microRNAs (miRNAs) are small noncoding RNA molecules involved in the regulation of gene expression and play critical roles in human malignancies. Next-generation sequencing analysis of the MCF-7 breast cancer cell line overexpressing miR-335-5p and miR-335-3p demonstrated that the miRNA duplex repressed genes involved in the ERα signaling pathway, and enhanced resistance of MCF-7 cells to the growth inhibitory effects of tamoxifen. These data suggest that despite its conventional role in tumor suppression, the miR-335 transcript can also play an oncogenic role in promoting agonistic estrogen signaling in a cancerous setting.
Keywords: breast cancer; endocrine resistance; estrogen receptor; isoform; miRNA-335; microRNA.
© 2016 Federation of European Biochemical Societies.