metallothionein and Carcinoma--Ductal--Breast

Myoepithelial cells participate in the development of mammary glands and have been suggested to play a role in the biology of mammary cancer. Recent studies demonstrated in the cells expression and overexpression of metallothionein (MT): a low molecular weight, cystein-rich protein which participates, i.a., in the multidrug resistance to cvtostatic drugs. The present study was aimed at examining the relation between results of immunocytochemical (ICC) detection of MT expression in myoepithelial cells, present in structures of a ductal mammary carcinoma, and survival of the patients. In sections originating from 43 patients with ductal mammary carcinoma ICC reactions were performed to detect MT and to confirm the presence of myoepithelial cells (using antibodies to smooth muscle actin). Survival of the patients was also determined in the course of 7-year observations. Statistical analysis using the Coxe's model did not detect relations between MT expression intensity, in the myoepithelium on one hand and patient survival on the other (chi2=0.003 p=0.96).

Topics: Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Ductal, Breast; Female; Humans; Immunohistochemistry; Metallothionein; Middle Aged; Myoepithelioma; Paraffin Embedding; Survival Analysis

This study was designed to evaluate the changes in promoter CpG islands hypermethylation during breast cancer progression from pre-invasive lesions [flat epithelial atypia (FEA), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS)] to invasive ductal carcinoma (IDC). We performed MethyLight analysis for the methylation status of 57 promoter CpG island loci in 20 IDCs and their paired normal breast tissues. After selecting 15 CpG island loci showing breast cancer-specific DNA methylation, another set of normal breast tissue (n = 10), ADH/FEA (n = 30), DCIS (n = 35), and IDC (n = 30) of the breast were analyzed for these loci. We found six new methylation markers of breast cancer, namely DLEC1, GRIN2B, HOXA1, MT1G, SFRP4, and TMEFF2, in addition to APC, GSTP1, HOXA10, IGF2, RARB, RASSF1A, RUNX3, SCGB3A1 (HIN-1), and SFRP1. The number of methylated genes increased stepwise from normal breast to ADH/FEA and DCIS, while IDC did not differ from DCIS. Methylation levels and frequencies of APC, DLEC1, HOXA1, and RASSF1A promoter CpG islands were significantly higher in ADH/FEA than in normal breast tissue. GRIN2B, GSTP1, HOXA1, RARB, RUNX3, SFRP1, and TMEFF2 showed higher methylation levels and frequencies in DCIS than in ADH/FEA. DICS and IDC did not differ in the methylation levels or frequencies for most CpG island loci except SFRP1 and HOXA10. Our findings showed that promoter CpG island methylation changed significantly in pre-invasive lesions, and was similar in IDC and DCIS, suggesting that CpG island methylation of tumor-related genes is an early event in breast cancer progression.

Topics: Adult; Aged; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Ductal, Breast; Carcinoma, Intraductal, Noninfiltrating; CpG Islands; Disease Progression; DNA Methylation; DNA, Neoplasm; Female; Homeodomain Proteins; Humans; Hyperplasia; Membrane Proteins; Metallothionein; Middle Aged; Neoplasm Proteins; Promoter Regions, Genetic; Proto-Oncogene Proteins; Receptors, N-Methyl-D-Aspartate; Retrospective Studies; Transcription Factors; Tumor Suppressor Proteins

Our study aimed at examining significance of metallothionein (MT) expression in ductal breast cancers by determination of a relationship between expression of MT protein (MT-1/2) and selected prognostic factors, including grade of histological differentiation (G), expression of Ki-67 proliferative antigen, expression of estrogen receptors (ER) and progesterone receptors (PgR) and expression of HER-2 receptor. Material for the studies involved 54 samples of invasive ductal breast cancer, manifesting malignancy grades of G1-G3. In paraffin sections of examined tumours immunohistochemical reactions were performed using specific antibodies directed to MT, Ki-67, ER, PgR or HER-2. Intensity of MT-specific immunohistochemical reactions was measured using the semiquantitative IRS scale of Remmele. Intensity of colour reactions targeted at Ki-67, ER, PgR was evaluated scoring proportions of positive cells, while HER-2-specific reactions were evaluated in the scale of 0-3 points. The lowest level of MT expression was detected in breast cancer cases of G1 malignancy grade (G1 vs G3 p=0.020). A positive correlation between MT and Ki-67 antigen expression (r=0.32, p=0.019) was disclosed. Moreover, MT expression exhibited negative correlations with expression of ER (r=-0.35, p=0.008) and PgR (r=-0.27, p=0.046). No relationships could be detected between expression of MT and expression of HER-2 (r=0.12, p=0.37). The obtained results suggest that MT expression might be helpful in prognostic evaluation of ductal breast cancers.

