Epidermal growth factor, transforming growth factor-alpha, and epidermal growth factor receptor content in normal and carcinomatous gastric and colonic tissue.
Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are polypeptides which bind to the EGF receptor (EGFr) and may play a role in cell growth and carcinogenesis. Our study investigated the content of EGF, TGF-alpha, and EGFr in tumors of the stomach and the colon in comparison with the surrounding mucosa. EGF was detected in half of the stomach specimens with concentrations between 1 and 9 ng/g weight irrespective of histology. In the colon no EGF was found in the tumor or normal mucosa. In the stomach normal mucosa contained higher TGF-alpha concentrations (mean 22.4 ng/g) than the tumors (mean 11.8 ng/g), but the difference was not statistically significant because of a wide variation in mucosal values. By contrast, the colon mucosa displayed significantly higher TGF-alpha concentrations than the tumor tissues (33 ng/g versus 12 ng/g; P < 0.01). EGFr content in the gastric mucosa was lower compared to gastric carcinoma (48 fmol/g versus 75 fmol/g) yet not significantly different. In contrast, colorectal tumor specimens disclosed significantly higher concentrations than the mucosal tissues (mean of 155 fmol/g versus 80 fmol/g; P < 0.01). In conclusion, TGF-alpha should not be considered a tumorigenic but a physiological growth factor in the stomach and colon. An elevated EGFr content in colorectal tumors in comparison with the normal mucosa could lead to a growth advantage by an autostimulating mechanism.
Borlinghaus
P
P
Medizinische Klinik II, Klinikum Grosshadern, Ludwig-Maximilians-Universität München.
Wieser
S
S
Lamerz
R
R
D003110:Colonic Neoplasms / Q000737:chemistry*; D004815:Epidermal Growth Factor / Q000032:analysis*; D066246:ErbB Receptors / Q000032:analysis*; D005753:Gastric Mucosa / Q000737:chemistry; D006801:Humans; D007413:Intestinal Mucosa / Q000737:chemistry; D012016:Reference Values; D013274:Stomach Neoplasms / Q000737:chemistry*; D016211:Transforming Growth Factor alpha / Q000032:analysis*
D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D066246:ErbB Receptors