miR-142-5p Affects Oral Squamous Cell Carcinoma by Regulating PIAS3/pSTAT3.

Objective: miR-142-5p's role in tumors is inconsistent. The PIAS3/pSTAT3 signaling is an important regulator of the tumor microenvironment. Our study assessed whether miR-142-5p and PIAS3/pSTAT3 affect oral squamous cell carcinoma (OSCC).

Methods: 83 OSCC patients were recruited to analyze the baseline characteristics. In TCGA database, we found 18 miRNAs in tumor tissues, including miR-142-5p. STAT3 protein expression was measured in tissues by IHC and the relationship of miR-142-5p with PIAS3/pSTAT3 was assessed along with cellular location of miR-142-5p by immunofluorescence staining.

Results: In TCGA database, 18 miRNAs were found to be expressed in OSCC samples. miR-142-5p was significantly downregulated in OSCC tissues compared to normal tissues. Meanwhile, PIAS3 has complementary sequences with hsa-miR-142-5p and luciferase activity was reduced. STAT3 was located in the nucleus of miR-142-5p-transfected cells. In OSCC, miR-142-5p activated PIAS3, leading to STAT3 activation. Patients with positive STAT3 expression had better survival outcomes than patients with negative STAT3 level.

Conclusion: miR-142-5p directly targets PIAS3 and induces up-regulation of STAT3 through miR-142-5p/PIAS3/pSTAT3 axis, thereby affecting the survival outcome of OSCC patients.