Retinoic acid causes a decline in TGF-alpha expression, cloning efficiency, and tumorigenicity in a human embryonal cancer cell line.
The human teratocarcinoma NTERA-2 cl. D1 (NT2/D1) cell is a cloned multipotential embryonal cancer cell line that differentiates into a neuronal phenotype and other cellular lineages with retinoic acid (RA) treatment. Here we report that mRNA for the transforming growth factor-alpha is expressed in these RA-untreated cells and that RA-treatment results in a reduction of mRNA expression within 24 hr of treatment. In total cellular RNA, TGF-alpha mRNA is not detectable by Northern analysis at 6 days when there is increased expression of the human homeotic genes Hu-1 (Hox 2.1) and Hu-2 (Hox 2.2), known markers of RA response in NT2/D1 cells. RA treatment also causes a marked reduction in cloning efficiency and tumorigenicity of these cells. The addition of TGF-alpha or EGF (epidermal growth factor) protein to RA-untreated NT2/D1 cells augments soft agar cloning under limited fetal calf serum conditions. Blocking monoclonal antibodies directed against the EGF receptor (EGFr) can prevent this augmentation. We conclude that TGF-alpha expression inversely correlates with the state of RA-induced differentiation of this human teratocarcinoma cell and that TGF-alpha and EGF proteins are stimulatory growth factors in NT2/D1 cells under these culture conditions.
Dmitrovsky
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E
Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Moy
D
D
Miller
W H
WH
Li
A
A
Masui
H
H
D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002999:Clone Cells; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D012333:RNA, Messenger / Q000235:genetics*; D013724:Teratoma; D014158:Transcription, Genetic / Q000187:drug effects; D015291:Transforming Growth Factors / Q000096:biosynthesis / Q000235:genetics*; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D012333:RNA, Messenger; D014212:Tretinoin; D015291:Transforming Growth Factors