Growth regulation of A431 cells. Modulation of expression of transforming growth factor-alpha mRNA and 2',5'-oligoadenylate synthetase activity.
To explore bidirectional regulatory interactions between interferons and autocrine polypeptide factors, we examined the modulation of expression of transforming growth factor-alpha and 2',5'-oligoadenylate synthetase activity in A431 epidermoid carcinoma cells after treatment with interferon-gamma and transforming growth factor-alpha. Treatment of A431 cells with interferon-gamma increased steady state levels of transforming growth factor-alpha mRNA by 4-fold and increased the levels of transforming growth factor-alpha in the culture medium. There were additive growth inhibitory effects upon coaddition of exogenous transforming growth factor-alpha and interferon-gamma to the cultures. Addition of transforming growth factor-alpha to A431 cell cultures in the absence of interferon could stimulate the induction of 2',5'-oligoadenylate synthetase activity by more than 2-fold. These findings demonstrate that the induction of transforming growth factor-alpha in interferon-gamma-treated A431 cells could act to regulate interferon-induced gene(s), e.g. 2',5'-oligoadenylate synthetase, suggesting interactions between a potential autocrine growth factor and the interferon system in the growth regulation of A431 cells.
Kumar
R
R
Laboratory of Receptor Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Mendelsohn
J
J
D015088:2',5'-Oligoadenylate Synthetase / Q000096:biosynthesis*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D004790:Enzyme Induction / Q000187:drug effects; D066246:ErbB Receptors / Q000235:genetics; D005786:Gene Expression Regulation; D007371:Interferon-gamma / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis*; D007700:Kinetics; D008970:Molecular Weight; D012333:RNA, Messenger / Q000096:biosynthesis*; D015291:Transforming Growth Factors / Q000235:genetics* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D007527:Isoenzymes; D012333:RNA, Messenger; D015291:Transforming Growth Factors; D007371:Interferon-gamma; D066246:ErbB Receptors; D015088:2',5'-Oligoadenylate Synthetase