miR-556-3p regulates viability,migration and invasion of endometrial cancer cells by targeting SASH1

AIM To investigate whether microRNA-556-3p （miR-556-3p） regulates the viability， migration and invasion of endometrial cancer cells by targeting SASH1 gene. METHODS The expression of miR-556-3p， and the mRNA and protein levels of SASH1 in endometrial cancer tissues were detected by RT-qPCR and Western blot. Anti-miR-556-3p or pcDNA-SASH1 was transfected into endometrial cancer Ishikawa cells. The cell viability was detected by MTT assay， the migration and invasion abilities of the cells were detected by Transwell chamber method， and the protein expression levels of cyclin D1， p21， matrix metalloproteinase-2 （MMP-2） and MMP-9 were detected by Western blot. StarBase prediction and dual-luciferase reporter experiments were used to analyze the targeting relationship between miR-556-3p and SASH1. Anti-miR-556-3p and si-SASH1 were co-transfected into the Ishikawa cells， and their effects on cell viability， migration and invasion were examined by the methods described above. RESULTS Compared with adjacent tissues， the expression of miR-556-3p in endometrial cancer tissues was increased significantly， and the expression of SASH1 at mRNA and protein levels was decreased significantly （P<0.05）. Inhibition of miR-556-3p expression or induction of SASH1 over-expression obviously reduced the viability of Ishikawa cells， the number of migratory cells， the number of invasive cells and the protein levels of cyclin D1， MMP-2 and MMP-9， and dramatically increased the protein level of p21 （P<0.05）. miR-556-3p targeted SASH1 and negatively regulated its expression. Knock-down of SASH1 expression reversed the inhibitory effect of miR-556-3p expression inhibition on the viability， migration and invasion of Ishikawa cells. CONCLUSION Inhibition of miR-556-3p expression suppresses the viability， migration and invasion of endometrial cancer cells. The mechanism is related to the regulation of its target gene SASH1.