Abstract: Objective To investigate the effect of miR-145 on EMT and proliferation of pancreatic cancer cell line PANC-1 and to explore the related mechanism. Methods miR-145 group, contral group and blank group were set up.miR-145 over-expressed lentiviral vector was constructed and transfected into PANC-1 cells. RT-qPCR was used to testify miR-145 mRNA expressions；adhesion experiments were used to detect the ability of homogeneous and heterogeneous cells intercellular adhesion of each group, which was observed under fluorescence microscopy.The characteristic changes of tumor stem cells were measured by spheroid formation assay; Meanwhile, RT-qPCR and Western blotting were performed to examine mRNA and protein expressions of E-cadherin、N-cadherin and OCT4, respectively. Results The expression of mRNA of miR-145 significantly was increased after transfecting miR-145 over-expressed lentiviral vector; Compared with contral group and blank group,the miR-145 group homogeneous cells intercellular adhesion was increased and heterogeneous cells intercellular was opposite,the number and the size of tumorspheres was obviously reduced(p<0.05). meanwhile,the expression of mRNA and protein of E-cadherin was up-regulated,and N-cadherin and OCT4 were declined(p<0.05). Conclusions Up-regulating miR-145 can reverse the EMT and inhibit the characteristic acquisition of cancer stem cell line PANC-1, its mechanism may be related to the up-regulation of E-cadherin and the down-regulation of N-cadherin and OCT4.

Key words: Pancreatic cancer, Cancer stem cells, epithelial-mesenchymal transition(EMT), MiRNA-145