Epidermal growth factor receptors in cancer tissues of esophagus, lung, pancreas, colorectum, breast and stomach

Epidermal growth factor receptor and oestrogen receptors in the non-malignant part of the cancerous breast

Fifty-one samples of non-malignant tissue from four mastectomies were analysed to assess oestrogen receptor (ER) and epidermal growth factor receptor (EGFR) status across the cancerous breast. No significant relationship was found between the presence of EGFR and ER. Eighty-four per cent of these samples were EGFR positive and 29% expressed both receptor types. EGFR and ER expression was not affected by histological sub-group. In contrast, analysis of 44 primary cancers showed, in agreement with the literature, a significant inverse relationship between the presence of ER and EGFR (Fisher's exact test P less than 0.002). The difference between malignant and non-malignant tissue appeared to result from the prevalence of co-expression of EGFR and ER in the non-malignant specimens. This suggests different regulation of receptor expression in malignant and non-malignant tissue.

Preparation of EGF labeled liposomes and their uptake by hepatocytes

The preparation of epidermal growth factor (EGF) bearing liposomes (EGF-liposomes) and their uptake by rat hepatocytes were described. EGF was bound to the liposomal surface by the disulfide bridge linkage using a heterobifunctional cross-linking reagent, N-hydroxysuccinimidyl-3-(2-pyridyl-dithio) propionate. EGF-liposomes were taken up in a significant amount by rat hepatocytes in an EGF receptor mediated manner, and their uptake was dependent on the amount of labeled EGF coupled to the liposomal surface. These results raise the possibility that the EGF-liposomes may be an effective drug carrier to the cells having EGF-receptors like some cancer cells.

Immunohistochemical expression of epidermal growth factor receptor in salivary gland tumours

Immunohistochemical localization of epidermal growth factor receptor (EGFR) in normal salivary glands and tumours (108 cases) was studied using a monoclonal antibody. In the normal salivary glands, EGFR was occasionally detected in ductal segments of intercalated, striated, and excretory ducts, but not in acinar cells. The frequency of positive EGFR staining in salivary gland tumours was not high: pleomorphic adenoma, 33.8%; mucoepidermoid tumour, 25.0%; adenolymphoma, 44.4%; and sialoadenocarcinoma, 66.6%. Pleomorphic adenomas showed positive staining for EGFR on the luminal side of luminal cells and in squamous metaplastic cells of tumour tissue. Some modified myoepithelial cells were also reactive whereas outer spindle tumour cells were unstained. Adenolymphomas regularly exhibited positive EGFR staining in the cell membrane; mucoepidermoid carcinoma displayed positive staining in cell membranes in epidermoid tumour cells and cytoplasmic staining in mucous-secreting tumour cells. Sialocarcinomas revealed cell membrane staining and whole cytoplasmic staining for EGFR. The immunohistochemical localization of EGFR could be classified into two types, one the cell membrane-positive type found in epithelial tumour cells, and the second the cytoplasmic positive type seen in normal ductal cells, the luminal tumour cells of pleomorphic adenomas and mucous-secreting tumour cells.