Clinical and biological significance of microRNA-127 and microRNA-138 expression in women with breast cancer: response to treatment and survival impact

Background and Objective Genetic and epigenetic changes characterize the multi-step process of breast carcinogenesis. It is believed that abnormal microRNA (miRNA) expression has a role in the onset and progression of breast cancer. This study aimed to examine the link between miRNA-127 and miRNA-138 and metastasis, tumor invasion, and apoptosis in Egyptian women with breast cancer, as well as their correlation with its molecular types. Methodology A total of 150 participants were included in this study, including 75 women with breast cancer and 75 supposedly healthy women who were age and gender-matched. Every patient underwent a thorough physical examination, a general clinical examination, a mammogram, and lab tests, such as the determination of the levels of miRNA-127 and miRNA-138 expression by real-time PCR and the measurement of blood carcinoembryonic antigen (CEA) and carcinoma antigen 15–3 (CA15-3) and CA15-3 and CEA levels. Results There was a significant low expression of miRNA-127 in favor of high TNM stage (Classification of Malignant Tumors), left-sided tumor, metastasis, high-grade disease, increased axillary nodal involvement, absence of estrogen and progesterone receptors, and low antigen Kiel 67 (Ki67) expression. Also, a significant expression of miRNA 127 in triple-negative breast cancer was found, followed by human epidermal growth factor receptor 2 (HER2/neu) overexpression, then luminal B, and the highest expression was with the Luminal A molecular subtype. A significant negative correlation existed between miRNA 127 and miRNA 138 with CEA and CA15.3 levels. Conclusion The miRNA-127 and miRNA-138 suppression may promote metastasis. Consequently, the restoration of miRNA-127 and miRNA-138 in breast cancer may have therapeutic potential; so, the miRNA-127 and miRNA-138 may play a role in breast cancer development.