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Overexpression of miR-200c induces chemoresistance in esophageal cancers mediated through activation of the Akt signaling pathway

icecream 添加于 2012-10-23 09:54 | 1149 次阅读 | 0 个评论

作者
Hamano R, Miyata H, Yamasaki M, Kurokawa Y, Hara J, Moon JH, Nakajima K, Takiguchi S, Fujiwara Y, Mori M, Doki Y
摘要
PURPOSE: To determine the relationship between resistance to chemotherapy and microRNA (miRNA) expression in esophageal cancer, we focused on miRNAs known to be associated with maintenance of stem cell function. EXPERIMENTAL DESIGN: Using 98 formalin-fixed, paraffin-embedded samples obtained from patients with esophageal cancer who had received preoperative chemotherapy followed by surgery, we measured expression levels of several miRNAs that are considered to be involved in the regulation of stem cell function (e.g., let-7a, let-7g, miR-21, miR-134, miR-145, miR-155, miR-200c, miR-203, and miR-296) by real-time reverse transcriptase PCR. Then, we examined the relationship between miRNA expression and prognosis or response to chemotherapy. To investigate the mechanism of miRNA-induced chemoresistance, in vitro assays were carried out using esophageal cancer cells. RESULTS: Analyses of the 9 miRNAs expression showed that overexpression of miR-200c (P = 0.037), underexpression of miR-145 (P = 0.023), and overexpression of miR-21 (P = 0.048) correlated significantly with shortened overall duration of survival. In particular, miR-200c expression correlated significantly with response to chemotherapy (P = 0.009 for clinical response; P = 0.007 for pathologic response). In vitro assay showed significantly increased miR-200c expression in cisplatin-resistant cells compared with their parent cells ( approximately 1.7-fold). In anti-miR-200c-transfected cells, chemosensitivity to cisplatin and apoptosis after exposure to cisplatin was found to increase as compared with the negative control. Western blotting showed that knockdown of miR-200c expression was associated with increased expression of PPP2R1B, a subunit of protein phosphatase 2A, which resulted in reduced expression of phospho-Akt. CONCLUSIONS: Results of this study emphasized the involvement of miR-200c in resistance to chemotherapy among esophageal cancers and that this effect was mediated through the Akt pathway.
详细资料
- 关键词: Aged; Antineoplastic Agents/pharmacology/therapeutic use; Carcinoma, Squamous Cell/diagnosis/drug therapy/*genetics/surgery; Cell Line, Tumor; Cisplatin/pharmacology/therapeutic use; Drug Resistance, Neoplasm/*genetics; Enzyme Activation/genetics/physiology; Esophageal Neoplasms/diagnosis/drug therapy/*genetics/surgery; Female; Gene Expression Regulation, Neoplastic/physiology; Humans; Male; MicroRNAs/*genetics/physiology; Middle Aged; Oncogene Protein v-akt/*metabolism/physiology; Prognosis; Si ...
- 文献种类: Journal Article
- 期刊名称: Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
- 期刊缩写: Clin Cancer Res
- 期卷页: 2011年第17卷第9期 3029-3038页
- 地址: Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
- ISBN: 1078-0432
学科领域生物医药 » 预防卫生学
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