Protein kinase A gating of a pseudopodial-located RhoA/ROCK/p38/NHE1 signal module regulates invasion in breast cancer cell lines
Protein kinase A gating of a pseudopodial-located RhoA/ROCK/p38/NHE1 signal module regulates invasion in breast cancer cell lines
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DOI：
10.1091/mbc.e04-10-0945
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发表时间：
2005-07-01
影响因子：
3.3
通讯作者：
Reshkin, SJ
中科院分区：
文献类型：
--
作者：
Cardone, RA;Bagorda, A;Reshkin, SJ
转移是由一系列选择性事件引起的，通常涉及与肿瘤特异性生理微环境元素的相互作用。这种微环境的低血清组分通过激活Na+/H+交换器亚型1（NHE 1）赋予乳腺癌细胞增加的运动性和侵袭性。本研究旨在表征NHE 1的血清剥夺依赖性激活和伴随的侵入特征（例如代表转移进展不同阶段的乳腺癌细胞系中前沿伪足发育和基质胶渗透）的信号转导机制。使用药理学和遗传操作与运输和激酶活性测定，我们观察到NHE 1的激活和随后的入侵转移性人乳腺细胞中的血清剥夺是协调的顺序RhoA/p160 ROCK/p38 MAPK信号通路门控直接蛋白激酶A磷酸化和抑制RhoA。荧光共振能量转移成像的RhoA活性和免疫荧光分析的磷酸-RhoA和NHE 1表明，血清剥夺动态重塑细胞，形成长，前沿伪足，这个信号模块优先划分在这些前沿伪足，这表明一个紧密的地形关系的信号模块的入侵特异性细胞结构。
Metastasis results from a sequence of selective events often involving interactions with elements of the tumor-specific physiological microenvironment. The low-serum component of this microenvironment confers increased motility and invasion in breast cancer cells by activating the Na+/H+ exchanger isoform 1 (NHE1). The present study was undertaken to characterize the signal transduction mechanisms underlying this serum deprivation-dependent activation of both the NHE1 and the concomitant invasive characteristics such as leading edge pseudopodia development and penetration of matrigel in breast cancer cell lines representing different stages of metastatic progression. Using pharmacological and genetic manipulation together with transport and kinase activity assays, we observe that the activation of the NHE1 and subsequent invasion by serum deprivation in metastatic human breast cells is coordinated by a sequential RhoA/p160ROCK/p38MAPK signaling pathway gated by direct protein kinase A phosphorylation and inhibition of RhoA. Fluorescence resonance energy transfer imaging of RhoA activity and immunofluorescence analysis of phospho-RhoA and NHE1 show that serum deprivation dynamically remodels the cell, forming long, leading edge pseudopodia and that this signal module is preferentially compartmentalized in these leading edge pseudopodia, suggesting a tight topographic relation of the signaling module to an invasion-specific cell structure.