Steady-state mRNA expression for growth factors in DMBA-induced rat mammary tumors.
Steady-state mRNA levels were examined for insulin-like growth factors (IGF) I and II, transforming growth factor alpha (TGF alpha) and its receptor and the epidermal growth factor (EGF) receptor in mammary tumors induced by DMBA in rats. An abundant 4.8 kb TGF alpha transcript was identified in all tumors, along with a 7.5-8.0 kb IGF-I transcript. A presumptive 2.9 kb IGF-II transcript was also identified in all tumors. Northern analyses and receptor autophosphorylation studies failed to detect EGF receptors in any mammary tumors. These findings suggest the potential for autocrine or paracrine influences of IGF-I and IGF-II in this tumor model and a possible paracrine influence of TGF alpha in tumor-induced neovascularization.
Ruggeri
B A
BA
Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104.
Klurfeld
D M
DM
Kritchevsky
D
D
Frick
K K
KK
D015127:9,10-Dimethyl-1,2-benzanthracene; D000230:Adenocarcinoma / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D015342:DNA Probes; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D005260:Female; D006133:Growth Substances / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D009376:Neoplasms, Hormone-Dependent / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D011919:Rats, Inbred Strains; D014158:Transcription, Genetic; D016211:Transforming Growth Factor alpha / Q000235:genetics
D015342:DNA Probes; D006133:Growth Substances; D012333:RNA, Messenger; D016211:Transforming Growth Factor alpha; D015127:9,10-Dimethyl-1,2-benzanthracene; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D066246:ErbB Receptors