Decreased fibronectin expression in Met/HGF-mediated tumorigenesis.
The tyrosine kinase receptor Met and its ligand, hepatocyte growth factor (HGF)/scatter factor are involved in the etiology and progression of a number of human cancers. Coexpression of Met and HGF in mesenchymal cells increases the tumorigenic and metastatic potential of the cells. In the studies described here, we used differential display screening to identify changes in gene expression that are initiated by Met/HGF, and that may lead to these phenotypes. We learned that Met/HGF signaling resulted in greatly decreased fibronectin mRNA production in three different human and mouse tumor cell lines; these decreases in fibronectin mRNA were paralleled by decreases in fibronectin protein. We also found a progressive decrease in fibronectin in tumor explants and metastases derived from the Met/HGF transformed cells. The absence of fibronectin expression is a frequent cancer phenotype; our results indicate that decreases in fibronectin correlate with, but are not essential for, MetHGF/SF-mediated tumorigenesis.
Taylor
G A
GA
ABL-Basic Research Program, NCI-Frederick Cancer Research and Development Center, Frederick, Maryland 21702, USA.
Jeffers
M
M
Webb
C P
CP
Koo
H M
HM
Anver
M
M
Sekiguchi
K
K
Vande Woude
G F
GF
D000818:Animals; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000235:genetics; D005353:Fibronectins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000494:pharmacology*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D005353:Fibronectins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met