Immunohistochemical Study of TGFalpha , EGF and EGF Receptor on the Epithelial Tumors of the Skin

Choi, Kyu Chul; Yoon, Young Kon; Oh, Chang Nam

Abstract

BACKGROUND: Several reports have demonstrated that TGFalpha and EGF are mitogenic for keratinocytes. Whenther its expression on epithelial tumors is a marker of malignancy or signifies an important step in the development of neoplasia is poorly understood. EGF receptors are also present in normal epidermis and epithelial tumors but their physiological roles are not yet understood.
OBJECTIVE
Our purpose was to examine the staining patterns of TGFalpha, EGF and EGF receptors on the npithelial tumors of the skin, and to investigate kinetics of expression of EGF receptors.
METHODS
We performed immunoperoxidase staining(ABC technique) with monoclonal anti-TGFalpha antibody, polyclonal anti-EGF antibody and polyclonal anti-EGF receptor antibody on the formalinfixed, paraffin-embedded tissue specimens of benign, premalignant and malignant skin tumors.
RESULTS
The density of the expression of TGFalpha and EGF was not correlated with the degree of the malignancy of the epithelial tumors and is neither constant in any kind of the tumors. However the infiltrative type of basal cell carcinoma(BCC) is stronger that its solid type on the expression of TGFalpha and EGF. All benign tumors demonstrated a diffuse pattern within tumor lobules. pression of TGFalpha and EGF. All benign tumors demonstrated a diffuse pattern within tumor lobules. Focal TGFalpha immunostaining was seen in three of 10 squamous cell carcinomas(SCC) and four of 10 BCCs. TGFalpha immunostaining was absent from the outermost one to two layers of tumor lobules of all keratoacanthomas. The specimens which increased the expression of TGFalpha and EGF tended to decrease the expression of EGF receptor.
CONCLUSION
These data suggest that the density of immunohistochemical expression of TGFalpha and EGF may be not dependent on the differentiation of tumor cells, and the pattern of immunohistochemical expression of TGFalpha can differentiate SCC from benign tumors such as keratoacanthoma. FGF receptor may be occupied by both of TGFalpha and EGF. With the receptors being occupied, a down regulation of the receptors may occur which results in decreased EGF receptor expression.