Association of MIAT genetic variants and expression with tumor grade in oral tongue cancer.

Oral tongue cancer is an aggressive malignancy and represents the most common subsite of head and neck cancer. The long non-coding RNA myocardial infarction associated transcript (MIAT) has been implicated in the development and progression of several cancers. This study aimed to investigate the association between MIAT single-nucleotide polymorphisms (SNPs) and oral cancer susceptibility as well as related clinicopathological characteristics. In this study, MIAT SNPs (rs4274, rs1061540, and rs1894720) were genotyped using real-time polymerase chain reaction in 1,194 controls and 397 male patients with tongue cancer. A significant association was observed between the MIAT rs4274 AA genotype and the occurrence of tongue cancer compared with controls (p = 0.018). Among the patients, carriers of the rs4274 A allele exhibited a higher likelihood of developing moderately or poorly differentiated tumors [OR (95% CI) = 2.246 (1.217-4.147); p = 0.001]. Betel-quid chewers and smokers carrying the A allele showed similarly elevated risks for poor tumor differentiation. Bioinformatic analyses further indicated that the rs4274 A allele is associated with increased MIAT expression, and higher MIAT levels correlated with higher tumor grade. In conclusion, the MIAT rs4274 A allele is linked to poorer tumor differentiation, particularly among betel-quid chewers and smokers, and elevated MIAT expression supports its potential as a biomarker of tumor aggressiveness.