Co-expression of cytokeratin and vimentin intermediate filament proteins in benign and neoplastic breast epithelium

Slug Is A Surrogate Marker of Epithelial to Mesenchymal Transition (EMT) in Head and Neck Cancer

Background: Epithelial to mesenchymal transition (EMT) promotes therapy resistance in head and neck cancer (HNC) cells. In this study, EMT was quantified in HNC tumor samples by the cellular co-localization of cytokeratin/vimentin, E-cadherin/β-catenin and by Slug expression. Methods: Tissue samples from HNC patients were stained with antibody pairs against cytokeratin/vimentin and E-cadherin/β-catenin. Epithelial–mesenchymal co-localization was quantified using immunofluorescence multichannel image cytometry. Double positivity was confirmed using confocal microscopy. Slug was semi-quantified by 2 specialists and quantified by bright field image cytometry. Results: Tumor samples of 102 patients were investigated. A loss of E-cadherin positive cells (56.9 ± 2.6% vs. 97.9 ± 1.0%; p < 0.0001) and E-cadherin/β-catenin double positive cells (15.4 ± 5.7% vs. 85.4 ± 1.2%; p < 0.0001) was observed in tumor samples. The percentage of Slug positive cells was increased in tumor samples (12.1 ± 3.6% vs. 3.2 ± 2.6%; p = 0.001). Ordinal Slug scores judged by two specialists closely correlated with percentage of Slug-positive cells (Spearman’s rho = 0.81; p < 0.001). Slug score correlated negatively with the percentage of E-cadherin positive cells (r = 0.4; p = 0.006), the percentage of E-cadherin/β-catenin positive cells (r = 0.5; p = 0.001) and positively with cytokeratin/vimentin positive cells (r = 0.4, p = 0.003). Conclusion: EMT can be assessed in HNC tumor probes by cytokeratin/vimentin co-expression and loss of E-cadherin/β-catenin co-expression. Slug score provides a convenient surrogate marker for EMT.

Adenoid Cystic Carcinoma of the Breast.: Value of Immunohistochemical Study in Diagnosis

An immunohistochemical study of 5 cases of adenoid cystic carcinoma (ACC) of the breast was performed with antibodies against keratin, EMA, vimentin, S-100 protein, alpha-smooth muscle actin and collagen IV. Results show the following: 1) ACC may be diagnosed and differentiated from ductal carcinoma (invasive or in situ). The key to diagnosis is positivity within tumor masses of alpha-smooth muscle actin, a specific marker for myoepithelial cells. Actin-rich cells are not generally observed in ductal carcinomas, except at the periphery of a few invaded ducts, corresponding to a residual myoepithelial cell layer. Other markers may be positive in both ACC and ductal carcinoma; these are not specific and only the percentage and distribution of positive cells are helpful for diagnosis (small clusters of keratin-positive cells in ACC « versus » most positive cells in ductal carcinoma). 2) The functional pleomorphism of the cell population is underlined with cells differentiating towards epithelium and myoepithelium stained by corresponding markers, and undifferentiated cells unstained by any marker. These results confirm the value of an immunohistochemical study in the diagnosis of ACC of the breast.

Poorly Differentiated Rectal Carcinoid in a Cow

A carcinoid tumor was found as a solitary soft mass in the wall of the rectum adjacent to the anorectal junction in an adult Holstein cow. Microscopically, the tumor involved the submucosa and partly invaded the muscular layer. It consisted of a compact arrangement of a great number of large polygonal cells and a small number of small dark cells, some of which showed argyrophilia (Grimelius positive). Immunohistochemically, both types of tumor cells were positive for vimentin, keratin, and S-100 protein and weakly positive for neuron-specific enolase (NSE), whereas they were negative for some endocrine markers such as chromogranin A, insulin, glucagon, somatostatin, serotonin, adrenocorticotropic hormone, and calcitonin. Electron microscopy revealed membrane-bound secretory granules in the cytoplasm of some small dark cells. In such a poorly differentiated carcinoid, the morphologic characteristics of the small dark cells were strong evidence for the diagnosis. This is the first description of a poorly differentiated carcinoid developing in the rectum of a cow.

Epithelial cell migration requires the interaction between the vimentin and keratin intermediate filaments

Epithelial migration plays a central role in development, wound repair and tumor metastasis, but the role of intermediate filament in this important event is unknown. We showed recently that vimentin coexists in the same cell with keratin-KRT14 at the leading edge of the migrating epidermal cells, and knockdown of vimentin impaired colony growth. Here we demonstrate that vimentin co-localizes and co-immunoprecipitates with keratin-KRT14, and mutations in the -YRKLLEGEE- sequence of vimentin significantly reduced migration of the keratinocytes. Our data demonstrates that keratinocyte migration requires the interaction between vimentin and keratins at the -YRKLLEGEE- sequence at the helical 2B domain of vimentin. These findings have broad implications for understanding the roles of vimentin intermediate filaments in normal and neoplastic epithelial cells.

