By a proteomics-based approach, we identified an overexpression of
fascin in
colon adenocarcinoma cells (FPCKpP-3) that developed from nontumorigenic human colonic
adenoma cells (FPCK-1-1) and were converted to tumorigenic by
foreign-body-induced chronic
inflammation in nude mice.
Fascin overexpression was also observed in the
tumors arising from rat intestinal epithelial cells (IEC 6) converted to tumorigenic in chronic
inflammation which was induced in the same manner. Upregulation of
fascin expression in FPCK-1-1 cells by transfection with sense
fascin cDNA converted the cells tumorigenic, whereas antisense
fascin-
cDNA-transfected FPCKpP-3 cells reduced
fascin expression and lost their
tumor-forming ability in vivo. The tumorigenic potential by
fascin expression was consistent with their ability to survive and grow in the three-dimensional multicellular spheroids. We found that resistance to anoikis (apoptotic cell death as a consequence of insufficient cell-to-substrate interactions), which is represented by the three-dimensional growth of solid
tumors in vivo, was regulated by
fascin expression through
caspase-dependent apoptotic signals. From these, we demonstrate that
fascin is a potent suppressor to
caspase-associated anoikis and accelerator of the conversion of colonic
adenoma cells into
adenocarcinoma cells by chronic
inflammation.