['The study was designed to investigate a potential role and mechanisms of fibronectin in tyrosine phosphorylation of focal adhesion kinase (FAK) and invasiveness of colon cancer cells.', 'A colorectal cancer cell line, Colo320, was stimulated by fibronectin with gradient concentrations. Phosphorylation of FAK tyrosine 397 (tyr-397), was detected by immunoprecipitation and western-blotting. The invasiveness of Colo320 cells was measured by the modified Boyden chamber assay. An antisense oligonucleotide of FAK was used to testify the role of FAK tyr-397 in the process of cell invasion enhanced by fibronectin.', 'The Colo320 cell showed a dose-independence on fibronectin in its invasion and phosphorylation of FAK tyr-397. Invasion and phosphorylation of FAK tyr-397 in Colo320 reached their climax when concentration of fibronectin reached 1 nmol/L. But they did not increased accordingly when the concentrations of fibronectin reached 10 nmol/L and 100 nmol/L. Antisense oligonucleotide decreased phosphorylation of FAK tyr-397 and the invasion of Colo320 cells significantly, compared with the controls.'] Does fibronectin promote invasiveness and focal adhesion kinase tyrosine phosphorylation of human colon cancer cell?