PARTIALLY TRANSFORMED, ANCHORAGE-INDEPENDENT HUMAN-DIPLOID FIBROBLASTS RESULT FROM OVEREXPRESSION OF THE C-SIS ONCOGENE - MITOGENIC ACTIVITY OF AN APPARENT MONOMERIC PLATELET-DERIVED GROWTH FACTOR-II SPECIES
PARTIALLY TRANSFORMED, ANCHORAGE-INDEPENDENT HUMAN-DIPLOID FIBROBLASTS RESULT FROM OVEREXPRESSION OF THE C-SIS ONCOGENE - MITOGENIC ACTIVITY OF AN APPARENT MONOMERIC PLATELET-DERIVED GROWTH FACTOR-II SPECIES
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DOI：
10.1128/mcb.8.5.2089
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发表时间：
1988-05-01
影响因子：
5.3
通讯作者：
FAHL, WE
中科院分区：
文献类型：
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作者：
STEVENS, CW;BRONDYK, WH;FAHL, WE
通过转染或电穿孔将表达载体中的人c-sis cDNA引入人二倍体成纤维细胞中。分离出显示异常密集集落形态的成纤维细胞克隆，发现其过表达3.6-β-淀粉酶sis mRNA种类和相关的免疫沉淀血小板衍生生长因子（PDGF）2蛋白。在琼脂中SIS mRNA表达和集落形成的细胞克隆中的平行分析表明，在阈值以上，SIS过表达和获得锚定独立性之间存在线性正相关。当注射到裸鼠体内时，过度表达sis的细胞形成短暂的、退化的肿瘤结节，这与它们保留的有限寿命一致。用抗人PDGF抗体免疫沉淀从两个过表达克隆中的转染的c-sis构建体产生的蛋白质产物。一个克隆含有21千道尔顿的表观PDGF二聚体;第二个克隆仅含有12千道尔顿的表观PDGF单体，这被证明是细胞中存在的所有促有丝分裂活性的原因，基本上所有这些活性都集中在膜部分中。结果表明SIS过表达和获得部分转化的锚定独立表型之间存在明确的联系，并且当与先前在人类肿瘤中SIS过表达的观察结果相结合时，清楚地暗示SIS过表达是有助于人类细胞转化的遗传机制。
A human c-sis cDNA in an expression vector was introduced into human diploid fibroblasts by transfection or electroporation. Fibroblast clones showing an aberrant, densely packed colony morphology were isolated and found to overexpress a 3.6-kilobase sis mRNA species and associated immunoprecipitable platelet-derived growth factor (PDGF) 2 proteins. Parallel analyses in cell clones of sis mRNA expression and colony formation in agar indicated that, above a threshold, a linear, positive correlation existed between sis overexpression and acquired anchorage independence. The sis-overexpressing cells formed transient, regressing tumor nodules when injected into nude mice, consistent with the finite life span which thay retained. Protein products generated from the transfected c-sis construct in two overexpressing clones were immunoprecipitated with anti-human PDGF antibodies. One clone contained an apparent PDGF dimer of 21 kilodaltons; the second clone contained only an apparent PDGF monomer of 12 kilodaltons, which was shown to account for all of the mitogenic activity present in the cells, essentially all of which was concentrated in the membrane fraction. The results demonstrate a clear link between sis overexpression and acquisition of a partially transformed, anchorage-independent phenotype, and when combined with previous observations of sis overexpression in human tumors, clearly implicate sis overexpression as a gentic mechanism which contributes to human cell transformation.