Aberrant expression of
microRNAs (
miRNAs) is involved in the development and progression of various types of
cancers. In this study, we investigated the role of miR-331-3p in cell proliferation and the expression of keratinocyte
differentiation markers of
uterine cervical cancer cells. Moreover, we evaluated whether
neuropilin 2 (NRP2) are putative target molecules that regulate the human papillomavirus (HPV) related
oncoproteins E6 and E7. Cell proliferation in the human
cervical cancer cell lines SKG-II, HCS-2, and HeLa was assessed using the
3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner
salt (MTS) assay. Cellular apoptosis was measured using the TdT-mediated dUTP nick end labeling (TUNEL) and
Annexin V assays. Quantitative RT-PCR was used to measure the
messenger RNA (
mRNA) expression of the NRP2, E6, E7, p63, and
involucrin (IVL) genes. A functional assay for cell growth was performed using cell cycle analyses. Overexpression of miR-331-3p inhibited cell proliferation, and induced G2/M phase arrest and apoptosis in SKG-II, HCS-2 and HeLa cells. The
luciferase reporter assay of the NRP2 3'-untranslated region revealed the direct regulation of NRP2 by miR-331-3p. Gene expression analyses using quantitative RT-PCR in SKG-II, HCS-2, and HeLa cells overexpressing miR-331-3p or suppressing NRP2 revealed down-regulation of E6, E7, and p63
mRNA and up-regulation of IVL
mRNA. Moreover, miR-331-3p overexpression was suppressed NRP2 expression in
protein level. We showed that miR-331-3p and NRP2 were key effectors of cell proliferation by regulating the cell cycle, apoptosis. NRP-2 also regulates the expression of E6/E7 and keratinocyte
differentiation markers. Our findings suggest that miR-331-3p has an important role in regulating
cervical cancer cell proliferation, and that miR-331-3p may contribute to keratinocyte differentiation through NRP2 suppression. miR-331-3p and NRP2 may contribute to anti-
cancer effects.