EZH2 Expression and Survival for ER plus /tamoxifen Treated Breast Cancer Patients with rs2302427 C>G: A Novel Prognostic and Risk Predictive Biomarker

Background and objectives. Overexpression of the EZH2 gene silences several genes involved in DNA repair, cell-cell adhesion, and tumor suppressor genes, resulting in the development of several types of cancers. In the present study, a genetic polymorphism analysis was performed by selecting three SNPs (rs.2302427C>G, rs.3757441C >T, and rs.6950683T>C) of the EZH2 gene based on our previous in silico studies. Methods. A total of 250 breast cancer patients and 250 healthy individuals were re-cruited for the study. Patients with pre-operative breast cancer with different clinical-pathological variables and age-matched healthy women were recruited for the EZH2 gene expression analysis. Results. The genetic polymorphism analysis revealed two SNPs (rs.2302427C>G and rs.6950683T>C) of the three studied SNPs of the EZH2 gene have a protective role in all three genetic models. The haplotype analysis predicted that two haplotypes ACGT and ACGC were significantly associated with a lower risk of breast cancer. Interpretation and Conclusions. Three significant findings of the SNP rs.2302427C>G (Asp193His) i.e., protective role against breast cancer, survival advantage in ER+/tamoxifen treated breast cancer patients, and decreased expression due to the presence of mutant GG genotype, suggests considering it as an important prognos-tic biomarker for a good survival outcome of breast cancer patients treated with ER+/tamoxifen. Compared with other studies, the other SNP rs.3757441T >C was ob-served to have a protective effect in breast cancer biology but plays an antagonistic role in colorectal cancer (CRC) biology. To our knowledge, this is the first detailed study on computationally validated EZH2 SNPs in breast cancer. (c) 2023 Instituto Mexicano del Seguro Social (IMSS). Published by Elsevier Inc. All rights reserved.