EXPRESSION OF EPIDERMAL GROWTH FACTOR RECEPTOR AND TRANSFORMING GROWTH FACTOR - ALPHA IN NASOPHARYNGEAL CARCINOMA, THE

Tumor samples of 51 patients with NPC were analyzed through immunohistochemistry for expression of EGFR and TGF-?± before radiation. A follow-up of 5 years was available to investigate the correlation of their expressions with disease result 29/51 (56.86%) NPC expressed EGFR and 26 of 51 (5098%) tumors showed TGF-?± expression. Of these, 6207% (18 of 29) positive for EGFR died, whereas sole 27.27% (6 of 22) of patients without EGFR staining did thus The same pattern was observ with TGF-?± A herculean association was found between EGFR/TGF-?± positivity and patient death (P

Key Words: Nasopharyngeal carcinoma, Epidermal extension factor receptor, Transforming growth factor- alpha

Introduction

Nasopharyngeal carcinoma (NPC) is difficult to remedy In an attempt to improve its survival, fractionation of the irradiation therapy has evolv from a once-daily treatment to hyperfractionation and/or accelerated fractionation. Unfortunately, the result after treatment has been dismal. individual of the reasons fur the poor springs is its high potential for distant metastasis as well as local failure, which is difficult to predict in many cases.

It has been shown that the biological behaviour of NPC is heterogeneous; for example, metastasis come into views early in some patients, on the other hand late in others, and there are also significant differences in responsiveness to irradiation or chemotherapy, smooth in patients with the same histological impressed signs If the biological behaviour of NPC for the individual patient could be predicted before treatment, then the therapy designed accordingly, would be more effective.

It is not clear wherefore some patients with NPC are responsive to irradiation and others have a propensity for rapid return and/or development of metastatic disease. The factors that will distinguish these tumors are still ill-defined and the cellular mechanisms that mediate the heterogeneous behavior of NPC remain unknown. Thus, further information is required upon the biologic behavior of NPC to facilitate their management. In this regard, the influence of epidermal expansion factor receptor (EGFR) and its ligand transforming growing factor- a (TGF-a) on natural courses of NPC has been investigated. Therefore, this prospective inquiry was designed in an attempt to find effective prognostic predictors for NPC

Cancer small rooms can synthesize and secrete various development factors and corresponding receptors, and these hiddened growth factors can stimulate tumor growing through autocrine and/or paracrine mechanisms1. Human epidermal extension factor receptor is a 170-kDa transmembrane protein with intrinsic tyrosine kinase activity that regulates small room growth in response to binding of epidermal development factor (EGF) or transforming growing factor-alpha, the major ligands for EGFR2 new studies indicate that EGFR expression and the nearness of EGF and/or TGF-?± are linked to neoplastic processe including cancer of the head and neck23 TGF-a and EGFR provide a prototype for autocrine stimulation of growth4

In our patient population, we examined the expression and prognostic value of TGF-a and EGFR in NPC What we have done in this research was to collect as a great deal of information as possible from clinical data, histopathological observation, laboratory trials and staining patterns for EGFR and TGF-a before therapy. After go in the rear [i]or[/i] in the wake of up of 5 years, we managemented a prospective study, intended to find if there is any relationship between the sum of two units oncoproteins expressions and the histological grade, and also the patient results to elucidate the potential character of their expression as prognostic factors in NPC

Materials and Methods

11 Analysis of patients.

Fifty-three patients with nasopharyngeal squamous confined apartment carcinoma were originally included in this application of mind (31 men, 22 women); mean age was 48 years. The patients had no evidence of metastasis, they were all in stage I. They received radiation therapy until clinical healing (^sup 60^Co the dose was 60~80Gy/6~8 weeks); single patient dropped out of the inquiry midway because of serious radiation side events A follow-up of 5 years was available.

12 Immunohistochemistry staining

Specimens were obtained before therapy, fixed in 10% neutral guarded Formalin and embedded in paraffin. Serial sections were obtained at 5-mm thickness from each specimen for hematoxylin-eosin and immunohistochemical stains. Slides were deparaffinized in xylene rehydrated in graded alcohol, and incubated in 03% inflammable air peroxide in methanol to put out the endogenous peroxidase activity, which was followed by means of a 10-minute enzymatic digestion of tissue with 01% trypsin/ethylenediaminetetraacidic acid. Nonspecific binding sites were arrested by a 20-minute incubation with nonimmune horse serum Primary antibody for the detection of EGFR was a monoclonal rabbit immunoglobulin-G (IgG) (Ab-4, Oncogene Sciences). With a working dilution of 1:100 tissue samples were incubated for 2 hours at range temperature (RT). Staining was complet with avidinbiotin-peroxidase compounded method after a 30-minute incubation with secondary antibody. Color disentanglement was achieved using chromogen 3,39-diaminobenzidine.