MicroRNA 145 may play an important role in uveal melanoma cell growth by potentially targeting insulin receptor substrate-1.
- Author:
Yang LI
1
,
2
;
Qiming HUANG
1
;
Xuehui SHI
1
;
Xiang JIN
1
;
Li SHEN
3
;
Xiaolin XU
1
;
Wenbin WEI
1
;
Author Information
- Publication Type:Journal Article
- MeSH: Apoptosis; genetics; physiology; Blotting, Western; Cell Cycle; genetics; physiology; Cell Line, Tumor; Cell Proliferation; genetics; physiology; Humans; In Vitro Techniques; Insulin Receptor Substrate Proteins; genetics; metabolism; Melanoma; genetics; metabolism; pathology; MicroRNAs; genetics; metabolism; Polymerase Chain Reaction; Uveal Neoplasms; genetics; metabolism; pathology
- From: Chinese Medical Journal 2014;127(8):1410-1416
- CountryChina
- Language:English
-
Abstract:
BACKGROUNDMicroRNAs (miRNAs) contribute to tumorigenesis by acting as either oncogenes or tumor suppressor genes. In this study, we investigated the role of miR-145 in the pathogenesis of uveal melanoma.
METHODSExpression profiles of miRNAs in uveal melanoma were performed using Agilent miRNA array. Quantitative real-time polymerase chain reaction was used to screen the expression levels of miR-145 in normal uveal tissue, uveal melanoma tissue, and uveal melanoma cell lines. Lenti-virus expression system was used to construct MUM-2B and OCM-1 cell lines with stable overexpression of miR-145. Cell proliferation, cell cycle, and cell apoptosis of these miR-145 overexpression cell lines were examined by MTT assay and flow cytometry respectively. The target genes of miR-145 were predicted by bioinformatics and confirmed using a luciferase reporter assay. The expression of insulin-like growth factor-1 receptor (IGF-1R), insulin receptor substrate-1 (IRS-1) proteins was determined by Western blotting analysis. IRS-1 was knocked down in OCM-1 cells. TUNEL, BrdU, and flow cytometry assay were performed in IRS-1 knocked down OCM-1 cell lines to analyze its function.
RESULTSForty-seven miRNAs were up regulated in uveal melanoma and 61 were down regulated. miR-145 expression was significantly lower in uveal melanoma sample and the cell lines were compared with normal uveal sample. Overexpression of miR-145 suppressed cell proliferation by blocking the G1 phase entering S phase in uveal melanoma cells, and promoted uveal melanoma cell apoptosis. IRS-1 was identified as a potential target of miR-145 by dual luciferase reporter assay. Knocking down of IRS-1 had similar effect as overexpression of miR-145.
CONCLUSIONmiR-145 might act as a tumor suppressor in uveal melanoma, and downregulation of the target IRS-1 might be a potential mechanism.