Topics: Breast Neoplasms; Carcinoma, Ductal, Breast; Female; Humans; Metallothionein; Prognosis

Metallothionein (MT) plays a role in fundamental cellular processes such as proliferation, apoptosis and differentiation. We examined MT expression in women with invasive breast ductal carcinoma who underwent mastectomy/lumpectomy without neo-adjuvant treatment. We showed that MT was over-expressed in 87.9% of breast cancer tissues examined, with the mean percentage of positive cells at 30%. There were two patterns of MT expression: predominantly cytoplasmic in 75.9% and nuclear in 24.1% of MT-positive cases. Higher MT scores were associated with poorer histological grade (p = 0.009) but were independent of age, tumour size and oestrogen receptor status. For patients who were treated with adjuvant chemotherapy (cyclophosphamide/methotrexate/5 fluorouracil- or doxorubicin-based regimes), those with high MT expression had a significantly lower recurrence-free survival (p = 0.048), suggesting a role of MT in predicting disease recurrence. Down-regulation of MT in MCF-7 cells by silencing the MT-2A gene (the most abundantly expressed of the 10 known functional MT isoforms) increased chemosensitivity of the cells to doxorubicin. To examine the mechanisms underlying these clinical data, we used siRNAs to decrease MT-2A mRNA expression and protein expression. In MT down-regulated cells challenged with the IC(50) concentration of doxorubicin, we observed a significant reduction in cell viability. Cell cycle analysis also revealed a corresponding increase in apoptosis in the MT down-regulated cells following doxorubicin exposure, showing that down-regulation of MT increased susceptibility to doxorubicin cytotoxicity. The data suggest that MT could be a potential marker of chemoresistance and a molecular therapeutic target.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents, Hormonal; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Ductal, Breast; Disease-Free Survival; Doxorubicin; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Metallothionein; Middle Aged; Neoplasm Staging; Prognosis; Protein Isoforms; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA, Small Interfering

Breast carcinoma is the most common malignancy in women. Estrogen is an important growth factor for breast tumor that plays an important role in regulating the proliferation and differentiation of normal and malignant mammary epithelial cells. Nuclear morphometry and metallothioneins (MTs) are indicators of proliferation that have been used as predictors of prognosis in many tumors. The present study aimed to study mean nuclear area (MNA) and MT; estrogen receptor (ER) expression in fibroadenoma (FA), ductal carcinoma in situ (DCIS), and infiltrating ductal carcinoma (IDC) of the breast. Also MNA and MT expression will be correlated with histologic grade and ER status in breast carcinoma. Breast tissues from 18 patients with FA, 10 patients with DCIS, and 40 patients with IDC were used in this study. MNA and MT expression; as proliferation markers; were investigated and correlated with ER status. All cases of FA, 7 out of 10 cases (70%) of DCIS and 23 out of 40 cases (57.5%) of IDC were positive for ER. MNA of cancer cells was significantly larger than that of normal and benign breast tissue. A significant direct correlation was found between MNA and histologic grades. MNA of ER-negative carcinomas was significantly larger than that of ER-positive tumors. In normal and benign breast tissue, myoepithelial cells consistently expressed the MT protein. Four out of 10 DCIS cases (40%) and 24 out of 40 cases of IDC cases (60%) were positively stained for MT. MT positivity was directly correlated with histologic grade of IDC. There was a highly significant inverse correlation between MT and ER overexpression. From this study, it is concluded that in invasive ductal carcinoma of the breast, the large MNA and MT overexpression are correlated with histologic grades and ER negativity. Therefore, large MNA and MT overexpression may be possible important indicators for more aggressive and less differentiated breast carcinoma.

