miR-1193 Suppresses Proliferation and Invasion of Human Breast Cancer Cells Through Directly Targeting IGF2BP2.

miRNAs are involved in breast cancer initiation and progression. In this study, we investigated the role of miR-1193, a newly found and poorly studied miRNA, in the proliferation and invasion of human breast cancer cells. Our results showed that compared with the adjacent tissues and MCF-10A human normal breast cells, miR-1193 was sharply reduced in breast cancer tissues and five breast cancer cell lines, including MDA-MB-231, MDA-MB-468, MDA-MB-435, SKBR3, and MCF-7. The oligo miR-1193 mimic or anta-miR-1193 was then transfected into MDA-MB-231 and MCF-7 breast cancer cell lines. Our results showed that the miR-1193 mimic robustly increased the miR-1193 level and decreased the proliferation and invasion in MDA-MB-231 and MCF-7 cells. In contrast, anta-miR-1193 had an opposite effect on miR-1193 expression, cell proliferation, and cell invasion. Moreover, bioinformatic and luciferase reporter gene assays confirmed that miR-1193 targeted the mRNA 3'-UTR region of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), an identified proto-oncogene. miR-1193 suppressed the protein level of IGF2BP2 and the activation of the ERK and PI3K/Akt signaling pathways. Moreover, suppression could be rescued by the transfection of pcDNA-IGF2BP2. In conclusion, miR-1193 suppressed proliferation and invasion of human breast cancer cells via translational suppression of IGF2BP2.