Buset M, Lipkin M, Winawer S, Swaroop S, Friedman E
Cancer Res. 1986 Oct;46(10):5426-30.
Nine patients at high risk of developing colon cancer were placed on daily p.o. supplementation of 1500 mg of calcium for 4-8 weeks. The colonic epithelial cells in six of these patients showed a statistically significant decrease in their [3H]thymidine labeling indices in tissue culture so that they resembled those of patients at low risk of developing colon cancer. The three nonresponders had similar labeling indices before and after calcium supplementation. Biopsies from each of nine high-risk patients exhibited a decrease in proliferation when they were cultured in vitro with a high level of CaCl2 (2.2 mM compared with the 0.1 mM optimum value for proliferation). Two adenomas and two carcinomas showed a different pattern of response than normal cells, exhibiting no inhibition of growth at 2.2 mM CaCl2. These data indicate that the growth inhibition induced by high levels of extracellular calcium levels is lost at a stage in tumor development before cells become malignant.
九名患结肠癌高风险患者每日口服补充1500毫克钙，持续4至8周。其中六名患者的结肠上皮细胞在组织培养中显示其[3H]胸苷标记指数有统计学意义的下降，使其类似于患结肠癌低风险患者的细胞。三名无反应者在补钙前后的标记指数相似。九名高风险患者的活检组织在体外与高浓度氯化钙（2.2 mM，相比增殖的最佳值0.1 mM）一起培养时，增殖出现下降。两个腺瘤和两个癌显示出与正常细胞不同的反应模式，在2.2 mM氯化钙时未表现出生长抑制。这些数据表明，在肿瘤发展到细胞恶变之前的某个阶段，高水平细胞外钙诱导的生长抑制作用消失了。
