Faiella L, Ng C, Hsieh T C, Wu J M, Mallouh C
Department of Urology, New York Medical College, Valhalla 10595, USA.
Biochem Mol Biol Int. 1996 Aug;39(6):1085-92. doi: 10.1080/15216549600201252.
The combined antimitogenic effects of IFN-beta and 1,25-dihydroxyvitamin D3 (vit. D3) were investigated by treating the androgen-independent JCA-1 cells, established from the primary prostatic tumor site prior to anti-hormonal therapy, with IFN-beta (1000 IU/ml), vit. D3 (100 nM), and both agents. Cell growth, changes in overall RNA and protein contents, and cell cycle regulatory proteins pRB/p53 were determined. After a 24 h exposure, a significant reduction in cell proliferation was observed in all three conditions. IFN-beta, vit D3, and their combination elicited, respectively, a 1.7-, 1.6- and 2.5-fold increase in total RNA and a corresponding 1.4-, 1.2- and 1.7-fold increase in soluble proteins. The IFN-inducible 2-5A synthetase activity was elevated by 15-, 1.4- and 21-fold, respectively. No differences in cell cycle phase distribution were found between control and treated samples. However, a significant change in pRB and p53 expression was observed upon exposure to these agents. A progressive increase in total pRB was observed in untreated JCA-1 cells, with the 48 h culture showing a 1.9-fold increase over the 6 h culture. The ratio of phosphorylated to the nonphosphorylated forms of pRB, however, decreased from 3.00 at 6 h to 1.2 at 48 h. The overall pRB increase as well as the modified:unmodified protein ratio change were both markedly decreased when the cells were treated with IFN-beta, vit. D3, or their combination. With p53, a similar progressive increase was also observed in control cells, which was largely abolished by IFN-beta but only partially blocked by vit. D3. The combination of IFN-beta and vit. D3 gave results similar to samples receiving vit. D3 alone suggesting that the effects of IFN-beta, insofar as p53 modulation is concerned, is distal to the effects of vit. D3.
通过用干扰素-β（1000 IU/ml）、1,25-二羟基维生素D3（维生素D3，100 nM）以及这两种药物处理抗激素治疗前从原发性前列腺肿瘤部位建立的雄激素非依赖性JCA-1细胞，研究了干扰素-β和1,25-二羟基维生素D3（维生素D3）的联合抗有丝分裂作用。测定了细胞生长、总RNA和蛋白质含量的变化以及细胞周期调节蛋白pRB/p53。暴露24小时后，在所有三种情况下均观察到细胞增殖显著减少。干扰素-β、维生素D3及其组合分别使总RNA增加1.7倍、1.6倍和2.5倍，可溶性蛋白质相应增加1.4倍、1.2倍和1.7倍。干扰素诱导的2-5A合成酶活性分别提高了15倍、1.4倍和21倍。对照样品和处理样品之间未发现细胞周期阶段分布的差异。然而，暴露于这些药物后，观察到pRB和p53表达有显著变化。在未处理的JCA-1细胞中观察到总pRB逐渐增加，48小时培养物比6小时培养物增加了1.9倍。然而，pRB磷酸化形式与非磷酸化形式的比率从6小时的3.00降至48小时的1.2。当细胞用干扰素-β、维生素D3或其组合处理时，总pRB的增加以及修饰蛋白与未修饰蛋白比率的变化均显著降低。对于p53，在对照细胞中也观察到类似的逐渐增加，这在很大程度上被干扰素-β消除，但仅被维生素D3部分阻断。干扰素-β和维生素D3的组合产生的结果与单独接受维生素D3的样品相似，这表明就p53调节而言，干扰素-β的作用在维生素D3的作用之后。
