Regulation of vimentin expression in cultured human mammary epithelial cells

Porcine and Chicken Intestinal Epithelial Cell Models for Screening Phytogenic Feed Additives—Chances and Limitations in Use as Alternatives to Feeding Trials

Numerous bioactive plant additives have shown various positive effects in pigs and chickens. The demand for feed additives of natural origin has increased rapidly in recent years to support the health of farm animals and thus minimize the need for antibiotics and other drugs. Although only in vivo experiments can fully represent their effect on the organism, the establishment of reliable in vitro methods is becoming increasingly important in the goal of reducing the use of animals in experiments. The use of cell models requires strict control of the experimental conditions so that reliability and reproducibility can be achieved. In particular, the intestinal porcine epithelial cell line IPEC-J2 represents a promising model for the development of new additives. It offers the possibility to investigate antioxidative, antimicrobial, anti- or pro-proliferative and antiviral effects. However, the use of IPEC-J2 is limited due to its purely epithelial origin and some differences in its morphology and functionality compared to the in vivo situation. With regard to chickens, the development of a reliable intestinal epithelial cell model has attracted the attention of researchers in recent years. Although a promising model was presented lately, further studies are needed to enable the standardized use of a chicken cell line for testing phytogenic feed additives. Finally, co-cultivation of the currently available cell lines with other cell lines and the development of organoids will open up further application possibilities. Special emphasis was given to the IPEC-J2 cell model. Therefore, all publications that investigated plant derived compounds in this cell line were considered. The section on chicken cell lines is based on publications describing the development of chicken intestinal epithelial cell models.

Diverse origins and activation of fibroblasts in cardiac fibrosis

Cardiac fibroblasts (cFBs) have emerged as a heterogenous cell population. Fibroblasts are considered the main cell source for synthesis of the extracellular matrix (ECM) and as such a dysregulation in cFB function, activity, or viability can lead to disrupted ECM structure or fibrosis. Fibrosis can be initiated in response to different injuries and stimuli, and can be reparative (beneficial) or reactive (damaging). FBs need to be activated to myofibroblasts (MyoFBs) which have augmented capacity in synthesizing ECM proteins, causing fibrosis. In addition to the resident FBs in the myocardium, a number of other cells (pericytes, fibrocytes, mesenchymal, and hematopoietic cells) can transform into MyoFBs, further driving the fibrotic response. Multiple molecules including hormones, cytokines, and growth factors stimulate this process leading to generation of activated MyoFBs. Contribution of different cell types to cFBs and MyoFBs can result in an exponential increase in the number of MyoFBs and an accelerated pro-fibrotic response. Given the diversity of the cell sources, and the array of interconnected signalling pathways that lead to formation of MyoFBs and subsequently fibrosis, identifying a single target to limit the fibrotic response in the myocardium has been challenging. This review article will delineate the importance and relevance of fibroblast heterogeneity in mediating fibrosis in different models of heart failure and will highlight important signalling pathways implicated in myofibroblast activation.

Characterization of rodent Sertoli cell primary cultures

Sertoli cells play a vital role in spermatogenesis by offering physical and nutritional support to the differentiating male germ cells. They form the blood-testis barrier and secrete growth factors essential for germ cell differentiation. Sertoli cell primary cultures are critical for understanding the regulation of spermatogenesis; however, obtaining pure cultures has been a challenge. Rodent Sertoli cell isolation protocols do not rule out contamination by the interstitial or connective tissue cells. Sertoli cell-specific markers could be helpful, but there is no consensus. Vimentin, the most commonly used marker, is not specific for Sertoli cells since its expression has been reported in peritubular myoid cells, mesenchymal stem cells, fibroblasts, macrophages, and endothelial cells, which contaminate Sertoli cell preparations. Markers based on transcription and growth factors also have limitations. Thus, the impediment to obtaining pure Sertoli cell cultures pertains to both the method of isolation and marker usage. The aim of this review is to discuss improvements to current methods of rodent Sertoli cell primary cultures, assess the properties of prepubertal versus mature Sertoli cell cultures, and propose steps to improve cellular characterization. Potential benefits of using contemporary approaches, including lineage tracing, specific cell ablation, and RNA-seq for obtaining Sertoli-specific transcript markers are discussed. Evaluating the specificity and applicability of these markers at the protein level to characterize Sertoli cells in culture would be critical. This review is expected to positively impact future work using primary cultures of rodent Sertoli cells.

Establishment and characterization of an immortalized renal cell line of the Chinese tree shrew (Tupaia belangeri chinesis)

The Chinese tree shrew holds a great potential as a viable animal model in biomedical research, especially for infectious diseases and neuropsychiatric disorders. A thorough understanding of the innate immunity, which represents the first line that defends the host against viral infection, of the Chinese tree shrew, is needed. However, the progress is hindered by the lack of a proper cell line for research usage. In this study, we established a cell line that is applicable to the study of tree shrew innate immune responses against viral infections. The Chinese tree shrew primary renal cells (TSPRCs) were immortalized by simian virus 40 large T antigen (SV40LT) transduction, and the immortalized cells were termed TSR6 (tree shrew renal cell #6). TSR6 showed a similar morphology to TSPRCs and expressed the epithelial cell-specific marker cytokeratin 18 (KRT18). In addition, TSR6 could be transfected by transfection reagent and was suitable for CRISPR/Cas9-mediated gene editing. Infection of Newcastle disease virus (NDV) or herpes simplex virus 1 (HSV-1) in TSR6 induced the mRNA expression of tree shrew interferon-β (tIFNB1) and myxovirus resistance protein 1 (tMx1) in a dose- and time-dependent manner. Collectively, we successfully established a tree shrew renal cell line and demonstrated that this cell line was suitable for the study of the innate immune response to viral infections.

Cardiac fibrosis: new insights into the pathogenesis

Cardiac fibrosis is defined as the imbalance of extracellular matrix (ECM) production and degradation, thus contributing to cardiac dysfunction in many cardiac pathophysiologic conditions. This review discusses specific markers and origin of cardiac fibroblasts (CFs), and the underlying mechanism involved in the development of cardiac fibrosis. Currently, there are no CFs-specific molecular markers. Most studies use co-labelling with panels of antibodies that can recognize CFs. Origin of fibroblasts is heterogeneous. After fibrotic stimuli, the levels of myocardial pro-fibrotic growth factors and cytokines are increased. These pro-fibrotic growth factors and cytokines bind to its receptors and then trigger the activation of signaling pathway and transcriptional factors via Smad-dependent or Smad independent-manners. These fibrosis-related transcriptional factors regulate gene expression that are involved in the fibrosis to amplify the fibrotic response. Understanding the mechanisms responsible for initiation, progression, and amplification of cardiac fibrosis are of great clinical significance to find drugs that can prevent the progression of cardiac fibrosis.

