放疗引发的化疗后恶性肿瘤影响的证据存在争议。我们评估了顺铂如何调节两种正常细胞类型在体外对分段放射线辐射的反应。AHH-1淋巴细胞和VH10成纤维细胞在12天和19天分别每周5次和3次的剂量为1Gy/次的情况下进行辐射，并同时两次每周进行0.1, 0.2, 0.4, 0.8, 1.7和3.3 µM的顺铂处理。监测治疗期间的细胞生长情况。细胞生长/细胞死亡量和与DNA损伤积累和癌变相关的指标，在接受放射线和最低顺铂剂量的细胞中进行了研究，观察了治疗后21天的情况。单独放射线显著减少了细胞生长。低于3.3 µM的顺铂对细胞的影响微弱。除VH10细胞中最低剂量顺铂外，顺铂减轻了放射线对细胞生长的抑制作用。联合组中的延迟细胞死亡最高，而DNA损伤的积累没有显示出明显的模式。总之，分段放疗和顺铂的联合暴露降低了对正常细胞增殖的放射线的抑制效应，并不增强由DNA损伤积累导致的延迟效应。© 2023. Springer Nature Limited.

Evidence on the impact of chemotherapy on radiotherapy-induced second malignant neoplasms is controversial. We estimated how cisplatin modulates the in vitro response of two normal cell types to fractionated radiation. AHH-1 lymphoblasts and VH10 fibroblasts were irradiated at 1 Gy/fraction 5 and 3 times per week during 12 and 19 days, respectively, and simultaneously treated with 0.1, 0.2, 0.4, 0.8, 1.7 and 3.3 µM of cisplatin twice a week. Cell growth during treatment was monitored. Cell growth/cell death and endpoints related to accumulation of DNA damage and, thus, carcinogenesis, were studied up to 21 days post treatment in cells exposed to radiation and the lowest cisplatin doses. Radiation alone significantly reduced cell growth. The impact of cisplatin alone below 3.3 µM was minimal. Except the lowest dose of cisplatin in VH10 cells, cisplatin reduced the inhibitory effect of radiation on cell growth. Delayed cell death was highest in the combination groups while the accumulation of DNA damage did not reveal a clear pattern. In conclusion, fractionated, concomitant exposure to radiation and cisplatin reduces the inhibitory effect of radiation on cell proliferation of normal cells and does not potentiate delayed effects resulting from accumulation of DNA damage.© 2023. Springer Nature Limited.