title: Heterogeneous immunoreactivity of frozen human benign and malignant breast lesions to C-MYC and C-Ha-ras cellular oncogenes.
abstract: C-myc and c-Ha-ras oncoprotein expression was studied by immunohistochemistry and gene detection by in situ hybridization on serial frozen sections of 32 breast lesions (19 benign biopsies and 13 infiltrating carcinomas). C-myc protein was expressed in 15/19 benign and 12/13 malignant lesions; c-myc gene was detected in 17/19 benign and 13/13 malignant lesions. Although a higher proportion of benign biopsies (8/9) showed more than 50% of protein-positive cells than malignant specimens, this cannot predict the outcome of a lesion. Conversely, p21 ras protein was expressed only in 2/19 benign lesions and in most cases of grade I to III carcinomas. The c-Ha-ras gene was always detected in a small percentage of cells, in both benign and malignant lesions. The results obtained with atypical hyperplasia, a doubtful proliferating lesion, suggests that p21 c-Ha-ras protein expression is not restricted to breast carcinomas. Although Southern blot is commonly considered as a very sensitive technique for oncogene analysis, no amplification of c-myc and c-Ha-ras gene has been demonstrated either in benign or malignant lesions. The detection, on serial frozen sections, of proteins and DNA of c-myc and c-Ha-ras, showed a possible amplification of the c-myc and c-Ha-ras genes in various benign and malignant lesions.
authors.affiliation: Unité de Morphologie Cellulaire et Tissulaire, Centre Léon Bérard, Lyon, France.
authors.forename: C
authors.initials: C
authors.lastname: Pechoux
authors.forename: Y
authors.initials: Y
authors.lastname: Chardonnet
authors.forename: M C
authors.initials: MC
authors.lastname: Chignol
authors.forename: P
authors.initials: P
authors.lastname: Noël
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001941:Breast Diseases / Q000378:metabolism* / Q000473:pathology; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology; D004273:DNA, Neoplasm / Q000302:isolation & purification*; D005260:Female; D005629:Frozen Sections; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008875:Middle Aged; D009857:Oncogenes; D016271:Proto-Oncogene Proteins c-myc / Q000302:isolation & purification*; D016283:Proto-Oncogene Proteins p21(ras) / Q000302:isolation & purification*; D014407:Tumor Cells, Cultured
chemical_list: D004273:DNA, Neoplasm; D016271:Proto-Oncogene Proteins c-myc; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)