Specific sequences of fibronectin activate the protein kinase C signal transduction pathway in invasive bladder cancer.
Specific sequences of fibronectin activate the protein kinase C signal transduction pathway in invasive bladder cancer.
复制标题
纤连蛋白的特定序列激活侵袭性膀胱癌中的蛋白激酶 C 信号转导途径。
DOI：
10.1016/0304-3835(95)04096-x
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发表时间：
1996
期刊：
影响因子：
9.7
通讯作者：
Liu,BC
中科院分区：
文献类型：
--
作者：
Margolis,EJ;Choi,JC;Shu,WP;Liu,BC
人膀胱癌细胞侵袭的机制尚不清楚，但似乎细胞外基质成分，如纤连蛋白，可能参与其中。为了研究纤维连接蛋白在肿瘤细胞侵袭和进展中的作用，我们使用体外侵袭实验来确定侵袭性人膀胱癌T24细胞的纤维连接蛋白的运动刺激片段。利用改良的Boyden小室法和纯化的纤连蛋白片段，我们证明了120 kDa糜蛋白酶都能产生纤连蛋白片段，（含有细胞附着RGD基序和朝向羧基末端肝素结合结构域的额外序列），以及胰蛋白酶产生的纤连蛋白的60 kDa片段（含有羧基末端肝素结合结构域和朝向细胞附着RGD基序的额外序列）能够刺激侵袭性人膀胱癌T24细胞的迁移。仅含有纤连蛋白的氨基末端明胶结合区的对照片段不刺激人膀胱癌T24细胞的运动性。为了确定这些片段可能刺激T24细胞迁移的分子机制，我们测定了细胞内信号转导途径蛋白激酶C（PKC）。我们证明了120 kDa和60 kDa片段都能够刺激蛋白激酶C的活化。纤维连接蛋白的非运动性刺激片段不能激活蛋白激酶C。我们的结论是，PKC信号转导通路可能参与基质介导的运动，并建议这种途径的抑制可能会改变人膀胱癌的恶性表型。
The mechanism of human bladder cancer cell invasion is not clear, but it appears that extracellular matrix components, such as fibronectin, may be involved. To investigate the role of fibronectin in tumor cell invasion and progression, we used an in vitro invasion assay to define the motility stimulating fragment of fibronectin for invasive human bladder cancer T24 cells. Using a modified Boyden chamber assay and purified fragments of fibronectin, we demonstrated that both the 120 kDa chymotrypsin generated fragment of fibronectin (containing the cell attachment RGD motif and additional sequences towards the carboxyl-terminal heparin binding domain), as well as the trypsin generated 60 kDa fragment of fibronectin (containing the carboxyl-terminal heparin binding domain and additional sequences towards the cell attachment RGD motif), were able to stimulate the migration of invasive human bladder cancer T24 cells. Control fragments containing only the amino-terminal gelatin binding region of fibronectin did not stimulate the motility of the human bladder cancer T24 cells. To determine the molecular mechanism in which these fragments may stimulate the migration of the T24 cells, we assayed for intracellular signal transduction pathway protein kinase C (PKC). We demonstrated that both the 120 kDa and the 60 kDa fragments were able to stimulate the activation of protein kinase C. Non-motility stimulating fragments of fibronectin were not able to activate protein kinase C. We conclude that the PKC signal transduction pathway may be involved in matrix mediated motility, and suggest that the inhibition of such pathway(s) may alter the malignant phenotype of human bladder cancer.