Association of Cytokeratin and Vimentin Protein in the Genesis of Transitional Cell Carcinoma of Urinary Bladder Patients

The aim of study was to examine the localization and distribution of cytokeratin (CK) and vimentin protein and their association with clinical outcome of the TCC patients. Expression pattern of cytokeratin and vimentin was evaluated by immunohistochemistry in TCC cases and inflammatory lesions. Cytoplasmic expression of CK was noticed in 52.17% of TCC cases and its expression was not observed in inflammatory lesions of bladder specimens. Vimentin showed expression in 69.00% cases of TCC. Significant differences were noticed in expression pattern of CK and vimentin in inflammatory lesion and Transitional Cell Carcinoma cases. Vimentin expression increased with the grade of TCC and this difference was statistically significant whereas expression of CK decreased according to the grade of TCC. Furthermore, it was also observed that expression pattern of vimentin was high in ≥55 years as compared to <55 age group patients and these differences were significant in men as compared to women. Expression pattern of CK did not show any significant relation with age and gender. Therefore, it can be concluded that cytokeratin and vimentin will be helpful markers in the early diagnosis of Transitional Cell Carcinoma/bladder carcinoma.

Breast carcinoma metastasis to the lacrimal gland: Two case reports

A 77-year-old female, with proptosis, reduced eye motility and diplopia which had developed over two to three months and a 69-year-old female with proptosis, oedema of the eyelid, reduced motility and ptosis, which had developed over three weeks, are presented in the present study. Computed tomography scans revealed irregular lacrimal gland tumours in the two patients. The two patients had history of breast cancer. The first breast cancer metastasis in the lacrimal gland demonstrated a cribriform growth pattern containing ductal elements. The epithelial tumour cells stained positive for cytokeratin (1-8, 10, 14-16, 18 and 19), oestrogen receptor, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA) and gross cystic disease fluid protein 15 (GCDFP-15). The second metastatic tumour was positive for EMA and estrogen receptor, but variably positive for CEA and GCDFP-15. The metastasis in the lacrimal gland was a pleomorphic tumour. The tumour cells were positive for EMA and variably positive for oestrogen and CEA. Metastases to the lacrimal gland are extremely rare, and metastases to the lacrimal gland should be considered in the diagnoses of lacrimal gland tumours. The present study aimed to describe two such cases and draw attention to breast carcinomas as a differential diagnosis and the most frequent cause of lacrimal gland metastasis.

Vimentin is necessary for colony growth of human diploid keratinocytes

The role of vimentin (Vim) in diploid epithelial cells is not well known. To understand its biological function, we cultured human epidermal keratinocytes under conditions that support migration, proliferation, stratification and terminal differentiation. We identified a keratinocyte subpopulation that shows a p63(+)/α5β1(bright) phenotype and displays Vim intermediate filaments (IFs) besides their keratin IF network. These cells were mainly located at the proliferative/migratory rim of the growing colonies; but also, they were scarce and scattered or formed small groups of basal cells in confluent stratified epithelia. Stimulation of cells with EGF and wounding experiments in confluent arrested epithelia increased the number of Vim(+) keratinocytes in an extent higher to the expected for a cell population doubling. BrdU labeling demonstrated that most of the proliferative cells located at the migratory border of the colony have Vim, in contrast with proliferative cells located at the basal layer at the center of big colonies which lacked of Vim IFs, suggesting that Vim expression was not solely linked to proliferation. Therefore, we silenced Vim mRNA in the cultured keratinocytes and observed an inhibition of colony growth. Such results, together with long-term cultivation assays which showed that Vim might be associated to pattern formation in cultured epithelia, suggest that Vim expression is essential for a highly motile phenotype, which is necessary for keratinocyte colony growth and possibly for development and wound healing. Vim(+)/p63(+)/α5β1(bright) epithelial cells may play a significant physiological role in embryonic morphogenetic movements; wound healing and other pathologies such as carcinomas and hyperproliferative diseases.

Molecular markers of epithelial-to-mesenchymal transition are associated with tumor aggressiveness in breast carcinoma

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is a transient process occurring during developmental stages and carcinogenesis, characterized by phenotypic and molecular alterations, resulting in increased invasive and metastatic capabilities of cancer cells and drug resistance. Moreover, emerging evidence suggests that EMT is associated with increased enrichment of cancer stem-like cells in neoplastic tissues. We interrogated the molecular alterations occurring in breast cancer using proposed EMT markers such as E-cadherin, vimentin, epidermal growth factor receptor (EGFR), platelet-derived growth factor (PDGF) D, and nuclear factor κ B (NF-κ B) to decipher their roles in the EMT and breast cancer progression.

