Vimentin and p53 expression on epidermal growth factor receptor-positive, oestrogen receptor-negative breast carcinomas

Vimentin-positive invasive breast carcinoma of no special type: A breast carcinoma with lethal biological characteristics

Vimentin is a stable mesenchymal immunohistochemical marker and is widely recognized as a major marker of mesenchymal tumors. The purpose of the present study was to investigate if the vimentin expression status might serve as a significant predictor of outcomes in patients with invasive breast carcinoma of no special type (IBC-NST) and to investigate, by comprehensive RNA sequencing analyses, the mechanisms involved in the heightened malignant potential of vimentin-positive IBC-NSTs. This study, conducted using the data of 855 patients with IBC-NST, clearly identified vimentin expression status as a very important independent biological parameter for accurately predicting the outcomes in patients with IBC-NST. RNA sequence analyses clearly demonstrated significant upregulation of coding RNAs known to be closely associated with cell proliferation or cellular senescence, and significant downregulation of coding RNAs known to be closely associated with transmembrane transport in vimentin-positive IBC-NSTs. We conclude that vimentin-positive IBC-NSTs show heightened malignant biological characteristics, possibly attributable to the upregulation of RNAs closely associated with proliferative activity and cellular senescence, and downregulation of RNAs closely associated with transmembrane transport in IBC-NSTs.

Measuring and Modelling the Epithelial- Mesenchymal Hybrid State in Cancer: Clinical Implications

The epithelial-mesenchymal (E/M) hybrid state has emerged as an important mediator of elements of cancer progression, facilitated by epithelial mesenchymal plasticity (EMP). We review here evidence for the presence, prognostic significance, and therapeutic potential of the E/M hybrid state in carcinoma. We further assess modelling predictions and validation studies to demonstrate stabilised E/M hybrid states along the spectrum of EMP, as well as computational approaches for characterising and quantifying EMP phenotypes, with particular attention to the emerging realm of single-cell approaches through RNA sequencing and protein-based techniques.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Immunohistochemical Distribution of Mucinous-like Carcinoma Associated Antigen (MCA) in Breast and Non-breast Cancer: Comparison with other Biological Parameters

The present study reports the immunohistochemical reactivity of the monoclonal antibody b-12 (MAb b-12) with malignant human tissues. 173 neoplastic tissues were tested: MAb b-12 stained all breast carcinomas independently of their histology, with different patterns within the various type of cancer. Some other carcinomas (stomach, bowel, ovary, lung, endometrium), were also reactive even if the fraction of positive cells was lower.

A comparison between the histological localization of MCA and that of CEA was performed; anti-CEA antibodies stained the cancer tissues with different reactivity and showed different percentages of positivity. MCA expression was also compared with other biological parameters such as the presence of estrogen receptors (ER), progesterone receptors (PgR), epithelial growth factor receptors (EGF-R), and oncoprotein p-53 which is encoded by the oncogene N-myc. The proliferative activity was also evaluated by measuring the growth fraction (GF) using the antibody Ki67. Any correlation was demonstrated between MCA and these parameters except for growth fraction as revealed by Ki67 antibody.

Epigenetic regulation of ZEB1-RAB25/ESRP1 axis plays a critical role in phenylbutyrate treatment-resistant breast cancer

Phenylbutyrate (PB) is a histone deacetylase antagonist that also exhibits antitumor activity. In this study, we used 7 breast cancer cell lines to identify biomarker candidates that predict PB sensitivity in breast cancer.

Comprehensive gene expression profiles were compared using microarrays, and the importance of the identified genes to PB sensitivity was confirmed in gene transfection experiments. CRL and MDAMB453 cells were identified as PB-sensitive, while MDAMB231 cells were PB-resistant.RAB25 and ESRP1 were identified as key regulators of PB sensitivity, while ANKD1, ETS1, PTRF, IFI16 and KIAA1199 acted as PB resistance-related genes. Expression of these genes was dramatically altered by DNA demethylation treatments. RAB25 expression inhibited IFI16 and PTRF, while ESRP1 expression suppressed ANKRD1, ETS1, and KIAA1199. Both RAB25 and ESRP1 were suppressed by ZEB1, which was in turn regulated via epigenetic mechanisms. Thus, PB sensitivity is influenced by epigenetic expression alteration of ZEB1. The genes associated with PB sensitivity are downstream targets of ZEB1. Epigenetic regulation of ZEB1 may prove valuable as a critical biomarker for predicting resistance to breast cancer therapies.

Clinical significance of vimentin expression and Her-2 status in patients with gastric carcinoma

OBJECTIVES

To determine whether vimentin could be used as a marker of gastric carcinomas with more aggressive behavior. To detect the extent of Her-2 status in gastric carcinoma and explore the correlation between vimentin expression and Her-2 status.

METHODS

Vimentin expression was detected in surgically resected gastric carcinoma tissue specimens from 143 patients by immunohistochemistry. The human epidermal growth factor receptor 2 (Her2) status was evaluated by fluorescence in situ hybridization (FISH). Correlations between vimentin expression, Her-2 status and clinicopathological factors were evaluated using Kaplan-Meier method and Cox multivariate survival models.

RESULTS

Vimentin expression was significantly correlated with age, advanced stage, poorly differentiated type, venous invasion, hepatic metastasis, and recurrence (p < 0.05). Her-2 gene was amplified in 16 (11.2%) out of the 143 gastric carcinoma tissue specimens. Her-2 status was correlated with advanced cancer, poor differentiation, venous invasion, hepatic metastasis, and recurrence (p < 0.05). The result of multivariate analysis showed that vimentin expression and lymph node metastasis were independent prognostic factors.

CONCLUSIONS

Vimentin expression in epithelial cells of the surgically resected gastric adenocarcinoma tissue is an independent predictor of short survival, and Her-2 status shows a valuable correlation with clinical parameters.

A comprehensive morphological study for basal-like breast carcinomas with comparison to nonbasal-like carcinomas

Background

Breast carcinomas can be classified into five subtypes based on gene expression profiling or immunohistochemical characteristics. Among these subtypes, basal-like breast carcinomas (BLBCs) are one of the most studied group, due to their poor prognosis. The aim of this study was to investigate the prevalance, morphological and immunohistochemical features of BLBCs, in Turkish population.

Methods

Five hundred invasive breast carcinomas were reviewed for several morphological features and immunostained for oestrogen and progesterone receptors, c-ERB-B2, cytokeratin5/6, cytokeratin14, vimentin and epidermal growth factor receptor (EGFR). Basal-like breast carcinoma was defined as a triple negative tumor with cytokeratin5/6 and/or EGFR positive.