Topics: Breast Neoplasms; Carcinoma, Ductal, Breast; Carcinoma, Intraductal, Noninfiltrating; Cell Nucleus; Female; Fibroadenoma; Humans; Immunohistochemistry; Metallothionein; Receptors, Estrogen

Determination of oestrogen receptor alpha (ER) represents at present the most important predictive factor in breast cancers. Data of ours and of other authors suggest that promising predictive/prognostic factors may also include pS2, metallothionein (MT) and CD24. Present study aimed at determining prognostic and predictive value of immunohistochemical determination of ER, pS2, MT, and CD24 expression in sections originating from 104 patients with breast cancer. An univariate and multivariate analysis was performed. Both univariate and multivariate analyses demonstrated that cytoplasmic-membranous expression of CD24 (CD24c-m) represents a strong unfavourable prognostic factor in the entire group and in most of the subgroups of patients. In several subgroups of the patients also a prognostic value was demonstrated of elevated expression of pS2 and of membranous expression of CD24. Our studies demonstrated that all patients with good prognostic factors (higher ER and pS2 expressions, lower MT expression, CD24c-m negativity) survived total period of observation (103 months). The study documented that cytoplasmic-membranous expression of CD24 represented an extremely strong unfavourable prognostic factor in breast cancer. Examination of the entire panel of the studied proteins permitted to select a group of patients of an exceptionally good prognosis.

Topics: Breast Neoplasms; Carcinoma, Ductal, Breast; CD24 Antigen; Cytoplasm; Disease Progression; Disease-Free Survival; Estrogen Receptor alpha; Female; Humans; Immunohistochemistry; Metallothionein; Middle Aged; Multivariate Analysis; Neoplasm Invasiveness; Predictive Value of Tests; Prognosis; Retrospective Studies; Survival Rate; Trefoil Factor-1; Tumor Suppressor Proteins

The generation of proper immune response in the tumor environment seems to be essential in antitumor defense. RCAS1 expression has been shown to participate in the regulation of immune cytotoxic activity, metallothionein participates in the protection of cells against immune mediated apoptosis. Since MT and RCAS1 expression is observed within healthy tumor environment we aimed to focus on the proteins expression in tumor and its healthy adjacent tissue in invasive ductal breast cancer regarding the immune cells presence and activity.. RCAS1, metallothionein, CD3, CD56, CD4, CD25, CD69, CD68 and CD16 antigens expression was assessed by immunohistochemistry in invasive ductal breast cancer. Tissue samples were obtained from 45 patients and were grouped according to the presence of lymph nodes metastases. Two groups were obtained: with and without lymph nodes metastases.. Significant differences were observed in RCAS1 and metallothionein expression in tumor and significant differences in metallothionein expression in healthy stroma regarding the presence of lymph nodes metastases. The significantly higher RCAS1 expression was noticed in tumor in comparison to stroma in patients with the presence of lymph nodes metastases. No such difference was observed in patients without the metastases. Significantly higher metallothionein expression was identified in tumor than in stroma in both groups of patients, with and without lymph nodes metastases. These changes in RCAS1 and metallothionein expression were significantly related with the changes in the number and activity of immune cells.. RCAS1 and metallothionein expression in breast cancer healthy stroma seems to be essential for the coexistence of cytotoxic immune cells and normal epithelial cells. The loss of the ability to compensate the growing cytotoxic immune response in the environment might participate in the development of tumor spread.