METHODS

Fifty-seven invasive ductal adenocarcinomas of the breast were assessed for the expression of E-cadherin, vimentin, EGFR, NF-κ B, and PDGF-D using immunohistochemical analysis. Tumors were categorized into three groups: A (ER+, and/or PR+, HER-2/neu-), B (ER+, and/or PR+, HER-2/neu+), and C (triple-negative: ER-, PR-, and HER-2/neu-). Immunostained slides were microscopically evaluated and scored using intensity (0, 1+, 2+, and 3+) and percentage of positive cells, and data were statistically analyzed.

RESULTS

Membranous E-cadherin was positive in all 57 cases (100%), whereas cytoplasmic E-cadherin was predominantly positive in groups B and C compared with group A (21%, 7%, and 0%, respectively). All group A cases were negative for vimentin and EGFR. There was statistically significant increased expression of vimentin (P < .0002), EGFR (P < .0001), and NF-κ B (P < .02) in triple-negative cases when compared with groups A and B.

CONCLUSIONS

Vimentin, EGFR, and NF-κ B were significantly increased in triple-negative tumors, which is consistent with the aggressiveness of these tumors. These markers could be useful as markers for EMT in breast cancers and may serve as predictive markers for designing customized therapy in the future.

Does vimentin help to delineate the so-called 'basal type breast cancer'?

Background

Vimentin is one of the cytoplasmic intermediate filament proteins which are the major component of the cytoskeleton. In our study we checked the usefulness of vimentin expression in identifying cases of breast cancer with poorer prognosis, by adding vimentin to the immunopanel consisting of basal type cytokeratins, estrogen, progesterone, and HER2 receptors.

Methods

179 tissue specimens of invasive operable ductal breast cancer were assessed by the use of immunohistochemistry. The median follow-up period for censored cases was 90 months.

Results

38 cases (21.2%) were identified as being vimentin-positive. Vimentin-positive tumours affected younger women (p = 0.024), usually lacked estrogen and progesterone receptor (p < 0.001), more often expressed basal cytokeratins (<0.001), and were high-grade cancers (p < 0.001). Survival analysis showed that vimentin did not help to delineate basal type phenotype in a triple negative (ER, PgR, HER2-negative) group. For patients with 'vimentin or CK5/6, 14, 17-positive' tumours, 5-year estimated survival rate was 78.6%, whereas for patients with 'vimentin, or CK5/6, 14, 17-negative' tumours it was 58.3% (log-rank p = 0.227).

Conclusion

We were not able to better delineate an immunohistochemical definition of basal type of breast cancer by adding vimentin to the immunopanel consisted of ER, PgR, HER2, CK5/6, 14 and 17 markers, when overall survival was a primary end-point.

Identification of pancreatic cancer invasion-related proteins by proteomic analysis

Background

Markers of pancreatic cancer invasion were investigated in two clonal populations of the cell line, MiaPaCa-2, Clone #3 (high invasion) and Clone #8 (low invasion) using proteomic profiling of an in vitro model of pancreatic cancer.

Materials and methods

Using 2D-DIGE followed by MALDI-TOF MS, two clonal sub-populations of the pancreatic cancer cell line, MiaPaCa-2 with high and low invasive capacities were incubated on matrigel 24 hours prior to analysis to stimulate cell-ECM contact and mimic in vivo interaction with the basement membrane.

Results

Sixty proteins were identified as being differentially expressed (> 1.2 fold change and p ≤ 0.05) between Clone #3 and Clone #8. Proteins found to have higher abundance levels in the highly invasive Clone #3 compared to the low invasive Clone #8 include members of the chaperone activity proteins and cytoskeleton constituents whereas metabolism-associated and catalytic proteins had lower abundance levels. Differential protein expression levels of ALDH1A1, VIM, STIP1 and KRT18 and GAPDH were confirmed by immunoblot. Using RNAi technology, STIP1 knockdown significantly reduced invasion and proliferation of the highly invasive Clone #3. Knockdown of another target, VIM by siRNA in Clone #3 cells also resulted in decreased invasion abilities of Clone #3. Elevated expression of STIP1 was observed in pancreatic tumour tissue compared to normal pancreas, whereas ALDH1A1 stained at lower levels in pancreatic tumours, as detected by immunohistochemistry.

Conclusion

Identification of targets which play a role in the highly invasive phenotype of pancreatic cancer may help to understand the biological behaviour, the rapid progression of this cancer and may be of importance in the development of new therapeutic strategies for pancreatic cancer.

Expression of basal keratins and vimentin in breast cancers of young women correlates with adverse pathologic parameters

Previous studies have suggested that breast cancer in young women has more aggressive biological features and poorer prognosis. However, the role of biological markers in these patients is not well understood. We aimed to learn more about this disease in a cohort of 125 young women from Singapore, Japan and Hong Kong, aged 35 years or less, with invasive breast cancer by evaluating the expression of vimentin and the basal cytokeratins CK14, CK5/6 and 34 beta E12. Both standard paraffin sections and tissue microarrays were used in the immunohistochemical evaluation of expression patterns of these four biological markers. CK5/6, CK14, vimentin and 34 beta E12, in increasing order of proportion, were detected in invasive carcinomas. Basal cytokeratins and vimentin showed significant inverse relationship with estrogen and progesterone receptor status while CK14 expression was found to be directly associated with c-erbB2 status. Basal cytokeratins and vimentin immunoreactivities were directly associated with CD117 and EGFR expression. Vimentin and 34 beta E12 immunopositivity correlated with tumor size, while vimentin was associated with higher histological grade. Our findings are in concert with reports that expression of basal cytokeratins and vimentin is correlated with adverse pathological parameters.

