Verbascoside inhibits oral squamous cell carcinoma cell proliferation, migration, and invasion by the methyltransferase 3-mediated microRNA-31-5p/homeodomain interacting protein kinase 2 axis

Objective

The study aimed to investigate the effects of verbascoside on oral squamous cell carcinoma (OSCC) cellular behaviors and underlying molecular mechanisms.

Design

For this purpose, SCC9 and UM1 cell lines were treated with verbascoside, and their biological behaviors, including proliferation, migration, and invasion, were evaluated using cell counting kit-8, 5-Ethynyl-2′-deoxyuridine, and Transwell assays. The expression of methyltransferase-3 (METTL3), microRNA (miR)− 31–5p, and homeodomain interacting protein kinase-2 (HIPK2) were examined using quantitative real-time polymerase chain reaction (qRT-PCR). The interaction between METTL3 and miR-31–5p was evaluated by RNA immunoprecipitation and methylated RNA immunoprecipitation, while the interaction between miR-31–5p and HIPK2 was evaluated by dual-luciferase reporter analysis.

Results

The results indicated inhibition of OSCC cell proliferation, migration, and invasion post verbascoside treatment. Similarly, METTL3 was upregulated in OSCC cells and was inhibited post-verbascoside treatment. Overexpressing METTL3 promoted the cellular processes. Moreover, miR-31–5p was upregulated in OSCC cells, where METTL3 facilitated the processing of miR-31–5p in an N6-methyladenosine (m6A)-dependent manner. The HIPK2 served as miR-31–5p target, where overexpressing miR-31–5p or HIPK2 knockdown reversed the suppression of verbascoside-induced biological behaviors.

Conclusions

Verbascoside inhibited the progression of OSCC by inhibiting the METTL3-regulated miR-31–5p/HIPK2 axis. These findings suggested that verbascoside might be an effective drug for OSCC therapy.