Increased extracellular pressure enhances cancer cell integrin-binding affinity through phosphorylation of β1-integrin at threonine 788/789
Increased extracellular pressure enhances cancer cell integrin-binding affinity through phosphorylation of β1-integrin at threonine 788/789
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DOI：
10.1152/ajpcell.00355.2008
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发表时间：
2009-01-01
影响因子：
5.5
通讯作者：
Basson, Marc D.
中科院分区：
文献类型：
--
作者：
Craig, David H.;Gayer, Christopher P.;Basson, Marc D.
首页--期刊主要分类--期刊细介绍--期刊题录与文摘--期刊详细文摘内容细胞外压力的增加通过苏氨酸788/789处的β(1)-整合素的磷酸化来增强癌细胞整合素的结合亲和力。Am J Physiol Cell Physiol 296：C193-C204,2009。2008年11月12日首次出版；DOI：10.1152/ajpcell.00355.2008。-细胞外压力增加刺激β(1)依赖整合素的癌细胞黏附。我们询问压力诱导的黏附是否通过β(1)-整合素结合亲和力或亲和力的变化来调节，以及这些变化是否依赖于磷酸化。我们通过测量可溶性Arg-Gly-Asp(RGD)-Fc配体和RGD-Fc-F(ab‘)(2)多聚体复合体在常压和15-mm Hg压力下结合的差异，评估了整合素在人结肠癌细胞SW620中的亲和力和聚集性。平行检测SW620和原代恶性结肠癌细胞中β(1)-整合素S785和T788/9残基的磷酸化。我们进一步使用稳定转染野生型β(1A)整合素、S785A、TT788/9AA或T788D突变体的GD25-β(1)整合素缺失的小鼠成纤维细胞来研究β(1)整合素位点特异性磷酸化的作用。RGD-Fc-F(ab‘)(2)多聚体与SW620的结合对整合素簇集敏感，而与可溶性RGD-Fc配体结合不敏感。在压力升高的情况下，RGD-Fc的配体结合显著增加，这表明压力调节了β(1)-整合素的亲和力。压力刺激β(1)-整合素S785和T788/9的磷酸化。GD25-β(1A)-整合素野生型和S785A细胞在加压下与纤维连接蛋白的粘附性增加，而整合素缺失的细胞和TT788/9AA细胞则没有这种作用。T788D替代显著增加了基底细胞的黏附，但在压力下没有进一步增加。这些结果表明，压力诱导的细胞黏附是由整合素β(1)-整合素T788/9磷酸化依赖的整合素结合亲和力的变化所介导的。
Craig DH, Gayer CP, Schaubert KL, Wei Y, Li J, Laouar Y, Basson MD. Increased extracellular pressure enhances cancer cell integrin-binding affinity through phosphorylation of beta(1)-integrin at threonine 788/789. Am J Physiol Cell Physiol 296: C193-C204, 2009. First published November 12, 2008; doi:10.1152/ajpcell.00355.2008.-Increased extracellular pressure stimulates beta(1)-integrin-dependent cancer cell adhesion. We asked whether pressure-induced adhesion is mediated by changes in beta(1)-integrin binding affinity or avidity and whether these changes are phosphorylation dependent. We evaluated integrin affinity and clustering in human SW620 colon cancer cells by measuring differences in binding between soluble Arg-Gly-Asp (RGD)-Fc ligands and RGD-Fc-F(ab')(2) multimeric complexes under ambient and 15-mmHg increased pressures. Phosphorylation of beta(1)-integrin S785 and T788/9 residues in SW620 and primary malignant colonocytes was assessed in parallel. We further used GD25-beta(1)-integrin-null murine fibroblasts stably transfected with either wild-type beta(1A)-integrin, S785A, TT788/9AA, or T788D mutants to investigate the role of beta(1)-integrin site-specific phosphorylation. SW620 binding of RGD-Fc-F(ab')(2) multimeric complexes, but not soluble RGD-Fc ligands, was sensitive to integrin clustering. RGD-Fc ligand binding was significantly increased under elevated pressure, suggesting that pressure modulates beta(1)-integrin affinity. Pressure stimulated both beta(1)-integrin S785 and T788/9 phosphorylation. GD25-beta(1A)-integrin wild-type and S785A cells displayed an increase in adhesion to fibronectin under elevated pressure, an effect absent in beta(1)-integrin-null and TT788/9AA cells. T788D substitution significantly elevated basal cell adhesion but displayed no further increase under pressure. These results suggest pressure-induced cell adhesion is mediated by beta(1)-integrin T788/9 phosphorylation-dependent changes in integrin binding affinity.