IL-3 affects endothelial cell-mediated smooth muscle cell recruitment by increasing TGF beta activity: potential role in tumor vessel stabilization.
Interleukin-3 (IL-3) expression by tumor-infiltrating lymphocytes (TILs) and its effects on vessel assembly were evaluated. TILs from 'in situ' human breast cancers expressed CD4/CD25 antigens and IL-3. An injection of Matrigel containing SMC and IL-3 or basic-fibroblast growth factor (bFGF) into SCID mice confirmed the neoangiogenetic effect of both factors. However, in response to IL-3, but not to bFGF, only few SMC became incorporated into the nascent vessels. To evaluate the possibility that signals emanated by the nascent vasculature in the presence of IL-3 may negatively regulate SMC recruitment, conditioned media (CM) from IL-3-treated endothelial cells (EC) or SMC were tested for their biological effects on SMC and EC. CM from IL-3-treated SMC stimulated the migration of EC. In contrast, the migration of SMC was not affected by CM from IL-3-stimulated EC; however, it was greatly enhanced by blocking transforming growth factor beta (TGF beta) activity. TGF beta immunoenzymatic assay demonstrated the following: (i) the absence of TGF beta activity in CM from IL-3-stimulated EC; (ii) a barely detectable TGF beta activity in CM from IL-3-stimulated SMC; and (iii) the presence of TGF beta activity in the supernatants of SMC stimulated with CM from IL-3-, but not from bFGF-stimulated EC. Increased TGF beta mRNA expression was only detected in SMC stimulated with CM from IL-3-treated EC. Finally, the inhibitory signals induced by IL-3 in vivo were abrogated by the addition of the neutralizing TGF beta antibody. Thus, the positive immunostaining for IL-3 by TILs in 'in situ' breast cancers sustains the possibility that early in tumor development, IL-3 can contribute to the chronic immaturity of these vessels.
Dentelli
Patrizia
P
Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126 Torino, Italy.
Rosso
Arturo
A
Calvi
Cristina
C
Ghiringhello
Bruno
B
Garbarino
Giovanni
G
Camussi
Giovanni
G
Pegoraro
Luigi
L
Brizzi
Maria Felice
MF
D000818:Animals; D001943:Breast Neoplasms / Q000098:blood supply* / Q000276:immunology; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D003094:Collagen; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004338:Drug Combinations; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006801:Humans; D007377:Interleukin-3 / Q000378:metabolism / Q000494:pharmacology*; D007797:Laminin; D008214:Lymphocytes / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D008934:Mitogens / Q000494:pharmacology; D008954:Models, Biological; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009389:Neovascularization, Pathologic; D011509:Proteoglycans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism
D017077:Culture Media, Conditioned; D004338:Drug Combinations; D007377:Interleukin-3; D007797:Laminin; D008934:Mitogens; D011509:Proteoglycans; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; C059485:matrigel; D003094:Collagen; D020778:Matrix Metalloproteinase 2