Results

The prevalance of BLBC was 9.6%. All medullary carcinomas and 55.6% of metaplastic carcinomas showed basal-like immunophenotype. Patients with BLBC were younger (p=0.04) and had higher-grade tumors (p<0.0001). Morphologic features associated with BLBC included increased mitosis, nuclear pleomorphism, presence of geographic and/or central necrosis, pushing margin of invasion and stromal lymphocytic response (p<0.0001). Presence of prominent nucleoli and vesicular nuclear chromatin were the cytological features correlated with basal-like phenotype (p<0.0001). On multivariate analyses, BLBCs were associated with high mitotic number (p<0.0001), the presence of vesicular chromatin (p=0.004), high tubular grade (p=0.011), lymphocytic response (p=0.031) and the absence of carcinoma insitu (p=0.039). Vimentin was positive in 53.2% of BLBCs, while cytokeratin14 was less frequently expressed (27.7%).

Conclusions

BLBCs have some distinctive, but not pathognomonical, morphological features. Paying attention to these features and adding cytokeratin14 and vimentin to the immunohistochemical panel can help the definitive diagnosis of BLBCs.

Virtual slide

Http://www.diagnosticpathology.diagnomx.eu/vs/5962175467857400

Antiestrogen therapy is active in selected ovarian cancer cases: the use of letrozole in estrogen receptor-positive patients

PURPOSE

To evaluate the efficacy of the aromatase inhibitor letrozole in preselected estrogen receptor (ER)-positive relapsed epithelial ovarian cancer patients and to identify markers that predict endocrine-sensitive disease.

EXPERIMENTAL DESIGN

This was a phase II study of letrozole 2.5 mg daily until clinical or marker evidence of disease progression in previously treated ER-positive ovarian cancer patients with a rising CA125 that had progressed according to Rustin's criteria. The primary end point was response according to CA125 and response evaluation criteria in solid tumors (RECIST) criteria. Marker expression was measured by semiquantitative immunohistochemistry in sections from the primary tumor.

RESULTS

Of 42 patients evaluable for CA125 response, 7 (17%) had a response (decrease of >50%), and 11 (26%) patients had not progressed (doubling of CA125) following 6 months on treatment. The median time taken to achieve the CA125 nadir was 13 weeks (range 10-36). Of 33 patients evaluable for radiological response, 3 (9%) had a partial remission, and 14 (42%) had stable disease at 12 weeks. Eleven patients (26%) had a PFS of >6 months. Subgroup analysis according to ER revealed CA125 response rates of 0% (immunoscore, 150-199), 12% (200-249), and 33% (250-300); P = 0.028, chi(2) for trend. Expression levels of HER2, insulin-like growth factor binding protein 5, trefoil factor 1, and vimentin were associated with CA125 changes on treatment.

CONCLUSIONS

This is the first study of a hormonal agent in a preselected group of ER-positive ovarian cancer patients. A signature of predictive markers, including low HER2 expression, predicts response.

Isogenic normal basal and luminal mammary epithelial isolated by a novel method show a differential response to ionizing radiation

Epithelial cells within the normal breast duct seem to be the primary target for neoplastic transformation events that eventually produce breast cancer. Normal epithelial cells are easily isolated and propagated using standard techniques. However, these techniques almost invariably result in populations of cells that are largely basal in character. Because only approximately 20% of human breast cancers exhibit a basal phenotype, our understanding of the disease may be skewed by using these cells as the primary comparator to cancer. Further, because germ line mutations in BRCA1 yield breast cancers that are most often of the basal type, a comparison of normal basal and luminal cells could yield insight into the tissue and cell type specificity of this hereditary cancer susceptibility gene. In this report, we describe a simplified and efficient method for isolating basal and luminal cells from normal human breast tissue. These isogenic cells can be independently propagated and maintain phenotypic markers consistent with their respective lineages. Using these cultured cells, we show that basal and luminal cells exhibit distinct responses to ionizing radiation. Basal cells undergo a rapid but labile cell cycle arrest, whereas luminal cells show a much more durable arrest, primarily at the G(2)-M boundary. Molecular markers, including p53 protein accumulation, p53-activated genes, and BRCA1 nuclear focus formation all correlate with the respective cell cycle responses. Further, we show that short-term cultures of human breast tissue fragments treated with ionizing radiation show a similar phenomenon as indicated by the biphasic accumulation of p53 protein in the basal versus luminal layer. Together, these results indicate that normal basal cells have a transitory cell cycle arrest after DNA damage that may underlie their increased susceptibility to transformation after the loss of functional BRCA1.

A collection of breast cancer cell lines for the study of functionally distinct cancer subtypes

Recent studies suggest that thousands of genes may contribute to breast cancer pathophysiologies when deregulated by genomic or epigenomic events. Here, we describe a model "system" to appraise the functional contributions of these genes to breast cancer subsets. In general, the recurrent genomic and transcriptional characteristics of 51 breast cancer cell lines mirror those of 145 primary breast tumors, although some significant differences are documented. The cell lines that comprise the system also exhibit the substantial genomic, transcriptional, and biological heterogeneity found in primary tumors. We show, using Trastuzumab (Herceptin) monotherapy as an example, that the system can be used to identify molecular features that predict or indicate response to targeted therapies or other physiological perturbations.

Basal phenotype of ductal carcinoma in situ: recognition and immunohistologic profile

The basal phenotype of breast carcinoma was demonstrated from a study of gene expression profiles, which demonstrated five carcinoma phenotypes with differing immunohistologic profiles and outcomes. The basal phenotype, so-named because of an immunohistologic profile that is similar to myoepithelial cells of the breast, has poor outcomes. While the invasive basal phenotype has been described, there is a paucity of literature regarding the existence or recognition of a precursor lesion. We searched our CoPath database for breast carcinomas in the age group of 37 years or less, and this yielded 98 cases from the years 2001 to April 2006. Pathology reports were screened for those cases that were negative for estrogen and progesterone receptors and HER-2/neu (triple negative). A total of 16 cases (16/98, 16%) fulfilled these criteria. Histology was reviewed and immunostains were performed for Cytokeratins 14, 17, and 5/6, vimentin, EGFR, c-kit, smooth muscle actin and p63. All 16 cases had a high-grade invasive ductal carcinoma, Nottingham score 9/9, with geographic necrosis, good circumscription and lymphoid infiltrates. Of the 16 cases, 13 exhibited at least one area of ductal carcinoma in situ (DCIS). The DCIS types were solid, flat or micropapillary, high nuclear grade, with comedonecrosis and invariably associated with intense lymphoid inflammatory cell infiltration. Of 16 invasive cases, 14 (88%) were positive for CK14, CK17, CK5/6 and EGFR; 94% were vimentin positive, while half or less of cases were positive for smooth muscle actin, c-kit or p63. All of the DCIS components demonstrated the same immunohistologic profile as the invasive component. A DCIS component of solid, flat or micropapillary type exists in the basal phenotype of breast carcinoma, and it demonstrates the same immunophenotype as the invasive carcinoma, typically positive for CK5/6, CK14, CK17, vimentin and EGFR, but negative for ER/PR and HER-2/neu.

