Beaton Lindsay A, Marro Leonora, Malone Shawn, Samiee Sara, Grimes Scott, Malone Kyle, Wilkins Ruth C
Environmental and Radiation Health Sciences Directorate, Health Canada, 775 Brookfield Road, Postal Locator 6303B, Ottawa, ON, Canada K1A 0K9 ; Department of Physics, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada.
Environmental and Radiation Health Sciences Directorate, Health Canada, 775 Brookfield Road, Postal Locator 6303B, Ottawa, ON, Canada K1A 0K9.
ISRN Radiol. 2013 Apr 10;2013:704659. doi: 10.5402/2013/704659. eCollection 2013.
Background and Purpose. This project examined the in vitro γ H2AX response in lymphocytes of prostate cancer patients who had a radiosensitive response after receiving radiotherapy. The goal of this project was to determine whether the γ H2AX response, as measured by flow cytometry, could be used as a marker of individual patient radiosensitivity. Materials and Methods. Patients were selected from a randomized clinical trial evaluating the optimal timing of Dose Escalated Radiation and short-course Androgen Deprivation Therapy. Of 438 patients, 3% developed Grade 3 late radiation proctitis and were considered to be radiosensitive. Blood was drawn from 10 of these patients along with 20 matched samples from patients with Grade 0 proctitis. Dose response curves up to 10 Gy along with time response curves after 2 Gy (0-24 h) were generated for each sample. The γ H2AX response in lymphocytes and lymphocyte subsets was analyzed by flow cytometry. Results. There were no significant differences between the radiosensitive and control samples for either the dose course or the time course. Conclusions. Although γ H2AX response has previously been demonstrated to be an indicator of individual patient radiosensitivity, flow cytometry lacks the sensitivity necessary to distinguish any differences between samples from control and radiosensitive patients.
背景与目的。本项目研究了接受放疗后具有放射敏感性反应的前列腺癌患者淋巴细胞中的体外γH2AX反应。本项目的目标是确定通过流式细胞术测量的γH2AX反应是否可作为个体患者放射敏感性的标志物。材料与方法。患者选自一项评估剂量递增放疗和短程雄激素剥夺治疗最佳时机的随机临床试验。在438例患者中，3%发生3级放射性直肠炎，被认为具有放射敏感性。从其中10例患者中采集血液，同时从0级直肠炎患者中采集20个匹配样本。为每个样本生成高达10 Gy的剂量反应曲线以及2 Gy（0 - 24小时）后的时间反应曲线。通过流式细胞术分析淋巴细胞和淋巴细胞亚群中的γH2AX反应。结果。对于剂量过程或时间过程，放射敏感样本与对照样本之间均无显著差异。结论。尽管γH2AX反应先前已被证明是个体患者放射敏感性的指标，但流式细胞术缺乏区分对照患者和放射敏感患者样本之间差异所需的敏感性。
