Hu T, Bach R R, Horton R, Konigsberg W H, Todd M B
Cancer Institute of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854.
Thromb Res. 1993 Oct 15;72(2):155-68. doi: 10.1016/0049-3848(93)90217-c.
The procoagulant activity observed in many types of tissue and cultured cells is due to tissue factor, a 30 kd transmembrane protein. The mRNA for tissue factor is a 2.2-kb species, which in some non-cancer cells can be up-regulated or induced by cytokines or by serum stimulation. In this study, induction of procoagulant activity in cancer cells was evaluated using the breast cancer cell line, MCF-7, and an adriamycin resistant subline, AdrRMCF-7, which has increased tumorigenicity in nude mice compared to the parental cell line. Procoagulant activity was factor VIIa dependent and was inhibited by an anti-tissue factor antibody. MCF-7 cells had minimal tissue factor activity, while AdrRMCF-7 cells had an 10-fold increase compared to the parental line. This increase was not observed in MCF-7 cells transfected with the multi-drug resistant gene, which is associated with adriamycin resistance. Serum stimulation of quiescent MCF-7 cells increased tissue factor activity 5-fold over baseline level, but did not increase activity in cells grown in serum-replete medium. Tissue factor activity of AdrRMCF-7 quiescent cells and AdrMCF-7 cells grown in serum-replete medium was enhanced 2-fold by serum stimulation. The predominant tissue factor mRNA species in MCF-7 cells was a 3.2 to 3.4-kb band, which increased in response to serum stimulation of cells grown in serum-replete medium. The mature 2.2-kb tissue factor mRNA band was detected in quiescent MCF-7 cells within six hours of serum stimulation and remained present 24 hours after stimulation. Synthesis of the 2.2-kb tissue factor mRNA species in MCF-7 and AdrRMCF-7 cells correlated with appearance of procoagulant activity. Thus, while procoagulant activity correlates with the level of the 2.2-kb tissue factor mRNA species in these cancer cells, there are inherent differences in tissue factor activity, antigen, and mRNA levels, as well as in regulation of its synthesis between these cells.
在多种类型的组织和培养细胞中观察到的促凝活性归因于组织因子，一种30kd的跨膜蛋白。组织因子的mRNA是一种2.2kb的物质，在一些非癌细胞中，它可被细胞因子或血清刺激上调或诱导。在本研究中，使用乳腺癌细胞系MCF-7和阿霉素耐药亚系AdrRMCF-7评估癌细胞中促凝活性的诱导情况，与亲代细胞系相比，AdrRMCF-7在裸鼠中的致瘤性增加。促凝活性依赖于因子VIIa，并被抗组织因子抗体抑制。MCF-7细胞的组织因子活性极低，而AdrRMCF-7细胞与亲代细胞系相比增加了10倍。在用与阿霉素耐药相关的多药耐药基因转染的MCF-7细胞中未观察到这种增加。血清刺激静止的MCF-7细胞可使组织因子活性比基线水平增加5倍，但在富含血清培养基中生长的细胞中，其活性并未增加。血清刺激可使在富含血清培养基中生长的AdrRMCF-7静止细胞和AdrMCF-7细胞的组织因子活性增强2倍。MCF-7细胞中主要的组织因子mRNA条带为3.2至3.4kb，在富含血清培养基中生长的细胞经血清刺激后其增加。在血清刺激后6小时内，在静止的MCF-7细胞中检测到成熟的2.2kb组织因子mRNA条带，刺激后24小时仍存在。MCF-7和AdrRMCF-7细胞中2.2kb组织因子mRNA物质的合成与促凝活性的出现相关。因此，虽然促凝活性与这些癌细胞中2.2kb组织因子mRNA物质的水平相关，但这些细胞之间在组织因子活性、抗原、mRNA水平及其合成调节方面存在内在差异。