Topics: Analysis of Variance; Antigens, CD; Antigens, Neoplasm; Apoptosis; Breast Neoplasms; Carcinoma, Ductal, Breast; Female; Gene Expression Regulation, Neoplastic; Humans; Immune Tolerance; Immunity, Cellular; Lymphatic Metastasis; Mammary Glands, Human; Metallothionein; Statistics, Nonparametric

The primary aims of this study were to examine the expression of metallothionein (MT) in 123 primary invasive breast carcinomas and the in situ components of these carcinomas and to assess the association between MT expression and certain socio-demographic and clinico-pathologic characteristics. MT expression was assessed using immunohistochemical procedures and semi-quantified using an immunoreactivity score.. Results showed that 57.7% of the invasive tumors and 43.3% of the in situ carcinomas in the study were MT-positive. Chi-squared analyses showed that MT expression was significantly higher in the tumors of women categorized as being of 'other' race and of women with tumors of high histological grade.. The results of this study suggest that MT is a biomarker of tumor differentiation and aggressiveness and that MT expression may differ by race.

Topics: Adult; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Ductal, Breast; Carcinoma, Intraductal, Noninfiltrating; Female; Humans; Immunohistochemistry; Maryland; Metallothionein; Middle Aged; Socioeconomic Factors

Elevated expression of the low molecular weight metallothionein (MT) proteins can be found typically in breast cancer cases with less favourable prognosis. The MT gene has been described to be potentially down-regulated by estrogen receptor alpha. The present study is aimed at examining the predictive value of MT expression for results of tamoxifen treatment in breast cancer in relation to steroid receptor status. Sixty patients with primary invasive ductal breast cancers with post-operative tamoxifen treatment were enrolled in the study. In paraffin sections of the studied tumours immmunohistochemical reactions were performed using antibodies directed against MT, estrogen receptors (ER) and progesterone receptors (PgR). Results of the immunohistochemical reactions and of clinical observations were analysed using multivariate progression analysis based on the Cox proportional hazard model. Elevated MT expression was demonstrated to be typical for cases with documented relapse of the disease (P<0.001) or terminated by death (P=0.03). Decreased ER expression was found to be typical for cases of a higher grade (P=0.02) and cases terminated by death (P=0.006). The multivariate analysis showed that elevated MT expression was characteristic for cases with shorter overall survival time (P=0.04). The data showed that MT carried an independent, and also independent from ER status, unfavourable predictive value as far as results of tamoxifen treatment were concerned.

Topics: Age Factors; Analysis of Variance; Antineoplastic Agents, Hormonal; Biomarkers; Breast Neoplasms; Carcinoma, Ductal, Breast; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Metallothionein; Middle Aged; Tamoxifen

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.. 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.. Statistical analysis (Spearman's rank correlation) demonstrated no relationships between the studied markers (p>0.05).. There is no correlation between metallothionein expression and proliferation and between Ki67 and AgNORs in ductal breast cancers of G2 grade of differentiation.

Topics: Breast Neoplasms; Carcinoma, Ductal, Breast; Cell Division; Female; Humans; Immunohistochemistry; Ki-67 Antigen; Metallothionein; Neoplasm Staging

Expression of the hormone-related proteins hsp27, pS2, and also of cathepsin D (CD) and metallothionein (MT) was studied by immunohistochemistry and analyzed against clinical data in breast cancer. Archived material of paraffin-embedded breast carcinoma tissues from a cohort of 134 patients with primary invasive breast cancer was used. Hsp27 and pS2 (>10% of tumor cells stained) were found to be expressed in 63.6% and 37.6% of cases, respectively, and were correlated negatively with grading (P=0.006 and 0.01) and positively with estrogen receptors (ER) (P=0.04 and 0.04). pS2 expression was correlated with lymph node status (P=0.02), tumor size (P=0.01), progesterone receptor (PR) content (P=0.02), hsp27 (P=0.015) and bcl-2 protein (P=0.001). An inverse relationship between pS2 expression and the expression of p53 protein (P=0.005) and proliferation-associated index MIB1 (P<0.0001) was noted. Stromal cathepsin D was positively correlated with tumor grade (P=0.01), PCNA (P=0.007), MIB1 (P=0.001) and p53 (P=0.01), and negatively with ER (P=0.04) and bcl-2 (P<0.0001). MT was correlated positively with stromal CD (P=0.007) and inversely with PgR (P=0.04). Univariate analysis showed CD expression to be a positive prognostic factor for survival (P=0.035), with borderline significance, while MT was more strongly positive (P=0.01). However, none of the proteins studied was found to be related to disease outcome in univariate analysis. Our data show that hsp27, pS2 and stromal CD expression may reflect tumor differentiation and the functional status of ER in breast cancer, but stromal CD and tumor MT expression were the only factors found that may be of limited prognostic value.

