改变细胞膜的脂肪酸组成可促进乳腺癌细胞凋亡

目的: 研究n-6脂肪酸脱氢酶 fat-1基因在人乳腺癌细胞内的表达，改变细胞膜脂肪酸组成，对乳腺癌细胞的凋亡作用。方法: 构建含有fat-1 基因的重组腺病毒载体 (Ad.GFP.fat-1)，通过包装细胞系（293）产生的腺病毒，感染人乳腺癌细胞MCF-7。提取细胞的总RNA，以fat-1的反义mRNA 作探针，用Northern Blot检测fat-1 基因在MCF-7细胞内的表达。MTT法分析fat-1 基因对MCF-7细胞增殖的影响,凋亡染色试剂盒检测细胞的凋亡。气相色谱仪分析对MCF-7细胞的n-6 PUFAs/n-3 PUFAs含量影响。结果: 通过基因重组技术，得到预期的重组病毒；fat-1 基因在人乳腺癌细胞MCF-7 中能有效异源表达，2天后，可检测到fat-1 mRNA的条带。与对照细胞相比，fat-1基因有效地抑制了MCF-7细胞的增殖（23%，p<0.05），促进了凋亡（增加35%）；同时降低了人乳腺癌细胞MCF-7细胞膜n-6 PUFAs/n-3 PUFAs的比率。结论: 腺病毒介导的fat-1 基因能在人乳腺癌细胞MCF-7内有效异源表达，且抑制了MCF-7细胞的增殖。机理为降低了细胞膜的n-6 PUFAs/n-3 PUFAs的比率。

Changing Composition of Fatty Acids of Cell Membrane Promotes

Objective: To study expression of the gene of n-6 fatty acid desaturase fat-1 in human breast cancer cell, composition change of fatty acids of cell membrane, and effect of the gene on apoptosis of breast cancer cell. Methods: Construct recombinant adenovirus vector (Ad.GFP.fat-1) containing fat-1 gene, the recombinant adenovirus was produced in 293 package cell, then it infected the breast cancer cells MCF-7; Total RNA of the cells was isolated and hybridized with antisense RNA probe of fat-1 mRNA by Northern to analyze the expression of fat-1 in MCF-7;The effect of fat-1on the proliferation of MCF-7 cell was analyzed by MTT method,apoptosis of the cells were detected by apoptosis kit;Content of n-6 PUFAs/n-3 PUFAs was analyzed by Gas Chromatography. Results: The proposed recombinant virus was got through DNA recombinant technique; fat-1 gene effectively expressed in human breast cancer cell MCF-7; The fat-1 mRNA band appeared 2 days after infection of virus Ad.GFP.fat-1;Compared with the control cell (Ad.GFP), proliferation of MCF-7 cell was markedly inhibited by the gene fat-1( 23%, p<0.05) and apoptosis of the cells was promoted;Moreover, fat-1 gene decreased ratio of n-6 PUFAs/n-3 PUFAs of MCF-7 cell membrane. Conclusion: The fat-1gene transfer mediated by adenovirus could heterologously express in human breast cancer cell MCF-7, inhibit proliferation of the cell. The mechanism analysis shown that fat-1 decreased ration of n-6 PUFAs/n-3 PUFAs of cell membrane.