Southern blot analysis showed close similarity of the restriction patterns of the rat c-erbB-2 gene and the rat neu oncogene, suggesting possible involvement of c-erbB-2 in human cancer.
These data suggest that 11p14 allelic loss plays a role in the evolution of human breast cancer, amplification of c-erbB-2 gene is associated with increasing stage of malignancy, and alteration of the c-myc gene in inflammatory breast carcinoma may contribute to the rapid progression of this human tumor subtype.
The occurrence of multiple copies of the c-erbB-2 in a percentage of colon lesions, however, suggests a possible role for this gene in some colon malignancies.
These findings suggest that increased ERBB3 expression, as in the case of epidermal growth factor receptor and ERBB2, may play a role in some human malignancies.
Comparison of erbB-2 overexpression with clinical disease parameters revealed a correlation of this alteration with inflammatory mammary carcinoma (P = 0.042) implying an association of elevated erbB-2 protein levels with enhanced malignancy of the tumor cell in vivo.
Among the neoplasms assayed p185 HER2 was expressed in 46% of primary breast cancers, in 28% of ovarian tumors and in 30% of colon rectum malignancies.
This assay, and the quantitation of shed antigen levels, may have diagnostic or monitoring utility in cancers, such as breast and ovarian, in which the c-erbB-2 protein is overexpressed.
This expression was regarded as baseline activity of the neu gene for the respective tissues and was used as standard for the evaluation of benign and malignant tumors.
The proto-oncogenes c-erbB-2 and epidermal growth factor (EGF) receptor which encode 2 closely homologous transmembrane glycoproteins have been found amplified and/or overexpressed in a range of epithelial malignancies.
The proto-oncogene designated erbB2 or HER2 encodes a 185-kilodalton transmembrane tyrosine kinase (p185erbB2), whose overexpression has been correlated with a poor prognosis in several human malignancies.
In marked contrast, c-erbB-2 proto-oncogene expression was found only in adenocarcinoma cells, and thus can be used as a marker for malignancy in diagnostic respiratory cytopathology.
One hundred seventy-nine primary human gastric tumors not associated with early cancer or noncurative resection were examined immunohistochemically for the expression of c-erbB-2 protein.