The over-expression of epidermal growth factor receptor (EGFR) and its ligands, epidermal growth factor (EGF) and transforming growth factor-alpha, is a common feature of epithelial carcinomas and correlates with neoplastic progression.
The EGF-like family of proteins, such as epidermal growth factor (EGF), transforming growth factor alpha (TGFalpha), amphiregulin (AR), betacellulin (BTC), cripto-1 (CR-1), and heregulin (HRG), plays an important role in the pathogenesis of several human carcinomas as autocrine growth factors.
A significantly higher incidence (P < 0.05) of expression of the following was noted; TGF-alpha in the polypoid carcinomas with an adenoma component, and EGF and c-ERBB2 gene product in the carcinomas without an adenoma component.
These studies suggest that TGF-alpha is likely to play a major role in neovascularization of clear cell carcinomas and that the growth factor may be more important in supporting proliferation of granular cell type tumors.
Transforming growth factor-alpha (TGF alpha), a peptide that binds to the epidermal growth factor receptor, is expressed by carcinomas and normal tissues.
The expression of mRNAs for epidermal growth factor (EGF), transforming growth factor alpha(TGF alpha), EGFR, platelet-derived growth factor (PDGF) A and B chain, PDGF receptor (PDGFR), transforming growth factor beta (TGF beta), erbB-2 and estrogen receptor (ER) genes was first examined in 6 human esophageal carcinoma cell lines, 6 xenoplanted and 15 surgically resected esophageal carcinomas.
The percentage of follicular carcinomas and Hürthle cell carcinomas that stained positively for the different oncogenes was as follows and respectively: Pan-ras 8% versus 63%; TGF-alpha 17% versus 63%; TGF-beta 25% versus 88%; IGF-1 17% versus 88%; and N-myc 17% versus 100%.
The fact that the overexpression of transforming growth factor-alpha in NSCLCs has been negatively correlated with patient survival and that most cell lines can be established only from poorly differentiated carcinomas may provide the explanation for a previous report that the capability for cell line establishment constitutes a negative prognostic indicator for patient survival.
The aim of this study was to investigate the expression of epidermal growth factor receptor (EGFR) and transforming growth factor alpha (TGF alpha) in 13 larynx carcinomas and 2 carcinomas of the oral cavity.
Expression of c-sis/platelet-derived growth factor B, insulin-like growth factor I, and transforming growth factor alpha messenger RNAs and their respective receptor messenger RNAs in primary human gastric carcinomas: in vivo studies with in situ hybridization and immunocytochemistry.
Modulation of pro-epidermal growth factor, pro-transforming growth factor alpha and epidermal growth factor receptor gene expression in human renal carcinomas.
These results strongly suggest that EGF and/or TGF-alpha produced by carcinoma cells function as autocrine growth factors for human esophageal carcinomas.
The expression of epidermal growth factor receptor (EGF-R), transforming growth factor alpha (TGF alpha) and the c-myc oncogene was investigated in different specimens of gynecologic carcinomas.
Multi-autocrine loops of the epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), platelet-derived growth factor (PDGF) and TGF beta system are expressed in human gastrointestinal carcinomas.
Although TGF alpha mRNA is associated with transformed cells from the gastro-intestinal tract, the presence of this mRNA at equivalent concentrations in normal mucosa suggests that over-production of TGF alpha is not an essential feature of carcinomas in the gastro-intestinal tract.
Thus far, the types of carcinomas with which abnormal TGF-alpha expression has been associated include liver, gastrointestinal, breast, skin, lung, brain and ovarian cancers.