Background Increased risk of bladder cancer has been reported in diabetic patients. This study was to investigate the roles of mitogen-activated protein kinase kinase （MEK） 1 and 2 in the regulation of human insulin...Background Increased risk of bladder cancer has been reported in diabetic patients. This study was to investigate the roles of mitogen-activated protein kinase kinase （MEK） 1 and 2 in the regulation of human insulin- and insulin glargine-induced proliferation of human bladder cancer T24 cells. Methods In the absence or presence of a selective inhibitor for MEK1 （PD98059） or a specific siRNA for MEK2 （siMEK2）, with or without addition of insulin or glargine, T24 cell proliferation was evaluated by cell counting kit （CCK）-8 assay. Protein expression of MEK2, phosphorylation of ERK1/2 and Akt was analyzed by Western blotting. Results T24 cell proliferation was promoted by PD98059 at 5-20 IJmol/L, inhibited by siMEK2 at 25-100 nmol/L. PD98059 and siMEK2 remarkably reduced phosphorylated ERKI/2. Insulin- and glargine-induced T24 cell proliferation was enhanced by PD98059, suppressed while not blocked by siMEK2. Insulin- and glargine-induced ERKI/2 activation was blocked by PD98059 or siMEK2 treatment, whereas activation of Akt was not affected. Conclusion MEK1 inhibits while MEK2 contributes to normal and human insulin- and insulin glargine-induced human bladder cancer T24 cell proliferation.展开更多
基金This work was supported by a grant from the National Natural Science Foundation of China （No. 81070598）.
文摘Background Increased risk of bladder cancer has been reported in diabetic patients. This study was to investigate the roles of mitogen-activated protein kinase kinase （MEK） 1 and 2 in the regulation of human insulin- and insulin glargine-induced proliferation of human bladder cancer T24 cells. Methods In the absence or presence of a selective inhibitor for MEK1 （PD98059） or a specific siRNA for MEK2 （siMEK2）, with or without addition of insulin or glargine, T24 cell proliferation was evaluated by cell counting kit （CCK）-8 assay. Protein expression of MEK2, phosphorylation of ERK1/2 and Akt was analyzed by Western blotting. Results T24 cell proliferation was promoted by PD98059 at 5-20 IJmol/L, inhibited by siMEK2 at 25-100 nmol/L. PD98059 and siMEK2 remarkably reduced phosphorylated ERKI/2. Insulin- and glargine-induced T24 cell proliferation was enhanced by PD98059, suppressed while not blocked by siMEK2. Insulin- and glargine-induced ERKI/2 activation was blocked by PD98059 or siMEK2 treatment, whereas activation of Akt was not affected. Conclusion MEK1 inhibits while MEK2 contributes to normal and human insulin- and insulin glargine-induced human bladder cancer T24 cell proliferation.
