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Shahin Rafii

Bio: Shahin Rafii is an academic researcher from Cornell University. The author has contributed to research in topics: Stem cell & Endothelial stem cell. The author has an hindex of 106, co-authored 375 publications receiving 52144 citations. Previous affiliations of Shahin Rafii include Howard Hughes Medical Institute & Kettering University.


Papers
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Journal ArticleDOI
08 Dec 2005-Nature
TL;DR: A requirement for VEGFR1+ haematopoietic progenitor cells that express vascular endothelial growth factor receptor 1 (VEGFR1) home to tumour-specific pre-metastatic sites and form cellular clusters before the arrival of tumour cells is demonstrated.
Abstract: The cellular and molecular mechanisms by which a tumour cell undergoes metastasis to a predetermined location are largely unknown. Here we demonstrate that bone marrow-derived haematopoietic progenitor cells that express vascular endothelial growth factor receptor 1 (VEGFR1; also known as Flt1) home to tumour-specific pre-metastatic sites and form cellular clusters before the arrival of tumour cells. Preventing VEGFR1 function using antibodies or by the removal of VEGFR1(+) cells from the bone marrow of wild-type mice abrogates the formation of these pre-metastatic clusters and prevents tumour metastasis, whereas reconstitution with selected Id3 (inhibitor of differentiation 3)-competent VEGFR1+ cells establishes cluster formation and tumour metastasis in Id3 knockout mice. We also show that VEGFR1+ cells express VLA-4 (also known as integrin alpha4beta1), and that tumour-specific growth factors upregulate fibronectin--a VLA-4 ligand--in resident fibroblasts, providing a permissive niche for incoming tumour cells. Conditioned media obtained from distinct tumour types with unique patterns of metastatic spread redirected fibronectin expression and cluster formation, thereby transforming the metastatic profile. These findings demonstrate a requirement for VEGFR1+ haematopoietic progenitors in the regulation of metastasis, and suggest that expression patterns of fibronectin and VEGFR1+VLA-4+ clusters dictate organ-specific tumour spread.

2,923 citations

Journal ArticleDOI
01 Feb 2000-Blood
TL;DR: In an in vivo human model, it is found that the neo-intima formed on the surface of left ventricular assist devices is colonized with AC133(+)VEGFR-2(+) cells, suggesting a phenotypically and functionally distinct population of circulating endothelial cells that may play a role in neo-angiogenesis.

2,404 citations

Journal ArticleDOI
TL;DR: It is demonstrated that recruitment of VEGF-responsive BM-derived precursors is necessary and sufficient for tumor angiogenesis and suggested new clinical strategies to block tumor growth are suggested.
Abstract: The role of bone marrow (BM)-derived precursor cells in tumor angiogenesis is not known. We demonstrate here that tumor angiogenesis is associated with recruitment of hematopoietic and circulating endothelial precursor cells (CEPs). We used the angiogenic defective, tumor resistant Id-mutant mice to show that transplantation of wild-type BM or vascular endothelial growth factor (VEGF)-mobilized stem cells restore tumor angiogenesis and growth. We detected donor-derived CEPs throughout the neovessels of tumors and Matrigel-plugs in an Id1+/-Id3-/- host, which were associated with VEGF-receptor-1-positive (VEGFR1+) myeloid cells. The angiogenic defect in Id-mutant mice was due to impaired VEGF-driven mobilization of VEGFR2+ CEPs and impaired proliferation and incorporation of VEGFR1+ cells. Although targeting of either VEGFR1 or VEGFR2 alone partially blocks the growth of tumors, inhibition of both VEGFR1 and VEGFR2 was necessary to completely ablate tumor growth. These data demonstrate that recruitment of VEGF-responsive BM-derived precursors is necessary and sufficient for tumor angiogenesis and suggest new clinical strategies to block tumor growth.

1,945 citations

Journal ArticleDOI
31 May 2002-Cell
TL;DR: In this article, BM ablation induces SDF-1, which upregulates MMP-9 expression, and causes shedding of sKitL and recruitment of c-Kit+ stem/progenitors.