Triple negative tumours: a critical review

Breast cancer is a heterogeneous disease that encompasses several distinct entities with remarkably different biological characteristics and clinical behaviour. Currently, breast cancer patients are managed according to algorithms based on a constellation of clinical and histopathological parameters in conjunction with assessment of hormone receptor (oestrogen and progesterone receptor) status and HER2 overexpression/gene amplification. Although effective tailored therapies have been developed for patients with hormone receptor-positive or HER2+ disease, chemotherapy is the only modality of systemic therapy for patients with breast cancers lacking the expression of these markers (triple-negative cancers). Recent microarray expression profiling analyses have demonstrated that breast cancers can be systematically characterized into biologically and clinically meaningful groups. These studies have led to the re-discovery of basal-like breast cancers, which preferentially show a triple-negative phenotype. Both triple-negative and basal-like cancers preferentially affect young and African-American women, are of high histological grade and have more aggressive clinical behaviour. Furthermore, a significant overlap between the biological and clinical characteristics of sporadic triple-negative and basal-like cancers and breast carcinomas arising in BRCA1 mutation carriers has been repeatedly demonstrated. In this review, we critically address the characteristics of basal-like and triple-negative cancers, their similarities and differences, their response to chemotherapy as well as strategies for the development of novel therapeutic targets for these aggressive types of breast cancer. In addition, the possible mechanisms are discussed leading to BRCA1 pathway dysfunction in sporadic triple-negative and basal-like cancers and animal models for these tumour types.

Basal-like breast cancer and the BRCA1 phenotype

Breast cancers arising in germline carriers of BRCA1 mutations have a characteristic phenotype that has been shown in many studies to differentiate BRCA1 tumours from sporadic tumours. Recently, it has become clear that the characteristic phenotype of BRCA1 tumours is due to expression of the basal-like phenotype. We review these phenotypes, the evidence for BRCA1 pathway dysfunction in sporadic basal-like cancers, and discuss the clinical significance of the basal-like phenotype for cancer genetics and treatment.

Intrauterine breast development and the mammary myoepithelial lineage

As their name implies, the myoepithelial cells found at the epithelial-mesenchymal interface of the human mammary gland disclose features suggestive of a dual epithelial-like and muscle-like differentiation, i.e. they co-express various keratins and vimentin intermediate filaments, as well as smooth muscle-related antigens. This article provides an overview of the literature on intrauterine breast development with special emphasis on the myoepithelial component of the fetal human mammary gland epithelium. It discusses original and recently published immunohistochemical data on myoepithelial precursors and reasserts the relevance of developmental, morphological fetal tissue-based studies to the understanding and the clinical management of adult diseases.

Basal cells of second trimester fetal breasts: immunohistochemical study of myoepithelial precursors

The molecular characterization of human mammary myoepithelial cells is incomplete, hindering our understanding of its importance in breast physiology and pathology. Because data on the precursors of this cell lineage remain scarce and often contradictory, basal epithelial cells of second trimester fetal breasts were studied by light microscopy (LM) and immunohistochemistry (IHC). Up to 20 wk of gestational age, the mammary rudiments only comprised roundish primary outgrowths, "primary buds," more likely to represent immature nipples than true mammary tissue. At 21 wk secondary outgrowths, "projections," extended from enlarged primary buds into well-vascularized layers of dense mesenchyme. Basal projection cells had a partial myoepithelial-like phenotype: they reacted with CD29, CD49f, CD104, keratin 14, vimentin, S100beta protein, and p63; furthermore, many became positive for keratin 17, alpha-smooth muscle actin, and CD10 (but not for keratin 19) between wk 21 and 25. The continuous basement membrane associated with the fetal mammary rudiments was strongly positive for collagens type IV and VII, and for laminin 5. Consistently strong and basally polarized staining for hemidesmosomal components suggested that although incompletely differentiated, most second trimester myoepithelial precursors might already mediate local epithelial-mesenchymal interactions, i.e., complex signaling pathways which are crucial for both orderly growth during development and maintenance of homeostasis during adult life. Because they are likely implicated in the phenomenon of menstrual cycle-related growth spurts in the adult resting breast, the strategically positioned cells of the myoepithelial lineage might constitute critical protagonists in defective epithelial-mesenchymal signaling associated with cancer progression.

