MicroRNA-433-3p regulates malignant biological behavior of pancreatic cancer PANC-1 cells by targeting Smoothened

Objective To explore the effect of microRNA-433-3p (miR-433-3p) on proliferation, invasion and migration of pancreatic cancer cells and its targeting relationship with Smoothened (SMO).

Methods Pancreatic cancer PANC-1 cells and human normal pancreatic epithelial cells HPNE were cultured. The miR-NC, miR-433-3p mimics, si-NC, si-miR-433-3p, Scramble (knocked down and empty loaded), si-SMO, Vector and SMO overexpression (OE-SMO) plasmids were transfected into PANC-1 cells respectively, which were recorded as miR-NC group, miR-433-3p group, si-NC group, si-miR-433-3p group, Scramble group, si-SMO group, Vector group and SMO group. Vector and OE-SMO plasmids were transfected into cells in the miR-433-3p group respectively, and were recorded as si-miR-433-3p+Scramble group and si-miR-433-3p+si-SMO group. Tetramethylazo blue (MTT) was used to detect cell proliferation ability, the Transwell test was used to detect cell invasion and migration abilities, the fluorescent quantitative polymerase chain reaction (RT-PCR) was used to detect the expression levels of cell SMO gene mRNA and miR-433-3p, the Western blot was used to detect the expression level of cell SMO protein, the TargetScan online website was used to predict the binding site of miR-433-3p and SMO, and double luciferase reporter gene test was used to verify the targeting relationship between miR-433-3p and SMO.

Results The expression levels of mRNA and protein of SMO gene in PANC-1 cells were significantly higher than those in HPNE cells (P < 0.05); the expression level of miR-433-3p in PANC-1 cells was significantly lower than that in HPNE cells (P < 0.05). Down-regulation of miR-433-3p and up-regulation of SMO were able to promote cell proliferation, invasion and migration, while up-regulation of miR-433-3p and silencing SMO were able to inhibit cell proliferation, invasion and migration. Down-regulation of SMO reversed the promotion of low expression of miR-433-3p on cell proliferation, invasion and migration. The miR-433-3p was able to negatively regulate SMO expression.

Conclusion The miR-433-3p can negatively regulate SMO to inhibit the proliferation, invasion and migration of pancreatic cancer cells.