AFP的亚细胞定位及对肿瘤细胞生长的影响

Expression and Effect of AFP on Cell Growth in Different Cancer Cell Lines

目的观察甲胎蛋白（AFP）在不同肿瘤细胞中的亚细胞定位及对肿瘤细胞生长的影响。方法运用免疫荧光的方法观察内源性AFP在HeI。a细胞、QGY-7703细胞、MCF-7细胞中的亚细胞定位。将构建的表达AFP的质粒pcDNA3-AFP及AFP腺病毒siRNA干涉载体Adv—AFPsiRNA作用于QGY-7703细胞，MCF-7细胞，运用M1Tr，集落形成实验检测细胞增殖状况。结果免疫荧光显示，内源性的AFP在HeLa细胞、QGY-7703细胞、MCF-7细胞均只在细胞质中表达。pcDNA3-AFP使QGY-7703的细胞活性增加了2l％（P〈0．05）及集落形成能力增加了32％（P〈0．01），MCF-7实验组比对照组细胞活性降低了30％（P〈0．01）．克隆形成能力降低82％（P〈0．01）。Adv—AFPsiRNA使QGY-7703的细胞活性降低了22％（P〈0．05），平均克隆形成能力降低52％（P〈0．01），MCF-7细胞活性提高了24．5％（P〈0．05），克隆形成能力提高了89％（P〈O．01）。结论内源性的AFP只在细胞质中表达。AFP能促进QGY-7703细胞的增殖及克隆形成能力，而在MCF-7细胞中发挥相反的作用。腺病毒介导的内源性的AFP表达的下调能降低QGY-7703的增殖，却增加了MCF-7的细胞活性及克隆形成能力。

Objective To observe the subcellular localization of endogenous AFP in different tumor cells and the effect of AFP on tumor cell proliferation. Methods Subcellular localization of endogenous AFP in HeLa, QGY-7703, and MCF-7 was detect by use of immunofluorescence. Cell activity and colony formation ability were measured in QGY-7703, MCF-7 which were treated with pcDNA3-AFP or Adv-AFPsiRNA. Results Immunofluorescence revealed that endogenous AFP is expressed only in cytoplasm. Ectogenous AFP enhanced cell proliferation （21% , P 〈 O. 05） and colony formation ability （ 32 % , P 〈 O. O1 ） of QGY-7703 cells, but decreased cell proliferation （30 % , P 〈0. O1 ） and colony formation ability （82 %, P 〈0. 01 ） of MCF-7 cells. In contrast, down-regulation of endogenous AFP by Adv-AFPsiRNA reduced proliferation to 22 % （P 〈 0. 05） and colony formation to 52% （P 〈 0. 01 ） in QGY-7703 cells, but increased cell proliferation to 24. 5 % （P 〈 O. 05 ） and colony formation to 89 % （P 〈 O. 01 ） in MCF-7 cells. Conclusion En- dogenous AFP is expressed only in the cytoplasm. Ectogenous AFP enhances cell proliferation and colony formation ability of QGY-7703 cells, but not MCF-7 cells.