结直肠癌染色体断裂率的研究

Mutagen sensitivity in colorectal cancer

目的 研究散发性结直肠癌患者对 DNA损伤的修复能力和集中的断裂位点 .方法 应用以博莱霉素为诱变剂的敏感性检测方法 ,检测 5 2例肿瘤患者和 76例对照的染色体断裂情况 ,并对部分样本进行 G显带 .结果 博莱霉素诱发后 ,肿瘤人群的染色体断裂率 (0 .841 b/ c)明显高于对照(0 .732 b/ c) ,肿瘤组博莱霉素敏感者所占的比例 (5 5 .8% )也明显高于对照组 (35 .5 % ) ;肿瘤的大小 (以 3cm为界 )、浸润深度 (以肌层为界 )与诱变剂敏感性呈正相关 ;有家族史的肿瘤患者平均发病年龄 (5 0 .0岁 )较无家族史者 (5 9.1岁 )明显提前 ,左半结肠肿瘤患者的诱变剂敏感性 (8/ 8)比右半结肠(1 / 3)和直肠 (2 0 / 41 )肿瘤患者的高 ,肿瘤患者常见的染色体断裂位点为 1 p32 - tem,1 q32 - 33,5 q2 1 - 31 ,7p1 5 ,1 4 q2 2 - 2 4.结论 1诱变剂敏感性是评价结直肠肿瘤易感性的简便而可靠的指标 ;2诱变剂敏感性是个可遗传的特征 ;3诱变剂敏感性与肿瘤的发展阶段有关 ;4结直肠肿瘤的发生与特定的染色体断裂有关 .

AIM To investigate DNA damage and/or repair capability of sporadic colorectal cancer patients. METHODS Bleomycin induced mutagen sensitivity was used to measure chromatid breaks of 52 cancer patients and 76 controls. RESULTS When exposed to Bleomycin, cancer patients had more chromatid breaks (0.841b/c) than controls (0.732b/c). The frequency of sensitive class was higher in cancer patients ( 55.8% ) than in controls (35.5%). The size and infiltration depth of tumor were positively related to the mutagen sensitivity. Cancer patients, who had first degree relative affected by cancer, were younger (50.0years) than those who hadn't (59.1 years). 1p32 tem, 1q32 33, 5q21 31, 7p15, 14q22 24 were the most frequently broken points in colorectal cancers. CONCLUSION ① Mutagen sensitivity is a simple and credible marker to evaluate the susceptibility to colorectal cancer; ② mutagen sensitivity is an inheritable character; ③ mutagen sensitivity is related to the progression of the tumor; ④ the development of colorectal cancer is related to non randomly distributed chromosome breaks.