RIP3基因重组质粒构建及其表达对MCF7细胞死亡方式的影响  

Construction of Recombinant Plasmid of Human RIP3 Gene and Its Effects on the Death of Breast Cancer MCF7 Cells

作　　者：路灿[1] 徐惠君[1] 贾勇圣[1] 佟仲生[1] 

机构地区：[1]天津医科大学肿瘤医院乳腺肿瘤内科,国家肿瘤临床医学研究中心,天津市肿瘤防治重点实验室,乳腺癌防治教育部重点实验室,300060

出　　处：《天津医药》2014年第2期109-112,I0002,共5页Tianjin Medical Journal

基　　金：天津市抗癌重大专项攻关计划(项目编号:12ZCDZSY16200)

摘　　要：目的建立稳定过表达RIP3基因的乳腺癌细胞株,并证实融合蛋白在细胞内的表达、定位及对MCF7细胞死亡方式的影响。方法逆转录聚合酶链反应(RT-PCR)检测4种乳腺癌细胞及正常乳腺上皮细胞中RIP3mRNA的表达。以正常乳腺上皮细胞MCF10A cDNA为模板,PCR扩增RIP3基因cDNA全长,将合成的RIP3编码区序列,克隆入mCherry载体的N末端,构建重组质粒mCherry-RIP3,对重组质粒进行酶切鉴定及DNA测序。钙法转染293T细胞,收集病毒感染MCF7细胞,杀稻瘟菌素(4 mg/L)维持筛选,构建稳定表达细胞株。Western blot、荧光显微镜等检测目的基因表达效率及蛋白定位。显微镜下观察肿瘤坏死因子(TNF)-α及Caspase抑制剂Z-VAD-FMK处理下mCherry-RIP3-MCF7细胞的死亡形态及比例。结果 RIP3 mRNA在乳腺癌细胞中普遍低表达。RIP3基因成功克隆入载体。过表达mCherry-RIP3基因的MCF7细胞可见红色荧光蛋白表达,定位于胞质。目的基因RIP3在转染细胞中为过表达。mCherry-RIP3转染后增强MCF7细胞对TNF-α联合Z-VAD-FMK诱导的细胞坏死的敏感性。结论成功构建RIP3基因过表达重组质粒,获得外源性RIP3稳定过表达的乳腺癌MCF7细胞株,mCherry-RIP3定位于胞质,并在TNF-α介导的程序性坏死中起作用。Objective To construct the recombinant RIP3 over-expressed plasmids and transfect them in breast cancer MCF7 cells, and identify the expression and localization of fusion protein, as well as its effect on the death way of MCF7 cells. Methods The expression levels of RIP3 mRNA in four breast cancer cell lines and normal mammary epithelial cells were detected by reverse transcription polymerase chain reaction （RT-PCR）. The RIP 3 coding sequence was amplified by polymerase chain reaction and subcloned into mCherry vector to construct recombinant plasmids. The plasmids were transfected into MCF7 cells by lentivirus after DNA sequencing, then screened by basticidin （4 mg/L） for 1 week. The efficiencies of RIP3 expression were validated by Western blotting assay. The death way of mCherry-RIP3-MCF7 cells was observed under the treatment of TNF-αand Z-VAD-FMK. Results The lowest expression of RIP3 mRNA was found in MCF7 cells. The sequencing results validated the well recombinant plasmids. The expression of mCherry-RIP3 fusion pro-tein with a molecular weight of 85 ku was detected by Western blot assay. The mCherry-RIP3 expression enhanced the sensi-tivity of MCF7 cells to TNF-αand Z-VAD-FMK induced cell death. Conclusion The recombinant RIP3 over-expressed plasmids were successfully constructed, and the stable MCF7 cells with ectopic RIP3 transfection were obtained. The mCher-ry-RIP3 fusion protein was expressed in the cytoplasm and was conformed to mediate TNF-αinduced necroptosis.

关 键 词：蛋白质类 蛋白质构象 乳腺肿瘤 质粒 坏死 细胞凋亡 肿瘤坏死因子α 存活率 

分 类 号：R73-3[医药卫生—肿瘤]