Phenotypic evaluation of the basal-like subtype of invasive breast carcinoma

Microarray profiling of invasive breast carcinomas has identified five distinct subtypes of tumors (luminal A, luminal B, normal breast-like, HER2 overexpressing, and basal-like) that are associated with different clinical outcomes. The basal-like subtype is associated with poor clinical outcomes and is the subtype observed in BRCA1-related breast cancers. The aim of this study was to characterize the histologic and immunophenotypic properties of breast basal-like carcinomas that were first positively identified using DNA microarray analysis. Detailed histologic review was performed on 56 tumors with known microarray profiles (23 basal-like, 23 luminal, and 12 HER2+). Immunohistochemistry for estrogen receptor (ER), HER2, EGFR, smooth muscle actin (SMA), p63, CD10, cytokeratin 5/6, cytokeratin 8/18, and vimentin was performed on 18 basal-like, 16 luminal, and 12 HER2+ tumors. The basal-like tumors were grade 3 ductal/NOS (21/23) or metaplastic (2/23) carcinomas that frequently showed geographic necrosis (17/23), a pushing border of invasion (14/23), and a stromal lymphocytic response (13/23). Most basal-like tumors showed immunoreactivity for vimentin (17/18), luminal cytokeratin 8/18 (15/18), EGFR (13/18), and cytokeratin 5/6 (11/18), while positivity for the myoepithelial markers SMA (4/18), p63 (4/18) and CD10 (2/18) was infrequent. All basal-like tumors tested were ER- and HER2-. Morphologic features significantly associated with the basal-like subtype included markedly elevated mitotic count (P<0.0001), geographic tumor necrosis (P=0.0003), pushing margin of invasion (P=0.0001), and stromal lymphocytic response (P=0.01). The most consistent immunophenotype seen in the basal-like tumors was negativity for ER and HER2, and positivity for vimentin, EGFR, cytokeratin 8/18, and cytokeratin 5/6. The infrequent expression of myoepithelial markers in basal-like carcinomas does not support a direct myoepithelial cell derivation of these tumors. These findings should further assist in the identification of basal-like carcinomas in clinical specimens, facilitating treatment and epidemiologic studies of this tumor subtype.

Breast cell invasive potential relates to the myoepithelial phenotype

On the basis of marker profile, the majority of breast carcinomas are thought to be derived from luminal epithelial cells; however, a subgroup of tumours with more mesenchymal characteristics are associated with a worse prognosis. The hypothesis of our study is that some breast carcinomas exhibit myoepithelial rather than pure mesenchymal differentiation and that acquisition of myoepithelial characteristics confers an aggressive phenotype. Pure luminal epithelial cells and fibroblasts are readily distinguished by many markers but distinguishing between myoepithelial and fibroblast cell lineages is more problematic. The markers found to be most discriminating in our study were CK14, alpha6beta4 integrin and the myoepithelial-associated desmosomal cadherin DSg3. These markers were applied to a series of breast cell lines and purified normal breast cell populations and the expression profile related to in vitro invasive behaviour. This demonstrated that expression of one or more myoepithelial markers by tumour cells (MDA MB 231, MDA MB 468, MDA MB 436) was associated with a high invasive capacity compared with cells with a pure luminal phenotype (MCF-7, T47D, ZR75). To address why myoepithelial characteristics are associated with higher invasion, the in vitro behaviour of normal myoepithelial cells and two other nontumourigenic breast cell lines (MCF-10A, HBL100) was also analysed. Primary myoepithelial cells from normal human breast exhibit a high invasive capacity when grown at low density, suggesting that invasive capacity is part of the myoepithelial phenotype. In keeping with this, both nontumourigenic cell lines exhibited features of the myoepithelial phenotype and a high invasive capacity. These results suggest that tumours that exhibit a myoepithelial phenotype may be clinically more aggressive because a high invasive capacity is intrinsic to the myoepithelial phenotype.

p53 mutation in breast cancer. Correlation with cell kinetics and cell of origin

AIM

Several studies have investigated the expression of the cytokeratins (CKs), vimentin, the epithelial growth factor receptor (EGFR), the oestrogen receptor (ER), and the progesterone receptor (PgR), in breast cancer, but no study has directly compared p53 mutations with these phenotypic and differentiation markers in the same case. The present study was designed to provide some of this information.

METHODS

The expression of the p53 and bcl-2 proteins was evaluated by immunohistochemistry in relation to phenotypic characteristics and cellular kinetic parameters (mitotic index and apoptotic index) in 37 cases of ductal carcinoma in situ (DCIS) and 27 cases of infiltrating ductal carcinoma (IDC) of the breast. In addition, p53 gene mutation was examined by polymerase chain reaction single strand conformation polymorphism analysis (SSCP).

RESULTS

Thirteen cases (eight DCIS and five IDC) showed expression of CK8, CK14, CK18, vimentin, and EGFR, consistent with a stem cell phenotype, whereas 44 cases (27 DCIS and 17 IDC) showed expression of CK8 and CK1, weak or negative expression of CK18, but were negative for vimentin and EGFR, consistent with a luminal cell phenotype. DCIS and IDC cases with a stem cell phenotype were ER/PgR negative and intermediately or poorly differentiated. In contrast, the cases with luminal cell phenotype were ER/PgR positive and well or intermediately differentiated. In addition, intermediately or poorly differentiated cases with a stem cell phenotype showed higher proliferative activity (per cent of MIB-l positive cells) than did intermediately or well differentiated cases with a luminal cell phenotype. Both DCIS and IDC cases with a stem cell phenotype were p53 positive and bcl-2 negative by immunohistochemistry. In IDC, p53 expression was associated with a reduction of both mitotic index and apoptotic index compared with DCIS. Most of the tumours showing a more differentiated phenotype (luminal) were p53 negative and bcl-2 positive. In these cases, cell kinetic parameters increased from DCIS to IDC. These data suggest the existence of subsets of DCIS and IDC that, because of their phenotypic characteristics, could be derived from subpopulations of normal breast cells having different control mechanisms of cell proliferation and neoplastic progression.

CONCLUSIONS

These results are compatible with the hypothesis that the phenotype of the cell of origin constrains both tumour phenotype and the choice of genetic events; however, the occurrence of p53 mutants by chance during neoplastic transformation cannot be excluded.

Computerized image analysis of p53 and proliferating cell nuclear antigen expression in benign, hyperplastic, and malignant endometrium

CONTEXT

The endometrium is an intrinsically dynamic tissue with great capability for regeneration and proliferation; consequently, there is some overlap between features seen in benign, premalignant, and malignant lesions. This leads to marked intrabiopsy, interbiopsy, and interobserver variability.

