TGF-beta1 resistance is not associated with alterations in TGF-beta type II receptors in immortalized human lung epithelial cells.
A frequent cause of TGF-beta resistance is decreased expression or mutation of TGF-beta receptor Type II (TGFbetaRII) protein. We previously isolated two isogeneic subclones of the human bronchial epithelial cell line BEAS-2B that are respectively resistant (R.1) or sensitive (S.6) to the growth inhibitory effects of TGF-beta1. In this study, we examined TGFbetaIIR expression, ability to bind TGF-beta1, and cDNA sequence in the resistant cell line. Immunofluorescent analyses with antibody to TGFbetaRII indicated that this protein was expressed at the surface of R.1 cells. Affinity binding studies showed that TGF-beta1 bound equally well to the resistant (R.1) and sensitive (S.6) cell lines. PCR cloning and sequencing of TGFbetaRII cDNA revealed no changes from wild type in the resistant cell line. We conclude that alterations in TGF-beta Type II receptor are not responsible for TGF-beta resistance in this cell line.
Hamburger
A W
AW
University of Maryland Cancer Center, Baltimore 21201, USA.
Smith
T
T
Elliget
K
K
Hagiwara
K
K
Gerwin
B I
BI
D002461:Cell Line, Transformed; D018076:DNA, Complementary / Q000032:analysis; D004351:Drug Resistance; D004848:Epithelium; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008168:Lung; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology*
D018076:DNA, Complementary; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II