RUNX3 inhibits laryngeal squamous cell carcinoma malignancy under the regulation of miR-148a-3p/DNMT1 axis

Laryngeal squamous cell carcinoma (LSCC) is a highly aggressive malignant cancer and accounts for 1% to 2% of all malignancies diagnosed worldwide. Runt-related transcription factor 3 (RUNX3), an important tumor suppressor, is known to related to lymph node metastasis and the development of LSCC. However, the biological roles and potential mechanisms RUNX3 expression was not well understood. In this study, we reported that the RUNX3 was significantly downregulated and highly methylated in LSCC compared with their matched normal. The enforced expression of RUNX3 inhibited LSCC cell migration, invasion, and proliferation, whereas the inhibition of RUNX3 did the opposite. We identified that RUNX3 was regulated by miR-148a-3p and found that the expression level of miR-148-3p was significantly decreased and positively related with the expression of RUNX3 in LSCC. We also identified that DNA methyltransferase enzyme DNA (cytosine-5-)-methyltransferase 1 (DNMT1) was targeted by miR-148a-3p in LSCC. The knockdown of DNMT1 promoted the expression of RUNX3 and inhibited migration, invasion, and proliferation in LSCC cells. In summary, our study demonstrated that miR-148a-3p may regulate RUNX3 expression through the modulation of DNMT1-dependent DNA methylation in LSCC, providing a novel target and a potential therapeutic pathway against LSCC. LSCC is a highly aggressive malignant cancer and accounts for 1% to 2% of all malignancies diagnosed worldwide. In this study, we reported that RUNX3, an important tumor suppressor, was significantly downregulated and highly methylated in LSCC compared with their matched normal. The overexpression of RUNX3 inhibited LSCC cell migration, invasion, and proliferation, whereas the inhibition of RUNX3 did the opposite. Moreover, RUNX3 was regulated by miR-148a-3p, which targeted DNA methyltransferase enzyme DNMT1 in LSCC cells. Therefore, miR-148a-3p may regulate RUNX3 expression through the modulation of DNMT1-dependent DNA methylation in LSCC, providing a novel target and a potential therapeutic pathway against LSCC.