Lentivirus media miR-1246 knockdown inhibits tumor growth and promotes apoptosis of SiHa cells

Abstract

Objective: To study the effect of lentivirus-mediated microRNA (miR) -1246 RNA interference (RNAi) on biological characteristics and behaviors in cervical cancer cells as well as to identify the downstream signaling pathways affected. Methods: MiR-1246 specific cDNA was synthesized and cloned into the recombinant lentiviral vector (LV-miR-1246-inhibitor) . The SiHa cells were devided into three groups: no viral infection (negative control, NC) , infection with control virus (LV-NC) , and infection with miR-1246-inhibitor virus (LV-miR-1246-inhibitor) . The expression of the miR-1246 was detected by reverse transcription (RT) -PCR. Cell growth was analyzed by cell counting kit 8 (CCK-8) assay. The invasion was dectected by transwell matrige gel. Cell apoptosis was detected by flow cytometer. The growth of xenograft tumors was also investigated. Expression of thrombospondin-2 (THBS2) , matrix metalloproteinase (MMP) 2, 9 were also evaluated in the cells. Results: (1) The expression level of miR-1246 in SiHa cells (0.11±0.13) was significantly lower in group LV-miR-1246-inhibitor than those in the group LV-NC and the group NC (1.14±0.86 and 1.30±0.73, respectively; P<0.01) . (2) The proliferation of SiHa was also markedly suppressed in CCK-8 at 96 hours (P<0.01) . (3) The number of group LV-miR-1246-inhibitor was significantly less than those in the LV-NC and NC groups in transwell invasion assay (71±4, 162±5 and 188±5, respectively; P<0.01) . (4) The apoptosis rate of SiHa cells in the group LV-miR-1246-inhibitor [ (16.10±3.37) %] was significantly lower than those of group LV-NC and group NC [ (5.67±0.89) % and (1.78±0.08) %,P<0.01]. (5) The tumor volume in the nude mice group LV-miR-1246-inhibitor [ (287±59) mm(3)] was significantly lower than those in the LV-NC and NC groups [ (571±137) and (657±144) mm(3), respectively; P<0.01]. (6) Compared with the LV-NC group and the NC group, THBS2 protein expression in the tumor tissue of the nude mice in the group LV-miR-1246-inhibitor was significantly increased (P<0.05) , while the expression levels of MMP-2 and MMP-9 protein were significantly decreased (P<0.01) . Conclusion: These results suggest that miR-1246 functions during cervical cancer pathogenesis and tumor formation via the THBS2, MMP signaling pathway.