Stromal cells in breast cancer as a potential therapeutic target

Breast cancer in the United States is the second most commonly diagnosed cancer in women. About 1 in 8 women will develop invasive breast cancer over the course of her lifetime and breast cancer remains the second leading cause of cancer-related death. In pursuit of novel therapeutic strategies, researchers have examined the tumor microenvironment as a potential anti-cancer target. In addition to neoplastic cells, the tumor microenvironment is composed of several critical normal cell types, including fibroblasts, vascular and lymph endothelial cells, osteoclasts, adipocytes, and immune cells. These cells have important roles in healthy tissue stasis, which frequently are altered in tumors. Indeed, tumor-associated stromal cells often contribute to tumorigenesis, tumor progression, and metastasis. Consequently, these host cells may serve as a possible target in anti-tumor and anti-metastatic therapeutic strategies. Targeting the tumor associated host cells offers the benefit that such cells do not mutate and develop resistance in response to treatment, a major cause of failure in cancer therapeutics targeting neoplastic cells. This review discusses the role of host cells in the tumor microenvironment during tumorigenesis, progression, and metastasis, and provides an overview of recent developments in targeting these cell populations to enhance cancer therapy efficacy.

Sensing of Vimentin mRNA in 2D and 3D Models of Wounded Skin Using DNA-Coated Gold Nanoparticles

Wound healing is a highly complex biological process, which is accompanied by changes in cell phenotype, variations in protein expression, and the production of active biomolecules. Currently, the detection of proteins in cells is done by immunostaining where the proteins in fixed cells are detected by labeled antibodies. However, immunostaining cannot provide information about dynamic processes in living cells, within the whole tissue. Here, an easy method is presented to detect the transition of epithelial to mesenchymal cells during wound healing. The method employs DNA-coated gold nanoparticle fluorescent nanoprobes to sense the production of Vimentin mRNA expressed in mesenchymal cells. Fluorescence microscopy is used to achieve temporal detection of Vimentin mRNA in wounds. 3D light-sheet microscopy is utilized to observe the dynamic expression of Vimentin mRNA spatially around the wounded site in skin tissue. The use of DNA-gold nanoprobes to detect mRNA expression during wound healing opens up new possibilities for the study of real-time mechanisms in complex biological processes.

Generation of full-thickness skin equivalents using hair follicle-derived primary human keratinocytes and fibroblasts

Skin equivalents are increasingly used as human-based test systems for basic and preclinical research. Most of the established skin equivalents are composed of primary keratinocytes and fibroblasts, isolated either from excised human skin or juvenile foreskin following circumcisions. Although the potential of hair follicle-derived cells for the generation of skin equivalents has been shown, this approach normally requires microdissections from the scalp for which there is limited subject compliance or ethical approval. In the present study, we report a novel method to isolate and cultivate keratinocytes and fibroblasts from plucked hair follicles that were then used to generate skin equivalents. The procedure is non-invasive, inflicts little-pain, and may allow easy access to patient-derived cells without taking punch biopsies. Overall, minor differences in morphology, ultrastructure, expression of important structural proteins, or barrier function were observed between skin equivalents generated from hair follicle-derived or interfollicular keratinocytes and fibroblasts. Interestingly, improved basal lamina formation was seen in the hair follicle-derived skin equivalents. The presented method here allows easy and non-invasive access to keratinocytes and fibroblasts from plucked hair follicles that may be useful particularly for the generation of skin disease equivalents.

Cardiac Fibroblast Activation Post-Myocardial Infarction: Current Knowledge Gaps

In response to myocardial infarction (MI), the wound healing response of the left ventricle (LV) comprises overlapping inflammatory, proliferative, and maturation phases, and the cardiac fibroblast is a key cell type involved in each phase. It has recently been appreciated that, early post-MI, fibroblasts transform to a proinflammatory phenotype and secrete cytokines and chemokines as well as matrix metalloproteinases (MMPs). Later post-MI, fibroblasts are activated to anti-inflammatory and proreparative phenotypes and generate anti-inflammatory and proangiogenic factors and extracellular matrix (ECM) components that form the infarct scar. Additional studies are needed to systematically examine how fibroblast activation shifts over the timeframe of the MI response and how modulation at different activation stages could alter wound healing and LV remodeling in distinct ways. This review summarizes current fibroblast knowledge as the foundation for a discussion of existing knowledge gaps.

S100A4 (metastasin) positive mesenchymal canine mammary tumour spheroids reduce Tenascin C synthesis under DMSO exposure in vitro

In breast cancer research S100A4-positive tumour-associated stromal cells are assumed as primary source of Tenascin C (TNC) in the metastatic environment. Aim of the present study was to isolate and characterize S100A4/TNC positive stromal canine mammary tumour (CMT) cells. Cells grown as scaffold-free spheroids were investigated for S100A4, TNC, and proliferative activity under 1.8% DMSO stimulation by means of Western blot and immunohistochemistry. DMSO is a commonly used drug solvent despite well-known side effects on cells including TNC expression. DMSO did not affect proliferation, but TNC was significantly reduced under DMSO exposure for 7 and 14 days, whereby for S100A4 a reducing effect was only observed after 14 days. Without DMSO, cells stably expressed TNC and S100A4 which makes them suitable to be used in experimental approaches requiring S100A4/TNC expressing CMT stromal cells. Results show that 1.8% DMSO should not be used as solvent for experiments concerning TNC/S100A4 expression.

