EXPRESSION OF THE C-ERBB-4 HER4 PROTEIN AND MESSENGER-RNA IN NORMAL HUMAN FETAL AND ADULT TISSUES AND IN A SURVEY OF 9 SOLID TUMOR TYPES/

The c-erbB-4/HER4 receptor belongs to the family of the type I growth factor receptors. Mouse monoclonal antibodies have been raised to the cytoplasmic domain of the c-erbB-4 receptor and characterized; the ant ibody HFR-1 has been used to determine the pattern of expression of th e c-erbB-4 protein immunohistochemically in formalin-fixed, paraffin-e mbedded adult and fetal tissues, The expression of c-erbB-4 mRNA was d etermined by using S-35-labelled riboprobes and tissue in situ hybridi zation. c-erbB-4 is widely expressed in many adult and fetal tissues, including the lining epithelia of the gastrointestinal, urinary, repro ductive, and respiratory tracts, as well as the skin, skeletal muscle, circulatory, endocrine, and nervous systems. The de, eloping brain an d heart notably express high levels of this receptor. The pattern of c -erbB-4 protein expression is also reported in a survey of common soli d human cancers. Loss of expression was noted in 40-80 per cent of ade nocarcinomas and up to 100 per cent of squamous cell carcinomas, where as overexpression was observed in about 10-20 per cent of adenocarcino mas and astrocytomas. In general, the pattern of c-erbB-4 expression i n normal tissues and cancers suggests that it tends to be associated w ith the differentiated compartment. (C) 1998 John Wiley & Sons, Ltd.