Topics: Adult; Aged; Aged, 80 and over; Analysis of Variance; Biomarkers, Tumor; Biopsy, Needle; Breast Neoplasms; Carcinoma, Ductal, Breast; Cathepsin D; Chi-Square Distribution; Cohort Studies; Female; Heat-Shock Proteins; Humans; Immunohistochemistry; Metallothionein; Middle Aged; Neoplasm Invasiveness; Neoplasm Proteins; Probability; Prognosis; Proteins; Sensitivity and Specificity; Survival Analysis; Trefoil Factor-1; Tumor Suppressor Protein p53; Tumor Suppressor Proteins

Metallothioneins (MTs), a group of cysteine-rich proteins with a small molecular mass, are known to have metalloregulatory functions. MT gene expression has been demonstrated to be cell type-specific and differentially regulated (possibly related to their germ layer origin and different functional states). In vitro studies suggest that MT-2A, MT-IE, and MT-1F isoforms may be related to breast cancer. In this study, data on MT-2A, MT-1E, MT-1F mRNA analysis via reverse transcription-polymerase chain reaction in invasive ductal breast cancer tissues and their adjacent benign breast tissues from 27 mastectomies are presented. Expression of mRNA in all the three MT isoforms was detected in both cancerous and adjacent benign breast tissues (with MT-2A mRNA expression being the highest). MT-1F expression was significantly higher in benign breast tissues compared with the breast cancers (P=0.017). In situ hybridization confirmed the expression of MT-2A mRNA in the myoepithelial cells of the breast tissues. Immunohistochemical localization of the MT protein revealed that myoepithelial cells consistently expressed the MT protein, while the cancer cells expressed MT with great variation. Based on our immunohistochemical and mRNA analysis, it is likely that the three MT isoforms are specifically expressed in myoepithelial cells of benign breast tissues and cancer cells of the invasive ductal breast cancer tissues. As MT expression occurs in myoepithelial cells and ductal breast cancer cells, our finding supports the proposition that loss of myoepithelial cells in invasive mammary cancers may be compensated in part by changes in the tumor cells, which may subsequently be the basis for studying the role of MT in breast physiology and carcinogenesis. Differential MT-1F expression in breast myoepithelial cells warrants further study.

Topics: Breast; Breast Neoplasms; Carcinoma, Ductal, Breast; Epithelial Cells; Female; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; In Situ Hybridization; Metallothionein; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Immunohistochemical expression of metallothioneins (MTs), a group of intracellular metal-binding proteins, is well documented in breast cancer. However, there is a paucity of information on the expression of the different MT isoforms in breast cancer tissues. The dichotomous association of MT overexpression with tumour types and progression led us to examine the role of the MT-1F mRNA isoform in breast cancer. We evaluated MT expression in 48 primary invasive ductal breast cancer tissues by immunohistochemistry, and the corresponding MT-1F mRNA expression via a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay. The specificity of the RT-PCR products was confirmed by direct cycle sequencing and restriction enzyme digestion. Immunohistochemical analysis of MT revealed a significantly higher MT expression in histological grade 3 tumours as compared to grade 1 and 2 tumours (p = 0.021). Similarly, MT-1F mRNA expression was found to be significantly higher in grade 3 tumours (p < 0.001). The results suggest that the MT-1F isoform influences histological differentiation in invasive ductal breast cancer. The converse is also true in that the histological grade may determine the level of MT-1F expression in breast cancer.

