Kantor G J, Mulkie J R, Hull D R
Department of Biological Sciences, Wright State University, Dayton, OH 45435.
Exp Cell Res. 1978 May;113(2):283-94. doi: 10.1016/0014-4827(78)90368-3.
Culture and UV (254 nm) irradiation conditions that are suggested as appropriate for a study of the effect of UV on the limited in vitro lifespan of a normal human diploid fibroblast (HDF) strain are first described. An inoculation density at each subcultivation of 1.8 x 10(4) viable cells/cm-2 permits the decline in proliferative capacity to occur with kinetics similar to that observed using a 1:2 split and prevents cell overlap at the time of irradiation. Doses of 5 and 10 J/m2 have only a slight effect on initial growth rates and little or no effect on cell density achieved at confluence. With these conditions populations can be irradiated several times throughout the in vitro lifespan. No effect of UV on the limited division potential was observed. In the extreme, a population irradiated 14 times, once every second passage starting at P-18 with doses of 5 or 10 J/m2 had the same lifespan as controls, as measured by lifespan determinations and thymidine labeling index. Transformed cells were not detected in the multi-irradiated populations. Evidently no accumulation in the populations of damage induced by UV that affected life span, thymidine labeling index, growth rates or confluent cell densities occurred. No selection of a population with altered sensitivity occurred. An argument that genome hits may not be a prime reason for the limited proliferative capacity of HDF populations is presented.
首先描述了被认为适合用于研究紫外线对正常人二倍体成纤维细胞（HDF）株体外有限寿命影响的培养和紫外线（254nm）照射条件。每次传代时1.8×10⁴个活细胞/cm²的接种密度能使增殖能力的下降以与使用1:2传代时观察到的类似动力学发生，并能防止照射时细胞重叠。5和10J/m²的剂量对初始生长速率只有轻微影响，对汇合时达到的细胞密度几乎没有影响。在这些条件下，细胞群体在整个体外寿命期间可以被照射多次。未观察到紫外线对有限分裂潜能有影响。极端情况下，从P - 18开始，每隔一代用5或10J/m²的剂量照射一次，共照射14次的细胞群体，通过寿命测定和胸苷标记指数测量，其寿命与对照相同。在多次照射的细胞群体中未检测到转化细胞。显然，在细胞群体中未发生影响寿命、胸苷标记指数、生长速率或汇合细胞密度的紫外线诱导损伤的积累。未出现对敏感性改变的细胞群体的选择。提出了一个观点，即基因组命中可能不是HDF细胞群体增殖能力有限的主要原因。
