IMMUNOHISTOCHEMICAL DEMONSTRATION OF METALLOTHIONEIN IN NORMAL HUMAN BREAST-TISSUE AND BENIGN AND MALIGNANT BREAST-LESIONS

Citation
B. Bier et al., IMMUNOHISTOCHEMICAL DEMONSTRATION OF METALLOTHIONEIN IN NORMAL HUMAN BREAST-TISSUE AND BENIGN AND MALIGNANT BREAST-LESIONS, Breast cancer research and treatment, 30(3), 1994, pp. 213-221
Citations number
45
Categorie Soggetti
Oncology
ISSN journal
01676806
Volume
30
Issue
3
Year of publication
1994
Pages
213 - 221
Database
ISI
SICI code
0167-6806(1994)30:3<213:IDOMIN>2.0.ZU;2-X
Abstract
Metallothioneins (MTs) are a set of low molecular weight proteins with a high binding affinity to metal ions. MT over-expression has been re cently demonstrated in invasive ductal carcinoma of the breast with po or clinical prognosis. In the present study, MTs have been immunohisto chemically investigated in normal human breast tissue and a variety of benign, pre-invasive, and malignant breast lesions. Tn normal breast tissue, MTs were present in myoepithelial cells whereas the vast major ity of luminal cells were MT negative. In lesions without increased ca ncer risk (adenosis and scleradenosis), MT was only immunolocalized in myoepithelial cells. In papillomas, MT was also found exclusively in myoepithelial cells. In most cases of epitheliosis, both the luminal a nd myoepithelial cells expressed MT. Atypical lobular hyperplasia,lobu lar carcinoma in situ, and 13/15 invasive lobular carcinomas showed no MT over-expression. The two invasive lobular carcinomas with MT over- expression were classified as pleomorphic lobular carcinomas with apoc rine differentiation. In contrast to lobular cancerization, 12/24 duct al in situ carcinomas and 9/20 invasive ductal carcinomas showed MT ov er-expression. In situ components found within invasive ductal carcino mas usually reflected the MT status of their invasive counterpart. It is concluded from our immunohistochemical results that breast carcinom a cases with MT overexpression arise from lesions which also show MT o verexpression. Thus MT expression in carcinomas may be regarded as a g enuine feature of the tumour cells and seems not to be related to endo genous or exogenous factors known to induce MT synthesis.