1,795 citations

Journal ArticleDOI
15 Jul 1998-Blood
TL;DR: It is demonstrated that a subset of CD34(+) cells have the capacity to differentiate into endothelial cells in vitro in the presence of basic fibroblast growth factor, insulin-like growth factor-1, and vascular endothelial growth factor.

1,654 citations


Cited by
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Journal ArticleDOI
19 Mar 1998-Nature
TL;DR: Once a neglected cell type, dendritic cells can now be readily obtained in sufficient quantities to allow molecular and cell biological analysis and the realization that these cells are a powerful tool for manipulating the immune system is realized.
Abstract: B and T lymphocytes are the mediators of immunity, but their function is under the control of dendritic cells. Dendritic cells in the periphery capture and process antigens, express lymphocyte co-stimulatory molecules, migrate to lymphoid organs and secrete cytokines to initiate immune responses. They not only activate lymphocytes, they also tolerize T cells to antigens that are innate to the body (self-antigens), thereby minimizing autoimmune reactions. Once a neglected cell type, dendritic cells can now be readily obtained in sufficient quantities to allow molecular and cell biological analysis. With knowledge comes the realization that these cells are a powerful tool for manipulating the immune system.

14,532 citations

Journal ArticleDOI
24 Jul 2008-Nature
TL;DR: The molecular pathways of this cancer-related inflammation are now being unravelled, resulting in the identification of new target molecules that could lead to improved diagnosis and treatment.
Abstract: The mediators and cellular effectors of inflammation are important constituents of the local environment of tumours. In some types of cancer, inflammatory conditions are present before a malignant change occurs. Conversely, in other types of cancer, an oncogenic change induces an inflammatory microenvironment that promotes the development of tumours. Regardless of its origin, 'smouldering' inflammation in the tumour microenvironment has many tumour-promoting effects. It aids in the proliferation and survival of malignant cells, promotes angiogenesis and metastasis, subverts adaptive immune responses, and alters responses to hormones and chemotherapeutic agents. The molecular pathways of this cancer-related inflammation are now being unravelled, resulting in the identification of new target molecules that could lead to improved diagnosis and treatment.

9,282 citations

Journal ArticleDOI
TL;DR: Vascular endothelial growth factor (VEGF) is a key regulator of physiological angiogenesis during embryogenesis, skeletal growth and reproductive functions and is implicated in pathologicalAngiogenesis associated with tumors, intraocular neovascular disorders and other conditions.
Abstract: Vascular endothelial growth factor (VEGF) is a key regulator of physiological angiogenesis during embryogenesis, skeletal growth and reproductive functions. VEGF has also been implicated in pathological angiogenesis associated with tumors, intraocular neovascular disorders and other conditions. The biological effects of VEGF are mediated by two receptor tyrosine kinases (RTKs), VEGFR-1 and VEGFR-2, which differ considerably in signaling properties. Non-signaling co-receptors also modulate VEGF RTK signaling. Currently, several VEGF inhibitors are undergoing clinical testing in several malignancies. VEGF inhibition is also being tested as a strategy for the prevention of angiogenesis, vascular leakage and visual loss in age-related macular degeneration.

8,942 citations

Journal ArticleDOI
19 Mar 2010-Cell
TL;DR: The principal mechanisms that govern the effects of inflammation and immunity on tumor development are outlined and attractive new targets for cancer therapy and prevention are discussed.

8,664 citations

Journal ArticleDOI
14 Sep 2000-Nature
TL;DR: Pathological angiogenesis is a hallmark of cancer and various ischaemic and inflammatory diseases and integrated understanding is leading to the development of a number of exciting and bold approaches to treat cancer and other diseases, but owing to several unanswered questions, caution is needed.
Abstract: Pathological angiogenesis is a hallmark of cancer and various ischaemic and inflammatory diseases Concentrated efforts in this area of research are leading to the discovery of a growing number of pro- and anti-angiogenic molecules, some of which are already in clinical trials The complex interactions among these molecules and how they affect vascular structure and function in different environments are now beginning to be elucidated This integrated understanding is leading to the development of a number of exciting and bold approaches to treat cancer and other diseases But owing to several unanswered questions, caution is needed

8,561 citations