piR-hsa-157573 promotes oral squamous cell carcinoma progression via interacting with hnRNPM.

Oral squamous cell carcinoma (OSCC) is among the most lethal heterogeneous tumors, with limited effective biomarkers and therapeutic targets for early diagnosis and treatment. PIWI-interacting RNAs (piRNAs) have become promising biomarkers and targets in various cancers. However, the expression profile, functions, and mechanisms of piRNAs in OSCC remain unclear. We conducted RNA sequencing to identify differentially expressed piRNAs in tumor tissues and paired normal tissues from OSCC patients. Reverse transcription-quantitative PCR (RT-qPCR) demonstrated that piR-hsa-157573 is highly expressed in OSCC tumors. Functional assays showed that knockdown of piR-hsa-157573 significantly inhibited the migration and proliferation of OSCC cells in vitro and decreased tumor development in subcutaneous xenograft models in vivo. RNA pull-down and RNA-binding protein immunoprecipitation (RIP) assays demonstrated that piR-hsa-157573 binds to heterogeneous nuclear ribonucleoprotein M (hnRNPM) and positively regulates hnRNPM protein expression. Collectively, our results demonstrate that piR-hsa-157573 binds to and positively regulates the expression of the cancer-associated protein hnRNPM, indicating its potential value as a biomarker and a target for therapy in OSCC.