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

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；MTF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。

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

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.