A serotonin-secreting human pancreatic carcinoid cell line (BON) is demonstrated to express transcripts for all three mammalian types of transforming growth factor β (TGFβ1, 2, and 3). Similarly, freshly excised carcinoid tumors from six patients were also found to express mRNA for all three of the type-β TGFs. Medium conditioned by BON cells had detectable TGFβ activity, although most of the activity was latent as determined by radioreceptor assay with and without prior acid treatment. However, nonactivated BON-conditioned medium stimulated DNA synthesis, soft agar growth, and an increase in TGFβ1 and fibronectin mRNA expression in AKR-2B fibroblasts. In addition, BON-conditioned medium had a potent endothelial cell growth-stimulatory activity. Since the TGFβs inhibit growth of endothelial cells, the presence of other growth factors was suspected. TGFα, c-sis, and basic fibroblast growth factor transcripts were also found to be expressed by the BON carcinoid cells. These data indicate that multiple peptide growth factors may have a paracrine role in the desmoplastic reaction accompanying carcinoid tumors.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Oct 1 1991|
ASJC Scopus subject areas
- Cancer Research