Wang X W, Costa M
Institute of Environmental Medicine, New York University Medical Center, New York 10016.
Biol Met. 1991;4(4):201-6. doi: 10.1007/BF01141181.
Treatment of wild-type Balb/c-3T3 cells with NiCl2 or N6,2-O-dibutyl-adenosine 3',5'-monophosphate (Bt2-cAMP) resulted in a high degree and frequency of cellular elongation. Nickel-resistant Balb/c-3T3 cells (B200) treated with Bt2-cAMP elongated at the same exposure concentration as wild-type cells. In contrast, treatment of the nickel-resistant cells with both non-cytotoxic and cytotoxic doses of NiCl2 failed to induce elongation. Nickel-resistant cells had two-thirds of the total protein-phosphorylation activity of wild-type cells. Both cAMP and NiCl2 enhanced phosphorylation of specific proteins in intact wild-type cells as detected by 32p autoradiography of these proteins separated on two-dimensional gels. A nickel-dependent phosphorylation of specific proteins is seen following NiCl2 treatment of wild-type cells but was not observed in B200 cells. In contrast, the pattern of Bt2-cAMP-stimulated protein phosphorylation was quite similar in both wild-type and nickel-resistant cells. Although it is unclear at present how nickel ions affect the cellular protein-phosphorylation system, these results suggested that targets controlling cellular elongation are sensitive to nickel, are altered in nickel-resistant cells and appear to involve protein phosphorylation. Further characterization of these targets may help in understanding the mechanisms of nickel carcinogenesis.
用氯化镍（NiCl2）或N6,2 - O - 二丁基 - 腺苷3',5' - 单磷酸（Bt2 - cAMP）处理野生型Balb/c - 3T3细胞，可导致细胞高度伸长且频率较高。用Bt2 - cAMP处理耐镍的Balb/c - 3T3细胞（B200），在与野生型细胞相同的暴露浓度下会发生伸长。相比之下，用非细胞毒性和细胞毒性剂量的NiCl2处理耐镍细胞均未能诱导其伸长。耐镍细胞的总蛋白磷酸化活性是野生型细胞的三分之二。通过对在二维凝胶上分离的这些蛋白质进行32P放射自显影检测发现，cAMP和NiCl2均能增强完整野生型细胞中特定蛋白质的磷酸化。野生型细胞经NiCl2处理后可观察到特定蛋白质的镍依赖性磷酸化，但在B200细胞中未观察到。相反，Bt2 - cAMP刺激的蛋白质磷酸化模式在野生型和耐镍细胞中非常相似。目前尚不清楚镍离子如何影响细胞蛋白质磷酸化系统，但这些结果表明，控制细胞伸长的靶点对镍敏感，在耐镍细胞中发生了改变，且似乎涉及蛋白质磷酸化。对这些靶点的进一步表征可能有助于理解镍致癌的机制。
