Expression of fibroblast growth factor gene family and its receptor gene family in the human upper gastrointestinal tract.

All of 13 human esophageal cancer cell lines contained mRNAs for both basic fibroblast growth factor (bFGF) and its receptor, FGFR1/N-sam protein, while they did not have mRNAs for keratinocyte growth factor (KGF) despite the presence of mRNAs for the KGF receptor gene, K-sam. The results indicate that in human esophageal cancer, bFGF plays roles in an autocrine manner, while KGF acts as a paracrine mediator. In contrast, only one of seven human gastric cancer cell lines contained bFGF mRNAs, while three out of the seven had mRNAs for FGFR1/N-sam protein. The KGF gene was not expressed in any of the gastric cancer cell lines, while K-sam mRNAs were detected in six out of the seven. The results demonstrate that in most human gastric cancers, bFGF does not act as an autocrine mediator, while KGF acts as a paracrine factor. The mRNAs for the other four members of the fibroblast growth factor (FGF) family, including acidic FGF, int-2 protein, hst-1 protein, FGF5 protein and FGF6/hst-2 protein could not be detected in the esophageal and gastric cancer cell lines.