MiR-301 regulates the SIRT1/SOX2 pathway via CPEB1 in the breast cancer progression

Abstract Breast cancer, the most common malignant tumor in women, has become a worldwide burden for family and society. MicroRNAs (miRs) are recognized as critical mediators of cancer-related processes, since they have the ability to coordinately suppress multiple target genes. In this study, we aim to find out specific miRs involved in the progression of breast cancer, and explore the underlying molecular mechanism. Bioinformatics analysis suggested miR-301 as a differentially over-expressed miR in breast cancer, which was confirmed by expression determination. Functional assays were employed to explore the effect of miR-301 and its downstream effectors CPEB1, SIRT1 and SOX2 on malignant phenotypes of breast cancer. The interaction among these factors was explained using luciferase and RIP assays. In addition, the in vivo impact of miR-301 on breast cancer was assessed by cellular tumorigenicity in nude mice. We found that miR-301 overexpression restricted CPEB1 level, and further promoted cell proliferation, metastasis and cell cycle progression, and impeded apoptosis. Moreover, CPEB1 regulated breast cancer development by mediating SIRT1/SOX2 pathway. Further, miR-301 overexpressing accelerated tumor formation in nude mice. Our results indicate that miR-301 overexpression accelerates the progression of breast cancer through the CPEB1/SIRT1/SOX2 axis.