Background:The metallothioneins (MTs) are a group of proteins which, due to their unique structure, fulfil numerous functions in the cell. They participate in growth, differentiation, and reparative processes, protect cells against free radicals, and are responsible for heavy metal homeostasis. Their involvement has been reported in the multidrug resistance to cytostatic drugs. Numerous reports document MT presence in cells of various tumors, including breast cancer. Augmented expression of MTs has been reported in less differentiated tumors. MT expression used to be linked to higher proliferative activity of tumor cells, shorter survival of the patients, and tamoxifen-resistance. The present study aimed at examining the relation between MT expression and the manifestation of proliferation exponents (Ki67, nucleolar organizers – AgNORs) in cells of ductal breast cancer of G2 grade of malignancy.Material/Methods: Reactions were performed to detect MTs (clone E9), Ki67 (clone MIB-1) (immunocytochemistry), and AgNORs (silver impregnation) in paraffin sections of breast cancers in G2 grade originating from 60 females. Results of the reactions were subjected to statistical analysis using Statistica 98 PL software.Results: Statistical analysis (Spearman’s rank correlation) demonstrated no relationships between the studied markers (p>0.05).Conclusions: There is no correlation between metallothionein expression and proliferation and between Ki67 and AgNORs in ductal breast cancers of G2 grade of differentiation.

Keywords: Breast Neoplasms - pathology, Carcinoma, Ductal, Breast - pathology, Cell Division - physiology, Ki-67 Antigen - metabolism, Metallothionein - metabolism, Breast Neoplasms - pathology, Carcinoma, Ductal, Breast - pathology, Cell Division - physiology, Ki-67 Antigen - metabolism, Metallothionein - metabolism