OBJECTIVE

We studied the specificity and sensitivity of computerized image analysis of molecular markers to evaluate its potential use as a diagnostic tool.

DESIGN

Specimens from 100 patients were examined and the following histologic diagnoses were assigned: proliferative endometrium (n = 10), secretory endometrium (n = 10), endometrial hyperplasia (n = 40; 30 with no atypia, 10 with atypia), and carcinoma (n = 40; 20 endometrioid, 10 serous, and 10 clear cell). All cases were evaluated immunohistochemically for p53 and proliferating cell nuclear antigen (PCNA) expression. Computerized image analysis was performed with a CAS 200 digital analyzer.

RESULTS

Expression of p53 was found only in carcinomas (65%) and endometrial hyperplasia with atypia (30%). Expression of p53 was higher in the poor prognostic categories (serous carcinoma and clear cell carcinoma) than in endometrioid carcinoma. In endometrioid carcinoma, p53 expression correlated with grade. Proliferating cell nuclear antigen showed a similar pattern of results to p53 in the various carcinoma subtypes and endometrioid carcinoma grades. Endometrial hyperplasia PCNA values were the lowest among all the groups. Both carcinomas and proliferative endometrium showed higher glandular and stromal PCNA values, significantly different from endometrial hyperplasia with atypia. In proliferative endometrium, stromal PCNA was the highest among all of the groups. The p53 and PCNA results correlated with each other for carcinoma.

CONCLUSIONS

Computerized image analysis correlates well with the established morphologic groups of endometrial pathology and yields results consistent with previous studies. Owing to its higher degree of sensitivity, computerized image analysis is of potential use in cases of diagnostic dilemmas and can help objectively allocate the case in the correct category (e.g., proliferative endometrium vs. endometrial hyperplasia, endometrial hyperplasia with atypia vs. endometrioid carcinoma). It is particularly useful in the evaluation of stromal changes.

SUM-159PT cells: a novel estrogen independent human breast cancer model system

Breast cancer remains one of the most common malignant diseases in women in North America and Western Europe, yet therapies for the more aggressive estrogen independent tumors are limited and few model systems are available for the study of this type of breast cancer. In these studies, we characterized a novel estrogen independent breast cancer cell line, SUM-159PT. SUM-159PT cells are epithelial in origin, demonstrated by expression of cytokeratin 18. SUM-159PT cells are estrogen independent, demonstrated by lack of estrogen receptor (ER) protein and ER ligand binding studies. Furthermore, SUM-159PT cells injected subcutaneously or orthotopically are tumorigenic in ovariectomized athymic nude mice in the absence of estradiol supplementation. SUM-159PT cells are capable of invading through an 8 microm Matrigel membrane and display a stellate morphology in Matrigel, indicative of a metastatic phenotype. Correlating with this phenotype, we have detected secondary tumors upon inoculation of SUM-159PT cells into the mammary fat pad. To further investigate the metastatic potential of the SUM-159PT cells, we examined the expression of two proteins, vimentin and E-cadherin, implicated in the transition of carcinoma cells to a metastatic phenotype. Western blot and immunohistochemical analysis demonstrated that both SUM-159PT cells and xenografts express vimentin. No expression of E-cadherin was detected in SUM-159PT cells. Our data indicate that despite estrogen independence, SUM-159PT cells are growth inhibited in vitro by compounds such as 1,25(OH)2D3, transforming growth factor beta (TGF-beta), and the phorbol ester TPA. These studies indicate that SUM-159PT cells represent a good model system for the study of late stage estrogen independent, invasive breast cancer.

The development of epithelial phenotypes in the human fetal and infant breast

In order to explain the molecular events that contribute to benign and malignant breast disease, it is essential to understand the cellular context in which these are occurring. This study describes a detailed analysis of the epithelial phenotypes in the human fetal and infant breast and provides a starting point for such consideration. Using methacarn-fixed, paraffin sections from ten fetal and 45 infant breast, immunostained with a panel of antibodies to cytoskeletal proteins and kappa-casein, it has been possible to define in detail the chronological evolution of the major cell types in the human breast from 16 weeks of intrauterine life to 2 years of age, in both sexes. Cells at the tips of the lobular buds and terminal end buds have a characteristic cytoskeletal protein profile, suggesting that they may have the capacity to generate both basal cells and luminal cells. Based on the expression of cytoskeletal proteins in the developing fetal and infant breast, a model system has been proposed for mammary epithelial differentiation.

Role of intermediate filaments in migration, invasion and metastasis

The expression of intermediate filament proteins is remarkably tissue-specific which suggests that the intermediate filament (IF) type(s) present in cells is somehow related to their biological function. However, in some cancers-particularly malignant melanoma and breast carcinoma, there is a strong indication that vimentin and keratin IFs are coexpressed, thus presenting as a dedifferentiated or interconverted (between epithelial and mesenchymal) phenotype. In this review, two in vitro models are presented which recapitulate the interconverted phenotype in human melanoma and breast carcinoma, and allow, for the first time, unique observations to be made with respect to the role of IFs in cancer progression. These studies have provided direct evidence linking overexpression of keratin IFs in human melanoma with increased migratory and invasive activity in vitro, which can be down-regulated by substituting dominant-negative keratin mutants. Overexpression of vimentin IFs in the breast carcinoma model leads to augmentation of motility and invasiveness in vitro, which can be transiently down-regulated by treatment with antisense oligonucleotides to vimentin. Additional experimental evidence suggests that the mechanism(s) responsible for the differential expression of metastatic properties associated with the interconverted phenotype rest(s) in the unique interaction, either direct or indirect, of IFs with specific integrins interacting with the extracellular matrix. In this review, we discuss the observations derived from the human melanoma and breast carcinoma models to address the hypothesis that the ability to coexpress vimentin and keratins confers a selective advantage to tumor cells in their interpretation of and response to signaling cues from the extracellular matrix. The ramifications of these observations are discussed with respect to the patholophysiology of the respective in situ tumors.

Vimentin expression in cervical carcinomas: association with invasive and migratory potential

Vimentin is an intermediate filament protein normally expressed in mesenchymal cells, but evidence is accumulating in the literature which suggests that the aberrant expression of vimentin in epithelial cancer cells might be related to local invasiveness and metastatic potential. Vimentin expression has previously been associated with invasive properties in an in vitro model consisting of a set of HPV-33-transformed cervical keratinocyte cell lines. In the present study, in order to emphasize those in vitro findings, the expression of vimentin has been investigated in cervical neoplasms of different grades, using immunohistochemistry. A clear association is reported between vimentin expression and metastatic progression, since vimentin was detected in all invasive carcinomas and lymph node metastases, but not in CIN III lesions. These in vivo results are compared with present and previous data obtained in vitro on cervical keratinocyte cell lines, where vimentin expression also correlated with in vitro invasiveness.

