Alterations of glutathione and GSTM1 mutations induce tumor metastasis and invasion via EMT pathway in breast cancer patients

Abstract

Purpose: Alteration in the Glutathione (GSH) and Glutathione S-Transferase (GST) family lead to various disorders including breast cancer. However, the role of GSH and GSTM1 in the onset of breast cancer is still not fully elucidated. Objective: In the present study we observed considerable deficiency in the levels of glutathione and genetic mutation in the GSTM1 enzyme that influence susceptibility to breast cancer metastasis and invasion via EMT pathway. Methods: GSTM1 genotype was identified by multiplex polymerase chain reaction (PCR), RT-PCR and western blotting in breast cancer tissue samples and ANCT samples. The endogenous glutathione levels were determined by HPLC. The tumor metastasis, invasion and EMT biomarkers were determined by RT-PCR and western blot. The relationship between breast cancer, disease progression and histological status were estimated by one way analysis of variance and descriptive statistic. Data were analyzed using OriginPro 2015 statistics software (OriginLab, Northampton, USA). The correlation among different factors was assessed at 95% confidence intervals (CI) using the Mann-Whitney, Kruskal Wallis, and ANOVA test. P<0.05 was considered significant. Results: In present study genotyping analysis of GST investigated that genetic mutation in GSTM1 was detected in breast cancer tissue samples. Moreover, messenger RNA and protein analysis showed that GSTM1 was significant downregulated in tumor tissues (p=0.005, p=0.02) of breast cancer patients. Furthermore, significant reduction in the level of total glutathione level (GSHt P<0.05) was observed among correlation with patient ages, stages and histological grades, of breast cancer patients. Additionally, the result revealed that downregulation of GSTM1 promotes EMT pathway that leads to enhanced the expression of tumor proliferation, invasion and metastasis in breast cancer tissue samples compared with the ANCT samples (P<0.05). Conclusions The present findings suggest that GSTM1 genotype could be a potential biomarker that regulate EMT pathway associated with breast cancer prognosis.