Topics: Adult; Aged; Aged, 80 and over; Breast Neoplasms; Carcinoma, Ductal, Breast; DNA, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Isomerism; Metallothionein; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Restriction Mapping; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sequence Analysis, DNA

Metallothioneins (MTs) protect the cell against reactive forms of oxygen, ionizing radiation, pharmacological agents and mutagens. Metallothioneins are also responsible for neoplastic cell resistance to cytostatic drugs. The aim of this study was to determine the MT level in cell fractions as well as to determine whether there is any change in the concentration of these proteins in a neoplastic cell, and in which cell fractions this change takes place. The neoplastic tissue examined was histopathologically ductal carcinoma invasive, and the control tissue was mastopathic tissue with proliferated connective and glandular tissue. The level of MTs was determined using cadmium isotope (109Cd). It was determined that there was an increase in MT level in the neoplastic tissue, the highest level being found in the mitochondrial fraction obtained from the control and mastopathic tissues. The greatest changes in MT concentrations in breast carcinoma were observed in the nuclear and cytosol fractions. In the nuclear fraction in the breast carcinoma tissue, the MT level was almost three times that of the control group.

Topics: Adult; Breast Neoplasms; Cadmium Radioisotopes; Carcinoma, Ductal, Breast; Cell Nucleus; Cytosol; Female; Humans; Metallothionein

The aim of this study was to assess the presence and clinical significance of metallothionein (MT) in primary invasive ductal carcinoma of the breast. We investigated 96 cases of routinely fixed and paraffin-embedded primary breast carcinomas with the immunohistochemical method. Positive staining for MT was observed in 52.1% of specimen. In most cases both nuclear and cytoplasmic staining was seen. A statistically significant association was found between MT-positive staining and nuclear grade (p < 0.01). MT-positive cases had a significantly poorer prognosis when compared with the MT-negative cases (p < 0.01). We concluded that the MT expression may be of a prognostic value for primary invasive ductal carcinoma of the breast and is possibly an indicator of more aggressive and less differentiated carcinoma cells.

Topics: Adult; Aged; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Ductal, Breast; Female; Humans; Immunohistochemistry; Metallothionein; Middle Aged; Neoplasm Invasiveness; Prognosis

Metallothioneins (MTs), a group of ubiquitous metalloproteins, comprise isoforms encoded by ten functional genes in humans. Different MT isoforms possibly play different functional roles during development or under various physiological conditions. The MT-1E isoform mRNA has been recently shown to be differentially expressed in oestrogen receptor (OR)-positive and OR-negative breast cancer cell lines. In this study, we evaluated MT-1E mRNA expression via semi-quantitative RT-PCR in 51 primary invasive ductal breast cancer tissues, concurrently with OR-positive and progesterone receptor (PR)-positive MCF7 cells, OR-negative and PR-negative MDA-MB-231 cells and PR-transfected MDA-MB-231 breast cancer cells (ABC28). We demonstrated significantly higher MT-1E mRNA expression in OR-negative compared with OR-positive breast cancer tissues (P = 0.026). MCF7 cells lacked MT-1E mRNA expression, while both OR- and PR-negative MDA-MD-231 cells exhibited a high level of MT-1E mRNA expression. The level of MT-1E mRNA expression in progesterone-treated and -untreated ABC28 cells remained similar as the parental cell line MDA-MB-231-C2 cells. The results suggest that MT-1E may have specific and functional roles in OR-negative invasive ductal breast cancers, possibly mediated via effector genes downstream of the oestrogen receptor, but not through the PR pathway.

Topics: Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Ductal, Breast; DNA Restriction Enzymes; Electrophoresis, Agar Gel; Female; Gene Expression Regulation, Neoplastic; Genetic Markers; Humans; Immunohistochemistry; Isomerism; Metallothionein; Receptors, Estrogen; Receptors, Progesterone; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sensitivity and Specificity; Transfection; Tumor Cells, Cultured

Immunocytochemically detectable MT and p53 have been found more commonly in comedo DCIS of the breast with high-grade cytology. The aim of this study is to confirm these findings and to investigate the relationship between MT and p53 in a single large series of cases of DCIS of the breast. To this end, 127 cases of DCIS were classified histologically according to architecture, cytonuclear differentiation (grade), presence and extent of intraduct necrosis, and using the Van Nuys system. Sections were immunostained for p53 and MT (E9) using established techniques, and the extent and intensity of staining were assessed semi-quantitively. The results confirmed that there was generally more MT and p53 positivity in poorly differentiated (grade 3) DCIS with extensive necrosis and that MT expression was greater in grade 2 lesions than p53 expression. However, overall there was no statistically significant correlation between p53 and MT staining. The results indicate that MT and p53 overexpression may arise from independent mechanisms in early breast neoplasia.

