G2期早熟染色体凝集技术预测肝癌细胞低LET射线辐射敏感性

Predict of radiosensitivity of human hepatoma cells irradiated with γ-rays by G2 PCC technique

用60Co产生的γ射线照射人肝癌细胞系SMMC-7721。以克隆形成法测定经照射后的细胞存活率,用化学诱导剂Calyculin-A诱导的早熟染色体凝集(Prematurechromosomecondensation,PCC)技术研究染色体损伤。结果显示G2期细胞内的染色单体和等点染色单体断裂数与照射剂量之间存在着线性相关性,染色单体断裂数与细胞存活率之间存在较好的线性相关性。表明辐射诱导的染色单体断裂可以作为预测SMMC-7721细胞内在辐射敏感性的指标,也可为临床诊断和治疗肝癌提供依据。

To investigate the radiation response of hepatoma cells SMMC-7721 the G2 premature chromosome condensation technique was used. SMMC-7721 cells （human hepatoma cells） were irradiated with ^60Co γ-rays. Then cell killing was documented by a colony assay. Initial chromatid breaks were measured by counting the number of chromatid breaks and isochromatid breaks immediately after prematurely chromosome condensed by Calyculin-A. A dose-dependent increase in radiation-induced chromatid / isochromatid breaks was observed in G2 phase. A good relationship was found between cell survival and chromatid breaks. This study implied that low LET radiation-induced chromatid / isochromatid breaks can be possibly used as a good predictor of radiosensitivity of SMMC-7721 hepatoma cells, also it could be used to design radiotherapy schedule for liver cancer patients.