Vimentin/cytokeratin coexpression foci in a well-differentiated canine hepatocellular carcinoma

A number of pale-stained cell foci were observed within a well-differentiated hepatocellular carcinoma which developed in a 10-year-old male mongrel dog. The foci were composed of hepatocyte-like cells, but did not contain glycogen granules in their cytoplasm. Immunohistochemically, the focus cells coexpressed both bile duct type cytokeratin and vimentin. Electronmicroscopically, they were abundant in cytoplasmic organelles and contained bile pigments. Bile canaliculi were noted between the focus cells. The focus cells in the present case were considered to be neoplastic hepatocytes expressed bipotential features of hepatic stem cells.

Association of in vitro invasiveness and gene expression of estrogen receptor, progesterone receptor, pS2 and plasminogen activator inhibitor-1 in human breast cancer cell lines

The invasive potential of tumor cells is usually tested either by in vitro invasion assays which evaluate cell spreading ability in basement membrane-like matrices or by in vivo invasion assays in nude mice. Both methods are laborious and time-consuming. Tumor invasiveness is accompanied by the changes in expression of various genes. The invasive behavior of cells is therefore represented by certain gene expression patterns. The purpose of this study was to investigate whether expression patterns of several genes are characteristic for the invasiveness of cultured cells. We examined the mRNA levels of estrogen receptor (ER), progesterone receptor (PR), estrogen inducible pS2 and plasminogen activator inhibitor-1 (PAI-1) in 23 cell lines derived from benign and malignant breast tissues using a competitive reverse transcription-polymerase chain reaction (cRT-PCR) system. We also evaluated the invasiveness of these cell lines by their ability to penetrate into a collagen-fibroblast matrix. We demonstrate that the gene expression pattern of breast cell lines is clearly associated with their in vitro invasiveness. In general, cells with ER, PR, pS2 but no PAI-1 expression showed a non-invasive phenotype, while cells expressing PAI-1 mRNA but not ER mRNA are invasive. Our study indicates that the invasiveness of breast cancer cell lines is characterized by PAI-1 gene expression and the lack of ER mRNA. This suggests that PAI-1 may participate in the invasive process.

Metaplastic breast tumors with a dominant fibromatosis-like phenotype have a high risk of local recurrence

BACKGROUND

In the current study the authors describe the clinicopathologic characteristics of a low grade variant of spindle cell metaplastic tumors of the breast. Previously these tumors have been considered within a larger group recognized as metaplastic carcinoma, including cases with higher grade features.

METHODS

Breast tumors comprised predominantly of low grade spindle cells, with sparse low grade epithelial elements, were selected. Clinical features as well as macroscopic, microscopic, and immunohistochemical findings were reviewed with emphasis on the biologic behavior and the differential diagnosis from other spindle cell lesions.

RESULTS

Of 30 tumors fulfilling strict criteria, 20 contained squamous or glandular elements associated with the spindle cells. Ten tumors were comprised entirely of low grade spindle cells with limited clustered epithelioid cells. At the periphery, all tumors showed a proliferation of bland spindle cells infiltrating the adjacent parenchyma and mimicking fibromatosis. The epithelioid cells and some spindle cells expressed both vimentin and one or more cytokeratins. Seven of eight patients treated by excisional biopsy developed local recurrence, whereas only one of ten patients treated with wide excisional biopsy developed a local recurrence. No distant or regional metastases occurred.

CONCLUSIONS

The presence of limited clusters of epithelioid cells along with a dominant fibromatosis-like pattern may be unique in the breast. The biologic potential of the fibromatosis-like, spindle cell, metaplastic breast tumors most likely is defined by their major histologic phenotype; they are capable of local recurrence with no demonstrated distant spread or regional metastases, as in pure fibromatosis of the breast.

Malignant rhabdoid tumor of the duodenum

A polypoid malignant rhabdoid tumor of the duodenum is presented. The pattern of metastatic spread in this 58-year-old man included multiple duodenal and small intestinal transmural tumor implants and a large peribronchial lymph node causing superior vena cava syndrome. Microscopically, the tumor was composed of a diffuse population of rhabdoid cells characterized by homogeneous globular cytoplasmic inclusions that tended to indent or displace eccentric, vesicular nuclei with nucleoli. No glandular features were noted. Immunohistochemical and ultrastructural evaluation revealed that these inclusions contained vimentin, an intermediate filament of the mesenchymal cytoskeleton. Phenotypic features of a rhabdoid tumor have been reported in 10 poorly differentiated malignancies of the gastrointestinal tract. This is the first case report of a malignant rhabdoid tumor of the small intestine. Regardless of the site of the lesion, tumors showing these features are generally associated with a poor prognosis.

