lncRNA PVT1 promotes cetuximab resistance of head and neck squamous cell carcinoma cells by inhibiting miR‐124‐3p

Abstract Background Cetuximab has been widely used in the clinical treatment of head and neck squamous cell carcinoma (HNSCC). However, whether long non‐coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) is correlated with cetuximab resistance remains unclear. Methods Western blot and qRT‐PCR were performed to quantify the levels of genes and proteins, respectively. Cell functions were measured using Cell Counting Kit‐8 (CCK‐8), Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry assays. The methylation level was tested using methylation‐specific PCR (MSP). Results PVT1 was upregulated and positively correlated with the poor prognosis of HNSCC. PVT1 overexpression markedly promoted the survival and weakened the cetuximab sensitivity of HNSCC cells, while miR‐124‐3p overexpression showed opposite effects. Mechanistically, the silence of PVT1 indirectly promoted miR‐124‐3p expression by reducing its promoter methylation. Importantly, miR‐124‐3p overexpression impeded the regulatory roles of PVT1 overexpression. Conclusion PVT1 decreased the sensitivity of HNSCC cells to cetuximab by enhancing methylation‐mediated inhibition of miR‐124‐3p, which might provide a new insight for the cetuximab chemoresistance of HNSCC.