Fibroblast activation in cancer: when seed fertilizes soil

In solid cancers, activated fibroblasts acquire the capacity to provide fertile soil for tumor progression. Specifically, cancer-associated fibroblasts (CAFs) establish a strong relationship with cancer cells. This provides advantages to both cell types: whereas cancer cells initiate and sustain CAF activation, CAFs support cancer cell growth, motility and invasion. This results in tumor progression, metastasis and chemoresistance. Numerous studies have detailed the mechanisms involved in fibroblast activation and cancer progression, some of which are reviewed in this article. Cancer cells and CAFs are "partners in crime", and their interaction is supported by inflammation. An understanding of the enemy, the cancer cell population and its "allies" should provide novel opportunities for targeted-drug development. Graphical Abstract Molecular mechanism of fibroblast activation. a Normal fibroblasts are the most common cell type in the extracellular matrix and are responsible for the synthesis of collagens and fibrilar proteins. Under normal conditions, fibroblasts maintain tissue homeostasis and contribute to proper cell communication and function. Fibroblasts can be activated by a diverse set of factors secreted from cancer or immune cells. Not only growth factors such as TGF-β, PDGF, HGF and FGF but also interleukins, metalloproteinases and reactive oxygen species can promote activation. Likewise, transcriptional factors such as NF-κB and HSF-1 play an important role, as do the gene family of metalloproteinase inhibitors, Timp and the NF-κB subunit, p62. Interestingly, fibroblasts themselves can stimulate cancer cells to support activation further. b Once activated, fibroblasts undergo a phenotype switch and become cancer-associated fibroblasts (CAFs) expressing various markers such as α-SMA, FSP1, vimentin and periostatin. c Recently, the LIF/GP130/IL6-R pathway has been identified as a signaling cascade involved in fibroblast activation. Upon LIF stimulation, JAK is phosphorylated and further activates STAT3, a transcriptional factor that is then translocated into the nucleus where it promotes the transcription of genes responsible for cell growth, differentiation, proliferation and apoptosis. Ruxolitinib can inhibit JAK and prevent STAT3 activation. Further on, the maintenance of JAK activation is supported by epigenetical changes and post-translational modifications. Once pSTAT3 is acetylated by histon acetyltransferase, p300, it leads to the loss of expression of SHP-1, which is a negative regulator of the JAK/STAT pathway. Silencing of SHP-1 steers the constitutive activation of JAK and STAT3.

Cardiac Fibrosis: The Fibroblast Awakens

Myocardial fibrosis is a significant global health problem associated with nearly all forms of heart disease. Cardiac fibroblasts comprise an essential cell type in the heart that is responsible for the homeostasis of the extracellular matrix; however, upon injury, these cells transform to a myofibroblast phenotype and contribute to cardiac fibrosis. This remodeling involves pathological changes that include chamber dilation, cardiomyocyte hypertrophy and apoptosis, and ultimately leads to the progression to heart failure. Despite the critical importance of fibrosis in cardiovascular disease, our limited understanding of the cardiac fibroblast impedes the development of potential therapies that effectively target this cell type and its pathological contribution to disease progression. This review summarizes current knowledge regarding the origins and roles of fibroblasts, mediators and signaling pathways known to influence fibroblast function after myocardial injury, as well as novel therapeutic strategies under investigation to attenuate cardiac fibrosis.

In vitro comparative models for canine and human breast cancers

During the past four decades, an increased number of similarities between canine mammary tumors and human breast cancer have been reported: molecular, histological, morphological, clinical and epidemiological, which lead to comparative oncological studies. One of the most important goals in human and veterinary oncology is to discover potential molecular biomarkers that could detect breast cancer in an early stage and to develop new effective therapies. Recently, cancer cell lines have successfully been used as an in vitro model to study the biology of cancer, to investigate molecular pathways and to test the efficiency of anticancer drugs. Moreover, establishment of an experimental animal model for the study of human breast cancer will improve testing potential anti-cancer therapies and the discovery of effective therapeutic schemes suitable for human clinical trials.

In this review, we collected data from previous studies that strengthen the value of canine mammary cancer cell lines as an in vitro model for the study of human breast cancer.

Upregulation of GM-CSF by TGF-β1 in epithelial mesenchymal transition of human HERS/ERM cells

Hertwig's epithelial root sheath/epithelial rests of Malassez (HERS/ERM) have been suggested to play an important role in tooth root formation, particularly in periodontal development. Epithelial mesenchymal transition (EMT) has been suggested to contribute to root development in tooth. However, the mechanism of interaction between HERS/ERM cells and dental mesenchymal cells has not been fully understood. In this study, we investigated the effect of exogenous transforming growth factor beta 1 (TGF-β1) in human HERS/ERM cells in order to verify the role of granulocyte macrophage colony-stimulating factor (GM-CSF) in EMT process. Antibody array was used to screen secretion factors by exogenous TGF-β1. Secretion of GM-CSF was increased by exogenous TGF-β1. Expression levels of EMT markers, vimentin, ZEB1 (zinc finger E-box binding homeobox 1), and E-cadherin, were confirmed using reverse transcription polymerase chain reaction and immunocytochemistry. Treatment with GM-CSF increased the expression of vimentin and ZEB1, similar to TGF-β1 treatment, and decreased the expression of E-cadherin. Our results suggest that GM-CSF could induce EMT in human HERS/ERM cells.

Improved cell line IPEC-J2, characterized as a model for porcine jejunal epithelium

Cell lines matching the source epithelium are indispensable for investigating porcine intestinal transport and barrier properties on a subcellular or molecular level and furthermore help to reduce animal usage. The porcine jejunal cell line IPEC-J2 is established as an in vitro model for porcine infection studies but exhibits atypically high transepithelial resistances (TER) and only low active transport rates so that the effect of nutritional factors cannot be reliably investigated. This study aimed to properly remodel IPEC-J2 and then to re-characterize these cells regarding epithelial architecture, expression of barrier-relevant tight junction (TJ) proteins, adequate TER and transport function, and reaction to secretagogues. For this, IPEC-J2 monolayers were cultured on permeable supports, either under conventional (fetal bovine serum, FBS) or species-specific (porcine serum, PS) conditions. Porcine jejunal mucosa was analyzed for comparison. Main results were that under PS conditions (IPEC-J2/PS), compared to conventional FBS culture (IPEC-J2/FBS), the cell height increased 6-fold while the cell diameter was reduced by 50%. The apical cell membrane of IPEC-J2/PS exhibited typical microvilli. Most importantly, PS caused a one order of magnitude reduction of TER and of trans- and paracellular resistance, and a 2-fold increase in secretory response to forskolin when compared to FBS condition. TJ ultrastructure and appearance of TJ proteins changed dramatically in IPEC-J2/PS. Most parameters measured under PS conditions were much closer to those of typical pig jejunocytes than ever reported since the cell line’s initial establishment in 1989. In conclusion, IPEC-J2, if cultured under defined species-specific conditions, forms a suitable model for investigating porcine paracellular intestinal barrier function.