Trichoblastoma and basal cell carcinoma are neoplasms with follicular differentiation sharing the same profile of cytokeratin intermediate filaments

Trichoblastoma and nodular basal cell carcinoma are generally held to be distinctive epithelial neoplasms with some overlapping features. We investigated 30 trichoblastomas in which the basaloid cells expressed cytokeratins (CK) CK5/6, CK14, CK17, CK19, and, in a few cells, vimentin. The cells of the periphery of small and large cysts showed the same profile. Cells lining the lumen of small cysts expressed CK14, CK17, and involucrin, and those in larger cysts showed a positivity for CK1, CK4, CK10, CK14, CK17, and involucrin. The remaining tested antibodies (CK7, CK8, CK13, CK18, CK20, alpha-smooth-muscle actin) were negative in all cases. The cells of the stroma expressed vimentin and in 22 cases, the CD34 antigen. Seventeen nodular basal cell carcinomas showed exactly the same staining pattern. Furthermore, there are striking immunohistochemical similarities between the neoplastic basaloid cells of both neoplasms and the cells of the hair germ. Therefore, trichoblastoma and nodular basal cell carcinoma cannot be distinguished by their pattern of cytokeratin expression in paraffin sections. The virtually identical cytokeratin pattern seen in trichoblastoma, basal cell carcinoma, and the developing fetal hair follicle is compelling evidence for common differentiation pathway.

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.

Malignant rhabdoid tumor in adults--heterogenous tumors with a unique morphological phenotype

Five cases of malignant rhabdoid tumors in adult patients are described. The tumors were characterized by sheets of poorly cohesive cells with distinctive hyaline cytoplasmic inclusions and eccentrically placed large vesicular nuclei with prominent nucleoli. A variety of lineage differentiation was shown by immunohistochemistry and electron microscopy, the lesions representing leiomyosarcoma, gastric carcinoma, epithelioid sarcoma, Merkel cell carcinoma and desmoplastic small round cell tumor. Previously reported cases of rhabdoid tumors in adults support the contention that such tumors, although of distinctive morphologic phenotype, are of heterogenous lineage differentiation, and do not represent a distinct clinicopathologic entity.

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.

Immunohistochemical distribution pattern of intermediate filament proteins in 50 feline neoplasms

Twenty-eight epithelial and 22 nonepithelial feline tumors were studied immunohistochemically. Epithelial tumors were 10 squamous cell carcinomas, two basal cell tumors, two sebaceous gland carcinomas, three apocrine gland carcinomas, three thyroid papillary carcinomas, one thyroid solid carcinoma, one renal clear cell carcinoma, one renal papillary carcinoma, one endometrial carcinoma, and four lung bronchioloalveolar carcinomas. Nonepithelial tumors were 10 fibrosarcomas, one liposarcoma, one leiomyosarcoma, one rhabdomyosarcoma, one hemangiosarcoma, two mast cell tumors, one osteosarcoma, three melanomas, and two lymphomas. Commercially available antibodies directed against high- and low-molecular-weight keratins (keratin, RCK-102, NCL-5D3), vimentin, desmin, glial fibrillary acidic protein (GFAP), and neurofilament intermediate filament (IF) proteins were used in the avidin-biotin-peroxidase complex technique on formalin-fixed, paraffin-embedded tumor tissue samples. All epithelial tumors except the endometrial carcinoma expressed some type of keratin protein. Squamous cell carcinomas expressed high-molecular-weight keratins exclusively. Coexpression of high- and low-molecular-weight keratins was observed in one basal cell tumor, sebaceous and apocrine adenocarcinomas, and thyroid, renal, and lung carcinomas. In addition to keratins, vimentin immunoreactivity was found in all basal cell tumors, all sebaceous gland, thyroid papillary, renal, and lung adenocarcinomas, and one of the apocrine gland adenocarcinomas. Immunoreactivity with GFAP antibody was found in one basal cell tumor and one sebaceous gland adenocarcinoma. The endometrial carcinoma did not react with any of the antibodies applied. Nonepithelial tumors analyzed expressed either vimentin (fibrosarcomas, liposarcoma, haemangiosarcoma, mast cell tumors, osteosarcomas, melanomas) or vimentin and desmin (leiomyosarcoma, rhabdomyosarcoma, one fibrosarcoma) IF proteins exclusively. Lymphomas did not react with any of the antibodies employed. These findings indicate that IF proteins antibodies can be included in diagnostic panels of antibodies for immunocharacterization of feline tumors. In addition, they can be used as a basis for the diagnoses of poorly differentiated or undifferentiated feline neoplasms.

DNA ploidy and vimentin expression in primary breast cancer

The DNA content of 50 breast cancers of varying tumour type, grade and stage was measured using static image cytometry, and correlated with vimentin expression in the tumour cells. A tendency to increased vimentin expression and aneuploidy was observed in high grade and late stage tumours. A statistically significant difference was observed in DNA index and ploidy balance between grade 1 and grades 2 and 3 carcinomas (P < 0.05) and between grade I and stage II carcinomas (P < 0.05). There was a significant difference in the expression of vimentin between grades 1, 2, 3 (P < 0.001), and stages I, II, and III ductal carcinomas (P < 0.05). No significant difference was observed in the proliferation index and the degree of hyperploidy (P > 0.05) Clonal heterogeneity was observed in 25% of breast carcinomas, and was associated with increased vimentin expression. These changes may be indicative of genomic alteration and tumour aggressiveness.

