Distinct signaling pathways regulate differential opioid effects on actin cytoskeleton in malignant MCF7 and nonmalignant MCF12A human breast epithelial cells
Distinct signaling pathways regulate differential opioid effects on actin cytoskeleton in malignant MCF7 and nonmalignant MCF12A human breast epithelial cells
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DOI：
10.1016/s0014-4827(03)00210-6
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发表时间：
2003-08-01
影响因子：
3.7
通讯作者：
Stournaras, C
中科院分区：
文献类型：
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作者：
Kallergi, G;Tsapara, A;Stournaras, C
阿片类药物调节恶性乳腺上皮细胞活性的机制目前尚不清楚。在本研究中，我们报告的差异肌动蛋白细胞骨架重组阿片类药物诱导恶性（MCF 7）和非恶性（MCF 12 A）乳腺上皮细胞表达功能性阿片受体。MCF 7细胞暴露于阿片激动剂α，酪啡肽诱导重要的肌动蛋白组装和重组，包括丝状伪足和板状伪足的形成。与此相反，MCF 12 A细胞与酪啡肽的孵育揭示了肌动蛋白微丝的部分但短暂的解体。免疫沉淀和免疫印迹分析显示，阿片类药物处理的MCF 7细胞的粘着斑激酶（FAK）和黏着斑蛋白的快速磷酸化。此外，FAK与磷脂酰肌醇-3（PI-3激酶）结合，后者随后被磷酸化和活化。此外，还观察到小GTdR Rac 1的大量活化。用特异性PI-3激酶抑制剂wortmannin预处理MCF 7细胞，可抑制Rac 1的激活和肌动蛋白的重组，而阿片类药物诱导的FAK和黏着斑蛋白的磷酸化不受影响。有趣的是，在阿片类药物处理的MCF 12 A细胞中，这种信号级联反应保持不活跃，而我们发现了调节蛋白质绒毛的肌动蛋白的快速磷酸化。最后，阿片类药物差异抑制细胞运动在每个细胞系。我们的数据表明，一个独特的，阿片类药物诱导的信号通路激活恶性乳腺上皮细胞，导致重要的肌动蛋白重组。这些发现可能表明阿片类药物的潜在的抑制作用，基于激活的差异信号传导机制。(C)2003 Elsevier Science（美国）。All rights reserved.
The mechanisms through which opioids regulate the activity of malignant breast epithelial cells are currently unknown. In the present study we report the differential actin cytoskeleton reorganization induced by opioids in malignant (MCF7) and nonmalignant (MCF12A) breast epithelial cells expressing functional opioid receptors. Exposure of MCF7 cells to the opioid agonist a, casomorphin induced important actin assembly and reorganization, including the formation of filopodia and lamellipodia. In contrast, incubation of MCF12A cells with as, casomorphin revealed a partial but transient disassembly of actin microfilaments. Immunoprecipitation and immunoblot analyses showed rapid phosphorylation of focal adhesion kinase (FAK) and vinculin in opioid-treated MCF7 cells. Moreover, FAK associates with phosphatidylinositol-3 (PI-3 kinase), the latter being subsequently phosphorylated and activated. In addition, a substantial activation of the small GTPase Rac1 was observed. Pretreatment of MCF7 cells with the specific PI-3 kinase inhibitor wortmannin abolished both the activation of Rac1 and actin reorganization, while the opioid-induced phosphorylation of FAK and vinculin remained unaffected. Interestingly, in opioid-treated MCF12A cells this signaling cascade remained inactive, while we identified rapid phosphorylation of actin regulating the protein villin. Finally, opioids differentially inhibited cell motility in each cell line. Our data suggest a distinct, opioid-induced, signaling pathway activated in malignant breast epithelial cells, leading to important actin reorganization. These findings may indicate a potential antineoplastic role of opiates, based on the activation of differential signaling mechanisms. (C) 2003 Elsevier Science (USA). All rights reserved.