Sensitization of human breast cancer cells to gemcitabine by the protein kinase C modulator bryostatin 1
Sensitization of human breast cancer cells to gemcitabine by the protein kinase C modulator bryostatin 1
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DOI：
10.1007/s00280-003-0628-6
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发表时间：
2003-09-01
影响因子：
3
通讯作者：
Philip, PA
中科院分区：
文献类型：
--
作者：
Ali, S;Aranha, O;Philip, PA
目的：蛋白激酶C（PKC）在细胞增殖、分化和凋亡中发挥重要作用。研究了人乳腺癌 MCF-7 和 MDA-MB-231 细胞以及未转化的 MCF-10a 人乳腺上皮细胞中 PKC 调节剂苔藓抑素 I (BRYO) 与吉西他滨之间的相互作用。方法：采用免疫印迹法测定PKC同工酶和参与细胞周期和凋亡的蛋白的表达。 MTT、ELISA 和流式细胞术测定用于确定细胞存活率。结果：用 BRYO 200 nM 处理细胞导致所有三种细胞系的细胞质 PKC 显着下调。然而，这些细胞中膜 PKC 的表达受到不同程度的影响。 BRYO (1-200 nM) 对任何细胞系的细胞活力均无显着影响。尽管如此，BRYO 显着增强了吉西他滨在 MCF-7 和 MDA-MB-231 细胞中的抗增殖和凋亡作用，但在 MCF10A 细胞中则没有。这与 bcl-2/bax 比率的显着降低有关。与经吉西他滨处理的细胞相比，经吉西他滨和BRYO组合处理的MCF7和MCF-10A细胞中p53、p21(waf)1和p27显着上调。结论：BRYO 增强吉西他滨的作用在 MCF-7 和 MDA-MB-231 细胞中得到证实，并且与特定的 PKC 调节模式相关。有必要进一步研究 PKC 特定亚型在吉西他滨诱导的细胞毒性下游分子事件中的作用。
Purpose: Protein kinase C (PKC) plays an important role in cell proliferation, differentiation, and apoptosis. The interaction between the PKC modulator bryostatin I (BRYO), and gemcitabine in human breast cancer MCF-7 and MDA-MB-231 cells and in the nontransformed MCF-10a human breast epithelial cells was investigated. Methods: Immunoblotting was used to determine the expression of PKC isoenzymes and proteins involved in the cell cycle and apoptosis. MTT, ELISA and flow cytometry assays were used to determine cell survival. Results: Treatment of cells with BRYO 200 nM resulted in a significant downregulation of cytoplasmic PKC in all three cell lines. However, the expression of membranous PKC was differentially affected in these cells. BRYO (1-200 nM) had no significant effects on cell viability in any of the cell lines. Nevertheless, BRYO significantly enhanced the antiproliferative and apoptotic effects of gemcitabine in the MCF-7 and MDA-MB-231 cells, but not in the MCF10A cells. This was associated with significant reduction in the bcl-2/bax ratio. There was a significant upregulation of p53, p2l(waf)l, and p27 in MCF7 and MCF-10A cells treated with the combination of gemcitabine and BRYO compared to gemcitabine-treated cells. Conclusions: The potentiation of the effect of gemcitabine by BRYO was demonstrated in MCF-7 and MDA-MB-231 cells and was associated with a specific pattern of PKC modulation. Further investigation of the role of specific isoforms of PKC in the downstream molecular events of gemcitabine-induced cytotoxicity is warranted.