Differentiation pathways in primary invasive breast carcinoma as suggested by intermediate filament and biopathological marker expression

The expression of intermediate filament proteins (IFPs) in 65 primary breast carcinomas was analysed by a panel of specific antibodies. Results were integrated with the oestrogen and progesterone receptor (ER and PGR) status, Ki-67 marking, and epidermal growth factor receptor (EGFr) expression. Invasive breast carcinomas could be divided into three main groups: group 1 revealed positivity only for 'simple epithelial' cytokeratins (CKs 7, 8, 18, and 19); group 2 also stained with the antibodies K8.12 and 34 beta E12; while group 3 showed co-expression of CKs 14 and 17, vimentin, and alpha-smooth muscle actin. Group 3 consistently comprised tumours with the highest Ki-67 levels, EGFr positivity, and ER-PGR negative status. On the other hand, groups 1 and 2 usually exhibited a positive hormonal status, lower proliferative activity, and EGFr negativity. The results of this study indicate that the determination of IFPs can significantly contribute to the identification of groups of patients with different biopathological settings and possibly different clinical behaviour.

Vimentin expression is not associated with poor prognosis in breast cancer

The clinical significance of vimentin intermediate filament (VIF) expression was studied in relation to other established prognostic parameters in primary breast cancer. Archival tumour samples embedded in paraffin were examined by immuno-histochemistry with monoclonal antibodies (MAbs) to VIF, p53 protein and cell proliferation marker MIB-I. The vimentin staining pattern was heterogeneous, but in vimentin-positive areas > 80% of the tumour cells were positive. There was no association between vimentin expression and tumour size or the number of axillary lymph nodes involved. Vimentin expression was significantly associated with high-grade tumours, absence of hormone receptors, increased p53 expression and high tumour proliferation fraction as estimated by MIB-I count. Despite these associations with several recognised features of tumour aggressiveness, vimentin expression was not associated with increase in risk of relapse or death from breast cancer.

Node negative breast carcinoma: hyperprolactinemia and/or overexpression of p53 as an independent predictor of poor prognosis compared to newer and established prognosticators

The purpose of this study was to investigate a prognostic indicator that can differentiate node negative breast cancer patients (N = 39, T2N0M0) with high risk and low risk for the development of recurrence or metastases. Preoperative plasma prolactin (PRL) was estimated by radioimmunoassay. The expression of PRL, p53, nm23, and c-erbB2 was investigated by immunohistochemical (IHC) localization; cathepsin D (CD, Enzyme Linked Sorbant Assay) and estrogen- and progesterone-receptors (ER and PR, Dextran coated charcoal method) were estimated in the tumor cytosols. The follow-up period was 2-6 years. Statistical comparisons were made between each marker for relapse-free survival (RFS) and overall survival (OS). Of the 39 patients, 18 had hyperprolactinemia (PRL > 20.0 ng/ml plasma), whereas overexpression of p53 was observed in 55% (17/31) tumors. These were independently and in combination associated with a reduced RFS and OS. The rest of the investigated markers did not show promising results. Hyperprolactinemia and/or overexpression of p53 were associated with aggressiveness of the tumor, early disease relapse or metastases, and poor OS in patients with node negative breast cancer. These two markers may enhance our ability to identify node negative breast cancer patients with aggressive tumors, for whom the use of adjuvant chemo and/or endocrine therapy is unequivocally justified.

p53 protein expression in fine-needle aspirates of breast cancer: an immunocytochemical assay for identifying high-grade ductal carcinomas

The expression of the p53 gene product was investigated immunocytochemically in a series of 51 fine-needle aspiration (FNA) samples of breast carcinomas. Results were compared with those obtained by immunocytochemically on paraffin embedded tissue sections of the corresponding surgical specimens. Cytological samples showed a variable degree of p53 immunoreactivity in 14 tumors (27.6%), all of ductal type, while p53 immunoreactive tumor cells were present in tissue sections from 15 carcinomas (29.4%). The only discordant case was a signet-ring cell carcinoma. Abnormal p53 expression was significantly associated with high nuclear grade in ductal carcinomas. No association was seen with tumor size, lymph node status, and age of the patient. Detection of p53 altered expression in FNA samples of breast carcinoma may play a role in the assessment of tumoral grading and is predictive of p53 immunoreactivity in histological specimens.

Prognostic value of p53 in breast invasive ductal carcinoma: an immunohistochemical study on 942 cases

P53 immunohistochemical detection using DO7 antibody on 942 cases of previously untreated breast invasive ductal carcinoma (IDC) with a median follow up of 117.9 months (89 to 160) was performed. Three hundred and three (32%) tumors were positive. All positive tumors were taken into account, positivity ranging from 1 to 100% of tumoral cells. The Chi square test showed significant negative correlation between p53 positivity and age (p = 0.01), estrogen receptor status (p < 0.0001), and progesterone receptor status (p = 0.0005), and significant positive correlation with tumor grade according to the Scarff, Bloom and Richardson system (SBR Grade) (p < 0.0001). There was no significant association with tumor size or nodal status. Concerning the univariate analysis, in the whole group and node-positive group (n = 544) p53 positivity was highly significant for overall survival (OS) (p < 0.0001 and p = 0.0003), disease-free interval (DFI) (p = 0.0001 and p = 0.0005), and metastasis-free interval (MFI) (p < 0.0001 and p = 0.0003). In the node-negative group (n = 398), p53 was significant with respect to OS (p = 0.01) and DFI (p = 0.04). P53 positivity came out as an independent prognostic parameter in the multivariate analysis in the whole group and the node-positive group, though of minor significance compared to axillary lymph node status, SBR grade, progesterone receptor status and tumor size.

High proliferative rates demonstrated by bromodeoxyuridine labeling index in breast carcinomas with p53 overexpression

The protein p53 is a product of a suppressor oncogene. Mutations occurring in 13-15% of breast carcinomas are associated with p53 stainability within nuclei and progression of the tumor. We determined the extent to which p53 abnormality was associated with proliferation by measuring p53 immunohistochemically with a polyclonal antibody and monoclonal PAb1801 in invasive carcinomas of known S-phase fraction (SPF) assessed histologically by bromodeoxyuridine incorporation. Results with the two antibodies always agreed. One of 20 low, 2/18 midrange, and 9/17 high SPF carcinomas were positive for p53. P53 positivity was also related to other indicators of aggressiveness including size of primary tumor, nuclear and nucleolar size, and estrogen and progesterone receptor content, but relationships between p53 and vascular invasion and lymph node metastasis were not found. We conclude that nuclear p53 accumulation is more closely related to proliferation than to invasion and metastasis, and that it identifies some but not all breast carcinomas with high proliferative indices.

