Chemistry: molecular biology and microbiology – Animal cell – per se ; composition thereof; process of...
Reexamination Certificate
2000-10-10
2004-11-16
McGarry, Sean (Department: 1635)
Chemistry: molecular biology and microbiology
Animal cell, per se ; composition thereof; process of...
C536S024500, C435S091310, C435S320100
Reexamination Certificate
active
06818447
ABSTRACT:
BACKGROUND OF THE INVENTION
The Sequence Listing file named “MBHB00,876-K SequenceListing.txt” (2,337,188 bytes in size) submitted on Compact Disc-Recordable (CD-R) medium (“010706
—
1627”) in compliance with 37 C.F.R. §1.52(e) is incorporated herein by reference.
This invention relates to methods and reagents for the treatment of diseases or conditions relating to the levels of expression of vascular endothelial growth factor (VEGF) receptor(s).
The following is a discussion of relevant art, none of which is admitted to be prior art to the present invention.
VEGF, also referred to as vascular permeability factor (VPF) and vasculotropin, is a potent and highly specific mitogen of vascular endothelial cells (for a review see Ferrara, 1993
Trends Cardiovas. Med.
3, 244; Neufeld et al., 1994
Prog. Growth Factor Res.
5, 89). VEGF induced neovascularization is implicated in various pathological conditions such as tumor angiogenesis, proliferative diabetic retinopathy, hypoxia-induced angiogenesis, rheumatoid arthritis, psoriasis, wound healing and others.
VEGF, an endothelial cell-specific mitogen, is a 34-45 kDa glycoprotein with a wide range of activities that include promotion of angiogenesis, enhancement of vascular-permeability and others. VEGF belongs to the platelet-derived growth factor (PDGF) family of growth factors with approximately 18% homology with the A and B chain of PDGF at the amino acid level. Additionally, VEGF contains the eight conserved cysteine residues common to all growth factors belonging to the PDGF family (Neufeld et al., supra). VEGF protein is believed to exist predominantly as disulfide-linked homodimers; monomers of VEGF have been shown to be inactive (Plouet et al., 1989
EMBO J.
8, 3801).
VEGF exerts its influence on vascular endothelial cells by binding to specific high-affinity cell surface receptors. Covalent cross-linking experiments with
125
I-labeled VEGF protein have led to the identification of three high molecular weight complexes of 225, 195 and 175 kDa presumed to be VEGF and VEGF receptor complexes (Vaisman et al., 1990
J. Biol. Chem.
265, 19461). Based on these studies VEGF-specific receptors of 180, 150 and 130 kDa molecular mass were predicted. In endothelial cells, receptors of 150 and the 130 kDa have been identified. The VEGF receptors belong to the superfamily of receptor tyrosine kinases (RTKs) characterized by a conserved cytoplasmic catalytic kinase domain and a hydrophylic kinase sequence. The extracellular domains of the VEGF receptors consist of seven immunoglobulin-like domains that are thought to be involved in VEGF binding functions.
The two most abundant and high-affinity receptors of VEGF are flt-1 (fms-like tyrosine kinase) cloned by Shibuya et al., 1990
Oncogene
5, 519 and KDR (kinase-insert-domain-containing receptor) cloned by Terman et al., 1991
Oncogene
6, 1677. The murine homolog of KDR, cloned by Mathews et al., 1991,
Proc. Natl. Acad. Sci
., USA, 88, 9026, shares 85% amino acid homology with KDR and is termed as flk-1 (fet al liver kinase-1). Recently it has been shown that the high-affinity binding of VEGF to its receptors is modulated by cell surface-associated heparin and heparin-like molecules (Gitay-Goren et al., 1992
J. Biol. Chem.
267, 6093).
VEGF expression has been associated with several pathological states such as tumor angiogenesis, several forms of blindness, rheumatoid arthritis, psoriasis and others. Following is a brief summary of evidence supporting the involvement of VEGF in various diseases:
1) Tumor Angiogenesis
Increased levels of VEGF gene expression have been reported in vascularized and edema-associated brain tumors (Berkman et al., 1993
J. Clini. Invest.
91, 153). A more direct demostration of the role of VEGF in tumor angiogenesis was demonstrated by Jim Kim et al., 1993
Nature
362,841 wherein, monoclonal antibodies against VEGF were successfully used to inhibit the growth of rhabdomyosarcoma glioblastoma multiforme cells in nude mice. Similarly, expression of a dominant negative mutated form of the flt-1 VEGF receptor inhibits vascularization induced by human glioblastoma cells in nude mice (Millauer et al., 1994,
Nature
367, 576).
