The negative correlation between miR-140-3-p and Metadherin gene in estrogen and progesterone receptor positive–breast cancer

Abstract Background Breast cancer is a complicated cancer with different etiologies including both environmental and genetic factors. Aberrant expression of many genes and proteins is essential for its development and progression. Metadherin (MTDH) gene is one of the tumor related genes that involved in tumorigenesis and metastasis. MicroRNAs (miRNAs) are widely involved in cell proliferation, tumor invasion and apoptotic processes. Dysregulation of miRNAs expression was related to carcinogenesis and tumor progression. Objective This study aimed to assess miR-140-3p expression and its possible target gene MTDH gene expression in breast tumor tissues. Moreover, we aimed to explore the correlation among their expression and different clinicopathological parameters. Methods Bioinformatics analysis was done and revealed that MTDH is a one of many target genes for miR-140-3p. Reverse Transcription-quantitative Real-Time PCR (RT-qPCR) was used to identify the expression level of miR-140-3p and MTDH in 50 breast cancer tissues and 25 normal breast tissues. Results indicated that miR-140-3p was significantly lower in breast cancer tissues than normal breast tissues (P Conclusion This study highlights on the innovative role of miR-140-3p as new biomarker in breast cancer. The findings reveal the potential role of miR-140-3p in breast cancer pathogenesis and prognosis through targeting MTDH expression. This may give an indication for the emerging effect for miR-140-3p as a new diagnostic and potentially a therapeutic goal in breast cancer.