Isolation and characterization of biliary epithelial and stromal cells from resected human cholangiocarcinoma: a novel in vitro model to study tumor-stroma interactions

Cholangiocarcinoma (CCA) is a devastating malignancy arising from the bile ducts. Cancer-associated fibroblasts (CAFs) are key players in CCA invasiveness and in the generation of a desmoplastic reaction. The aim of the present study was to develop a novel model by which to study tumor-stroma interactions using primary cultures of human biliary epithelial cells (hBECs) and stromal cells (SCs) in CCA. hBECs and SCs, isolated from surgical resections (n=10), were semi-purified by centrifugation on a Percoll gradient; hBECs were further immunopurified. hBECs and SCs were characterized using epithelial [cytokeratin 7 (CK7) and CK19] and mesenchymal [vimentin (VMN), α-smooth muscle actin (α-SMA), CD68] cell markers. The purity of cultured cells was assessed by fluorescent immunocytochemistry. hBECs were HEA125/CK7/CK19-positive and VMN/α-SMA-negative. SCs were VMN/α-SMA-positive and CK7/CK19-negative. CCA 2-D culture models have been described but they use long-standing CCA cell lines of various biliary tumor cell origins with stromal cells derived from non-cholangiocarcinoma tissues. Recently, a novel 3-D organotypic co-culture model of rat cholangiocarcinoma was described. In the present study, we obtained pure and stable primary cultures of hBECs and SCs from CCA surgical specimens. These cell cultures may provide a useful tool by which to study CCA tumor-stroma interactions.

Significance of podoplanin expression in cancer-associated fibroblasts: a comprehensive review

Cancer-associated fibroblasts (CAFs) are well-known to be part of the tumor microenvironment. This heterogeneous population of cells of the tumor microenvironment via secretion of various growth factors and cytokines was shown to contribute to increased cancer cell proliferation rate, migration, invasiveness and other key processes such as angiogenesis and lymphangiogenesis. Recent studies identified podoplanin as a marker of CAFs in various malignancies and its expression in these cells was shown to influence cancer progression. In some studies it yielded a prognostic impact on patient survival which was strongly dependent on the entity of the tumor. This review summarizes recent findings concerning the biology of podoplanin in cancer progression with particular emphasis on its expression in CAFs.

Cardiac fibroblasts, fibrosis and extracellular matrix remodeling in heart disease

Fibroblasts comprise the largest cell population in the myocardium. In heart disease, the number of fibroblasts is increased either by replication of the resident myocardial fibroblasts, migration and transformation of circulating bone marrow cells, or by transformation of endothelial/epithelial cells into fibroblasts and myofibroblasts. The primary function of fibroblasts is to produce structural proteins that comprise the extracellular matrix (ECM). This can be a constructive process; however, hyperactivity of cardiac fibroblasts can result in excess production and deposition of ECM proteins in the myocardium, known as fibrosis, with adverse effects on cardiac structure and function. In addition to being the primary source of ECM proteins, fibroblasts produce a number of cytokines, peptides, and enzymes among which matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitor of metalloproteinases (TIMPs), directly impact the ECM turnover and homeostasis. Function of fibroblasts can also in turn be regulated by MMPs and TIMPs. In this review article, we will focus on the function of cardiac fibroblasts in the context of ECM formation, homeostasis and remodeling in the heart. We will discuss the origins and multiple roles of cardiac fibroblasts in myocardial remodeling in different types of heart disease in patients and in animal models. We will further provide an overview of what we have learned from experimental animal models and genetically modified mice with altered expression of ECM regulatory proteins, MMPs and TIMPs.

Tamoxifen-resistant, ER-positive MAC 51 cell line with a high metastatic potential developed from a spontaneous breast cancer mouse model

We developed and characterized an estrogen-responsive and ER-positive murine breast cancer cell line (MAC51) from a spontaneous breast cancer animal model. These cells are overexpressed with K8, K18 and K19 proteins in an immunofluoresence assay. Upregulation of ER alpha was observed in the immunofluoresence assay, real-time PCR analysis and western blot assay. A colocalization experiment in MAC 51 showed cytoplasmic colocalization of K18 and K19 proteins with ER α. Real-time analysis of tumor samples from engrafted animals, MAC 51, metastatic liver and metastatic ovary revealed overexpression of K8 and K18 compared to the respective controls. A hormone responsive experiment in immunodeficient mice showed highly significant decreases in estrogen and tumor volume after 14 days ovariectomization. The tumorogenicity assay showed higher (3 × 10 (5)) and lower (3 × 10(4)) concentrations of MAC 51 cells that developed tumors within 2 weeks post-transplantation. Tumor morphology and histology resembled a sarcoma pattern but our spontaneous model appeared in an adenocarcinoma pattern. Metastasis to different organs occurred through hematogenous and lymphatic routes. We assessed the potency of the anticancer effect in MAC 51 cells by treating various anticancer drugs with E2, followed by studying apoptotic gene expression profiles. E2 and E2+ tamoxifen-treated cells showed upregulation of apoptotic genes caspase 1, 3, 9, P53 and Bcl-xl but the tamoxifen- and paclitaxel-treated cells did not upregulate the apoptotic genes. Tamoxifen-resistant, ER-positive and high metastatic potential cell lines from murine origin are very rare. Also, estrogen greatly induced apoptosis in this cell line, hence MAC 51 has a greater application potential to evaluate low doses of estrogen with other targeted therapeutic drugs to treat breast cancer.

Establishment and characterization of a buffalo (Bubalus bubalis) mammary epithelial cell line

BACKGROUND

The objective of this study was to establish the buffalo mammary epithelial cell line (BuMEC) and characterize its mammary specific functions.

METHODOLOGY

Buffalo mammary tissue collected from the slaughter house was processed enzymatically to obtain a heterogenous population of cells containing both epithelial and fibroblasts cells. Epithelial cells were purified by selective trypsinization and were grown in a plastic substratum. The purified mammary epithelial cells (MECs) after several passages were characterized for mammary specific functions by immunocytochemistry, RT-PCR and western blot.

