Department of Medical Biochemistry and Global COE Program, University of Shizuoka, Shizuoka, Japan.
Biol Pharm Bull. 2010;33(1):117-21. doi: 10.1248/bpb.33.117.
Successful avoidance of the immune surveillance system is critical for the development of a blood-borne metastasis. Previous findings suggest that experimental tumor metastasis was enhanced in senescence-accelerated mice prone 10 (SAMP10) due to a reduction in immune surveillance potential with age. In the present study, water containing green tea (GT)-catechins was freely given to SAMP10 mice, and the chemopreventive effect of GT-catechin intake on tumor metastasis was examined. Natural killer cell activity, which is an indicator of immune surveillance potential and is reduced in control mice with age, was maintained by GT-catechin intake. The early accumulation of lung-metastatic K1735M2 melanoma cells in lungs after intravenous injection of the cells and subsequent experimental lung metastasis was investigated in mice given GT-catechins. The accumulation at 6 and 24 h after injection of K1735M2 cells was significantly suppressed, and the number of lung-metastatic colonies was significantly reduced, in comparison with those in control mice. The results suggest that GT-catechin intake prevented the experimental tumor metastasis in aged SAMP10 mice via its inhibition of a reduction in immune surveillance potential with age.
成功逃避免疫监视系统对于血液传播转移的发展至关重要。先前的研究结果表明，由于年龄相关的免疫监视潜力降低，衰老加速小鼠 prone 10（SAMP10）中的实验性肿瘤转移增强。在本研究中，SAMP10 小鼠自由饮用含绿茶（GT）儿茶素的水，并检查 GT-儿茶素摄入对肿瘤转移的化学预防作用。GT-儿茶素摄入维持了自然杀伤细胞活性，而自然杀伤细胞活性随着年龄的增长而降低，是免疫监视潜力的一个指标。通过静脉注射细胞后在肺部早期积累肺转移性 K1735M2 黑色素瘤细胞，并随后在给予 GT-儿茶素的小鼠中研究实验性肺转移。与对照组相比，注射 K1735M2 细胞后 6 小时和 24 小时的细胞积累明显受到抑制，肺转移性菌落数量明显减少。这些结果表明，GT-儿茶素摄入通过抑制年龄相关的免疫监视潜力降低，防止了老年 SAMP10 小鼠的实验性肿瘤转移。
