MiR-135a-5p represses proliferation of HNSCC by targeting<i>HOXA10</i>

Abstract

<b>Objectives:</b> This research aimed to explore the role of miR-135a-5p in head and neck squamous cell carcinoma (HNSCC) cells and its influence on cell viability. Moreover, we aimed to compare effects of miR-135a-5p and miR-494 in HNSCC, which was found to repress <i>HOXA10</i> expression in oral cancer. <b>Methods:</b> The association between miR-135a-5p and <i>HOXA10</i> was confirmed by green fluorescence protein reporter assay and qRT-PCR. The expression levels of HOXA10 in HNSCC cell lines (CAL-27, FaDu and NEC) were examined using western blot. The expression levels of HOXA10 in FaDu cells and CAL-27 cells were examined by western blot after transfection with miR-135a-5p mimics and miR-494 mimics. Colony formation assay and flow cytometry assay were respectively utilized to detect the proliferation and apoptosis of HNSCC cells after transfection with <i>HOXA10</i> plasmids and <i>HOXA10</i>-KO plasmids. <i>In vitro</i> tumor xenograft experiments were performed to analyze the inhibitive effect of miR-135a-5p on <i>HOXA10</i> in BALA/c mice. <b>Results:</b> <i>HOXA10</i> was overexpressed in HNSCC cells, while miR-135a-5p was under-expressed. Therefore, low expression of <i>HOXA10</i> lengthened disease-free survival time and overall survival time. MiR-135a-5p overexpression could inhibit <i>HOXA10</i> expression by directly targeting <i>HOXA10</i> 3'UTR, and the inhibition was more effective than miR-494. <i>HOXA10</i> suppression inhibited proliferation and enhanced apoptosis of HNSCC cells. <i>In vivo</i> experiments showed that miR-135a-5p could decelerate the growth of tumor cells in mice by downregulating <i>HOXA10</i> expression. <b>Conclusion:</b> MiR-135a-5p could repress HNSCC cells proliferation and enhance apoptosis by directly targeting <i>HOXA10</i>, implying miR-135a-5p's significance on HNSCC treatment.