This invention relates to newly identified polynucleotides, polypeptides encoded by such polynucleotides, the use of such polynucleotides and polypeptides, as well as the production of such polynucleotides and polypeptides. The polypeptide of the present invention has been putatively identified as a human transforming growth factor alpha homolog. More particularly, the polypeptide of the present invention has been putatively identified as transforming growth factor alpha HII, sometimes hereafter referred to as xe2x80x9cTGFxcex1-HIIxe2x80x9d. The invention also relates to inhibiting the action of such polypeptides.
Cellular growth and differentiation appear to be initiated, promoted, maintained and regulated by a multiplicity of stimulatory, inhibitory and synergistic factors and hormones. The alteration and/or breakdown of the cellular homeostasis mechanism seems to be a fundamental cause of growth related diseases, including neoplasia. Growth modular factors are implicated in a wide variety of pathological and physiological processes including signal transduction, cell communication, growth and development, embryogenesis, immune response, hematopoiesis cell survival and differentiation, inflammation, tissue repair and remodeling, atherosclerosis and cancer. Epidermal growth factor (EGF), transforming growth factor alpha (TGFxcex1), betacellulin, amphiregulin, and vaccinia growth factor among other factors are growth and differentiation modulatory proteins produced by a variety of cell types either under normal physiological conditions or in response to exogenous stimuli and are members of the EGF family.
These peptide growth factors influence wound cells through autocrine and paracrine mechanisms. They also play important roles in normal wound healing in tissues such as skin, cornea and gastrointestinal tract and all share substantial amino acid sequence homology including the conserved placement of three intra-chain disulfide bonds. In addition, all the factors of this family bind to a 170,000 molecular weight transmembrane glycoprotein receptor and activate the tyrosine kinase activity in the receptor""s cytoplasmic domain (Buhrow, S. A. et al., J. Bio. Chem., 258:7824-7826 (1983)).
The receptors are expressed by many types of cells including skin keratinocytes, fibroblasts, vascular endothelial cells, and epithelial cells of the GI tract. These peptide growth factors are synthesized by several cells involved in wound healing including platelets, keratinocytes, and activated macrophages. These growth factors have also been implicated in both the stimulation of growth and differentiation of certain cells, for example, neoplasia, and the inhibition of other types of cells.
Betacellulin is a 32-kilodalton glycoprotein that appears to be processed from a larger transmembrane precursor by proteolytic cleavage. The carboxyl-terminal domain of betacellulin has 50% sequence similarity with that of rat transforming growth factor xcex1. Betacellulin is a potent mitogen for retinal pigment epithelial cells and vascular smooth muscle cells.
Amphiregulin is a bifunctional cell growth regulatory factor which exhibits potent inhibitory activity on DNA synthesis in neoplastic cells, yet promotes the growth of certain normal cells. A wide variety of uses for amphiregulin have been assigned including the treatment of wounds and cancers. For example, amphiregulin has potent anti-proliferative effects in vitro on several human cancer cell lines of epithelial origin. Amphiregulin also induces the proliferation of human foreskin fibroblasts as shown in U.S. Pat. No. 5,115,096.
TGFxcex1 has pleiotropic biological effects. The production of certain members of TGFxcex1 is synthesized by a number of oncogenically transformed fibroblasts (Ciardiello et al., J. Cell. Biochem., 42:45-57 (1990)), as well as by a variety of tumors, including renal, breast and squamous carcinomas, melanomas and glioblastomas (Derynck, R. et al., Cancer Res., 47:707-712 (1987)). There is direct evidence that TGFxcex1 expression can be a contributing factor in the conversion of a normal cell to its tumorigenic counterpart by analyzing transgenic mice in which tumor cells express high levels of TGFxcex1. TGFxcex1 transgenic animals display a variety of neoplastic lesions, depending on the strain of mouse and the choice of promotor regulating TGFxcex1 expression (Sandgren, et al., Cell, 61:1121-1135 (1990)).
TGFxcex1 also plays a role in normal embryonic development and adult physiology (Derynck, R. Adv. Cancer Res., 58:27-5 (1992)). TGFxcex1 has been expressed in many tissues including skin, brain, gastrointestinal mucosa and activating macrophages. Accordingly, TGFxcex1 is an important factor in controlling growth of epithelial cells and has a role in wound healing. TGFxcex1 has also been found to be angiogenic (Schreiber, et al., Science, 232:1250-1253 (1986)).
The polypeptide of the present invention has been putatively identified as transforming growth factor TGFxcex1-HII. This identification has been made as a result of amino acid sequence homology to human TGFxcex1.
In accordance with one aspect of the present invention, there are provided novel mature polypeptides, as well as biologically active and diagnostically or therapeutically useful fragments, analogs and derivatives thereof. The polypeptides of the present invention are of human origin.
In accordance with another aspect of the present invention, there are provided isolated nucleic acid molecules encoding the polypeptides of the present invention, including mRNAs, DNAs, cDNAs, genomic DNAs as well as analogs and biologically active and diagnostically or therapeutically useful fragments thereof.
In accordance with yet a further aspect of the present invention, there are provided processes for producing such polypeptide by recombinant techniques comprising culturing recombinant prokaryotic and/or eukaryotic host cells, containing a nucleic acid sequence encoding a polypeptide of the present invention.
In accordance with yet a further aspect of the present invention, there are provided processes for utilizing such polypeptides, or polynucleotides encoding such polypeptides for therapeutic purposes, for example, to stimulate wound healing to restore normal neurological functioning after trauma or AIDS dementia, to treat ocular disorders, to target certain cells, to treat kidney and liver disorders and to promote hair follicular development, to stimulate angiogenesis for the treatment of burns, ulcers and corneal incisions and to stimulate embryogenesis.
In accordance with yet a further aspect of the present invention, there is also provided nucleic acid probes comprising nucleic acid molecules of sufficient length to specifically hybridize to nucleic acid sequences of the present invention.
In accordance with yet a further aspect of the present invention, there are provided antibodies against such polypeptides.
In accordance with yet a further aspect of the present invention, there are provided agonists to the polypeptide of the present invention.
In accordance with yet another aspect of the present invention, there are provided antagonists to such polypeptides, which may be used to inhibit the action of such polypeptides, for example, in the treatment of corneal inflammation, neoplasia, for example, tumors and cancers and for psoriasis.
In accordance with still another aspect of the present invention, there are provided diagnostic assays for detecting diseases related to overexpression of the polypeptide of the present invention and mutations in the nucleic acid sequences encoding such polypeptide.
In accordance with yet a further aspect of the present invention, there is provided a process for utilizing such polypeptides, or polynucleotides encoding such polypeptides, for in vitro purposes related to scientific research, synthesis of DNA and manufacture of DNA vectors.
These and other aspects of the present invention should be apparent to those skilled in the art from the teachings herein.