肝组织多药耐药基因高表达与结肠癌肝转移的相关性研究

Relationship between high expression for MDR-1 gene and liver metastases from colon cancer

目的 探索早期检测肝组织多药性耐药基因对结肠癌肝转移的预测价值。方法 取裸鼠 4 0只 ,用人结肠癌SW4 80细胞系制作裸鼠原位结肠癌肝转移模型。模型建立的第 10天肝活检取左右肝叶各2mm3 组织 ,用实时荧光定量PCR方法检测多药耐药基因 (multidrugresistancegene,mdr- 1mRNA)的表达 ;模型建立的第 5周观察裸鼠肝脏是否形成肉眼转移灶。结果 经实时荧光定量RT -PCR检测肝活检组织mdr- 1基因 ,在存活的 36只裸鼠中 2 2例高表达 ,平均CT值 (Cyclethreshold ,即反应管内的荧光信号到达设定的域值时所经历的循环数 )为 2 5 90 1,平均拷贝数为 4 2 7× 10 7/ugRNA ,并高表达的 2 2只裸鼠均有肉眼肝转移灶形成 (10 0 % ) ;mdr - 1基因低表达 (平均CT值 33 36 8,平均拷贝数 2 11× 10 5)及无表达的 14只裸鼠中 ,仅 1例形成肉眼肝转移灶 (7 1% ) ,其余 13例均无肉眼肝转移灶形成 (P <0 0 1)。结论 结肠癌肝活检肿瘤细胞mdr- 1mRNA基因高表达与异时的肝转移灶形成有明显的相关性 ,提示检测结肠癌肝组织多药性耐药基因的高表达可以预测异时的肝转移灶形成。

Objective To investigate the value of early predicting liver metastases from colon cancer by detecting multidrug resistance gene(mdr-1 mRNA)of liver tissue.Methods The first step was to proof the detecting methods and index,we drew 30 ml blood from a healthy volunteer through heparin anticoagulant and divided equally into 16 tubes.The former 8 tubes were blank comparison,the later 8 tubes in turn were added in 5、10、25、50、102、103、104、105 sw480 cell cline of human colon cancer.All above were detected mdr-1 gene with fluorogenioc quantitative.Then the second step:We established the mode of liver metastases from colon cancer with a SW480 human colon cell clot planted in cecum of nude mice,a splenectomy was performed at the same time,10 days later,2mm3 tissue from both left and right liver lobes was removed,which was used for genetic detecting mdr-1 mRNA by real time fluorogenic quantitative RT-PCR; 5 weeks later we observed whether the macroscopic liver metastases would happen.Results Twenty two of 36 survive cases were high expression for mdr-1 mRNA in the biotic liver tissue.The average CT value was 25.342,and the average number of copy was 4.27×107/ugmRNA.Macroscopic liver metastases were found in all these 22 cases.There were macroscopic liver metastases in 1 of 11 cases of low expression for mdr-1 mRNA,whereas other 11 cases and 2 cases of no expression for mdr-1 mRNA did not form macroscopic liver metastases.There were significantly difference (P<0 01).Conclusion There are definite association between mdr-1 gene high expression in early liver tissue of colon cancer and macroscopic liver metastases.Liver metastases can be predicted by detecting liver micrometastases.