The relationship of p53 protein and lymph node metastases in invasive breast cancer

The p53 expression in invasive breast cancers from 106 patients was correlated with clinicopathological variables to ascertain its usefulness for estimating prognosis. The p53 expression was significantly associated with the number of axillary lymph node metastases and the presence of internal mammary lymph node metastases; however, it was not associated with age, menopausal status, histologic type, or tumor size. Although p53 expression was a significant prognostic factor according to univariate analysis, it did not appear to be an independent prognostic factor according to multivariate analysis. Thus, the prognostic power of p53 expression is likely to be weak and therefore probably of limited clinical value. Nevertheless, the number of patients in our study was small, and we believe that an investigation of a larger series of patients is indicated.

E-cadherin distribution in interleukin 6-induced cell-cell separation of ductal breast carcinoma cells

E-cadherin is expressed in both the ZR-75-1-Tx and the ZR-75-1-Ro sublines of ductal breast carcinoma cells and is concentrated at cell-cell borders as shown by immunocytochemical examination. Free cell borders generally show no or little staining. The localized decrease in E-cadherin expression observed after interleukin 6 (IL-6) treatment of either subline correlates with the increase in free cell borders as IL-6 causes cell-cell separation. As we previously reported, many IL-6-treated ZR-75-1-Tx cells round up and detach from the substratum while ZR-75-1-Ro cells remain adherent and display prominent processes. The results are consistent with the view that E-cadherin expression is not responsible for the marked difference in the IL-6-induced phenotypes in these cell lines, although the localized decrease may play a role in cell-cell separation. ZR-75-1-Tx cells are deficient in desmosomes and show a wider intercellular space than ZR-75-1-Ro cells. Alternative mechanisms involving different aspects of the interlinked cytoskeletal and cell adhesion structures are considered to account for the IL-6-induced antimorphogenetic effect.

p53 alteration correlates with negative ER, negative PgR, and high histologic grade in breast cancer

Seventy tumors of invasive ductal carcinoma of the breast were examined for p53 alteration by the RT-PCR-SSCP method. Sixty-five samples (92.9%) were investigated in the regions of codons 101-200 and 201-300. In total, 16 samples (24.6%) showed p53 gene alteration. We found that p53 gene alteration showed a correlation with (1) a negative ER status, (2) a negative PgR status, and (3) a high histologic grade (especially numerous mitotic figures) of the tumor. However, we found no correlation between p53 gene alteration and the lymph node status or clinical stage. Thus, p53 gene alteration in breast cancer may occur in highly malignant breast cancer other than advanced clinical stage cancer or node-positive cancer.

Oncogene-induced basement membrane invasiveness in human mammary epithelial cells

Expression of the intermediate filament protein vimentin, and loss of the cellular adhesion protein uvomorulin (E-cadherin) have been associated with increased invasiveness of established human breast cancer cell lines in vitro and in vivo. In the current study, we have further examined these relationships in oncogenically transformed human mammary epithelial cells. A normal human mammary epithelial strain, termed 184, was previously immortalized with benzo[a]pyrene, and two distinct sublines were derived (A1N4 and 184B5). These sublines were infected with retroviral vectors containing a single or two oncogenes of the nuclear, cytoplasmic, and plasma membrane-associated type (v-rasH, v-rasKi, v-mos, SV40T and c-myc). All infectants have been previously shown to exhibit some aspects of phenotypic transformation. In the current study, cellular invasiveness was determined in vitro using Matrigel, a reconstituted basement membrane extract. Lineage-specific differences were observed with respect to low constitutive invasiveness and invasive changes after infection with ras, despite similar ras-induced transformation of each line. Major effects on cellular invasiveness were observed after infection of the cells with two different oncogenes (v-rasH + SV40T and v-rasH + v-mos). In contrast, the effects of single oncogenes were only modest or negligible. All oncogenic infectants demonstrated increased attachment to laminin, but altered secretion of the 72 kDa and 92 kDa gelatinases was not associated with any aspect of malignant progression. Each of the two highly invasive double oncogene transformants were vimentin-positive and uvomorulin-negative, a phenotype indicative of the epithelial-mesenchymal transition (EMT) previously associated with invasiveness of established human breast cancer cell lines. Weakly invasive untransformed mammary epithelial cells in this study were positive for both vimentin and uvomorulin, suggesting that uvomorulin may over-ride the otherwise vimentin-associated invasiveness.

Coexpression of cytokeratin and vimentin intermediate filaments in benign and malignant sweat gland tumors

The coexpression of cytokeratin and vimentin intermediate filaments has been immunohistochemically evaluated in 124 benign and malignant sweat gland tumors of various types in comparison to normal sweat glands. In addition, all neoplasms have been stained by an antibody to alpha-smooth muscle actin. Epithelial cells reacted with the pan-cytokeratin antibody lu-5. In normal sweat glands, vimentin immunoreactivity was restricted to myoepithelial cells and to some cells of the coiled duct. In benign sweat gland tumors (n = 88), coexpression of vimentin and alpha-smooth muscle actin was frequently found in basal cells of neoplasms considered to differentiate towards the secretory coil of the eccrine or apocrine gland. These included eccrine spiradenoma, apocrine cystadenoma, hidradenoma papilliferum, syringocystadenoma papilliferum, and cylindroma. Thus, in these tumors, vimentin-reactive cells corresponded to myoepithelial cells. Vimentin-positive cells were also found in 14 of 36 sweat gland carcinomas, including 1 case of sclerosing sweat duct carcinoma, 1 case of porocarcinoma, 4 cases of eccrine adenocarcinoma, 1 case of mucinous eccrine carcinoma, and 5 cases of apocrine adenocarcinoma. Co-expression of vimentin and alpha-smooth muscle actin was observed in some cells of eccrine and apocrine adenocarcinomas. Therefore, in these neoplasms, some vimentin-positive cells appear to represent myoepithelial cells. In contrast, vimentin-positive cells in all other malignant tumors did not express alpha-smooth muscle actin. Our results indicate that coexpression of cytokeratin and vimentin may be frequently found in a variety of benign and malignant sweat gland tumors. In the majority of these neoplasms, vimentin-positive cells correspond to myoepithelial cells. Because vimentin is not specific for myoepithelial cells, additional stains for alpha-smooth muscle actin should be performed to prove the myoepithelial nature of vimentin-positive cells.

