Investigation of HEYL gene rs41264499 and rs11206478 single nucleotide polymorphisms and susceptibility to laryngeal and hypopharyngeal squamous cell carcinoma

Background and Objectives Head and neck cancer is the 6th most common cancer worldwide. This is a large group of cancers that are different in their representation, aggressiveness and outcomes. Laryngeal squamous cell carcinoma (LSCC) accounts for 30-40 % and hypopharyngeal squamous cell carcinoma (HSCC) for around 3-5 % of head and neck cancers. Though there are a few known risk factors of these diseases, most notably alcohol and tobacco consumption, only a small number of patients that are exposed are diagnosed with these cancers. This suggest that there is individual genetic predisposition to the disease, although the genetic biomarkers are yet to be discovered. One of the target genes of Notch signaling pathway, a process which is linked with tumor formation, is HESR family genes, including HEYL gene. Some studies suggest HEYL gene and its single nucleotide polymorphisms (SNPs) to have association with risk of various cancers, though its impact on head and neck cancers remains unclear. The objective of this study was to evaluate the association between selected single nucleotide polymorphisms HEYL rs41264499 and rs11206478 and risk of LSCC and HSCC; secondly, the objective was to assess if there is a link between HEYL selected SNPs and LSCC as well as HSCC pathomorphological characteristics. Material (patients) and research method used Two groups, consisting of 251 male patients were included in this retrospective casecontrol study study: 79 male patients with diagnosed hypopharyngeal squamous cell carcinoma and 172 male patients with diagnosed laryngeal squamous cell carcinoma. There was a control group of 220 healthy male individuals included during their routine annual health checkup at the family doctor in Kaunas Clinics. The study was approved by the Kaunas Regional Biomedical Research Ethics Committee (Protocols No. BE-2- 37, No. BE-2-10, and No. P1-BE-2-10/2014.). Data was collected on tumor size, lymph node involvement, extranodular extention, distant metastasis, stage, histological grade and association with HPV infection. DNA was extracted from peripheral venous blood samples of all individuals using a commercial DNA extraction kit (Thermo Fisher Scientific Baltics) as indicated on the manufacturer's guidelines. Genotyping of the selected polymorphisms HEYL rs41264499 and rs11206478 was performed using TaqMan® SNP Genotyping Assays on the QuantStudio™ 3 Real-Time PCR System. Statistical analysis was performed using IBM SPSS Statistics for Windows, v. 25.0. Findings/results in sufficient details to support conclusions In this study we determined that the HEYL rs41264499 CG genotype carriers had a 1.874-fold increased risk of LSCC (OR = 1.874, CI 95% (1.057-3.323), p = 0.031). Additionally, we found that the distribution of HEYL rs41264499 G allele carriers and non-carriers is statistically significantly different in patients with LSCC compared to the control group (p = 0.030). The binary logistic regression analysis showed that the G allele carriers of HEYL rs41264499 had an increased risk of LSCC (OR = 1.838, CI 95% (1.055-3.203), p = 0.032). No clear link was found between HEYL rs11206478 and risk of LSCC. Both of the selected polymorphisms showed no association on risk of HSCC. In addition, there was no significant association between selected HEYL SNPs and tumor size, lymph node involvement, metastasis, stage, histological grade, HPV infection and extranodular extention. Conclusions and recommendations HEYL rs41264499 CG genotype carriers as well as G allele carriers in the allelic model had an increased risk of developing laryngeal squamous cell carcinoma. There was no association between selected SNPs and laryngeal and hypopharyngeal cancer pathomorphological features. Study results suggest that HEYL rs41264499 may have a value in determining risk of LSCC.