High levels of c-myc protein in human breast tumours determined by a sensitive ELISA technique.

We have previously examined the expression of (H-ras) oncogene related transcripts (Spandidos and Agnantis: Anticancer Res 4: 269-272, 1984) and also the activation of the H-ras oncogene (Spandidos: Anticancer Res 7: 991-996, 1987) in human malignant breast cancers. Our results revealed overexpression of the H-ras transcripts in malignant compared to normal tissues, while in the same tumour specimens certain point mutations and other genetic changes have been found in the H-ras gene. In this paper we have investigated c-myc oncoprotein expression in the same tumour samples using an ELISA technique (Moore et al: Oncogene Res 2: 65-80, 1989). Elevated c-myc oncoprotein expression was found in all of the tumour specimens compared with normal breast tissues from a patient with no evidence of the disease. A correlation was found between T stage and c-myc expression in both the normal tissue from the resection margin and in the breast tumour specimens. However, no correlation was found between survival and elevated c-myc expression.