Differentiation state and invasiveness of human breast cancer cell lines

Eighteen breast cancer cell lines were examined for expression of markers of epithelial and fibroblastic differentiation: E-cadherin, desmoplakins, ZO-1, vimentin, keratin and beta 1 and beta 4 integrins. The cell lines were distributed along a spectrum of differentiation from epithelial to fibroblastic phenotypes. The most well-differentiated, epithelioid cell lines contained proteins characteristic of desmosomal, adherens and tight junctions, were adherent to one another on plastic and in the basement membrane matrix Matrigel and were keratin-positive and vimentin-negative. These cell lines were all weakly invasive in an in vitro chemoinvasion assay. The most poorly-differentiated, fibroblastic cell lines were E-cadherin-, desmoplakin- and ZO-1-negative and formed branching structures in Matrigel. They were vimentin-positive, contained only low levels of keratins and were highly invasive in the in vitro chemoinvasion assay. Of all of the markers analyzed, vimentin expression correlated best with in vitro invasive ability and fibroblastic differentiation. In a cell line with unstable expression of vimentin, T47DCO, the cells that were invasive were of the fibroblastic type. The differentiation markers described here may be useful for analysis of clinical specimens and could potentially provide a more precise measure of differentiation grade yielding more power for predicting prognosis.

p53 protein and vimentin in invasive ductal NOS breast carcinoma--relationship with survival and sites of metastases

p53 protein and vimentin status were available from immunocytochemical studies of 253 formalin-fixed paraffin-embedded invasive ductal not otherwise specified (NOS) carcinomas from patients for whom follow-up data was also on file. For the 127 node-negative patients, multivariate analysis showed a highly significant correlation between p53 and vimentin (P < 0.001), a strong correlation between vimentin and probability of survival to 90 months but only a weak association between p53 and survival to 90 months. p53 also never entered trees of prognostic indicators derived using stepwise regression with Kaplan-Meier statistics for node-negative and node-positive subgroups, while vimentin status dominated the node-negative trunk. In addition, p53 and vimentin status were analysed versus the site of the first distant metastasis for node-negative and node-positive patients. Analysis by p53 status showed no significant effect on visceral metastases. In contrast, vimentin-positive primaries metastasised twice (and in node-negative patients, 3.5 times) as often to lung, liver and brain as did the vimentin-negative primaries. Both p53-positive and vimentin-positive tumours showed a significantly lower tendency to metastasise to the bone than did their negative counterparts.

Collagen induced MMP-2 activation in human breast cancer

Matrix metalloproteinase-2 (MMP-2), a zymogen requiring proteolytic activation for catalytic activity, has been implicated broadly in the invasion and metastasis of many cancer model systems, including human breast cancer (HBC). MMP-2 has been immunolocalized to carcinomatous human breast, where the degree of activation of MMP-2 correlates well with tumor grade and patient prognosis. Using Matrigel assays, we have stratified HBC cell lines for invasiveness in vitro, and compared this to their potential for metastatic spread in nude mice. HBC cell lines expressing the mesenchymal marker protein vimentin were found to be highly invasive in vitro, and tended to form metastases in nude mice. We have further discovered that culture on collagen-I gels (Vitrogen; Vg) induces MMP-2-activator in highly invasive but not poorly invasive HBC cell lines. As seen for other MMP-2-activator inducing regimens, this induction requires protein synthesis and an intact MMP-2 hemopexin-like domain, appears to be mediated by a cell surface activity, and can be inhibited by metalloproteinase inhibitors. The induction is highly specific to collagen I, and is not seen with thin coatings of collagen I, collagen IV, laminin, or fibronectin, or with 3-dimensional gels of laminin, Matrigel, or gelatin. This review focuses on collagen I and MMP-2, their localization and source in HBC, and their relationship(s) to MMP-2 activation and HBC metastasis. The relevance of collagen I in activation of MMP-2 in vivo is discussed in terms of stromal cell: tumor cell interaction for collagen I deposition, MMP-2 production, and MMP-2-activation. Such cooperativity may exist in vivo for MMP-2 participation in HBC dissemination. A more complete understanding of the regulation of MMP-2-activator by type I collagen may provide new avenues for improved diagnosis and prognosis of human breast cancer.

Immunohistochemical profile of invasive lobular carcinoma of the breast: predominantly vimentin and p53 protein negative, cathepsin D and oestrogen receptor positive

Vimentin, p53 protein and cathepsin D positivity were assessed by immunohistochemistry, and oestrogen receptor (ER) by an enzyme immunoassay, in invasive lobular carcinomas (LC) of the breast. While vimentin was positive in only 5% (3/57) and p53 protein was positive only in 3% (2/63), cathepsin D was expressed in 86% (48/56) and ER in 78% (25/32). Classical LC were negative for p53 protein and all except one were cathepsin D positive. These results are in contrast to invasive ductal breast carcinomas (DC), where the reported average incidence of vimentin and p53 protein is much higher (19% and 33% respectively) and that of cathepsin D and ER lower (63% and 67% respectively). Thus lack of expression of vimentin and lack of p53 positivity together with high incidence of expression of cathepsin D and ER are more often associated with lobular than with ductal differentiation of invasive breast cancer. The results show that LC, distinguished morphologically, can further be defined by its immunohistochemical profile. This in turn may point to underlying biological differences between LC and DC.

Vimentin expression in 98 breast cancers with medullary features and its prognostic significance

The expression of vimentin, as assessed by immunohistochemistry, has been evaluated in 69 medullary carcinomas of the breast: 28 typical medullary carcinomas (TMC), 41 atypical medullary carcinomas (AMC), and 29 invasive ductal carcinomas with subtle medullary features that, however, did not fulfill the strict criteria of TMC or AMC. Immunoreactivity of at least 10% of the component cells was found in 14 of the medullary carcinomas (5 out of 28 TMC, 9 out of 41 AMC whereas only 1 of the invasive ductal carcinomas was vimentin-positive. The patients were followed for 8-13 years. No difference in recurrence-free survival or overall survival could be documented between vimentin-positive and vimentin-negative carcinomas with medullary features. No biological significance could be established for vimentin labelling in these lesions.

Molecular and cellular analysis of basement membrane invasion by human breast cancer cells in Matrigel-based in vitro assays

In vitro analyses of basement membrane invasiveness employing Matrigel (a murine tumor extract rich in basement membrane components) have been performed on human breast cancer model systems. Constitutive invasiveness of different human breast cancer (HBC) cell lines has been examined as well as regulation by steroid hormones, growth factors, and oncogenes. Carcinoma cells exhibiting a mesenchymal-like phenotype (vimentin expression, lack of cell border associated uvomorulin) show dramatically increased motility, invasiveness, and metastatic potential in nude mice. These findings support the hypothesis that epithelial to mesenchymal transition (EMT)-like events may be instrumental in the metastatic progression of human breast cancer. The MCF-7 subline MCF-7ADR appears to have undergone such a transition. The importance of such a transition may be reflected in the emergence of vimentin expression as an indicator of poor prognosis in HBC. Matrix degradation and laminin recognition are highlighted as potential targets for antimetastatic therapy, and analyses of laminin attachment and the matrix metalloproteinase (MMP) family in HBC cell lines are summarized. Matrigel-based assays have proved useful in the study of the molecular mechanisms of basement membrane invasiveness, their regulation in HBC cells, and their potential as targets for antimetastatic therapy.

