title: Angiogenic acceleration of Neu induced mammary tumor progression and metastasis.
abstract: The Neu (ErbB2, HER2) member of the epidermal growth factor receptor family is implicated in many human breast cancers. We have tested the importance of increased angiogenic signaling in the NeuYD [mouse mammary tumor virus (MMTV)-Neu(ndl)-YD5] mammary tumor model. Transgenic mice expressing vascular endothelial growth factor (VEGF)(164) from the MMTV promoter were generated. These mice expressed VEGF(164) RNA and protein at 20- to 40-fold higher levels throughout mammary gland development but exhibited normal mammary gland development and function. However, in combination with the NeuYD oncogene, VEGF(164) expression resulted in increased vascularization of hyperplastic mammary epithelium and dramatic acceleration of tumor appearance from 111 to 51 days. Gene expression profiling also indicated that the VEGF-accelerated tumors were substantially more vascularized and less hypoxic. The preferential vascularization of early hyperplastic portions of mammary epithelia in NeuYD;MMTV-VEGF animals was associated with NeuYD RNA expression, disorganization of the tight junctions, and overlapping transgenic VEGF expression. NeuYD;MMTV-VEGF(164) bigenic, tumor-bearing animals resulted in an average of 10 tumor cell colonies/lung lodged within vascular spaces. No similar lung colonies were found in control NeuYD mice with similar tumor burdens. Overall, these results demonstrate the angiogenic restriction of early hyperplastic mammary lesions. They also reinforce in vivo the importance of activated Neu in causing disorganization of mammary luminal epithelial cell junctions and provide support for an invasion-independent mechanism of metastasis.
authors.affiliation: Oncodevelopmental Biology Program, The Burnham Institute, La Jolla, California 92037, USA. rgoshima@burnham.org
authors.forename: Robert G
authors.initials: RG
authors.lastname: Oshima
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Lesperance
authors.forename: Varinia
authors.initials: V
authors.lastname: Munoz
authors.forename: Lionel
authors.initials: L
authors.lastname: Hebbard
authors.forename: Barbara
authors.initials: B
authors.lastname: Ranscht
authors.forename: Niki
authors.initials: N
authors.lastname: Sharan
authors.forename: William J
authors.initials: WJ
authors.lastname: Muller
authors.forename: Craig A
authors.initials: CA
authors.lastname: Hauser
authors.forename: Robert D
authors.initials: RD
authors.lastname: Cardiff
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018450:Disease Progression; D008325:Mammary Neoplasms, Experimental / Q000098:blood supply* / Q000473:pathology*; D008324:Mammary Tumor Virus, Mouse; D051379:Mice; D008822:Mice, Transgenic; D009362:Neoplasm Metastasis; D009389:Neovascularization, Pathologic / Q000473:pathology*; D016133:Polymerase Chain Reaction; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
chemical_list: D017931:DNA Primers; D018719:Erb-b2 Receptor Tyrosine Kinases; D042461:Vascular Endothelial Growth Factor A