miR-137 restoration sensitizes multidrug-resistant MCF-7/ADM cells to anticancer agents by targeting YB-1

Area of Science:

• Molecular Biology
• Oncology
• Biochemistry

Background:

• Multidrug resistance (MDR) poses a significant challenge in breast cancer chemotherapy.
• Understanding the molecular mechanisms underlying MDR is crucial for developing effective treatment strategies.

Purpose of the Study:

• To investigate the role of microRNA-137 (miR-137) in regulating MDR in breast cancer.
• To elucidate the mechanism by which miR-137 influences the sensitivity of MCF-7/ADM cells to chemotherapeutic agents.

Main Methods:

• Quantitative real-time PCR to assess miR-137 expression.
• Luciferase reporter assay and Western blot to confirm YB-1 as a direct target of miR-137.
• Cell viability assays to evaluate the sensitivity of MCF-7/ADM cells to anticancer agents.

Main Results:

• miR-137 was found to be downregulated in multidrug-resistant MCF-7/ADM cells.
• miR-137 expression inversely correlated with Y-box binding protein-1 (YB-1) and P-glycoprotein (P-gp) levels.
• Overexpression of miR-137 reduced YB-1 and P-gp levels, enhancing sensitivity to anticancer drugs, an effect reversed by YB-1 restoration.

Conclusions:

• miR-137 plays a critical role in overcoming MDR in breast cancer by targeting YB-1 and subsequently modulating P-gp expression.
• miR-137 represents a promising therapeutic target for reversing or preventing MDR in tumor cells.