PRINCIPAL FINDINGS

The established buffalo mammary epithelial cell line (BuMEC) exhibited epithelial cell characteristics by immunostaining positively with cytokeratin 18 and negatively with vimentin. The BuMEC maintained the characteristics of its functional differentiation by expression of β-casein, κ-casein, butyrophilin and lactoferrin. BuMEC had normal growth properties and maintained diploid chromosome number (2n = 50) before and after cryopreservation. A spontaneously immortalized buffalo mammary epithelial cell line was established after 20 passages and was continuously subcultured for more than 60 passages without senescence.

CONCLUSIONS

We have established a buffalo mammary epithelial cell line that can be used as a model system for studying mammary gland functions.

A mammary stem cell population identified and characterized in late embryogenesis reveals similarities to human breast cancer

Gene expression signatures relating mammary stem cell populations to breast cancers have focused on adult tissue. Here, we identify, isolate, and characterize the fetal mammary stem cell (fMaSC) state since the invasive and proliferative processes of mammogenesis resemble phases of cancer progression. fMaSC frequency peaks late in embryogenesis, enabling more extensive stem cell purification than achieved with adult tissue. fMaSCs are self-renewing, multipotent, and coexpress multiple mammary lineage markers. Gene expression, transplantation, and in vitro analyses reveal putative autocrine and paracrine regulatory mechanisms, including ErbB and FGF signaling pathways impinging on fMaSC growth. Expression profiles from fMaSCs and associated stroma exhibit significant similarities to basal-like and Her2+ intrinsic breast cancer subtypes. Our results reveal links between development and cancer and provide resources to identify new candidates for diagnosis, prognosis, and therapy.

The origin of fibroblasts and mechanism of cardiac fibrosis

Fibroblasts are at the heart of cardiac function and are the principal determinants of cardiac fibrosis. Nevertheless, cardiac fibroblasts remain poorly characterized in molecular terms. Evidence is evolving that the cardiac fibroblast is a highly heterogenic cell population, and that such heterogeneity is caused by the distinct origins of fibroblasts in the heart. Cardiac fibroblasts can derive either from resident fibroblasts, from endothelial cells via an endothelial-mesenchynmal transition or from bone marrow-derived circulating progenitor cells, monocytes and fibrocytes. Here, we review the function and origin of fibroblasts in cardiac fibrosis.NB. The information given is correct.

Fibroblasts in cancer

Tumours are known as wounds that do not heal - this implies that cells that are involved in angiogenesis and the response to injury, such as endothelial cells and fibroblasts, have a prominent role in the progression, growth and spread of cancers. Fibroblasts are associated with cancer cells at all stages of cancer progression, and their structural and functional contributions to this process are beginning to emerge. Their production of growth factors, chemokines and extracellular matrix facilitates the angiogenic recruitment of endothelial cells and pericytes. Fibroblasts are therefore a key determinant in the malignant progression of cancer and represent an important target for cancer therapies.

Telomere dysfunction drives chromosomal instability in human mammary epithelial cells

The development of genomic instability is an important step toward generating the multiple genetic changes required for cancer. Telomere dysfunction is one of the factors that contribute to tumorigenesis. Telomeres shorten with each cell division in the absence of telomerase. Human mammary epithelial cells (HMECs) obtained from normal human tissue demonstrate two growth phases. After an initial phase of active growth, HMECs exhibit a growth plateau termed selection. However, some cells can emerge from this growth plateau by spontaneously losing expression of the p16(INK4a) protein. These post-selection HMECs are capable of undergoing an additional 20-50 population doublings in culture. Continued proliferation of these post-selection HMECs leads to further telomere erosion, loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter bridge-fusion-breakage (BFB) cycles, generating massive chromosomal instability before terminating in a population growth plateau termed agonescence. We have found that the chromosome arms carrying the shortest telomeres are those involved in telomere-telomere type rearrangements. In addition, we found that the risk of a particular chromosome being unstable differs between individuals. Most importantly, we identified sister chromatid fusion as a first event in generating genomic instability in HMECs. During post-selection HMEC growth, double strand breaks are generated by both fused chromosomes as well as individual chromosomes with fused chromatids entering BFB cycles. These broken chromosome extremities are able to join other broken ends or eroded telomeres, producing massive chromosomal instability at the later passages of the cell culture. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.

Myoepithelial cells: good fences make good neighbors

The mammary gland consists of an extensively branched ductal network contained within a distinctive basement membrane and encompassed by a stromal compartment. During lactation, production of milk depends on the action of the two epithelial cell types that make up the ductal network: luminal cells, which secrete the milk components into the ductal lumen; and myoepithelial cells, which contract to aid in the ejection of milk. There is increasing evidence that the myoepithelial cells also play a key role in the organizational development of the mammary gland, and that the loss and/or change of myoepithelial cell function is a key step in the development of breast cancer. In this review we briefly address the characteristics of breast myoepithelial cells from human breast and mouse mammary gland, how they function in normal mammary gland development, and their recently appreciated role in tumor suppression.

TCDD causes suppression of growth and differentiation of MCF10A, human mammary epithelial cells by interfering with their insulin receptor signaling through c-Src kinase and ERK activation

One of the proposed mechanisms of carcinogenic action of TCDD (=dioxin) on breast cells is that it causes significant inhibition of proper differentiation of mammary duct epithelial cells and thereby increases the number of terminal end buds, which are susceptible to other carcinogens (Fenton et al., Toxicol Sci 2002;67:63-74; Brown et al., Carcinogenesis 1998; 19:1623-1629; Lamartiniere, J Mammary Gland Biol Neoplasia 2002;7:67-76). To address this topic, we selected MCF10A, a line of immortalized normal human breast epithelial cells as an in vitro model. An initial effort was made to optimize the cultural condition of MCF10A cells to promote the cell differentiation effect of insulin. Under this condition, TCDD clearly antagonized the action of insulin only in the presence of cholera toxin that is known to promote the differentiation of normal human breast epithelial cells. To test the hypothesis that TCDD-induced c-Src kinase activation is casually related to this compound's antagonistic action against insulin, we treated MCF10A cells with two c-Src blocking agents, an anti-Src antisense oligonucleotides blocker and a known specific inhibitor of c-Src kinase, PP-2 and studied the effect of insulin and TCDD on cell proliferation. The results showed that, in cells treated with either of these two c-Src blocking agents, the antagonistic effect of TCDD disappeared. It was also found that agents which specifically block the activation of ERK could also abrogate the action of TCDD to suppress insulin signaling. Together, these results indicate that the mechanism of the antagonistic action of TCDD on insulin signaling is mainly mediated through c-Src signaling through activation of ERK.

