lncRNA HOTAIRM1 Facilitates Nasopharyngeal Carcinoma Resistance to Irradiation and Ferroptosis by Increasing SLC7A11 Stability and Expression via METTL3-mediated m6A Methylation

Radiotherapy has become a main treatment for patients with nasopharyngeal carcinoma (NPC), who often develop residual or recurrent tumors due to radioresistance. The lncRNA HOTAIRM1 plays crucial roles in the formation and development of various cancers, but the interaction between HOTAIRM1 and radioresistant NPC remains unclear. In this study, we evaluated the potential of HOTAIRM1 as a biomarker of NPC radioresistance. Proliferation, apoptosis, DNA damage, and RNA-seq analyses were conducted to examine the mechanisms by which HOTAIRM1 contributes to NPC radioresistance, and in vivo experiments were performed using nude mice. Our findings indicated that HOTAIRM1 levels were upregulated in radioresistant NPC tissues and cell lines. High HOTAIRM1 expression was associated with increased NPC cell proliferation, decreased apoptosis, and decreased cellular DNA damage after radiotherapy. Mechanistically, HOTAIRM1 promoted NPC radioresistance by increasing SLC7A11 stability and expression through METTL3-mediated m6A demethylation. Additionally, high HOTAIRM1 expression decreased SLC7A11-associated ferroptosis. Our findings demonstrate that HOTAIRM1 promotes METTL3-mediated m6A methylation to increase SLC7A11 expression and stability, thereby inhibiting ferroptosis to trigger NPC radioresistance. This novel molecular mechanism underlying the role of HOTAIRM1 in the regulation of radioresistant NPC may aid in the identification of biomarkers and therapeutic targets for the treatment of radioresistant NPC. The total RNA of C666-1R-shNC and C666-1R-shHOTAIRM1 was isolated and purified. RNA libraries were sequenced on the Illumina NovaSeq 6000 platform at Huayin Health Medical Group Co., Ltd. (Guangzhou, China). Differentially expressed genes (DEGs) were identified based on a cutoff p-value < 0.05 and | logFC| > 1.