Modulation of tumor angiogenesis by stem cell factor.
Mast cells accumulate within solid tumors and can release many angiogenic factors, suggesting that they may modulate vascularization of tumors. Stem cell factor (SCF) stimulates mast cell migration, proliferation, and degranulation and therefore may influence mast cell behavior within tumors. We investigated the contribution of SCF to tumor angiogenesis by manipulating its level in mammary tumors. Sense or antisense cDNA fragments of rat SCF were ligated into an episomal expression vector. Ethylnitrosourea-induced rat mammary tumor cell lines were transfected with vector containing either control (no insert, C-P), sense (S-P), or antisense (AS-P) SCF DNA. The functional nature of the transfectants was confirmed by measuring SCF in cell lysates and conditioned media. Immunohistochemical analysis of the tumors induced in Berlin-Druckrey rats by these transfected cells demonstrated that mast cell number and microvascular density were significantly higher in S-P tumors and significantly lower in AS-P tumors, compared with C-P tumors. The expression of von Willebrand factor, an endothelial cell marker, showed a similar pattern. AS-P tumors were significantly smaller than either C-P or S-P tumors. These data suggest that SCF modulates tumor growth and angiogenesis via the involvement of mast cells.
Zhang
W
W
Cardiovascular Research Institute and Department of Medical Physiology, The Texas A&M University System Health Science Center, College Station, Texas 77843-1114, USA.
Stoica
G
G
Tasca
S I
SI
Kelly
K A
KA
Meininger
C J
CJ
D000818:Animals; D016373:DNA, Antisense / Q000008:administration & dosage / Q000235:genetics; D018076:DNA, Complementary / Q000008:administration & dosage / Q000235:genetics; D016228:Endothelial Growth Factors / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis / Q000235:genetics; D008222:Lymphokines / Q000096:biosynthesis / Q000235:genetics; D008325:Mammary Neoplasms, Experimental / Q000098:blood supply* / Q000235:genetics / Q000473:pathology; D008407:Mast Cells / Q000502:physiology; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism; D051381:Rats; D019089:Stem Cell Factor / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016373:DNA, Antisense; D018076:DNA, Complementary; D016228:Endothelial Growth Factors; D008222:Lymphokines; D019089:Stem Cell Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2