TGF-α ELISA Kit, Human

BACKGROUND Transforming growth factor alpha (TGF alpha) is a 6 kDa polypeptide mitogen that interacts with the epidermal growth factor receptor and activates its intrinsic tyrosine kinase. The mature 50 amino acid TGF alpha is released from a 159 or 160 amino acid integral membrane glycoprotein precursor, denoted proTGF alpha, via cleavage at both termini by protease with elastase-like specificity.¹ Expression of TGF alpha is most prevalent and abundant in transformed cells and tumors, but also detectable at modest levels in a limited number of normal cells and tissues. In addition, TGF-alpha is transiently expressed in some fetal and adjacent maternal tissues during development. Tthis pattern of expression suggests that the growth factor is involved in several distinct physiological functions.² In many neoplastic cells, proteolytic processing of proTGF alpha is incomplete and/or inefficient, resulting in the preponderance of soluble and/or membrane-bound forms larger than the mature TGF alpha. Moreover, TGF-alpha and the EGF receptor are coexpressed in a number of human and rodent tumors and tumor cell lines--which suggests that TGF-alpha can function as an autocrine or paracrine growth factor.³