Peer-Reviewed Journal Details
Mandatory Fields
Selcuklu, SD;Donoghue, MTA;Rehmet, K;Gomes, MD;Fort, A;Kovvuru, P;Muniyappa, MK;Kerin, MJ;Enright, AJ;Spillane, C
2012
August
Journal Of Biological Chemistry
MicroRNA-9 Inhibition of Cell Proliferation and Identification of Novel miR-9 Targets by Transcriptome Profiling in Breast Cancer Cells
Published
Altmetric: 1WOS: 103 ()
Optional Fields
COLORECTAL-CANCER TUMOR-SUPPRESSOR CYCLIN G1 MICROARRAY ANALYSIS EXPRESSION ANALYSIS OVARIAN-CANCER IN-VITRO GENE CARCINOMA APOPTOSIS
287
29516
29528
Although underexpression of miR-9 in cancer cells is reported in many cancer types, it is currently difficult to classify miR-9 as a tumor suppressor or an oncomir. We demonstrate that miR-9 expression is down-regulated in MCF-7 and MDA-MB-231 breast cancer cells compared with MCF-10-2A normal breast cell line. Increasing miR-9 expression levels in breast cancer cells induced anti-proliferative, anti-invasive, and pro-apoptotic activity. In addition, microarray profiling of the transcriptome of MCF-7 cells overexpressing miR-9 identified six novel direct miR-9 targets (AP3B1, CCNG1, LARP1, MTHFD1L, MTHFD2, and SRPK1). Among these, MTHFD2 was identified as a miR-9 target gene that affects cell proliferation. Knockdown of MTHFD2 mimicked the effect observed when miR-9 was overexpressed by decreasing cell viability and increasing apoptotic activity. Despite variable effects on different cell lines, proliferative and anti-apoptotic activity of MTHFD2 was demonstrated whereby it could escape from miR-9-directed suppression (by overexpression of MTHFD2 with mutated miR-9 binding sites). Furthermore, endogenous expression levels of miR-9 and MTHFD2 displayed inverse expression profiles in primary breast tumor samples compared with normal breast samples; miR-9 was down-regulated, and MTHFD2 was up-regulated. These results indicate anti-proliferative and pro-apoptotic activity of miR-9 and that direct targeting of MTHFD2 can contribute to tumor suppressor-like activity of miR-9 in breast cancer cells.
0021-9258
10.1074/jbc.M111.335943
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