Effects of N,N-dimethylformamide and extracellular matrix on transforming growth factor-beta binding to a human colon carcinoma cell line.
Alterations in the binding of transforming growth factor-beta (TGF-beta) to the MOSER human colon carcinoma cell line caused by N,N-dimethylformamide (DMF) or extracellular matrix (ECM) were examined. DMF induced a more differentiated phenotype in the MOSER cells and resulted in a twofold increase in TGF-beta binding to the cells. This was due to an increase in receptor number with no significant alteration in the KD. The extent of increased TGF-beta binding was dependent on the dose and time of exposure to DMF. Upon removal of DMF, the receptor level returned to that of untreated cells within 6 hr. The binding of TGF-beta 1 and TGF-beta 2 to the cells was increased equally. Despite this increase in TGF-beta binding in the presence of DMF, the sensitivity of the MOSER cells to the growth inhibitory effects of TGF-beta was unaltered. Growth of the MOSER cells on ECM derived from a well-differentiated colon cell line increased the TGF-beta receptor number twofold without altering the KD. No change was observed if the MOSER cells were grown on ECM derived from a poorly differentiated cell line. While no alteration in sensitivity to TGF-beta was observed on cells grown in the presence of DMF, MOSER cells grown on the ECM derived from well-differentiated colon carcinoma cell lines were twofold more sensitive to the growth inhibitory effects of TGF-beta. These results indicated that growth conditions which resulted in a more differentiated phenotype resulted in an increase in the cellular receptors for TGF-beta.
Levine
A E
AE
Bristol-Baylor Laboratory, Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030.
Black
B
B
Brattain
M G
MG
D002277:Carcinoma / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism*; D004126:Dimethylformamide / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D015291:Transforming Growth Factors / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D015291:Transforming Growth Factors; D004126:Dimethylformamide