Downregulation of microRNA-1246 inhibits tumor growth and promotes apoptosis of cervical cancer cells by targeting thrombospondin-2.

Abstract

Cervical cancer pathogenesis is regulated by numerous factors, including microRNAs. MicroRNA 1246 (miR-1246) has been shown to serve a role in cervical cancer tumorigenesis. However, the mechanisms through which miR-1246 exerts its oncogenic effects are largely unknown. The aim of the current study was to evaluate the effects of lentivirus-mediated miR-1246 knockdown on the biological characteristics and behavior of cervical cancer cells, and to identify the downstream signaling pathways affected by miR-1246 knockdown. Short hairpins inhibiting miR-1246 were synthesized and cloned into a recombinant lentiviral vector (LV-miR-1246-Inh), which was then used to infect SiHa cervical cancer cells. The effects of LV-miR-1246-Inh infection on cell invasion, proliferation and apoptosis were evaluated by Transwell assay, Cell Counting Kit-8 assay and flow cytometry, respectively. Thrombospondin-2 (THBS2), matrix metalloproteinase 2 (MMP2), MMP9 and extracellular matrix (ECM) component expression levels were evaluated, and the growth of xenograft tumors formed following injection of SiHa cells with knockdown of miR-1246 was assessed. miR-1246 downregulation in SiHa cells decreased proliferation, induced apoptosis and upregulated THBS2 expression. Furthermore, MMP2 and MMP9 levels were downregulated, whereas components of the ECM were upregulated subsequent to miR-1246 knockdown, indicating that this miRNA regulates cervical cancer cell pathogenesis via the THBS2/MMP/ECM pathway. Notably, SiHa cells with miR-1246 downregulation had a markedly decreased ability to form tumors in vivo. These results suggest that miR-1246 functions during cervical cancer pathogenesis and tumor formation via the THBS2/MMP/ECM signaling pathway. These findings support the future use of miR-1246 suppression in the treatment of cervical cancer.