INTEGRATED ANALYSIS OF ERΑ, TP53, AND PGR PROTEINS WITH MIR-372, MIR-373, AND MIR-519D DYSREGULATION IN FEMALE BREAST...

Breast cancer is the most prevalent cancer among women in the world and is one of the causes of mortality due to cancer. Estrogen receptor alpha (ERα) and progesterone receptor (PGR), as well as tumor suppressor protein TP53, are the hormone receptors that are of critical importance in tumor progression and response to treatment. There is emerging evidence that miRNAs (miR-372, miR-373 and miR-519d) have a role to play in breast cancer pathogenesis by post-transcriptionally regulating genes. Nevertheless, the joint analysis of these protein markers and miRNAs is not studied thoroughly.

To evaluate serum levels of ERα, TP53, and PGR proteins and assess the expression of miR-372, miR-373, and miR-519d in breast cancer patients compared with healthy controls, and to determine their diagnostic and clinicopathological significance.

This case-control study included 53 female breast cancer patients and 25 healthy controls. Serum protein concentrations of ERα, TP53, and PGR were measured using sandwich ELISA. Total RNA was extracted from peripheral blood leukocytes, and miRNA expression was quantified using RT-qPCR with the 2^-ΔΔCT method. Statistical analyses were performed using SPSS, including independent t-tests, ANOVA, Pearson correlation, and ROC curve analysis. Statistical significance was set at p≤0.05.

ERα and TP53 levels in serum were extremely high in patients with breast cancer as compared to controls (p<0.001). There was a significant difference in PGR levels between the stage III and IV disease (p=0.01). Invasion ductal carcinoma (IDC) had significantly higher ERα levels than lobular carcinoma (p=0.03), whereas lobular carcinoma had significantly higher TP53 levels (p=0.05). The miR-372, miR-373 and miR-519d levels of expression were found significantly lower in the patients than in the controls (p<0.001). ROC curve analysis indicated that ERα (AUC=0.99), TP53 (AUC=1.0) and PGR (AUC=0.98) had excellent diagnostic results, whereas miRNAs under study had inverse discriminatory performance. There was strong positive association between ERα, TP53 and PGR (p=0.001) as well as there was strong positive association between the miRNAs being studied (p=0.001). Interestingly, there were significant negative relationships between the level of proteins and the level of miRNA (p=0.001).

High levels of serum ERα, TP53 and PGR have a close correlation with the presence of breast cancer and its subtype variation and have high diagnostic specificity. The down regulation of miR-372, miR-373 and miR-519d may indicate a possible tumor-suppressive effect and regulatory interplay with hormone and tumor suppressor pathways. These results show that protein and miRNA biomarkers are both useful in relation to breast cancer diagnosis, and possibly in determining individual therapeutic approaches.