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Published on: April 6, 2012
MicroRNA-302b suppresses human epithelial ovarian cancer cell growth by targeting RUNX1
Tingting Ge1, Mingzhu Yin, Meng Yang
1Department of Gynecology, the Affiliated Tumor Hospital, Harbin Medical University, Harbin, China.
Background:
The microRNA (miR)-302 family functions as a tumor suppressor in human cancer. However, its role in epithelial ovarian carcinoma (EOC) remains unknown. Here, we investigated the role of miR-302b and its target gene RUNX1 in EOC.
Methods:
The expression levels of miR-302b and RUNX1 were assessed by quantitative real-time PCR and western blotting. The effects of ectopic expression of miR-302b were evaluated by the MTT assay, colony forming assay and flow cytometry. RUNX1 was identified as a target of miR-302b and their interaction was confirmed by luciferase activity assays, RUNX1 silencing and overexpression of a RUNX1 mutant construct lacking the 3'UTR. The effect of miR-302b on the suppression of tumor growth was investigated in vivo in a xenograft mouse model.
Results:
MiR-302b levels were markedly decreased in EOC specimens. Ectopic expression of miR-302b in EOC cells inhibited cell proliferation and colony formation, induced G0/G1 arrest, and promoted apoptosis. RUNX1 was identified as a direct target of miR-302b, and knockdown of RUNX1 inhibited cell growth in a manner similar to miR-302b overexpression, whereas introduction of a 3'UTR mutant of RUNX1 reversed the suppressive effect of miR-302b. Furthermore, miR-302b overexpression led to the inactivation of the STAT3 signaling pathway in EOC cells and inhibited tumor growth in a xenograft mouse model.
Conclusions:
MiR-302b functions as a tumor suppressor in EOC by targeting RUNX1 and modulating the activity of the STAT3 signaling pathway.
Insights
MicroRNA (miR)-302b acts as a tumor suppressor in epithelial ovarian carcinoma (EOC) by targeting RUNX1. This study reveals miR-302b's potential to inhibit EOC growth and STAT3 signaling.
Area of Science:
- Oncology
- Molecular Biology
- Gene Regulation
Background:
- The miR-302 family is recognized as a tumor suppressor in various human cancers.
- The specific role of miR-302b in epithelial ovarian carcinoma (EOC) has not been previously elucidated.
Purpose of the Study:
- To investigate the function of miR-302b and its target gene RUNX1 in epithelial ovarian carcinoma (EOC).
- To determine the mechanism by which miR-302b influences EOC progression.
Main Methods:
- Quantitative real-time PCR and western blotting were used to assess miR-302b and RUNX1 expression.
- In vitro assays (MTT, colony formation, flow cytometry) evaluated the effects of miR-302b.
- Luciferase assays, gene silencing, and mutant constructs confirmed RUNX1 as a direct miR-302b target.
- In vivo studies using a xenograft mouse model assessed tumor growth suppression.
Main Results:
- MiR-302b expression was significantly downregulated in EOC tissues.
- Overexpression of miR-302b suppressed EOC cell proliferation, colony formation, induced cell cycle arrest, and promoted apoptosis.
- RUNX1 was validated as a direct target of miR-302b; RUNX1 knockdown mimicked miR-302b effects.
- MiR-302b inactivated the STAT3 signaling pathway and inhibited tumor growth in vivo.
Conclusions:
- MiR-302b functions as a tumor suppressor in EOC.
- The tumor-suppressive activity of miR-302b is mediated through the direct targeting of RUNX1.
- Modulation of the STAT3 signaling pathway is a key mechanism in miR-302b-driven EOC suppression.
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