Expression of tumour necrosis factor (TNFα) and its receptors in benign and malignant breast tissue

Abstract
As well as having anti‐tumour activity in animal models, TNFα has been implicated in the promotion of tumour invasion and metastasis. Expression and localization of TNFα mRNA and protein has been investigated in a series of benign and malignant breast tissues. TNFα mRNA was expressed in a minority of cells (≤0.5%) in 4/11 cases of benign breast tissue and in a higher proportion of invasive carcinomas (43/49 cases). Expression of TNFα mRNA was focal and confined to the tumour stroma. The presence of TNFα protein was confirmed by immunohistochemistry and again was predominantly stromal. Expression of mRNA and protein localized to infiltrating macrophages defined by the antibody EBM/11 in adjacent sections and using 2‐colour immunofluoresence. Although the average number of macrophages per high‐power field did not vary among invasive carcinomas of different histological type or grade, the number of cells expressing TNFα increased with increasing tumour grade. Immunodetectabfe p75 TNF receptor and to a lesser extent p55 receptor was present on cells of the mononuclear infiltrate and on the endothelium of invasive carcinomas, but not on the tumour cells themselves.

This publication has 20 references indexed in Scilit: