Notch4 is required for tumor onset and perfusion
- Equal contributors
1 Laboratory for Accelerated Vascular Research, Division of Vascular Surgery, Department of Surgery, University of California, San Francisco, CA 94143, USA
2 Center for Molecular Medicine, Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA
3 Present address: Department of Pediatrics and Program in Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
4 Present address: Tech Data Services, LLC, King of Prussia, PA19406, USA
5 Present address: Novartis Healthcare Pvt. Ltd., Hyderabad, India
6 Present address: Department of Urology, Massachusetts General Hospital, Boston, MA 02114, USA
7 Present address: Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA
8 Present address: School of Public; Division of Infectious Diseases and Vaccinology, University of California Davis Medical Center, Sacramento, CA 95817, USA
Vascular Cell 2013, 5:7 doi:10.1186/2045-824X-5-7Published: 20 April 2013
Notch4 is a member of the Notch family of receptors that is primarily expressed in the vascular endothelial cells. Genetic deletion of Notch4 does not result in an overt phenotype in mice, thus the function of Notch4 remains poorly understood.
We examined the requirement for Notch4 in the development of breast cancer vasculature. Orthotopic transplantation of mouse mammary tumor cells wild type for Notch4 into Notch4 deficient hosts enabled us to delineate the contribution of host Notch4 independent of its function in the tumor cell compartment.
Here, we show that Notch4 expression is required for tumor onset and early tumor perfusion in a mouse model of breast cancer. We found that Notch4 expression is upregulated in mouse and human mammary tumor vasculature. Moreover, host Notch4 deficiency delayed the onset of MMTV-PyMT tumors, wild type for Notch4, after transplantation. Vessel perfusion was decreased in tumors established in Notch4-deficient hosts. Unlike in inhibition of Notch1 or Dll4, vessel density and branching in tumors developed in Notch4-deficient mice were unchanged. However, final tumor size was similar between tumors grown in wild type and Notch4 null hosts.
Our results suggest a novel role for Notch4 in the establishment of tumor colonies and vessel perfusion of transplanted mammary tumors.