Topics: Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Cell Transformation, Neoplastic; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Metallothionein; Necrosis; Tumor Suppressor Protein p53

Metallothioneins are a family of intracellular metalloproteins that have been thought to be involved in anticancer drug resistance. However, the role of metallothioneins in pancreatic cancer has not been investigated in detail. The immunohistochemical localization of metallothionein was examined in normal human adult pancreas tissue and in 75 pancreatic duct cell carcinomas, using monoclonal anti-metallothionein antibody. Furthermore, in vitro studies on the sensitivity of pancreatic cancer to cisplatin were performed in 10 cases of pancreatic carcinoma. Metallothionein staining was weakly positive in the acinar and islet cells and intralobular ducts but was negative in the large pancreatic ducts. In pancreatic carcinomas, metallothionein staining was diffusely positive in 6 (8%), focally positive in 25 (33%) and negative in 44 (59%) of the 75 pancreatic carcinomas. The expression of metallothioneins in pancreatic tumors was related to metastasis, poor prognosis and poor histological grading (poorer glandular differentiation and nuclear anaplasia). The in vitro study of tumor sensitivity to cisplatin showed no significant correlation between metallothionein expression and resistance to cisplatin. Metallothionein-positive pancreatic carcinoma will be potentially highly malignant or acquire an enhanced ability to produce metallothioneins as the malignant potential increases. The expression of metallothionein could be a prognostic indicator in pancreatic carcinomas.

Topics: Adult; Carcinoma, Ductal, Breast; Humans; Immunohistochemistry; Metallothionein; Pancreas; Pancreatic Neoplasms

Metallothionein (MT) is a low-molecular-weight protein with a high affinity for group II metal ions, especially zinc and copper. MT serves as an intracellular reservoir of these ions, but may also be involved in the detoxification of certain toxic metal ions such as cadmium. In addition, high MT contents might protect tumour cells from alkylating agents and irradiation. The aim of this study was to evaluate the prognostic significance of immunohistochemically detected MT overexpression in patients with primary breast carcinoma: 478 patients with primary breast carcinoma diagnosed during the period 1980-1985 were included. Formalin-fixed and paraffin-embedded tissue was used. Immunoreactivity for MT was found to be independent of the length of formalin fixation if the sections were microwave processed before incubation with the primary antibody. Patients were divided into two groups: those with MT overexpression (more than 10% positive tumour cells) and those with low expression (less than 10% positive tumour cells). MT overexpression was correlated with postmenopausal status, large tumour size, presence of lymph node metastases, high number of mitoses, severe nuclear pleomorphism, high histological grade (poor differentiation), and absence of PgR. In univariate analysis of survival data, MT overexpression was a predictor of poor overall survival in the entire group of patients. In multivariate analysis, MT overexpression failed to be of prognostic significance, whereas classical histopathological parameters such as tumour size, histological grade, and PgR were of independent prognostic significance.

