Molecular biological study for association mitochondrial DNA somatic mutation with acquired anti-cancer drug resistance in digestive system cancer

我们利用线粒体杂交（cybrids）技术发现，线粒体DNA （mtDNA：来自胰腺癌、胃癌和结直肠癌细胞系）的突变与体外和体内抗癌药物耐受（5FU、CDDP、CPT-11、吉西他滨）有关。我们使用跨线粒体杂交细胞（cybrids）通过排除核背景的任何影响来揭示mtDNA突变在胰腺癌中的作用。将mtDNA突变的去核胰腺癌、胃癌和结直肠癌细胞系的mtDNA重新填充到缺乏mtDNA的HeLa细胞中，构建了cy杂种。我们构建了来自癌细胞突变的细胞系和来自健康个体的野生mtDNA细胞系，并将突变型和野生型细胞系移植到裸鼠体内产生肿瘤。我们比较了5FU、CDDP、CPT-11和吉西他滨给药后突变型杂交肿瘤和野生型杂交肿瘤的肿瘤生长和大量凋亡情况。所有实验均按照日本医学院动物使用伦理委员会的指导方针进行。结果：在多种抗肿瘤药物作用下，突变型细胞系衍生的肿瘤在抑制肿瘤生长和诱导大量细胞凋亡方面均优于野生型细胞系衍生的肿瘤。

We showed that mutations in mitochondrial DNA (mtDNA: derived from pancreatic cancer, gastric cancer and colorectal cancer cell lines) are responsible for anticancer drug tolerance(5FU, CDDP, CPT-11, Gemcitabine) in vitro and in vivo with trans-mitochondrial hybrids(cybrids) technique.We used trans-mitochondrial hybrid cells (cybrids) to reveal the role of mutations in mtDNA in the pancreatic cancer by excluding any effects of the nuclear background. Cybrids were constructed by repopulating HeLa devoid of mtDNA with mtDNA derived from enucleated the pancreatic cancer, gastric cancer and colorectal cancer cell lines sharboring mtDNA mutations. We constructed several cybrids with mutations derived from the cancer cells as well as those with wild mtDNA derived healthy individuals, and transplanted mutant and wild type cybrids into nude mice to generate tumors. We compared tumor growth and massive apoptosis of mutant cybrid tumors to wild cybrid tumors administrated of 5FU, CDDP, CPT-11, Gemcitabine. All experiments were performed in accordance with the guidelines of the Animal Use Ethics Committee of Nippon Medical School.Result:Tumors derived from mutant cybrids were more resistant than those from wild-type cybrids in suppressing tumor growth and inducing massive apoptosis when the all of anti-cancerdrugs were administered.