Tumour-stromal interactions. Transforming growth factor-beta isoforms and hepatocyte growth factor/scatter factor in mammary gland ductal morphogenesis.
The mammary gland undergoes morphogenesis through the entire reproductive life of mammals. In mice, ductal outgrowth from the nipple across the fat pad results in an intricate, well spaced ductal tree that further ramifies and develops alveolar structures during pregnancy. Ductal morphogenesis is regulated by the concerted action of circulating steroid and polypeptide hormones, and local epithelial-mesenchymal inductive signals. Transforming growth factor (TGF)-beta1-3 and hepatocyte growth factor (HGF)/scatter factor (SF) are important components of this latter signaling pathway. TGF-beta1 and TGF-beta3 have roles in both promotion and inhibition of branching morphogenesis that are dependent on concentration and context. HGF/SF promotes ductal outgrowth and tubule formation in the mammary gland. These data suggest that these two growth factors have complementary roles in promoting mammary ductal morphogenesis and in maintaining ductal spacing. In addition, TGF-beta3 triggers apoptosis in the alveolar epithelia, which is a necessary component of mammary gland involution and return of the ductal structure to a virgin-like state after lactation.
Pollard
J W
JW
Departments of Developmental and Molecular Biology, and OB/GYN and Women's Health, Center for the Study of Reproductive Biology and Women's Health, Albert Einstein College of Medicine, New York, New York, USA. pollard@aecom.yu.edu
D000818:Animals; D017209:Apoptosis; D001940:Breast / Q000254:growth & development*; D001943:Breast Neoplasms / Q000503:physiopathology*; D004847:Epithelial Cells / Q000473:pathology / Q000502:physiology; D005260:Female; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D006801:Humans; D007536:Isomerism; D007774:Lactation / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009024:Morphogenesis; D015398:Signal Transduction; D017154:Stromal Cells / Q000473:pathology / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D016212:Transforming Growth Factor beta; D017228:Hepatocyte Growth Factor