2) Ocular Diseses
Aiello et al., 1994
New Engl. J. Med.
331, 1480, showed that the ocular fluid, of a majority of patients suffering from diabetic retinopathy and other retinal disorders, contains a high concentration of VEGF. Miller et al., 1994
Am. J. Pathol.
145, 574, reported elevated levels of VEGF mRNA in patients suffering from retinal ischemia. These observations support a direct role for VEGF in ocular diseases.
3) Psoriasis
Detmar et al., 1994
J. Exp. Med.
180, 1141 reported that VEGF and its receptors were over-expressed in psoriatic skin and psoriatic dermal microvessels, suggesting that VEGF plays a significant role in psoriasis.
4) Rheumatoid Arthritis
Immunohistochemistry and in situ hybridization studies on tissues from the joints of patients suffering from rheumatoid arthritis show an increased level of VEGF and its receptors (Fava et al., 1994
J. Exp. Med.
180, 341). Additionally, Koch et al., 1994
J. Immunol.
152, 4149, found that VEGF-specific antibodies were able to significantly reduce the mitogenic activity of synovial tissues from patients suffering from rheumatoid arthritis. These observations support a direct role for VEGF in rheumatoid arthritis.
In addition to the above data on pathological conditions involving excessive angiogenesis, a number of studies have demonstrated that VEGF is both necessary and sufficient for neovascularization. Takashita et al., 1995
J. Clin. Invest.
93, 662, demonstrated that a single injection of VEGF augmented collateral vessel development in a rabbit model of ischemia. VEGF also can induce neovascularization when injected into the cornea. Expression of the VEGF gene in CHO cells is sufficient to confer tumorigenic potential to the cells. Kim et al., supra and Millauer et al., supra used monoclonal antibodies against VEGF or a dominant negative form of flk-1 receptor to inhibit tumor-induced neovascularization.
During development, VEGF and its receptors are associated with regions of new vascular growth (Millauer et al. 1993
Cell
72, 835; Shalaby et al., 1993
J. Clin. Invest.
91, 2235). Furthermore. transgenic mice lacking either of the VEGF receptors are defective in blood vessel formation, infact these mouse do not survive; flk-1 appears to be required for differentiation of endothelial cells, while flt-1 appears to be required at later stages of vessel formation (Shalaby et al., 1995
Nature
376, 62; Fung et al., 1995
Nature
376, 66). Thus, these receptors must be present to properly signal endothelial cells or their precursors to respond to vascularization-promoting stimuli.
All of the conditions listed above, involve extensive vascularization. This hyper-stimulation of endothelial cells may be alleviated by VEGF antagonists. Thus most of the therapeutic efforts for the above conditions have concentrated on finding inhibitors of the VEGF protein.
Kim et al., 1993
Nature
362, 841 have been successful in inhibiting VEGF-induced tumor growth and angiogenesis in nude mice by treating the mice with VEGF-specific monoclonal antibody.
Koch et al., 1994
J. Immunol.
152, 4149 showed that the mitogenic activity of microvascular endothelial cells found in rheumatoid arthritis (RA) synovial tissue explants and the chemotactic property of endothelial cells from RA synovial fluid can be neutralized significantly by treatment with VEGF-specific antibodies.
Ullrich et al., International PCT Publication No. WO 94/11499 and Millauer et al., 1994
Nature
367, 576 used a soluble form of flk-1 receptor (dominant-negative mutant) to prevent VEGF-mediated tumor angiogenesis in immunodeficient mice.
Kendall and Thomas, International PCT Publication No. WO 94/21679 describe the use of naturally occuring or recombinantly-engineered soluble forms of VEGF receptors to inhibit VEGF activity.
Robinson, International PCT Publication No. WO 95/04142 describes the use of antisense
Escobedo Jaime
McSwiggen James
Pavco Pamela
Stinchcomb Daniel
Epps-Ford Janet L
McDonnell Boehnen & Hulbert & Berghoff LLP
McGarry Sean
Sirna Therapeutics, Inc.
LandOfFree
Method and reagent for the treatment of diseases or... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and reagent for the treatment of diseases or..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and reagent for the treatment of diseases or... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3307941