Targeting GSK3β and signaling pathways in breast cancer: role of individual members of miR- 23/24/27 cluster.

BACKGROUND: The high mortality rate of breast cancer and the difficulties associated with therapeutic resistance, especially in cases where targeted treatments are unavailable, make it a serious threat to women's health. This study examines the relationship between three mature microRNAs (miRNAs) that are clustered together, namely miR- 23a, miR- 27a, and miR- 24-2, as well as their potential correlation with breast cancer. METHODS: We identified common gene targets of miR- 23a, miR- 27a, and miR- 24-2 using computational analysis. We also checked for the levels of miR- 23a, miR- 27a, and miR- 24-2 in 26 breast tumor tissues (with their matched control) as well as MCF7 and MDA-MB- 231 cell lines using qRT-PCR. Dual-luciferase reporter assay was conducted to validate the binding site of the microRNAs in their target gene. Western blot was performed to study the expression of various breast cancer related genes in the presence of the three microRNAs. In addition, the effect of microRNAs in cancer cell metastasis and cell division was carried out using invasion and cell cycle assay. RESULTS: Computational analysis identified key genes, including GSK3β, NCOA1 and SP1, which are functionally linked to tumor progression and various other malignancies. All three microRNAs were found to be significantly downregulated in the breast cancer tissue samples in comparison to their respective controls. Kaplan-Meier plot analysis revealed that the expression levels of these genes and associated microRNAs correlates with breast cancer patient survival rates. Reduced SP1 and NCOA1 levels predicted a worse prognosis, but elevated levels of GSK3β were linked with decreased survival. Moreover, miR- 23a and miR- 24-2 specifically target GSK3β, potentially disrupting the Wnt/β-catenin pathway involved in breast cancer development. Functional tests showed that miR- 23a, miR- 27a and miR- 24-2 affect expression of EMT related genes, influencing cell invasion and migration, impacting ERK signaling and EMT, critical in the spread of breast cancer. CONCLUSION: This study unlocks the potential of targeting the microRNA cluster as a therapeutic approach and emphasizes the complex regulatory roles of each individual members of the miR- 23a/27a/24-2 cluster in the pathogenesis of breast cancer.