c-myc反义寡核苷酸对表达FHIT基因的结肠癌细胞增殖及凋亡作用的影响

Effect of c-myc antisense oligodeoxynucleotide on proliferation and apoptosis of colon cancer SW480 cells with FHIT gene re-expression

目的:观察脂质体介导的c-myc反义寡核苷酸对表达FHIT基因的结肠癌细胞增殖及凋亡作用的影响。方法:用脂质体法将重组FHIT基因的PRC/CMV质粒和空载体质转染到人结肠细胞株SW480,随后分别转染c-myc反义寡核苷酸。Western blot法检测细胞FHIT和c-myc的表达;MTT法检测细胞的增殖;AO/EB染色法和流式细胞分析技术检测细胞的凋亡。结果:转染FHIT基因后,SW480细胞有明显的FHIT蛋白表达而转染空载体的细胞未检测到FHIT蛋白表达。C-myc反义寡核苷酸转染后,对SW480细胞c-myc的表达有明显的抑制作用(P<0.01);对FHIT+/-SW480细胞的增殖均有明显的抑制作用(P<0.01),且对FHIT+SW480细胞的抑制作用明显强于FHIT-SW480细胞(P<0.05)。同时,c-myc反义寡核苷酸对FHIT+/-SW480细胞的凋亡均有明显的促进作用,对FHIT+SW480细胞凋亡的促进作用明显强于FHIT-SW480细胞(P<0.05)。结论:FHIT基因的表达和癌基因c-myc的表达抑制共同作用可以发挥较强的抗肿瘤细胞的效果,为多基因联合干预治疗肿瘤奠定了理论基础。

Objective：To study the effect of the c-myc antisense oligodeoxynucleotide （ASODN） on the proliferation and apoptosis of colon cancer cells with FHIT gene expression. Methods： PRC/CMV vector expressing FHIT gene and empty vector were transfected into human colon cancer SW480 cells by liposome mediation, respectively. Then, c-myc ASODN was transfected into SW480 cells. The FHIT and c-myc proteins were detected by western blotting. The proliferation of SW480 cells was assessed by MTT assay. The apoptosis was determined by AO/EB staining and flow cytometry analysis. Results： Marked expression of FHIT protein was detected in SW480 cells after transfection with PRC/CMV vector. But it was not observed in SW480 cells after transfection with empty vector. The expression of c-myc protein was significantly inhibited in SW480 cells after transfection with c-myc ASODN （ P 〈 0.01 ）. ASODN of c-myc inhibited the proliferation and induced the apoptosis of SW480 cells. However the growth-inhibiting and apoptosis-inducing effect of c-myc ASODN were stronger on FHIT ＋ SW480 cells compared with FHIT - SW480 cells （ P 〈 0.05 ）. Conclusions： The expression of tumor suppressor gene FHIT and down-regulation of oncogene c-myc have stronger anti-tumor efficiency and provides the basis for multiple gene interference therapy.