tailieunhanh - Báo cáo khoa học: "The radiosensitizing effect of Ku70/80 knockdown in MCF10A cells irradiated with X-rays and p(66)+Be(40) neutrons"

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: The radiosensitizing effect of Ku70/80 knockdown in MCF10A cells irradiated with X-rays and p(66)+Be(40) neutrons. | Vandersickel et al. Radiation Oncology 2010 5 30 http content 5 1 30 RADIATION ONCOLOGY RESEARCH Open Access The radiosensitizing effect of Ku70 80 knockdown in MCF10A cells irradiated with X-rays and p 66 Be 40 neutrons Veerle Vandersickel1 Monica Mancini2 Jacobus Slabbert3 4 Emanuela Marras2 Hubert Thierens1 Gianpaolo Perletti 2 and Anne Vral1 Abstract Background A better understanding of the underlying mechanisms of DNA repair after low- and high-LET radiations represents a research priority aimed at improving the outcome of clinical radiotherapy. To date however our knowledge regarding the importance of DNA DSB repair proteins and mechanisms in the response of human cells to high-LET radiation is far from being complete. Methods We investigated the radiosensitizing effect after interfering with the DNA repair capacity in a human mammary epithelial cell line MCF10A by lentiviral-mediated RNA interference RNAi of the Ku70 protein a keyelement of the nonhomologous end-joining NHEJ pathway. Following irradiation of control and Ku-deficient cell lines with either 6 MV X-rays or p 66 Be 40 neutrons cellular radiosensitivity testing was performed using a crystal violet cell proliferation assay. Chromosomal radiosensitivity was evaluated using the micronucleus MN assay. Results RNAi of Ku70 caused downregulation of both the Ku70 and the Ku80 proteins. This downregulation sensitized cells to both X-rays and neutrons. Comparable dose modifying factors DMFs for X-rays and neutrons of and respectively were obtained with the cell proliferation assay which points to the similar involvement of the Ku heterodimer in the cellular response to both types of radiation beams. After using the MN assay to evaluate chromosomal radiosensitivity the obtained DMFs for X-ray doses of 2 and 4 Gy were and respectively. After neutron irradiation the DMFs for doses of 1 and 2 Gy were and respectively. The fact that DMFs are in the same range .