Differential effect of the focal adhesion kinase Y397F mutant on v-Src-stimulated cell invasion and tumor growth.
Upon cell adhesion to extracellular matrix proteins, focal adhesion kinase (FAK) rapidly undergoes autophosphorylation on its Tyr-397 which consequently serves as a binding site for the Src homology 2 domains of the Src family protein kinases and several other intracellular signaling molecules. In this study, we have attempted to examine the effect of the FAK Y397F mutant on v-Src-stimulated cell transformation by establishing an inducible expression of the Y397F mutant in v-Src-transformed FAK-null (FAK(-/-)) mouse embryo fibroblasts. We found that the FAK Y397F mutant had both positive and negative effects on v-Src-stimulated cell transformation; it promoted v-Src-stimulated invasion, but on the other hand it inhibited the v-Src-stimulated anchorage-independent cell growth in vitro and tumor formation in vivo . The positive effect of the Y397F mutant on v-Src-stimulated invasion was correlated with an increased expression of matrix metalloproteinase-2, both of which were inhibited by the specific phosphatidylinositol 3-kinase inhibitor wortmannin or a dominant negative mutant of AKT, suggesting a critical role for the phosphatidylinositol 3-kinase/AKT pathway in both events. However, the expression of the Y397F mutant rendered v-Src-transformed FAK(-/-) cells susceptible to anoikis, correlated with suppression on v-Src-stimulated activation of ERK and AKT. In addition, under anoikis stress, the induction of the Y397F mutant in v-Src-transformed FAK(-/-) cells selectively led to a decrease in the level of p130(Cas), but not other focal adhesion proteins such as talin, vinculin, and paxillin. These results suggest that FAK may increase the susceptibility of v-Src-transformed cells to anoikis by modulating the level of p130(Cas).
Chang
Liang-Chen
LC
Institute of Biomedical Sciences, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, 40227, Taiwan.
Huang
Chi-Hui
CH
Cheng
Chi-Hung
CH
Chen
Bor-Huah
BH
Chen
Hong-Chen
HC
D000199:Actins / Q000737:chemistry; D000362:Agar / Q000737:chemistry; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D023102:Anoikis; D001665:Binding Sites; D002448:Cell Adhesion; D002453:Cell Cycle; D002460:Cell Line; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic; D003094:Collagen / Q000737:chemistry; D050719:Crk-Associated Substrate Protein / Q000378:metabolism; D004338:Drug Combinations; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000235:genetics*; D022001:Focal Adhesions; D005780:Gelatin / Q000737:chemistry; D005799:Genes, Dominant; D015151:Immunoblotting; D047468:Immunoprecipitation; D007797:Laminin / Q000737:chemistry; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis; D051379:Mice; D008819:Mice, Nude; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D009154:Mutation; D009361:Neoplasm Invasiveness; D015688:Oncogene Protein pp60(v-src) / Q000378:metabolism*; D051419:Paxillin / Q000737:chemistry; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D011509:Proteoglycans / Q000737:chemistry; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction; D016608:Talin / Q000737:chemistry; D013997:Time Factors; D014162:Transfection; D014443:Tyrosine / Q000737:chemistry; D016596:Vinculin / Q000737:chemistry; D000077191:Wortmannin; D019061:src-Family Kinases / Q000378:metabolism
D000199:Actins; D000730:Androstadienes; D050719:Crk-Associated Substrate Protein; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D007797:Laminin; D051419:Paxillin; D011509:Proteoglycans; D016608:Talin; C059485:matrigel; D016596:Vinculin; D014443:Tyrosine; D005780:Gelatin; D000362:Agar; D003094:Collagen; D019869:Phosphatidylinositol 3-Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src); D019061:src-Family Kinases; D051057:Proto-Oncogene Proteins c-akt; D020778:Matrix Metalloproteinase 2; D000077191:Wortmannin