Epithelial to mesenchymal transition in human breast cancer can provide a nonmalignant stroma

A breast carcinoma biopsy showed cytochemical evidence of epithelial mesenchymal transition and an alpha-smooth muscle actin-positive stromal reaction. To study the lineage, and the nature of the cells in the stromal reaction, we derived a novel cell line, HBFL-1, from the explanted biopsy. HBFL-1 cells are immortal and exhibit a shared non-random X-chromosome inactivation pattern with the epithelial tumor of origin. Yet they closely resemble normal, finite-life-span fibroblasts by morphology, lack of tumor formation in nude mice, marker expression profile, protein pattern using two-dimensional gel electrophoresis and the ability to undergo myofibroblast conversion. HBFL-1 interacts reciprocally with tumor cells in collagen gel to induce activation of MMP2, leading to tumor-like behavior of epithelial colonies. In vivo, HBFL-1 cells resembled normal-derived myofibroblasts and conferred a significant 3.5- to 7-fold increase in MCF-7 tumor size in nude mice. However, that they were indeed not normal fibroblasts was revealed by residual keratin expression and formation of epithelial microfoci in a reconstituted basement membrane and in nude mice. We conclude that breast cancer can generate its own nonmalignant stroma and that one function for this is that of a reciprocal interaction with epithelial tumor cells to facilitate tumor growth.

Follicular growth of a thyroid carcinoma cell line (KAT-4) with abnormal E-cadherin and impaired epithelial barrier

Loss of the epithelial phenotype is a well-established phenomenon during progression of carcinomas to a more malignant state. In the present study, we describe a human thyroid tumor cell line (KAT-4), established from a poorly differentiated carcinoma, which displays exceptional features. In culture, the KAT-4 cells had a fast proliferation rate that was not restricted by high cell density, resulting in multilayered growth. Unexpectedly, the cells expressed normal levels of epithelial markers, e.g., cytokeratin, occludin, and E-cadherin, showed apical-basolateral polarization of the plasma membrane including microvilli and junction complexes, and formed intercellular lumens resembling thyroid follicles. Yet, when grown on filter, the cells were unable to establish a tight paracellular barrier. Moreover, E-cadherin expressed at the cell surface consisted of two peptides with abnormal size (135 and 95 kd, respectively) as compared to mature E-cadherin (120 kd) in nonneoplastic thyrocytes. Northern blot analysis and examination of immunoreactivity, glycosylation, and catenin binding suggested that E-cadherin was aberrant because of altered posttranscriptional processing. Thus, the KAT-4 thyroid carcinoma cell line has a unique phenotype, with maintained epithelial morphology despite dysfunctioning tight junctions, abnormal E-cadherin, and loss of contact-inhibited growth, that is not previously identified in other wild-type tumor cell lines.

Vimentin expression does not assist in predicting survival in ductal carcinoma of the breast

AIMS

To establish the value of vimentin expression in predicting survival in patients with breast cancer.

METHODS

Five-year follow-up data were obtained for 68 patients with ductal carcinoma (NOS) of the breast in whom vimentin expression had been studied in fresh frozen and formalin-fixed, paraffin-embedded tissue. The predictive value on survival of tumour size, growth fraction (as assessed using the Ki67 monoclonal antibody), oestrogen receptor status and Bloom and Richardson grade of the primary tumour, and the presence or absence of lymph node metastases in axillary samples, were also studied.

RESULTS

Twenty-two patients died of their disease within 5 years of diagnosis. Vimentin expression either on frozen or paraffin sections did not provide a statistically significant prediction of survival. On univariate analysis tumour grade, size and the presence of lymph node metastases provided prognostic information. Only lymph node status was of independent prognostic importance on multivariate analysis.

CONCLUSIONS

Whilst these results confirm the value of established prognostic factors, they do not support the use of vimentin expression in either fresh or fixed tissue for the prediction of survival in ductal carcinoma (NOS) of the breast.

IMPAN cells: a pancreatic model for differentiation into endocrine cells

It is currently believed that pancreatic progenitor or stem cells exist in the ductal cell population and that these cells have the ability to be grown and differentiated into endocrine cells for the treatment of diabetes. In this study, we have examined this potential in IMPAN (Immortalized Pancreatic) cells. These cells are derived from the adult H-2K(b)-tsA58 transgenic mouse. We observed an increased mRNA expression of insulin, proendocrine gene neurogenin 3, and beta-cell transcription factor Pdx1 when the cells were grown on bovine collagen I gels. The induction profile of these three genes was similar under the tested conditions. No glucagon or other endocrine-specific transcription factors were detectable. Application of GIP, GLP-1 derivative NN2211, and activin-A/betacellulin to IMPAN cells in normal culture did not lead to endocrine differentiation. In conclusion, it appears that the ability of IMPAN cells to mature to endocrine cells is limited.

Lactation affects expression of intermediate filaments in human breast epithelium

The human breast contains two epithelial lineages, luminal epithelial and myoepithelial. Specific patterns of expression of intermediate filaments have previously been demonstrated in the resting breast. To determine how terminal differentiation and lactation influenced expression of intermediate filaments in breast epithelial cells, we used Western blot analysis to measure the levels of vimentin, alpha-smooth muscle actin, keratin 14, and keratin 18 in the resting and lactating breast. Confocal immunofluorescence was used to determine the subcellular site of localization of the intermediate filaments. Vimentin was localised to myoepithelial cells in both the resting and lactating gland. There was a four-fold increase in vimentin protein levels in lactating tissue relative to resting tissue, and this may be related to increased cellular activity of the myoepithelial cells which surround secretory alveoli. Alpha-smooth muscle actin and keratin 14 were detected in myoepithelial cells, and similar levels of expression were found in lactating and resting tissue. In the resting breast, keratin 18 and keratin 8 were detected in luminal epithelial cells in a filamentous form, whereas in lactating tissue it was present in a punctate form in luminal cells and also seen as granules in the lumen of alveoli. Our results indicate that intermediate filament expression patterns are altered in the lactating human breast, and this may reflect their role in the fully functional gland.

