Iron deprivation inhibits cyclin-dependent kinase activity and decreases cyclin D CDK4 protein levels in asynchronous MDA-MB-453 human breast cancer cells
Iron deprivation inhibits cyclin-dependent kinase activity and decreases cyclin D CDK4 protein levels in asynchronous MDA-MB-453 human breast cancer cells
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DOI：
10.1006/excr.1996.0343
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发表时间：
1996-11-25
影响因子：
3.7
通讯作者：
Vulliet, PR
中科院分区：
文献类型：
--
作者：
Kulp, KS;Green, SL;Vulliet, PR
已知铁螯合可以阻止细胞周期的进展，我们检查了铁螯合对细胞周期蛋白依赖性蛋白激酶 (cdk) 活性和亚基水平的影响。用铁螯合剂含羞草或去铁胺 (DFO) 处理异步 MDA-MB-453 细胞 24 小时，细胞分裂停止，但没有产生单一的同步块。 DNA含量分析表明，虽然大多数细胞被阻断在G1期（87.3%），但出人意料的是，大部分细胞被阻断在S期（11.5%）。对处理后的裂解物进行蛋白质印迹分析，证明了细胞周期蛋白 B 的存在，证实了部分细胞群被阻断在 S 期。含羞草碱处理释放后，84% 的细胞群在 G1 期保持长达 8 小时。用 400 μM 含羞草碱处理乳腺癌细胞 24 小时，可将细胞周期蛋白 E 和细胞周期蛋白 A 相关激酶活性抑制 85% 或更多，尽管使用抗细胞周期蛋白 A、细胞周期蛋白 E、cdc2 和 cdk2 抗体进行的免疫印迹显示这些关键亚基仍以治疗前水平存在于细胞中。有趣的是，蛋白质印迹分析还表明，与对照相比，铁螯合降低了细胞周期蛋白 D 和 cdk4 亚基的蛋白水平，并导致视网膜母细胞瘤蛋白磷酸化发生变化。这些结果表明，缺铁会影响细胞周期蛋白依赖性激酶的活性和蛋白质水平，并最终影响控制细胞分裂的途径。 (C) 1996 学术出版社
Iron chelation, known to block progression through the cell cycle, was examined for effects on the activity and subunit levels of the cyclin-dependent protein kinases (cdk). Treatment of asynchronous MDA-MB-453 cells with the iron chelators mimosine or desferrioxamine (DFO) for 24 h stopped cell division, but did not produce a single, synchronous block. DNA content analysis demonstrated that although a majority of the cells were blocked in G1 (87.3%), an unexpectedly large fraction of the cells were blocked in S phase (11.5%). Western blot analysis of the treated lysates demonstrated the presence of cyclin B, confirming that part of the cell population was blocked in S phase. After release from mimosine treatment, 84% of the cell population remained in G1 up to 8 h. Treating breast cancer cells with 400 mu M mimosine for 24 h inhibited cyclin E- and cyclin A-associated kinase activity by 85% or more, although immunoblots using anti-cyclin A, cyclin E, cdc2, and cdk2 antibodies showed that these key subunits were still present in the cells at pretreatment levels. Interestingly, Western blot analysis also demonstrated that iron chelation decreased the protein levels of the cyclin D and cdk4 subunits as compared to control and produced a change in retinoblastoma protein phosphorylation. These results indicate that iron deprivation effects the activity and protein levels of the cyclin-dependent kinases, and ultimately, the pathways that control cell division. (C) 1996 Academic Press, Inc.