Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: MicroRNA-17-92 significantly enhances radioresistance in human mantle cell lymphoma cells. | Jiang et al. Radiation Oncology 2010 5 100 http content 5 1 100 RESEARCH RADIATION ONCOLOGY Open Access MicroRNA-17-92 significantly enhances radioresistance in human mantle cell lymphoma cells Ping Jiang1 En Y Rao2 Na Meng1 Yong Zhao2 Jun J Wang1 Abstract The microRNA-17-92 miRNA-17-92 cluster at chromosome 13q31-q32 also known as oncomir-1 consists of seven miRNAs that are transcribed as a polycistronic unit. Over-expression of miRNA-17-92 has been observed in lymphomas and other solid tumors. Whether miRNA-17-92 expression affects the response of tumor cells to radiotherapy is not addressed so far. In the present study we studied the effects of miRNA-17-92 on the radiosensitivity of human mantle cell lymphoma MCL cells Z138c. Over-expression of miRNA-17-92 significantly increased survival cell number cell proliferation and decreased cell death of human MCL cells after different doses of radiation. Immunoblot analysis showed that phosphatase and tension homolog PTEN and PHLPP2 was down-modulated and pAkt activity was enhanced in MCL cells after over-expressing miRNA-17-92 after irradiation. These findings are the first direct evidence that over-expression of miRNA-17-92 cluster significantly increases the radioresistance of human MCL cells which offers a novel target molecule for improving the radiotherapy of MCL in clinic. Introduction The importance of microRNAs in cancer is highlighted by the observation that approximately 50 of miRNA genes are located in cancer-associated genomic regions or in fragile sites 1 2 which are frequently amplified or deleted in tumorigenesis. Mantle cell lymphoma MCL is an aggressive hematological malignancy characterized by the chromosomal translocation t 11 14 q13 q32 which results in deregulated aberrant expression of cyclin D1 and comprises 5 -10 of human B-cell malignancies 3 . The median survival of patients with MCL ranges between 3 and 5 years according to most studies 4 5 . Studies in transgenic mice .
