstly, Immunohistochemiscal assay, Western blot and RT-PCR were used to research the expression of RARa in clinical specimens and cancer cells. Secondly, MTT assay, colony-formation, subcutaneously transplanted tumor assay in nude mice, flow cytometry and drug combination were adopted to study the effect of RARa on bile duct cancer cell cycle, growth, tumorigenesis and drug resistance. Then scratch test, gelatin zymography and transwell assay were employed to analyze the impact of RARa on invasiveness and migration capability of cholangiocarcinoma. Finally, the possible molecular mechanism of cell growth, invasion and migration and drug resistance generation were clarified by exploring the underlying relationship among RARa, Wnt and Akt signaling pathway.Herein report showed that RARa expression of human cholangiocarcinoma tissue was significantly higher than adjacent normal tissue. Decrease expression of RARa significantly inhibited cholangiocarcinoma cells proliferation, meanwhile suppressed colony formation and the ability of tumorigenesis. This may be associated with decreased expression of CyclinDl and increased expression of p21, which induced cell cycle arrest in G1/S phase. RARa gene interference significantly reduced MMP2mRNA expression and enzyme activity, accordingly restraining the ability of migration and invasion of cholangiocarcinoma cell. Moreover, lowering expression of MDR1on account of down-regulation of RARa reinforced cell susceptible to chemotherapy drug such as5-FU. RARa specificity agonist AM580can act synergistically with antineoplastic effect of5-FU. Further study showed that RARa interference decreased the phosphorylation levels of Akt,(β-catenin,(S9)-GSK-3(3, but no changes of GSK-3β and Akt. Therefore, this investigation proposed hypothesis that RARa may affect the development of cholangiocarcinoma through regulating Akt and Wnt signaling.