Laboratory of Carcinogenesis and Aging, N.N. Petrov Research Institute of Oncology, St. Petersburg, Russia.
Cell Cycle. 2013 Jun 1;12(11):1785-90. doi: 10.4161/cc.24879. Epub 2013 May 6.
The effect of the constant illumination on the development of spontaneous tumors in female 129/Sv mice was investigated. Forty-six female 129/Sv mice starting from the age of 2 mo were kept under standard light/dark regimen [12 h light (70 lx):12 hr dark; LD, control group], and 46 of 129/Sv mice were kept under constant illumination (24 h a day, 2,500 lx, LL) from the age of 5 mo until to natural death. The exposure to the LL regimen significantly accelerated body weight gain, increased body temperature as well as acceleration of age-related disturbances in estrous function, followed by significant acceleration of the development of the spontaneous uterine tumors in female 129/Sv mice. Total tumor incidence as well as a total number of total or malignant tumors was similar in LL and LD group (p > 0.05). The mice from the LL groups survived less than those from the LD group (χ ( 2) = 8.5; p = 0.00351, log-rank test). According to the estimated parameters of the Cox's regression model, constant light regimen increased the relative risk of death in female mice compared with the control (LD) group (p = 0.0041). The data demonstrate in the first time that the exposure to constant illumination was followed by the acceleration of aging and spontaneous uterine tumorigenesis in female 129/Sv mice.
本研究旨在探讨持续光照对雌性 129/Sv 小鼠自发性肿瘤发展的影响。46 只 2 月龄雌性 129/Sv 小鼠按标准光照/黑暗周期（12 小时光照[70 lx]：12 小时黑暗；LD，对照组）饲养，46 只 129/Sv 小鼠从 5 月龄开始持续光照（每天 24 小时，2500 lx，LL）直至自然死亡。暴露于 LL 方案显著加速了体重增加，升高了体温，并加速了发情功能的年龄相关性紊乱，随后加速了雌性 129/Sv 小鼠自发性子宫肿瘤的发展。LL 和 LD 组的总肿瘤发生率和总肿瘤或恶性肿瘤的总数相似（p＞0.05）。LL 组的小鼠存活时间少于 LD 组（χ（2）=8.5；p=0.00351，对数秩检验）。根据 Cox 回归模型的估计参数，与对照组（LD 组）相比，持续光照方案增加了雌性小鼠死亡的相对风险（p=0.0041）。数据首次表明，持续光照暴露后，雌性 129/Sv 小鼠的衰老和自发性子宫肿瘤发生加速。
