线粒体DNA拷贝数在结直肠癌术后复发病例中变化的意义

Significance of mitochondrial DNA copy number in postoperative recurrence of colorectal cancer cases

目的 :探讨结直肠癌(CRC)术后复发患者的线粒体DNA(mtDNA)拷贝数异常与临床病理指标的关系。方法:选取50例术后复发CRC患者及50例初发CRC患者肿瘤、癌旁组织及外周血标本,分别提取基因组DNA,进而计算出mtDNA拷贝数;然后与临床及病理指标相比较分析。结果:无论是复发CRC患者还是初发CRC患者,肿瘤组织内mtDNA拷贝数均明显低于癌旁组织(P<0.05),同时其外周血中mtDNA拷贝数明显低于正常健康人(P<0.05);mtDNA拷贝数高低与复发CRC患者肿瘤的分化程度及淋巴结转移率密切相关(P<0.05),而与性别、年龄、肿瘤浸润深度及远处转移无相关性(P>0.05)。结论:线粒体DNA拷贝数的降低与复发CRC发生、发展和复发密切相关。

Objective： To investigate the relationship between mitochondrial DNA copy number and clinicopathological parameters in postoperative recurrence of colorectal cancer cases.Methods： Total DNA was extracted from cancer, pericancerous tissues and peripheral blood from50 patients with recurrence colorectal cancer and 50 patients with incipient colorectal cancer, and the mitochondrial DNA copy numbers were determined by RT-PCR. The relationship between clinical and pathological indicators and mitochondrial copy number was detected. Results： The mean copy number of mtDNA in cancer tissue was significantly lower than that of corresponding pericancerous tissue of these patients（P〈0.05）.The mean copy number of mtDNA in peripheral blood of cancer patients was significantly lower than that of health persons. No significant correlation wasfound between mtDNA copy number and other variables including age,gender,and tumor stage（P〈0.05）.However,there was a significant correlation between copy number and pathological type,lymph nodes stage（P〈0.05）. Conclusion： There is a significant reduction of mtDNA in the progression of postoperative recurrence of colorectal cancer cases.