Association of Glutathione-S-Transferases M1 and T1 Deletional Variants with Development of Oral Squamous Cell Carcinoma: A Study in the South-East of Iran

Abstract

Background: The role of genetic polymorphisms in genes of Glutathione-S-transferases (GST) enzymes in susceptibility<br />to oral cavity cancers is controversial. Oral Squamous Cell Carcinoma (OSCC) is the most common oral cavity neoplasm.<br />Aimed to evaluate the potential impacts of two well-known null variants residing in the gene encoding GSTM1 and<br />GSTT1 enzymes of OSCC patients in the southeast of Iran. Methods: In a case-control design, 113 individuals (50<br />OSCC patients, and 63 healthy subjects) were included. DNA was extracted using paraffin-embedded tissues. GST<br />genotyping was carried out using multiplex PCR. Results: In 113 participants, 41 (36.3%) and 72 (63.7%) were males<br />and females respectively. No significant difference was recognized for distribution of GSTM1 (P=0.11) and GSTT1<br />(P=0.28) null genotypes between OSCC patients (58%, and 24% respectively) and healthy controls (42.9% and 15.9%<br />respectively). Also, no significant difference was noted regarding the frequency of GSTM1 null genotype in different<br />histological grades, however, those patients with more aggressive disease (poorly differentiated or grade III) revealed<br />with a significantly higher ratio (66.7%) of GSTT1 null genotype (P=0.002). The highest odds ratio for OSCC was related<br />to combined null genotypes for GSTM1 and GSTT1 (OR=2.5, 95% CI: 0.7-9.2), however, this was not statistically<br />significant finding (P=0.15). Conclusion: Null genotypes polymorphisms were more common in OSCC than healthy<br />individuals. GSTT1 null genotype may be an important genetic factor in the progression of OSCC.