Abstract 2146: Expression of SLC22A23 gene in laryngeal carcinoma
Authors: Buyru Nur , Ekizoglu Seda , Karaman Emin , Ulutin Turgut 
Published: July 2017

Laryngeal squamous cell carcinoma (LSCC) accounts for approximately 30-40% of head and neck cancers. Although tobacco and alcohol consumption are considered the major risk factors for LSCC, various genetic and epigenetic factors have also been associated with LSCC development and progression. Since early detection and diagnosis of LSCC can greatly increase the chance of a successful treatment and survival, several studies have addressed the identification of target genes involved in LSCC pathogenesis. In this study we aimed to identify differentially expressed genes involved in the pathogenesis of LSCC using the Genefishing technique. As a result of this investigation we identified the SLC22A23 gene as one of the differentially expressed gene.

Solute carriers (SLC) comprise the largest family of membrane transport proteins with more than 300 members which have been divided into 52 families. The main functions of these proteins is to transfer a wide range of substrates such as amino acids, lipids, inorganic ions, peptides, saccharides, metal ions, proteins, xenobiotics and drugs. It is well known that cancer cells need extra metabolic requirements during rapid cell cycles. One of the known functions of the SLC proteins is to facilitate the uptake of nutrients and removal of metabolites. SLC22A23 (solute carrier family 22, member 23) belongs to the SLC family of organic ion transporters that are responsible for the uptake or excretion of many compounds including drugs, toxins and endogenous metabolites in a variety of tissues. SLC22A23 is expressed in various tissues but no substrates or functions have yet been identified for SLC22A23. Altough the exact function is unknown, single-nucleotide polymorphisms which are located in the SLC22A23 gene have been associated with inflammatory bowel disease, endometriosis-related infertility and the clearance of antipsychotic drugs. On the other hand, SLC22A23 was identified as a prognostic gene to predict the recurrence of triple-negative breast cancer.

In this study, to confirm the GeneFishing assay data, we investigated expression of the SLC22A23 gene in laryngeal tissue samples obtained from 83 patients by quantitative RT-PCR. We detected statistically significant upregulation of the SLC22A23 mRNA in laryngeal tumor tissues (55.4%) (p&lt;0.001). However, no significant correlation was found between SLC22A23 expression and clinicopathological parameters including age, sex, stage, histological grade and smoking (p&gt;0.05).

To understand the association between the SNPs in SLC22A23 and LSCC we also investigated the frequency of different genetic variants (rs4959235, rs6923667, rs9503518). 77.2% of patients were homozygote for the rs9503518-AA genotype and %52.2 of these patients had increased SLC22A23 expression (p=0.046).

Our results indicate that there is a clear need for further studies investigating the SLC22A23 gene to identify its exact function and way of action in LSCC.

Citation Format: Nur Buyru, Seda Ekizoglu, Emin Karaman, Turgut Ulutin. Expression of SLC22A23 gene in laryngeal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2146. doi:10.1158/1538-7445.AM2017-2146