Dimberg Jan, Hugander Anders, Wågsäter Dick
Department of Natural Science and Biomedicine, University College of Health Sciences, SE-551 11 Jönköping, Sweden.
Oncol Rep. 2006 May;15(5):1197-200.
The cytokine CD137, a member of the TNF receptor family, is expressed by T cells and regulates activation and proliferation of these cells. The CD137 ligand (CD137L) is expressed by antigen-presenting cells including macrophages, but also on various carcinoma cells. CD137/CD137L interaction plays a central role in sustaining T cell and macrophage activation, i.e. in antitumour immunity. The present study was designed to investigate whether CD137 and CD137L protein levels are altered in colorectal tumours compared with paired normal tissues. The CD137 and CD137L plasma levels from patients with colorectal cancer were also examined. Collectively, we noted a significantly lower CD137L level in cancerous tissue compared with paired normal tissue, and the difference in CD137L protein level was significantly lower in the colon cancer subgroup compared with paired normal colon tissue. On the other hand, we found an elevated CD137 protein level in the rectal cancer subgroup compared with paired normal rectal tissue. Patients with a tumour localised in the colon revealed significantly higher soluble CD137 protein concentration in the plasma than patients with a tumour localised in the rectum, and there was a tendency toward a higher concentration of CD137L protein in the plasma from patients with tumour localised in the colon. Moreover, the plasma concentrations of CD137 and CD137L proteins were strongly and significantly correlated. The different expression levels of CD137 and CD137L in the colon and rectum may reflect divergent mechanisms involved in the pathogenesis of colorectal cancer and lead to dissimilar protective immunity.
细胞因子CD137是肿瘤坏死因子受体家族的成员之一，由T细胞表达并调节这些细胞的激活和增殖。CD137配体（CD137L）由包括巨噬细胞在内的抗原呈递细胞表达，但也在各种癌细胞上表达。CD137/CD137L相互作用在维持T细胞和巨噬细胞激活即抗肿瘤免疫中起核心作用。本研究旨在调查与配对的正常组织相比，结直肠癌组织中CD137和CD137L蛋白水平是否发生改变。还检测了结直肠癌患者的CD137和CD137L血浆水平。总体而言，我们发现癌组织中的CD137L水平显著低于配对的正常组织，与配对的正常结肠组织相比，结肠癌亚组中CD137L蛋白水平的差异显著更低。另一方面，我们发现直肠癌亚组中的CD137蛋白水平高于配对的正常直肠组织。肿瘤位于结肠的患者血浆中可溶性CD137蛋白浓度显著高于肿瘤位于直肠的患者，且肿瘤位于结肠的患者血浆中CD137L蛋白浓度有升高趋势。此外，血浆中CD137和CD137L蛋白浓度呈强显著相关性。结肠和直肠中CD137和CD137L的不同表达水平可能反映了结直肠癌发病机制中不同的机制，并导致不同的保护性免疫。
