GROWTH Inhibition of Gastrointestinal Cancers with Antisense Oligonucleotides to Oncogenes in vitro and in vivo.

在这项研究中，我们研究了癌基因的反义寡核苷酸是否可以在体外和体内抑制胃肠道肿瘤的生长。硫代磷酸酯修饰的c-myc和bcl-2癌基因反义寡核苷酸在0.1- 10 μ M浓度下以剂量依赖性方式抑制过表达这两种癌基因的胃癌细胞系MKN-45的生长，而互补正义寡核苷酸则无此作用。Ki-ras癌基因的反义寡核苷酸也抑制DLD-1细胞的生长，DLD-1细胞是一种携带突变Ki-ras基因的结肠癌细胞系。通过RT-PCR和c-myc流式细胞术分析，c-myc反义寡核苷酸在mRNA水平和蛋白水平特异性抑制c-myc癌基因的表达。缺口末端标记法检测凋亡细胞，结果显示c-myc和bcl-2反义寡核苷酸可增加MKN-45细胞的凋亡，提示其抑制MKN-45细胞生长的作用可能与凋亡有关。此外，c-myc和Ki-ras的反义寡核苷酸抑制裸鼠皮下移植的MKN-45细胞和DLD-1细胞的生长，而生理盐水和正义寡核苷酸没有影响。这些结果表明，癌基因的反义寡核苷酸可能作为一种可能的治疗方法，胃肠道肿瘤的进一步研究。

In this study, we examined if antisense oligonucleotides to oncogenes can suppress growth of gastrointestinal cancers in vitro and in vivo. Phosphorothioate-modified antisense oligonucleotides to the c-myc and bcl-2 oncogenes depressed growth of MKN-45 cells, a gastric cancer cell line overexpressing both onccogenes, in a dose dependent manner at concentrations of 0.1-10muM in vitor, whereas the complementary sense oligonucleotides had no effect. Antisense oligonucleotide to the Ki-ras oncogene also inhibited growth of DLD-1 cells, a colon cancer cell line carrying a mutated Ki-ras gene. When analyzed by RT-PCR and c-myc flow cytometry, the c-myc antisense oligonucleotide specifically inhibited expression of the c-myc oncogene in mRNA level as well as in protein level. Nick-end labelling method for histological detection of apoptotic cells revealed that the c-myc and the bcl-2 antisense oligonucleotides increased apoptotic MKN-45 cells, suggesting that apoptosis may be involved in their inhibitory effect on MKN-45 cell growth. Further, antisense oligonucleotides to c-myc and Ki-ras suppressed growth of MKN-45 cells and DLD-1 cells subcutaneously transplanted in nude mice, whereas saline and sense oligonucleotides had no effect. These results suggest that antisense oligonucleotides to oncogenes might be further studied as a possible treatment method for gastrointestinal cancers.