Analysis of oncogenes and tumor suppressor genes in human breast cancer

Oncogenes (c-erbB-2, c-myc, and some genes linked to the 11q13 lesion), tumor suppressor genes (retinoblastoma gene, p53) and an antimetastatic gene (nm23/nucleoside diphosphate kinase) play important roles in breast cancer progression. Amplification of c-erbB-2, c-myc, and int-2, and expression of RB, p53(mutant), and NDP kinase were determined in 77 primary breast cancer specimens. nm23-H1 allelic loss was also studied. c-erbB-2 and c-myc amplification, loss of RB expression, p53(mutant) expression, and nm23-H1 allelic loss were also found in non-invasive carcinoma. int-2 amplification was significantly correlated with lymph node status (P = 0.02) and a significant association was found between p53(mutant) expression and tumor size (P = 0.04). c-erbB-2 amplification was strongly associated with disease-free and overall survival in multivariate analysis (P = 0.002). All of the c-erbB-2 amplified cases and all but one of the int-2 amplified cases in node-positive patients had relapsed within 2 years post resection. The cancer cells may acquire new proliferative pathways sequentially as a result of multiple genetic alterations which enable them to bypass the estrogen-dependent proliferation.

p53 protein expression in mammary ductal carcinoma in situ: relationship to immunohistochemical expression of estrogen receptor and c-erbB-2 protein

The immunohistochemical expression of the p53 gene protein was examined in a consecutive series of 143 cases of pure ductal carcinoma in situ (DCIS) of the breast. Expression of wild-type and/or mutant p53 protein was detected in 36 (25.2%) of the cases examined, as evidenced by positive nuclear staining with the monoclonal antibody DO 7. Thirty-four (35.8%) of the large cell cases showed p53 protein expression compared with two (4.1%) of the small cell cases (chi 2 = 15.3 [df = 1], P < .001). p53 Protein expression also was associated with an increased histologic degree of necrosis, with a nearly significant association of negative tumor estrogen receptor status and p53 protein expression. No significant association of p53 protein expression and c-erbB-2 protein expression was seen. Immunohistochemical expression of p53 protein is present in approximately 25% of DCIS cases and is confined almost exclusively to large cell DCIS, a morphologic subtype of in situ breast carcinoma thought to be more biologically aggressive. Expression of p53 protein may be important in the neoplastic progression of DCIS, reflecting the acquisition of p53 gene mutations in large cell DCIS cases. Therefore, p53 may be implicated in mammary tumor evolution from in situ to invasive disease.

Vimentin expression in benign and malignant breast epithelium

AIMS

To determine vimentin expression in epithelial cells in benign breast disease and malignant breast tumours; to assess the value of vimentin expression as a prognostic indicator in breast carcinoma.

METHODS

Frozen and formalin fixed, paraffin wax embedded sections from 78 carcinomas, three phyllodes tumours, 19 fibroadenomas and 19 cases of fibrocystic disease were examined with a monoclonal antibody from the V9 clone. A correlation between vimentin expression and known prognostic indicators was sought in ductal carcinomas. The intracellular localisation of vimentin was examined in benign and malignant lesions.

RESULTS

Vimentin expression was identified on frozen section in the cells of ductal (53%), lobular (86%), and mucinous (33%) carcinomas and in the luminal epithelium of fibroadenomas (68%), cases of fibrocystic disease (47%), and a malignant phyllodes tumour. Formalin fixation reduced the percentage of carcinomas and cases of benign disease in which vimentin was detected. This reduction was more pronounced in fibroadenoma and fibrocystic disease than in ductal carcinoma. Associations were identified between vimentin expression as detected on frozen section and tumour grade, size, number of lymph nodes affected, oestrogen receptor content and growth fraction. Only the association with grade was significant (p = 0.045). There was no significant correlation between any of these prognostic variables and vimentin expression on paraffin wax sections. There was no difference in the intracellular localisation of vimentin staining between benign and malignant lesions, or between low and high grade ductal carcinomas.

CONCLUSION

There is some loss of vimentin immunoreactivity after formalin fixation. Vimentin expression does not assist in differentiating between benign and malignant breast disease, but is correlated with tumour grade in ductal carcinoma.

Expression of epidermal growth factor receptor (proto-oncogene c-erbB-1) and estrogen receptor in human breast carcinoma. An immunocytochemical study of 70 cases

In vitro studies have shown that growth factors may mediate the growth stimulatory effect of estrogen in hormone-dependent human breast carcinomas while the constitutive expression of same growth factors might by-pass the need for estrogenic stimulus in hormone-independent neoplasms. We have performed immunocytochemical analysis of the expression of epidermal growth factor receptor (EGF-R or proto-oncogen c-erbB-1) and estrogen receptor (ER) in 70 cases of human breast carcinoma. We found an inverse relationship between the expression of EGF-R and ER (Kendall's tau b = -0.1997, P < 0.03), which prompts us to conclude that ER(-) breast carcinomas may grow in a hormone-independent manner through the over-expression of the proto-oncogene c-erbB-1, which is the receptor for epidermal (EGF) and alpha transforming (TGFalfa) growth factors.

Expression of vimentin and epidermal growth factor receptor in effusions from patients with breast cancer; correlation with oestrogen and progesterone receptor status

The epidermal growth factor receptor (EGFr) status and the vimentin (V) status of malignant cells in pleural fluids from patients with breast cancer were determined using an immunoperoxidase labelling technique. The results were correlated with the oestrogen receptor (ER) and the progesterone receptor (PR) status of the primary tumour and with disease-free survival time of the patient. A negative correlation between EGFr and V status and hormone receptor status was found. The longest mean survival time occurred in patients with negative EGFr and V status and positive hormone receptor (ER and PR) status. The shortest mean survival time occurred in patients with positive EGFr and V and negative ER and PR status.

Nuclear p53 protein accumulates preferentially in medullary and high-grade ductal but rarely in lobular breast carcinomas

Striking differences were found between different histological types of breast cancer when 263 invasive breast carcinomas were tested for nuclear p53 accumulation in formaldehyde-fixed paraffin sections. Nuclear p53 accumulation was found in > 10% of tumor cells in 61% of medullary carcinomas (22/36), 37% of grade 3 ductal not otherwise specified carcinomas (32/86), 4% of lobular carcinomas (2/47), and 0% (0/7) of mucinous carcinomas. Strong cytoplasmic p53 staining was noted in 32% of lobular carcinomas. High percentages of medullary and high-grade ductal breast carcinomas accumulate nuclear p53, but these tumors have favorable and poor prognoses, respectively. Thus, whereas nuclear p53 accumulation can be associated in these tumors with high morphological malignancy grades in general and with tumor cell proliferation in particular, p53 accumulation is not necessarily correlated with biological aggressiveness. Overall incidence of p53-positive tumors in a particular series of breast carcinomas (in our study 28%) will depend on the ratio of ductal not otherwise specified, medullary, and lobular carcinomas.