MALAT1 decreases the sensitivity of head and neck squamous cell carcinoma cells to radiation and cisplatin

Background/Aim: Two-thirds of head and neck squamous cell carcinoma (HNSCC) patients present with locally advanced (LA) stages and have a poor survival rate. The aim of this study was to investigate the roles of the long non-coding RNAs MALAT1 on radiation and cisplatin sensitivity of HNSCC cells. Materials and Methods: Clonogenic, cell viability, and apoptosis assays were performed in cells following MALAT1 knockdown using CRISPR/Cas9 system. Results: MALAT1 was overexpressed in HNSCC cell lines as compared to a non-tumorigenic cell line. The number of colonies formed after radiation was significantly reduced in MALAT1 knockdown cells. The IC50 value of cisplatin in MALAT1 knockdown cells was lower than that of the control cells. MALAT1 knockdown resulted in cell cycle arrest at G2/M phase, DNA damage and apoptotic cell death. Conclusion: MALAT1 knockdown enhanced the sensitivity of HNSCC cells to radiation and cisplatin partly through the induction of G2/M cell cycle arrest resulting in DNA damage and apoptosis.