Application of Modified FISH to Analyze Chromosomes of Radioresistant Tumor Cell and Development of Its Clinical Application

目前有很多研究分析肿瘤细胞和正常淋巴细胞辐照后的染色体畸变。在传统的染色体分析中，处于m期的细胞可以作为目标细胞。然而，这种方法的效率很低，不能得到充分的结果。当以染色体的转化为指标时，该方法的灵敏度也较低。此外，染色体易位也无法检测到。因此，染色体畸变分析一直是一项艰巨的任务。本研究用荧光染料对含有Calicrein A的浓缩染色体进行特异性染色，而不是常规染色方法。在这项研究中，我们计划分析辐照细胞中的染色体畸变，并发现放射敏感性与异常染色体畸变之间的关系。2001年，对辐射敏感的成纤维细胞、AT细胞和正常成纤维细胞进行辐照。与正常成纤维细胞相比，辐照后AT细胞对DNA损伤的修复能力较差，尤其是G1期。2002年，用FISH分析了辐照AT细胞和正常成纤维细胞辐照后染色体的转化和易位。结果表明，对放射敏感的成纤维细胞产生更多的错误修复。当重离子（碳束）照射成纤维细胞时，出现了比放射敏感性预期更多的碎片。我们对放射敏感性和染色体畸变没有明确的解释。这项研究将在未来的肿瘤细胞中继续进行。

There are many studies to analyze the chromosomal aberration after irradiation to the cancer cells and normal lymphocytes. In the conventional chromosome analysis, the cells in the M-phase can be the target. However, the efficiency of this method was very low and sufficient results could not be expected. When the transformation of the chromosome was adapted as the index, the sensitivity of this method was also low. Also, it was impossible to detect the chromosomal translocation. As a result, analysis of chromosome aberration had been a tough business. The condensed chromosomes with Calicrein A were stained with fluorescent dyes for the specific chromosome in this study instead of the conventional method. In this study, we planned to analyze the chromosomal aberrations in the irradiated cells and discover the relationship between radiosensitivity and abnormal chromosomal aberrations. In 2001, radiosensitive fibroblast, AT cells, and normal fibroblast cells were irradiated. It was found that AT cells have poor repair of DNA damage, especially G1 stage, after irradiation, comparing to normal fibroblasts. In 2002, transformation of chromosomes and translocation after irradiation were analyzed with FISH in irradiated AT cells and normal fibroblasts. As a results, it was determined that radiosensitive fibroblasts made more missrepairing. When heavy ions (carbon beams) was irradiated to fibroblasts, there appeared much more fragments than expected from radiosensitivity. We could not get the definitive explanation about the radiosensitivity and chromosomal aberration. This study will be continued with tumor cells in the future.