Immunohistochemical study on expression patterns of tumor growth related factors in salivary gland tumors

Kim, Han Seok; Kim, Soung Min; Park, Young Wook

Abstract

OBJECTIVE
Lots of papers have revealed that tumor growth related factors such as EGF, EGFR, c-erbB-2 play an important role in tumorigenesis and proliferation. These factors are found in most tumors of ectodermal origin. But, documentations of tumor growth related factors on salivary gland tumors were rare. Therefore, we determined expressions of tumor growth related factors; PCNA, p53, EGF, EGFR, cerbB2(HER-2), Maspin, DMBT-1, N-Ras in representative salivary gland tumors.
MATERIALS AND METHODS
A few types of salivary tumors were examined by immunohistochemical assays. Each antibody was applied to specimens of tumors. Specimens were composed of 5 pleomorphic adenomas (PA), 3 mucoepidermoid carcinomas (MEC), 2 adenoid cystic carcinomas (ACC) and 2 squamous cell carcinomas (SCC) from 12 patients. One specimen was selected randomly as negative control. For evaluation of staining intensity, each stained sample was divided into 5 grade; no staining, obscure, weak staining, moderate staining, strong staining.
RESULTS
Strong expressions of PCNA were found in all tumors except of PA. EGF was expressed strongly in SCC, ACC sequently. But in both PA and MEC, EGF expression was weak. EGFR and c-erbB-2 expression showed similar patterns in all salivary gland tumor tissues. P53 showed weak expression generally in all salivary gland tumors. DMBT-1 was expressed in SCC rather than in ACC or in MEC. N-Ras showed weak expressions in all salivary gland tumors except of squamous cell carcinoma.
CONCLUSION
Taken together, tumor growth related factors were expressed in salivay tumors as well as mucosal squamous cell carcinoma. Especially EGFR and c-erbB-2 could be candidates as diagnostic markers for estimating clinical grade of salivary gland tumors. But further studies with reliable methods will be needed to confirm the results of this study.