Seifert Markus, Rech Martin, Meineke Viktor, Tilgen Wolfgang, Reichrath Jörg
Department of Dermatology, The Saarland University Hospital, Homburg, Germany.
J Steroid Biochem Mol Biol. 2004 May;89-90(1-5):375-9. doi: 10.1016/j.jsbmb.2004.03.002.
1,25-DihydroxyVitamin D(3) and analogs have been shown to inhibit proliferation and to induce differentiation in different cell types, including human melanocytes. However, various tumor cell lines that fail to respond to the antiproliferative effects of Vitamin D analogs have also been reported. Using real-time PCR (LightCycler), we have compared mRNA expression of Vitamin D receptor (VDR), Vitamin D-25-hydroxylase (25-OHase), 25-hydroxyVitamin D-1alpha-hydroxylase (1alpha-OHase), and 1,25-dihydroxyVitamin D-24-hydroxylase (24-OHase) in a melanoma cell line that responds to antiproliferative effects of Vitamin D (MeWo) with a non-responsive melanoma cell line (SkMel5). Additionally, modulation of cell proliferation by calpain inhibitors, as well as regulation of mRNA expression of VDR, 1alpha-OHase, and 24-OHase genes by Vitamin D analogs were assessed in melanoma cell lines in vitro using a WST-1 based colorimetric assay and real-time PCR, respectively. RNA for VDR, 25-OHase, 1alpha-OHase, and 24-OHase was detected in melanoma cell lines. In contrast to SkMel5 cells, treatment of MeWo cells with calcitriol resulted in a dose-dependent increase in mRNA for VDR and 24-OHase as well as in a suppression of cell proliferation (up to approximately 50%). Our findings demonstrate that local synthesis or metabolism of Vitamin D metabolites may be of importance for growth regulation of MM and melanoma cell lines. Additionally, metastasizing MM represents a promising target for palliative treatment with new Vitamin D analogs that exert little calcemic side effects or for pharmacological modulation of calcitriol synthesis/metabolism in these tumors.
1,25 - 二羟基维生素D(3)及其类似物已被证明能抑制不同细胞类型（包括人类黑素细胞）的增殖并诱导其分化。然而，也有报道称各种肿瘤细胞系对维生素D类似物的抗增殖作用没有反应。我们使用实时定量聚合酶链反应（LightCycler），比较了对维生素D抗增殖作用有反应的黑色素瘤细胞系（MeWo）和无反应的黑色素瘤细胞系（SkMel5）中维生素D受体（VDR）、维生素D - 25 - 羟化酶（25 - OHase）、25 - 羟基维生素D - 1α - 羟化酶（1α - OHase）和1,25 - 二羟基维生素D - 24 - 羟化酶（24 - OHase）的mRNA表达。此外，分别使用基于WST - 1的比色法和实时定量聚合酶链反应，在体外黑色素瘤细胞系中评估了钙蛋白酶抑制剂对细胞增殖的调节作用，以及维生素D类似物对VDR、1α - OHase和24 - OHase基因mRNA表达的调节作用。在黑色素瘤细胞系中检测到了VDR、25 - OHase、1α - OHase和24 - OHase的RNA。与SkMel5细胞不同，用骨化三醇处理MeWo细胞会导致VDR和24 - OHase的mRNA呈剂量依赖性增加，同时细胞增殖受到抑制（高达约50%）。我们的研究结果表明，维生素D代谢产物的局部合成或代谢可能对黑色素瘤和黑色素瘤细胞系的生长调节具有重要意义。此外，转移性黑色素瘤是使用几乎没有高钙血症副作用的新型维生素D类似物进行姑息治疗或对这些肿瘤中骨化三醇合成/代谢进行药理学调节的一个有前景的靶点。