Expression and ligand binding of alpha 2 beta 1 integrin on breast carcinoma cells

We examined the expression and ligand specificity of the alpha 2 beta 1 integrin on human mammary epithelial cells (HMEC) and a panel of breast carcinoma cell lines in vitro. We found that the alpha 2 beta 1 integrin was universally, but quite variably expressed on these cells by FACS analysis. No significant correlation was observed between its expression and other known cellular phenotypes. Substrate attachment assays using blocking antibodies demonstrated that alpha 2 beta 1 integrin served as a receptor for collagen on HMEC and almost all breast carcinoma cells. However, its contribution to laminin binding of these cells appeared to be related to cellular differentiation as evaluated by sex steroid receptor status and by markers of epithelial-mesenchymal transition, i.e. loss of E-cadherin and expression of vimentin. Two different populations of non-malignant immortalized HMEC (184A1N4 and MCF-10A) contained cells capable of using alpha 2 beta 1 integrin as a laminin receptor. Breast cancer cell lines positive for estrogen receptor (ER) and E-cadherin (MCF-7, T47D, ZR75-1) could also use alpha 2 beta 1 integrin as a laminin receptor. Conversely, alpha 2 beta 1 integrin appeared to be incapable of binding to laminin or to be a very minor receptor for laminin on metastatic ER-negative breast carcinoma cells that expressed vimentin (MDA-MB 231, MDA-MB 435, and MDA-MB 436). These findings suggest that the ligand specificity of alpha 2 beta 1 integrin, i.e. its function as a laminin receptor, may be regulated during the malignant progression of breast carcinoma cells. A reduced contribution of alpha 2 beta 1 integrin to the cellular laminin binding appears to be associated with an increased malignant phenotype and with an epithelial-mesenchymal transition of breast carcinoma cells.

MCF-7 breast cancer cells transfected with protein kinase C-alpha exhibit altered expression of other protein kinase C isoforms and display a more aggressive neoplastic phenotype

Increased protein kinase C (PKC) activity in malignant breast tissue and positive correlations between PKC activity and expression of a more aggressive phenotype in breast cancer cell lines suggest a role for this signal transduction pathway in the pathogenesis and/or progression of breast cancer. To examine the role of PKC in the progression of breast cancer, human MCF-7 breast cancer cells were transfected with PKC-alpha, and a group of heterogenous cells stably overexpressing PKC-alpha were isolated (MCF-7-PKC-alpha). MCF-7-PKC-alpha cells expressed fivefold higher levels of PKC-alpha as compared to parental or vector-transfected MCF-7 cells. MCF-7-PKC-alpha cells also displayed a substantial increase in endogenous expression of PKC-beta and decreases in expression of the novel delta- and eta-PKC isoforms. MCF-7-PKC-alpha cells displayed an enhanced proliferative rate, anchorage-independent growth, dramatic morphologic alterations including loss of an epithelioid appearance, and increased tumorigenicity in nude mice. MCF-7-PKC-alpha cells exhibited a significant reduction in estrogen receptor expression and decreases in estrogen-dependent gene expression. These findings suggest that the PKC pathway may modulate progression of breast cancer to a more aggressive neoplastic process.

The relationship of cytoplasmic intermediate filaments and membrane antigens with hormone receptors, nuclear staining density, and mode of stromal invasion in human breast cancer

Serial sections on biopsies of 26 women with invasive breast carcinoma were stained for low molecular weight keratins (LKER), high molecular weight keratins (HKER), epithelial membrane antigen (EMA), vimentin (VIM), carcinoembryonic antigen (mCEA and pCEA), and nuclear estrogen (mER) and progesterone receptors (mPGR), using monoclonal and polyclonal sera. Specified areas were identified on serially sectioned slides and staining reactions were compared among areas as well as among patients. The study concludes: (1) LKER staining was positively related to (a) the percentage of tumor cells with densely stained nuclei, (b) a trabecular mode of stromal invasion, and (c) HKER and EMA staining, and inversely related to (d) VIM staining and gross tumor size. (2) HKER was also inversely related to gross tumor size. (3) VIM staining was positively related to pCEA staining. (4) VIM staining was inversely related to staining ER and PGR. (5) LKER, HKER, and EMA staining was stronger in areas of trabecular rather than confluent areas of stromal invasion within the same biopsy. (6) Staining for ER and PGR was not related to mode of stromal invasion, but showed a strong inverse relationship with mitotic index. Positive staining for LKER may be an indicator of better differentiation together with densely staining nuclei and trabecular mode of stromal invasion, whilst VIM and pCEA appear to be related to features indicative of lack of differentiation. Hormone receptor positivity seems to be strongly related to mitotic activity rather than differentiation.

