To investigate the regulatory function of microRNA-330-3p (miR-330-3p) on the cell growth and apoptosis in oral squamous cell carcinoma (OSCC) , and to screen and verify the revelant target genes.

The expressions of miR-330-3p were measured in OSCC tissues, adjacent normal tissues and OSCC cell lines by quantitative real-time PCR. Then miR-330-3p inhibitor and mimics were transfected into OSCC cell line HN13 cells, and their transfection efficiency was detected by quantitative real-time PCR. And then, cell proliferation assay, cell cloning experiments and flow cytometry were conducted to determine the effects of miR-330-3p on the proliferation and apoptosis of OSCC cells. We found 9 putative targets through miRanda and TargetScan that matching the data of related gene chip. Then quantitative real-time PCR, Western blot test and Dual-Luciferase Reporter assay were used to verify the putative targets of miR-330-3p.

compared with adjacent normal tissues, the expression of miR-330-3p was upregulated in OSCC tissues and cell lines. The inhibitor and mimics of miR-330-3p could significantly downregulate or upregulate the expression of miR-330-3p in transfected HN13 cells. miR-330-3p-inhibitor-transfected HN13 cells had lower proliferation rate and higher apoptosis rate. And HN13 cells showed an opposite change of proliferation rate and apoptosis when transfected with miR-330-3p mimics. MiR-330-3p can negatively regulate the translation of PDCD4.

miR-330-3p is a tumor promoter in OSCC by repressing the post-transcriptional translation of PDCD4 through binding with 3’UTR, and its inhibitor has the anticancer potential. So our study provides a new candidate molecule to gene-targeting treatment in OSCCs.