C-erbB2 mRNA expression in human breast tumours: comparison with c-erbB2 DNA amplification and correlation with prognosis.
In this study, we have investigated the expression of the proto-oncogene c-erbB2 in a total of 70 human primary breast tumours. In agreement with other workers, we observed c-erbB2 gene amplification in 17.5% of the tumours studied. In addition, we carried out a comprehensive analysis of c-erbB2 mRNA expression in the tumours using RNase mapping and in situ hybridisation techniques. Our results indicated a more frequent (30%) overexpression of c-erbB2 mRNA, which was associated only with breast carcinomas of a ductal origin. Furthermore, analysis of the c-erbB2 mRNA gene locus in the same tumours demonstrated that enhanced c-erbB2 expression could occur in the presence or absence of gene amplification, suggesting that additional molecular mechanisms may result in overexpression of c-erbB2 mRNA in human mammary tumours. In situ hybridisation showed that elevated levels of c-erbB2 mRNA were specific to malignant cells within the breast tumour. Analysis of the association between c-erbB2 mRNA overexpression and clinicopathological factors revealed a significant correlation with poor tumour grade, but not with steroid receptor status or patient menopausal status. No significant correlation was observed between overexpression of c-erbB2 mRNA and early disease recurrence in our group of patients, although there was a definite trend towards poorer prognosis.
Parkes
H C
HC
Department of Biochemistry, University College, London, UK.
Lillycrop
K
K
Howell
A
A
Craig
R K
RK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000737:chemistry / Q000235:genetics; D004273:DNA, Neoplasm / Q000032:analysis; D066246:ErbB Receptors; D005784:Gene Amplification; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*; D012334:RNA, Neoplasm / Q000032:analysis*
D004273:DNA, Neoplasm; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D066246:ErbB Receptors