Research Laboratories, Giovanni Paolo II Center for High Technology Research, and Education in Biomedical Sciences, Catholic University, Largo Gemelli 1, 86100 Campobasso, Italy.
Thromb Res. 2012 May;129(5):641-7. doi: 10.1016/j.thromres.2011.07.037. Epub 2011 Aug 15.
Obesity is a risk factor for both cardiovascular disease and cancer development. Leptin, a cytokine produced by adipose tissue, controls different processes in peripheral tissues, including cancer development and thrombotic disorders in patients with a variety of clinical disorders. Tissue factor (TF), the trigger of blood clotting, is abundant in the adipose tissue. Since TF, often expressed by cancer cells, is considered a hallmark of cancer progression, we investigated whether leptin could modulate TF in the human metastatic breast carcinoma cell line MCF-7.
MCF-7 cells were incubated with or without the different reagents at 37 °C. At the end of incubation, cells were tested for procoagulant activity by a one-stage clotting assay, TF and TNF-α antigen levels and mRNA by ELISA and real-time RT-PCR, respectively. Leptin receptor was studied by FACS.
Both TF activity and antigen constitutively expressed by MCF-7 were significantly increased by leptin in a dose-dependent fashion. TF mRNA levels were also enhanced indicating that leptin exerts its effect at the transcription level. The effect of leptin was specific and required binding to its receptor (Ob-R), which was found on the surface of the cells, since antibodies against leptin and Ob-R completely prevented TF expression upregulation. In addition, leptin enhanced both TNF-α mRNA synthesis and secretion from MCF7. An anti-TNF-α MoAb completely abolished the leptin-induced TF expression.
These data support the hypothesis that leptin, by its upregulation of TF, possibly mediated by TNF-α synthesis, may contribute to processes underlying both cancer and vascular cell disorders.
肥胖是心血管疾病和癌症发展的一个风险因素。瘦素是一种由脂肪组织产生的细胞因子，控制着外周组织的不同过程，包括癌症发展和各种临床疾病患者的血栓形成障碍。组织因子（TF），即血液凝固的触发因子，在脂肪组织中大量存在。由于 TF 通常由癌细胞表达，被认为是癌症进展的标志之一，因此我们研究了瘦素是否可以调节人转移性乳腺癌细胞系 MCF-7 中的 TF。
MCF-7 细胞在 37°C 下与或不与不同试剂孵育。孵育结束时，通过一步凝血测定法测试细胞的促凝活性，通过 ELISA 和实时 RT-PCR 分别测定 TF 和 TNF-α 抗原水平和 mRNA。通过 FACS 研究瘦素受体。
瘦素以剂量依赖的方式显著增加 MCF-7 细胞中 TF 的活性和抗原表达。TF mRNA 水平也升高，表明瘦素在转录水平发挥作用。瘦素的作用是特异性的，需要与它的受体（Ob-R）结合，因为针对瘦素和 Ob-R 的抗体完全阻止了 TF 表达的上调。此外，瘦素增强了 MCF7 中 TNF-α mRNA 的合成和分泌。抗 TNF-α MoAb 完全消除了瘦素诱导的 TF 表达。
这些数据支持了这样一种假设，即瘦素通过上调 TF，可能通过 TNF-α 合成介导，可能有助于癌症和血管细胞紊乱的发生过程。
