Genetic Signatures: <i>CD44</i> Single-Nucleotide Polymorphisms Affect Cell Surface Expression and Elevate Risk in Head and Neck Squamous Cell Carcinoma.

Abstract

This study aimed to investigate the impact of single-nucleotide polymorphisms (SNPs) in the <i>CD44</i> gene, specifically in the 3'UTR region (rs13347) and intronic region (rs187115), on the cell surface expression of CD44 protein and the risk of development of head and neck squamous cell carcinoma (HNSCC). The study involved analysis of 85 samples and 85 healthy controls. Immunohistochemistry (IHC) and flow cytometry were used to assess cell surface protein expression using CD44 antibody. DNA from formalin-fixed paraffin-embedded tissue sections was isolated and amplified using targeted primers. Sanger sequencing of the resultant amplified products was performed to determine the genotypes of the <i>CD44</i> rs13347 and rs187115 SNPs. GTEx and RegulomeDB were queried to evaluate the genotypic effects of these variants on target gene expression and regulation. A comparison between patients with HNSCC and healthy controls revealed a significant association between <i>CD44</i> rs13347 and an increased risk of HNSCC in all the analyzed models, especially the TT genotype showed a significantly higher risk with an odds ratio of 8.69 (95% CI, 2.35 to 32.09; <i>P</i> = .0003). However, no significant association was found between <i>CD44</i> rs187115 and HNSCC in any of the models analyzed (all <i>P</i> > .05). Other notable findings included significant associations between <i>CD44</i> rs13347 genotype and age (<i>P</i> = .031), number of CD44-positive tumor cells (<i>P</i> = .049), CD44 staining intensity (SI; <i>P</i> = .039), and CD44 immunoreactivity score (IRS) status (<i>P</i> = .019). The T allele and homozygous TT genotype of <i>CD44</i> rs13347 SNP were associated with increased susceptibility to HNSCC and decreased proportion of CD44-positive tumor cells, low SI, and reduced IRS.