Howard S P, Groch K M, Lindstrom M J, Messing E M, Gould M N
Department of Human Oncology, University of Wisconsin-Madison 53792, USA.
Radiat Res. 1995 Aug;143(2):229-33.
The survival of human prostatic epithelial cells irradiated in different physiological states is reported. Exponentially growing cells and contact-inhibited cells grown and irradiated in the presence of the growth factors epidermal growth factor (EGF) and bovine pituitary extract (bPE) had overlapping radiation dose-cell survival curves. However, when EGF and bPE were removed from exponentially growing cells before irradiation, an increase in radiosensitivity was observed if the cells were replated into medium containing growth factors (EGF and bPE) immediately after irradiation. Treating cells with the nonspecific growth factor receptor antagonist suramin had similar effects as did growth factor deprivation. In contrast, when growth factor-deprived cells were maintained in this same medium for 12 h postirradiation, an increase in radiation survival was observed. This increase in survival is attributed to the repair of potentially lethal damage (PLD). Both the increase in radiosensitivity induced by deprivation of growth factor before irradiation and the repair of PLD caused by deprivation of growth factor after irradiation were independent of changes in cellular proliferation.
本文报道了处于不同生理状态下的人前列腺上皮细胞受辐照后的存活情况。在表皮生长因子（EGF）和牛垂体提取物（bPE）等生长因子存在的情况下培养并辐照的指数生长期细胞和接触抑制细胞，其辐射剂量 - 细胞存活曲线相互重叠。然而，在辐照前从指数生长期细胞中去除EGF和bPE后，如果在辐照后立即将细胞重新接种到含有生长因子（EGF和bPE）的培养基中，则会观察到放射敏感性增加。用非特异性生长因子受体拮抗剂苏拉明处理细胞产生的效果与生长因子剥夺类似。相反，当生长因子剥夺的细胞在辐照后在同一培养基中维持12小时时，观察到辐射存活率增加。这种存活率的增加归因于潜在致死性损伤（PLD）的修复。辐照前生长因子剥夺诱导的放射敏感性增加以及辐照后生长因子剥夺导致的PLD修复均与细胞增殖的变化无关。