Establishment of human pancreatic ductal cells in a long-term culture

Cultivation and preservation of human pancreatic ductal cells have remained a challenge. With a defined culture medium and refinement of culturing techniques, we have been able to maintain human pancreatic ductal cells without any genetic manipulation in culture for more than 16 months. Freshly isolated ductal fragments were placed on a rocker in M3:5 medium free of collagen for 14 days to remove fibroblasts and endocrine cells before allowing them to attach. The cells produced an excessive amount of mucin and expressed the duct specific cytokeratins (CK) 7 and 19, DU-PAN2, CA19-9, carbonic anhydrase II (CA II), and secretin receptors. During the course of the culture, however, the cells gradually lost the expression of CA II, secretin receptors, DU-PAN2, and CA 19-9 and assumed an undifferentiated phenotype, which showed an upregulation of transforming growth factor alpha (TGFalpha) and epidermal growth factor receptor (EGFR), an increase in the expression of Ki-67, and an increased binding to Phaseolus vulgaris leucoagglutinin (PHA-L) and tomato lectin. These ductal cells present a useful source with which to study physiologic aspects of ductal cells including differentiation.

Mucin gene expression in cultured human middle ear epithelial cells

For the advanced study of the cell and molecular biology of middle ear mucosa, an in vitro cell culture system is required. Although middle ear epithelial cells have been cultured from various species of laboratory animal, there have been no reports concerning a serial subculture system of human middle ear epithelial cells. In this paper, we describe the establishment of a primary culture system of human middle ear epithelial cells using a serum-free conditioned medium and the characterization of these cells by the expression of phenotypic characteristics of epithelial cells and mucin genes. Cultured cells were anchorage-dependent in terms of growth and showed a polygonal cobblestone-like appearance: desmosomes in the cell junction were observed by electron microscopy. In the immunocytochemical study, cytokeratin (epithelial cell marker) was expressed in all cultured cells. but von Willebrand factor (endothelial cell marker) was not. Unexpectedly, vimentin (fibroblast marker) was locally expressed, and a double stain showed the co-expression of both cytokeratin and vimentin in the same cell. The products of reverse transcriptase polymerase chain reaction from cultured cells yielded distinct bands compatible with the expected sizes of the MUC1, MUC2, MUC5AC and MUC5B genes. This culture system will allow us to prepare the cell line and to perform advanced studies of human middle ear mucosal biology.

Human mammary luminal epithelial cells contain progenitors to myoepithelial cells

The origin of the epithelial and myoepithelial cells in the human breast has not been delineated. In this study we have addressed whether luminal epithelial cells and myoepithelial cells are vertically connected, i.e., whether one is the precursor for the other. We used a primary culture assay allowing preservation of basic phenotypic traits of luminal epithelial and myoepithelial cells in culture. The two cell types were then separated immunomagnetically using antibodies directed against lineage-specific cell surface antigens into at best 100% purity. The cellular identity was ascertained by cytochemistry, immunoblotting, and 2-D gel electrophoresis. Luminal epithelial cells were identified by strong expression of cytokeratins 18 and 19 while myoepithelial cells were recognized by expression of vimentin and alpha-smooth muscle actin. We used a previously devised culture medium (CDM4) that allows vigorous expansion of proliferative myoepithelial cells and also devised a medium (CDM6) that allowed sufficient expansion of differentiated luminal epithelial cells based on addition of hepatocyte growth factor/scatter factor. The two different culture media supported each lineage for at least five passages without signs of interconversion. We used parallel cultures where we switched culture media, thus testing the ability of each lineage to convert to the other. Whereas the myoepithelial lineage showed no signs of interconversion, a subset of luminal epithelial cells, gradually, but distinctly, converted to myoepithelial cells. We propose that in the mature human breast, it is the luminal epithelial cell compartment that gives rise to myoepithelial cells rather than the other way around.

Deficient epithelial-fibroblast heterocellular gap junction communication can be overcome by co-culture with an intermediate cell type but not by E-cadherin transgene expression

Epithelial, fibroblast and intermediate cell lines were employed to examine the mechanism(s) essential for heterocellular gap junction intercellular communication in vitro. These cell lines were characterized extensively for cell type based on morphology, intermediate cytoskeletal proteins, cell adhesion molecules and their associated proteins, tight junction proteins as well as functional differentiation. All cell types expressed connexin43 and were dye-coupled in homocellular culture. Epithelial and intermediate cells or fibroblasts and intermediate cells readily assembled heterocellular connexin43-positive gap junction plaques when co-cultured, while gap junction plaques in mixed cultures of epithelial cells and fibroblasts were rare. Dye microinjection studies were used to show that there was little gap junction intercellular communication between epithelial cells and fibroblasts. However, intermediate cells were able to communicate with epithelial cells and, to a lesser extent, fibroblasts and could transfer dye to both epithelial cells and fibroblasts when all three cell types were cultured together. Fibroblasts that were stably transfected with a cDNA encoding E-cadherin had a greater tendency to aggregate and exhibited a more epithelial-like phenotype but heterocellular gap junction intercellular communication with epithelial cells, which endogenously express E-cadherin, was not enhanced. These results suggest that mutual expression of E-cadherin is insufficient to stimulate gap junction formation between epithelial cells and fibroblasts. Moreover, our results also demonstrate that communication gaps between epithelial cells and fibroblasts can be bridged by intermediate cells, a process that may be important in mammary gland development, growth, differentiation and cancer.

Relationships between intermediate filaments and cell-specific functions in renal cell lines derived from transgenic mice harboring the temperature-sensitive T antigen

Four renal cell lines were derived from glomeruli, proximal, distal, and cortical collecting tubules microdissected from the kidneys of transgenic mice carrying the temperature-sensitive mutant of the simian virus 40 large T antigen under the control of the vimentin promoter. All four cell lines contained large T antigen in their nuclei, grew rapidly, and contained vimentin filaments when grown in serum-enriched medium at the permissive temperature of 33 degrees C. The glomerular cell line formed multiple layers of cells and contained smooth muscle actin and desmin filaments, features of mesangial cells. The three tubule cell lines formed monolayers of polarized cuboid cells separated by tight junctions and having a patchy distribution of cytokeratins K8-K18. A shift from 33 degrees C to the restrictive temperature (39.5 degrees C) stopped cell growth in all cell lines and caused profound changes in the content of intermediate filaments. Vimentin was still present in mesangial-like cells, but the proximal, distal, and collecting tubule cells contained uniform networks of cytokeratins K8-K18 and desmoplakin I and II around the cell peripheries. Potassium transport, mediated by Na+-K+ ATPase pumps and specific cAMP hormonal sensitivities, significantly increased in proximal, distal, and collecting tubule cells when shifted from 33 degrees C to 39.5 degrees C. Thus, the temperature-dependent inactivation of large T antigen, responsible for the arrest of cell growth, did not affect the phenotype of mesangial-like glomerular cells but induced some changes in the expression of intermediate filaments and restored, at least partially, the main parental cell-specific functions in proximal, distal, and collecting tubule cultured cells.

