Golovko Olga, Nazarova Nadya, Tuohimaa Pentti
Department of Anatomy, Medical School, University of Tampere, FIN-33014, Tampere, Finland.
Life Sci. 2005 Jun 17;77(5):562-77. doi: 10.1016/j.lfs.2004.10.072. Epub 2005 Feb 25.
1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3 or calcitriol) is an active hormone that regulates cellular proliferation and induces apoptosis in cancer cells. Here we report on a new calcitriol target gene in prostate cancer cells, tumour necrosis factor alpha (TNF-alpha). Calcitriol and its analogue CB1093 up-regulate TNF-alpha mRNA expression in LNCaP and PC-3 cells. The stimulation is dose-dependent in both of these cell lines, demonstrated by the quantitative real-time polymerase chain reaction. Calcitriol and CB1093 act synergistically with human recombinant TNF-alpha in activation of TNF-alpha mRNA expression in LNCaP but not in PC-3 cells. Transcriptional activation of TNF-alpha gene by calcitriol or CB1093 does not lead to TNF-alpha protein secretion, however calcitriol and CB1093 enhance TPA-stimulated TNF-alpha production in LNCaP cells. We did not observe any significant effect of calcitriol on regulation of TNFR1 at the level of gene expression. Nor does calcitriol affect transcriptional regulation of cytokine (IL-1, IL-6) and cytokine receptor genes in LNCaP and PC-3 prostate cancer cell lines. Calcitriol and its analogue CB1093 at 10 nM concentration induce programmed cell death in LNCaP cells. Combined addition of human recombinant TNF-alpha with calcitriol or CB1093 cause enhanced effect in induction of apoptosis. We conclude that under physiological conditions vitamin D activates only the transcription of TNF-alpha gene, for TNF-alpha protein synthesis additional cofactors are required. Therefore a cooperation of vitamin D and TNF-alpha may play an important role in the control of cell growth in prostate cancer.
1α,25 - 二羟基维生素D3（1α,25(OH)2D3或骨化三醇）是一种活性激素，可调节细胞增殖并诱导癌细胞凋亡。在此，我们报告前列腺癌细胞中的一个新的骨化三醇靶基因——肿瘤坏死因子α（TNF-α）。骨化三醇及其类似物CB1093可上调LNCaP和PC - 3细胞中TNF-α的mRNA表达。定量实时聚合酶链反应表明，在这两种细胞系中这种刺激都是剂量依赖性的。在LNCaP细胞中，骨化三醇和CB1093与人重组TNF-α协同激活TNF-α的mRNA表达，但在PC - 3细胞中则不然。骨化三醇或CB1093对TNF-α基因的转录激活不会导致TNF-α蛋白分泌，然而骨化三醇和CB1093可增强LNCaP细胞中佛波酯（TPA）刺激的TNF-α产生。我们未观察到骨化三醇在基因表达水平对TNFR1调节有任何显著影响。骨化三醇也不影响LNCaP和PC - 3前列腺癌细胞系中细胞因子（IL - 1、IL - 6）和细胞因子受体基因的转录调控。10 nM浓度的骨化三醇及其类似物CB1093可诱导LNCaP细胞发生程序性细胞死亡。人重组TNF-α与骨化三醇或CB1093联合添加可增强诱导凋亡的效果。我们得出结论，在生理条件下维生素D仅激活TNF-α基因的转录，TNF-α蛋白合成还需要其他辅助因子。因此，维生素D和TNF-α的协同作用可能在前列腺癌细胞生长控制中起重要作用。
