Ngo Tung H, Barnard R James, Tymchuk Christopher N, Cohen Pinchas, Aronson William J
Department of Physiological Science, University of California, Los Angeles, CA 90095, USA.
Cancer Causes Control. 2002 Dec;13(10):929-35. doi: 10.1023/a:1021911517010.
Accumulating evidence indicates that prostate cancer is associated with high levels of serum IGF-I. This study was conducted to determine whether a low-fat diet and exercise (DE) intervention may modulate the IGF axis and reduce prostate cancer cell growth in vitro.
Fasting serum was obtained from 14 men (age 60 +/- 3 years) participating in an 11-day DE program and from eight similarly aged men who had followed the DE program for 14.2 +/- 1.7 years (long-term). Insulin, IGF-I, IGFBP-1, and IGFBP-3 were measured by ELISA, and serum was used to stimulate LNCaP cell growth in vitro.
Serum IGF-I levels decreased by 20% while IGFBP-1 increased by 53% after 11-day DE. In the long-term group, IGF-I was 55% lower, while IGFBP-1 was 150% higher relative to baseline. Serum insulin decreased by 25% after 11-day DE and was 68% lower in the long-term group, relative to baseline. No changes in serum IGFBP-3 were observed. Serum-stimulated LNCaP cell growth was reduced by 30% in post-11-day serum and by 44% in long-term serum relative to baseline. LNCaP cells incubated with post-DE serum showed increased apoptosis/ necrosis, compared to baseline.
A low-fat diet and exercise intervention induces in-vivo changes in the circulating IGF axis and is associated with reduced growth and enhanced apoptosis/necrosis of LNCaP tumor cells in vitro.
越来越多的证据表明前列腺癌与血清胰岛素样生长因子-I（IGF-I）水平升高有关。本研究旨在确定低脂饮食和运动（DE）干预是否能调节IGF轴并在体外降低前列腺癌细胞的生长。
从14名参与为期11天DE计划的男性（年龄60±3岁）以及8名年龄相仿、已遵循DE计划14.2±1.7年（长期）的男性中获取空腹血清。通过酶联免疫吸附测定法（ELISA）检测胰岛素、IGF-I、胰岛素样生长因子结合蛋白-1（IGFBP-1）和胰岛素样生长因子结合蛋白-3（IGFBP-3），并使用血清在体外刺激LNCaP细胞生长。
经过11天的DE后，血清IGF-I水平下降了20%，而IGFBP-1增加了53%。在长期组中，相对于基线，IGF-I降低了55%，而IGFBP-1升高了150%。经过11天的DE后，血清胰岛素下降了25%，在长期组中相对于基线降低了68%。未观察到血清IGFBP-3有变化。相对于基线，11天后血清刺激的LNCaP细胞生长减少了30%，长期血清刺激的减少了44%。与基线相比，用DE后血清培养的LNCaP细胞凋亡/坏死增加。
低脂饮食和运动干预可引起循环IGF轴的体内变化，并与体外LNCaP肿瘤细胞生长减少及凋亡/坏死增强有关。