Topics: Analysis of Variance; Breast Neoplasms; Carcinoma, Ductal, Breast; Female; Humans; Immunohistochemistry; Lymphatic Metastasis; Metallothionein; Mitosis; Postmenopause; Prognosis; Receptors, Progesterone; Survival Rate

In a previous study immunocytochemically detectable metallothionein (MT) expression in tumor cells of invasive duct carcinoma of the breast was shown to be associated with a more aggressive behavior and these findings have been subsequently confirmed by others. The aim of this study was to examine the prevalence and significance of MT positivity in preinvasive duct carcinoma in situ (DCIS). Fifty-five specimens of pure screen-detected DCIS were stained immunocytochemically for MT using the antibody E9. The intensity and distribution of MT staining were assessed using a semiquantitative method resulting in intensity distribution (ID) scores allowing duct by duct analysis in relation to architectural and cytological features of the DCIS. In general, myoepithelial cells around benign and malignant structures stained uniformly strongly for MT. Staining in DCIS was analyzed by architecture irrespective of cytology and by nuclear grade irrespective of architecture. The results showed that MT staining was significantly greater in comedo (ducts with necrosis) DCIS (ID = 97) compared with noncomedo (ducts without necrosis) DCIS (ID = 56) (P = .05 by Mann Whitney U statistic) and that low cytological grade (ID = 50) was associated with less MT staining than was high cytological grade (ID = 92) (P = .05 by Mann Whitney U statistic). These observations thus are consistent with the previously observed association between MT positivity and more aggressive behavior in invasive duct carcinoma of the breast.

Topics: Aged; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Humans; Metallothionein; Middle Aged; Neoplasm Proteins

Metallothioneins (MTs) are low-molecular-weight proteins with specific binding for group II metal ions. MTs are involved in the detoxification of metals, but can also play a role in protection of the cell against certain anticancer agents and from damage of irradiation. High expression of MTs in primary breast carcinomas has been found to be associated with poorer prognosis. Expression of MT (MT) was examined immunohistochemically in 160 breast carcinomas and their concomitant lymph node metastases. The immunoreactivity appeared to be independent of the length of fixation when the section was microwaved before incubation with the primary antibody, a monoclonal antibody E-9. The findings were correlated with various histopathological factors, disease-free survival and over-all survival. Patients were divided into two groups, those with MT over-expression (above 10% of positive tumour cells), and those with low MT expression (below 10% positive). MT over-expression was found to be correlated with postmenopausal status and inversely with positive progesterone receptor status (PgR). MT over-expression showed statistically significant correlation with poor over-all survival. No differences in survival were seen between pre- and postmenopausal patients. PgR was in univariate analysis a poor prognostic parameter. In one fourth of the patients, the lymph node metastases showed increased MT expression compared with the primary tumour. These patients had a poorer, but not statistically significant different survival. MT expression was not correlated to chemo- or radiation therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Breast Neoplasms; Carcinoma; Carcinoma, Ductal, Breast; Carcinoma, Lobular; Disease-Free Survival; Female; Gene Expression Regulation, Neoplastic; Humans; Immunoenzyme Techniques; Lymphatic Metastasis; Metallothionein; Neoplasm Proteins; Survival Rate

Metallothioneins (MTs) are a set of low molecular weight proteins with a high binding affinity to metal ions. MT over-expression has been recently demonstrated in invasive ductal carcinoma of the breast with poor clinical prognosis. In the present study, MTs have been immunohistochemically investigated in normal human breast tissue and a variety of benign, pre-invasive, and malignant breast lesions. In normal breast tissue, MTs were present in myoepithelial cells whereas the vast majority of luminal cells were MT negative. In lesions without increased cancer 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 and myoepithelial cells expressed MT. Atypical lobular hyperplasia, lobular 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 apocrine differentiation. In contrast to lobular cancerization, 12/24 ductal in situ carcinomas and 9/20 invasive ductal carcinomas showed MT over-expression. In situ components found within invasive ductal carcinomas usually reflected the MT status of their invasive counterpart. It is concluded from our immunohistochemical results that breast carcinoma cases with MT overexpression arise from lesions which also show MT overexpression. Thus MT expression in carcinomas may be regarded as a genuine feature of the tumour cells and seems not to be related to endogenous or exogenous factors known to induce MT synthesis.

Topics: Breast; Breast Neoplasms; Carcinoid Tumor; Carcinoma; Carcinoma, Ductal, Breast; Epithelial Cells; Epithelium; Female; Fibrocystic Breast Disease; Humans; Immunohistochemistry; Metallothionein; Papilloma, Intraductal; Reference Values; Risk Factors