Experimental Study On The Relation Of Epithelial-mesenchymal Transition Of Bladder Cancer And Notch Signal Pathway Regulated By MicroRNA-200b

Objective:To explore the microRNA-200b how to regulate Notch signaling pathways andits effect on EMT bladder cancer.Methods:Bladder cancer T24and5637cells were transfected with has-microRNA-200bmimic by using liposome Lipofectamine2000. Observe the growth and the change ofT24and5637cells by inverted microscope. Transfection efficiency was tested byqRT-PCR; The transcription of mRNA such as E-cadherin、N-cadherin、vimentin、alpha-smooth muscle actin、Notch-1、Jagged-1will be test by the technology of PCR,and the corresponding protein expression will be also test by western blot; MTT assaywas performed to examine the change of drug-resistance of transfected bladder cancercell line; Hoechst dyeing was used to detect the change of anti-apoptosis; Flowcytometry was used to detect the change of cell apoptosis rate; The changes, invasionability of transfected bladder cancer cell line, was evaluated by Transwell.Results:The number of bladder cells became less, the distribution was more diffused，thevolume of cells increased obviously and the form is more irregular, all thesephenomenon could be observed in experimental group. qRT-PCR results showed thatmicroRNA-200b were significantly up-regulated after transfection for48hours（p＜0.05）. RT-PCR and western blot results showed that the transcription and expressionlevels of E-cadherin mRNA and protein were increased significantly (p＜0.05), whilethe levels of mRNA and corresponding protein such as N-cadherin, vimentin,alpha-smooth muscle actin, Notch-1and Jagged-1were decreased significantly (p＜0.05). MTT assay results suggested that the cisplatin-resistance of experimental groupcell line became more weak (p＜0.05). Hoechst dyeing shows that the anti-apoptosisability of experimental bladder cancer cell lines was weakened.(p＜0.05). Flowcytometry results found that the early and late apoptosis rate of experimental group cell rise significantly (P＜0.05). Transwell showed that the invasion ability oftransfected bladder cancer cell line was weakened significantly(p＜0.05).Conclusion:The up-regulated microRNA-200b can inhibit the transcription and expression ofNotch-1,Jagged-1, thus interdict the Notch signal pathway, thereby inhibiting theoccurrence of EMT in bladder cancer, at the same time the drug resistance of bladdercancer cells, apoptosis resistance and invasion will be influenced.