Division of Cell and Experimental Pathology, Department of Laboratory Medicine, Lund University, Skåne University Hospital, Malmö, Sweden.
PLoS One. 2013 Sep 5;8(9):e73466. doi: 10.1371/journal.pone.0073466. eCollection 2013.
The expression of the inflammatory G-protein coupled receptor CysLT1R has been shown to be upregulated in colon cancer patients and associated with poor prognosis. The present study investigated the correlation between CysLT1R and colon cancer development in vivo using CysLT1R antagonists (ZM198,615 or Montelukast) and the nude mouse xenograft model. Two drug administration regimens were established. The first regimen was established to investigate the importance of CysLT1R in tumor initiation. Nude mice were inoculated with 50 µM CysLT1R antagonist-pretreated HCT-116 colon cancer cells and received continued treatment (5 mg/kg/day, intraperitoneally). The second regimen aimed to address the role of CysLT1R in tumor progression. Nude mice were inoculated with non-pretreated HCT-116 cells and did not receive CysLT1R antagonist treatment until recordable tumor appearance. Both regimens resulted in significantly reduced tumor size, attributed to changes in proliferation and apoptosis as determined by reduced Ki-67 levels and increased levels of p21(WAF/Cip1) (P<0.01), cleaved caspase 3, and the caspase-cleaved product of cytokeratin 18. Decreased levels of VEGF (P<0.01) and reduced vessel size (P<0.05) were also observed, the latter only in the ZM198,615-pretreatment group. Furthermore, we performed a series of in vitro studies using the colon cancer cell line HCT-116 and CysLT1R antagonists. In addition to significant reductions in cell proliferation, adhesion and colony formation, we observed induction of cell cycle arrest and apoptosis in a dose-dependent manner. The ability of Montelukast to inhibit growth of human colon cancer xenograft was further validated by using two additional colon cancer cell lines, SW-480 and HT-29. Our results demonstrate that CysLT1R antagonists inhibit growth of colon cancer xenografts primarily by reducing proliferation and inducing apoptosis of the tumor cells.
炎症 G 蛋白偶联受体 CysLT1R 的表达在结肠癌患者中上调，并与预后不良相关。本研究使用 CysLT1R 拮抗剂（ZM198,615 或孟鲁司特）和裸鼠异种移植模型在体内研究了 CysLT1R 与结肠癌发展之间的相关性。建立了两种药物给药方案。第一种方案旨在研究 CysLT1R 在肿瘤起始中的重要性。将 50µM CysLT1R 拮抗剂预处理的 HCT-116 结肠癌细胞接种于裸鼠，并继续进行治疗（5mg/kg/天，腹腔内注射）。第二种方案旨在研究 CysLT1R 在肿瘤进展中的作用。将未经预处理的 HCT-116 细胞接种于裸鼠，直到可记录的肿瘤出现时才给予 CysLT1R 拮抗剂治疗。两种方案均导致肿瘤体积显著缩小，这归因于增殖和凋亡的变化，表现为 Ki-67 水平降低，p21(WAF/Cip1) 水平升高（P<0.01），cleaved caspase 3 和细胞角蛋白 18 的半胱天冬酶裂解产物增加。还观察到 VEGF 水平降低（P<0.01）和血管大小减小（P<0.05），仅在 ZM198,615 预处理组中观察到后者。此外，我们使用结肠癌细胞系 HCT-116 和 CysLT1R 拮抗剂进行了一系列体外研究。除了显著降低细胞增殖、黏附和集落形成外，我们还观察到细胞周期阻滞和凋亡呈剂量依赖性诱导。孟鲁司特抑制人结肠癌细胞异种移植生长的能力进一步通过使用另外两种结肠癌细胞系 SW-480 和 HT-29 得到验证。我们的结果表明，CysLT1R 拮抗剂主要通过减少肿瘤细胞的增殖和诱导其凋亡来抑制结肠癌细胞异种移植的生长。
