Study On The Molecular Mechanism Of TSPAN3 Promoting Non-small Cell Lung Cancer Cell Proliferation

Objective: In this study,we detected the expression of TSPAN3 in non-small cell lung cancer and lung cancer cells and its relationship with clinic pathological factors.We also observed the biological function of TSPAN3 in vitro,and the possible mechanisms,which plays an important role in the development of non-small cell lung cancer.Methods: The relationship between TSPAN3 protein expression and clinic pathological factors in non-small cell lung cancer(NSCLC)was studied by immunohistochemistry and Western blot.Regulate the expression of protein TSPAN3 in lung cancer cell lines,combined with Western blot,colony formation,MTT method,to explore its mechanism for the proliferation of non-small cell lung cancer.Results: 1.The expression of TSPAN3 in non-small cell lung cancer was significantly higher than that in non-small cell lung cancer.The high expression of TSPAN3 is positively correlated with high TNM stage and lymph node metastasis in non-small cell lung cancer patients.The expression of TSPAN3 in lung cancer cell lines was higher than that in normal bronchial epithelial cell line HBE.2.In non-small cell lung cancer(NSCLC)cell lines,down-regulating the expression of TSPAN3 inhibited NSCLC cell’s proliferation,colony formation and induced G1 phase arrest.3.In NSCLC cells,overexpression of TSPAN3 upregulated the expression of cell cycle regulatory proteins,including: Cyclin D1,Cyclin B1,CDK2,CDK4,while knockdown of TSPAN3 downregulated the expression of these proteins.4.In NSCLC cells,overexpression of TSPAN3 upregulated the level of p-P65,p-IκB,p-IKKβ,as well as the nucleus level of p65,while the level of p65,IκB,IKKβ was remained.Knockdown of TSPAN3 downregulated induced opposite results.5.In NSCLC cells,overexpression of TSPAN3 upregulated the levels of p-FAK,p-MEK,p-ERK,while the level of FAK,MEK,ERK was remained.Knockdown of TSPAN3 downregulated induced opposite results.Conclusion: 1.TSPAN3 has high expression in cytoplasm of non-small cell lung cancer cells,and it is associated with poorly differentiated non-small cell lung cancer,high TNM stage,lymph node metastasis and poor prognosis.2.TSPAN3 can promote the proliferation of non-small cell lung cancer through activating the NF-κB,FAK-Ras/MAPK pathway.