Structural and biological consequences of increased vimentin expression in simple epithelial cell types

Cytoskeletal intermediate filaments (IFs) constitute a diverse family of proteins whose members are expressed in tissue-specific patterns. Although vimentin IFs are normally restricted to mesenchyme, a variety of cell types express vimentin alone or together with cell-specific IFs during growth, differentiation, and neoplasia. In this study, we have investigated the influence of increased vimentin expression on the simple epithelial cell phenotype. An expression vector encoding a human vimentin cDNA was transfected into murine HR9 endoderm and F9 embryonal carcinoma cell lines, which serve as models for early extraembryonic epithelial differentiation. Stable clones that expressed varying levels of human vimentin were characterized by human vimentin were characterized by immunofluorescence and biochemical analysis. A relatively high level of vimentin expression in HR9 and differentiated F9 epithelial cells resulted in aberrant vimentin structures with co-collapse of keratin K8/K18 filaments and lowered amounts of keratin protein. In F9 epithelial cells, the desmosomal proteins DP I/II did not appear to localize to cell surface desmosome s but rather but rather co-aggregated with the perturbed IFs. Although overall cell morphology was not dramatically altered, individual nuclei were distorted by excess intracellular vimentin. Furthermore, cell proliferation as well as the cell spreading response time were slowed. Ther appears to be a threshold effect regarding overall vimentin levels as cells that expressed lower amounts of the human vimentin exhibited no obvious structural nor biological effects. Our results demonstrate that wild-type vimentin can act as a "mutant" protein when present at high intracellular levels, inducing a variety of phenotypic changes.

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.

Phyllodes tumor of the breast. An immunohistochemical study of 28 cases with special attention to the role of myofibroblasts

The presence of myofibroblasts in the stroma of Phyllodes tumor of the breast has been documented in single cases by means of electron microscopy and immunohistochemistry. In this study, we re-evaluate the immunophenotype exhibited by 28 Phyllodes tumors (14 benign, 6 borderline and 8 malignant) in order to state the relevance of myofibroblasts as active stromal elements in these tumors. Vimentin showed positive immunostaining in the stroma of all the cases (100%), muscle-specific actin in 21 (75%), and desmin in 7 (25%). By contrast, stromal cells were uniformly negative for S-100 protein, keratins (AE1/AE3 and CAM 5.2), and epithelial membrane antigen (EMA). The epithelial component showed the typical two-layered arrangement of ducts in every case. Myoepithelial (outer) cells immunostained with muscle-specific actin and S-100 protein, and in some cases with EMA and keratins, whereas the epithelial (inner) layer did so with keratins and EMA. To conclude, we have found a prominent myofibroblastic differentiation in stromal cells of many of such tumors. Our results also prove that no differences in intensity or distribution of such actin-positive stromal cells are seen between benign, borderline or malignant counterparts.

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.

Immunohistochemical reactivity in mesothelioma and adenocarcinoma: a stepwise logistic regression analysis

Histological sections from 103 malignant mesotheliomas and 43 adenocarcinoma metastases in pleural biopsies were investigated for reactivity against a panel of 11 different antibodies. The size of the material allowed the evaluation by stepwise logistic regression analysis, which selected five parameters of major importance: vimentin reactivity in epithelial cells, reactivity to low-molecular-weight keratins in fibrous cells, strong membrane accentuation of EMA reactivity, and lack of reactivity to LeuM1 and BerEp4. Three of these criteria were sufficient to identify a mesothelioma with high specificity and with a sensitivity of approximately 70%. Whilst the monoclonal anti-CEA tested was the most valuable single parameter, it did not add any diagnostic information to the combination of criteria selected by the stepwise logistic regression analysis. However, this antibody can be used to exclude most of the adenocarcinomas from further analysis with the more extensive panel.

Immunohistochemical localisation of cytokeratin and vimentin intermediate filament proteins in canine mammary tumours

Monoclonal antibodies to human stratifying keratin (StK), simple keratin (SK), broad spectrum keratin (BSK) and vimentin were applied to 47 canine mammary tumours (three benign hyperplasia, 26 benign mammary tumours, one malignant mixed tumour, two malignant complex tumours, seven lobular carcinomas, three papillary carcinomas and five squamous cell carcinomas). In benign hyperplasia the SK antibody reacted with acinar and duct epithelial cells; the StK and BSK antibodies reacted strongly with duct epithelial cells in the canine mammary tumours expressed mainly keratins of stratified epithelia rather than those of simple epithelia. Myoepithelial cells in complex and mixed tumours can express StK and vimentin. The finding might be helpful in the assessment of complex tumours where stromal reactions may be confused with myoepithelial neoplastic proliferation. Stromal mesenchymal tissues, including precartilage in complex tumours, and clearly differentiated myoepithelial cells always stained positively for vimentin. Occasional carcinoma cells stained positively for vimentin.

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.