Enhancement of @entity5 growth and vascular density by transfection of vascular endothelial cell growth factor into MCF-7 @entity1 XXXX cells.

@entity1 @entity172 @entity0 @entity440 @entity7 @entity5 @entity19 @entity95 @entity189 @entity2279 @entity3
BACKGROUND: @entity7 ( @entity7 ) is a secreted endothelial-specific growth factor that is angiogenic in vivo. It is commonly expressed in a range of @entity189 . PURPOSE: The study was designed to investigate the effect of constitutive expression of @entity7 on @entity5 formation by @entity172 -dependent @entity1 MCF-7 @entity0 cells. METHODS: A full-length complementary DNA encoding the shortest isoform of @entity7 ( @entity7 ) was stably transfected into MCF-7 cells. Transfected clones were screened for @entity7 messenger RNA (mRNA) expression by ribonuclease protection analysis and for secretion of @entity7 protein by Western blot analysis. Secretion of biologically active @entity7 by transfectants was confirmed by 1) a competitive radioreceptor-binding assay, 2) stimulation of the growth of microvascular endothelial cells in vitro, and 3) potent angiogenic activity in the @entity95 corneal assay. @entity5 models were then established by subcutaneously implanting wild-type or @entity7 -transfected MCF-7 cells, together with either @entity19 BALB/3T3 clone A31 fibroblasts or @entity1 MDA-435S @entity0 cells, into ovariectomized @entity19 either with or without a separately implanted slow-release @entity172 pellet. @entity5 vascularity was quantitatively assessed by capillary vessel counting after staining with the pan-endothelial marker @entity2279 . RESULTS: Stable @entity7 -overexpressing MCF-7 cells were isolated and designated V12 cells. When implanted into the @entity95 cornea, V12 cells elicited a strong directional outgrowth of capillaries. The growth rate of V12 cells in vitro was indistinguishable from that of MCF-7 wild-type cells. V12 cells formed faster growing @entity5 than did wild-type cells (P < .01) when xenografted subcutaneously into @entity19 with either 3T3 fibroblasts or MDA-435S cells. @entity5 formed from V12 cells were more vascular (P < .01) and showed a heterogeneous distribution of vessels when compared with the homogeneous distribution seen in @entity5 formed from wild-type cells. @entity7 overexpression had no effect on hormone dependence or @entity440 sensitivity of @entity5 formation by MCF-7 cells in @entity19 . No macroscopic evidence for @entity3 from subcutaneous implants was obtained. CONCLUSIONS: @entity7 expression by @entity0 cells confers a growth advantage in vivo but not in vitro. @entity5 formed by V12 transfectants were more vascular than those formed by wild-type MCF-7 cells, and we surmise that the growth advantage arises from @entity5 vascularization induced by @entity7 . IMPLICATIONS: @entity5 formation by V12 cells could provide a useful model for the assessment of anti-angiogenic drugs.
