DIFFERENT VIMENTIN EXPRESSION IN 2 CLONES DERIVED FROM A HUMAN COLOCARCINOMA CELL-LINE (LOVO) SHOWING DIFFERENT SENSITIVITY TO DOXORUBICIN
DIFFERENT VIMENTIN EXPRESSION IN 2 CLONES DERIVED FROM A HUMAN COLOCARCINOMA CELL-LINE (LOVO) SHOWING DIFFERENT SENSITIVITY TO DOXORUBICIN
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DOI：
10.1038/bjc.1995.101
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发表时间：
1995-03-01
影响因子：
8.8
通讯作者：
BROGGINI, M
中科院分区：
文献类型：
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作者：
CONFORTI, G;CODEGONI, AM;BROGGINI, M
我们选择了两个克隆，从人结肠癌细胞系LoVo中分离，显示出对阿霉素的敏感性类似于（LoVo克隆5）或比（LoVo克隆7）亲本细胞系低三倍。由于波形蛋白在对阿霉素耐药的人乳腺癌细胞系中表达，我们观察了这两个对药物具有自发性不同敏感性的克隆中的波形蛋白表达。为了进行比较，我们使用了亲本细胞系LoVo WT和LoVo/DX产生耐药突变。波形蛋白的mRNA在LoVo WT和LoVo克隆5中通过北方印迹分析检测不到，而该基因在LoVo克隆7和LoVo/DX中表达较高。这种mRNA水平的增加与DNA的扩增无关，如Southern印迹分析所示。免疫荧光和免疫细胞化学结果证实，在蛋白质水平，mRNA的数据。在LoVo克隆5和7中，分别有8.6%和71%的波形蛋白阳性细胞，尽管这两个克隆显示出相似的多药耐药基因1（mdr-1）表达和细胞内阿霉素的积累水平相似。类似地，两个克隆的药物外排相同。我们的研究结果第一次表明，阿霉素耐药细胞表达波形蛋白的MDR糖蛋白的独立性。然而，当来自克隆5的细胞用人波形蛋白cDNA转染时，它们没有变得具有抗性，这表明波形蛋白可以被认为是这些细胞中的抗性标记，但其本身不产生抗性表型。
We selected two clones, isolated from the human colocarcinoma cell line LoVo, showing a sensitivity to doxorubicin similar to (LoVo clone 5) or three times lower than (LoVo clone 7) the parental cell line. Since vimentin was atypically expressed in a human breast carcinoma cell line made resistant to doxorubicin, we looked at vimentin expression in these two clones with spontaneously different sensitivity to the drug. For comparison we used the parental cell line LoVo WT and LoVo/DX made resistant pharmacologically. mRNA for vimentin was undetectable by Northern blot analysis in LoVo WT and in LoVo clone 5, while expression of this gene was high in LoVo clone 7 and in LoVo/DX. This increase in mRNA levels was not related to an amplification of DNA, as suggested by Southern blot analysis. Immunofluorescence and immunocytochemistry findings confirmed, at protein level, the mRNA data. In LoVo clones 5 and 7, there were respectively 8.6% and 71% vimentin-positive cells, although the two clones showed similar expression of multidrug resistance gene 1 (mdr-1) and accumulated intracellular doxorubicin at similar levels. Similarly, drug efflux was the same for both clones. Our results show for the first time that cells resistant to doxorubicin express vimentin independently of the mdr glycoprotein. However when cells from clone 5 were transfected with human vimentin cDNA, they did not become resistant, indicating that vimentin can be considered as a marker of resistance in these cells but does not give rise to a resistant phenotype by itself.