Evaluation of Circulating miRNA145 Gene Expression as a Potential Biomarker in Breast Cancer: A Comprehensive Correlational Study with Hormonal Receptors, Clinical Parameters and Therapeutic Response

Abstract

Objective: To investigate microRNA-145 gene expression levels in the blood of breast cancer patients versus healthy subjects and examine its relationship with molecular, clinical, and therapeutic features.

Study Design: Case-control study
Place and Duration of Study: This study was conducted at the Imam Hussein (AS) Center for Oncology and Hematology, Karbala, Iraq, from 1st December 2024 to 31st July 2025.

Methods: The samples comprised two groups of women (patients and a control group). The gene expression levels were quantified using quantitative reverse transcription-polymerase chain reaction, with U6 being the normalization gene. Statistical analysis was conducted to establish the correlation between gene levels and hormone receptors (estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2), histological features (tumor size, metastasis) and treatments (chemotherapy, biological, radiation).

Results: Significant differences were evident in the microRNA-145 expression levels between patients and controls (0.37 vs. 1.00; p=0.0001). A significant difference existed between the expression level and the hormone receptor status (estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2), tumor size and lymph
node invasion. The radiation group exhibited the lowest expression levels of the gene (0.361) as opposed to the chemotherapy and biological groups.

Conclusion: The reduced microRNA-145 expression in breast cancer patients and supports its role as a diagnostic and prognostic biomarker