Establishment and characterization of a bovine mammary myoepithelial cell line

The thermolabile large T-antigen, encoded by the simian virus 40 early region mutant tsA58, was used to establish clonal cell lines (BMM-UV) from primary bovine myoepithelial cells. The BMM-UV cells have undergone more than 300 population doublings without any signs of senescence, and they contain the intranuclear large T antigen. At low confluency, they grow in a spindlelike manner and develop very long projections that most likely allow for communication of cells at a distance from each other. Establishment results in a decrease in the number of cells that contract in response to oxytocin compared with the parental nontransfected cells (20% versus 45%). Oxytocin responsiveness of BMM-UV cells increases when the cells are cultured in a medium supplemented with staphylococcal proteases. Proliferation of BMM-UV cells increases when they are cultured in the presence of epidermal growth factor (10 ng/ml) or insulinlike growth factor I (50 ng/ml). The BMM-UV cells may become a useful model to study growth properties, cell-to-cell communication, and the function of bovine mammary myoepithelial cells.

Vimentin and cytokeratin expression in nodular hyperplasia and carcinoma of the prostate

AIM

To assess the value of vimentin and cytokeratin (CK) intermediate filament proteins (IFPs) in distinguishing between nodular hyperplasia and carcinoma of the prostate and in predicting prognosis in prostatic cancer.

METHODS

Fifteen carcinomas and 49 cases of nodular hyperplasia were studied using frozen sections and monoclonal antibodies to CK and vimentin IFPs.

RESULTS

There was no statistically significant difference in vimentin expression between nodular hyperplasia and carcinoma. The luminal epithelium in both also reacted with antibodies which detect CK8, 18 and 19. CK 7 expression was found in 57% of cases of nodular hyperplasia and was not identified in any carcinoma. There was a reaction with antibodies to CK1, 2, 3, 4, 10, 11, and 13 in only a minority of cases. There was no statistically significant difference in vimentin and CK reactivity in high and low grade carcinomas.

CONCLUSION

Neither vimentin nor CK expression assists in establishing whether a prostatic lesion is benign or malignant or in predicting the biological behaviour of a prostatic carcinoma.

Establishment and characterization of a new, spontaneously immortalized, pancreatic ductal cell line from the Syrian golden hamster

Spontaneously immortal pancreatic cell lines are not available. By use of a defined culture medium, such a line (TAKA-1) was established from the Syrian golden hamster. Cytological, cytogenetic, molecular biological, enzymatic and receptor patterns as well as antigenicity were studied and were compared with those of the normal hamster pancreatic ductal cells in vivo. TAKA-1 cells grew exponentially in a monolayer on collagen gel in a defined medium but did not proliferate in soft agar. Ultrastructurally, the cells closely resembled the normal hamster pancreatic ductal cells. Similarities and dissimilarities were found between the normal ductal cells and TAKA-1 cells. Similarities included the presence of cytokeratin, carbonic anhydrase and some tumor-associated antigens. However, unlike the normal ductal cells, TAKA-1 cells expressed blood group A antigen and anti-vimentin, showed affinity to selected lectins, and an abnormality of chromosome 3, which is suggested to be associated with immortality. Moreover, unlike the hamster pancreatic ductal cancer cells but like the normal hamster pancreatic ductal cells, TAKA-1 cells did not have a c-Ki-ras mutation. EGF, TGF-alpha and secretin, but not CCK or GRP, bound to the TAKA-1 cells. TAKA-1 cells produced TGF-alpha, and their growth was stimulated by exogenous EGF in serum-free medium. This cell line presents a suitable model for biologic and pathologic study of the hamster pancreatic ductal cells in vitro.

Cytokeratin intermediate filament expression in benign and malignant breast disease

AIM

To carry out a comprehensive study of cytokeratin expression in benign and malignant breast epithelium and breast myoepithelial cells; to examine changes in the cytokeratin profile in malignant and benign epithelium and in carcinomas of increasing histological grade.

METHODS

Frozen sections from fibroadenomas (19 cases), fibrocystic disease (19 cases), and infiltrating ductal (68 cases), lobular (seven cases), and mucinous carcinomas (three cases) were examined using a panel of monoclonal antibodies.

RESULTS

The luminal epithelium in all fibroadenomas and all cases of fibrocystic disease, as well as tumour cells in most carcinomas, reacted with the specific antibodies to cytokeratins 7, 8, 18, and 19 and to antibodies which included these cytokeratins in their specificities (Cam 5.2, AE1, AE3, RCK102, and LP34). In a few ductal carcinomas none of the tumour cells reacted for cytokeratins 7, 8, or 18. Three ductal carcinomas expressed cytokeratin 14. Only occasional cases expressed cytokeratins 3, 4, 10, and 13. Antibodies which included cytokeratins 5 and 14 in their specificities detected myoepithelial cells less efficiently than antiactin antibodies.

CONCLUSION

The cytokeratin profiles in the luminal epithelium in benign breast disease and in tumour cells in most carcinomas are similar in most cases. Some carcinomas, however, are negative for cytokeratins 7, 8, or 18. This may provide a means of predicting the biological behaviour of a histologically borderline lesion.

Immunohistochemical distribution of vimentin, desmin, glial fibrillary acidic protein and neurofilament proteins in feline tissues

The immunohistochemical distribution pattern of vimentin, desmin, glial fibrillary acidic protein and neurofilaments intermediate filament proteins has been analyzed in a wide range of formalin fixed, paraffin embedded tissues using polyclonal and monoclonal antibodies raised against non-feline antigens. The vimentin antibody reacted with mesenchymal cells, the desmin antibody with striated and smooth muscle fibres, the glial fibrillary acidic protein antibody with glial cells in the central and peripheral nervous system, and the neurofilament proteins antibody with neuronal cell bodies and processes. In addition, some epithelial cells were vimentin positive, perisinusoidal liver cells were desmin positive, and basal/myoepithelial cells of the mammary gland, and luteinic cells were glial fibrillary acidic protein positive. These staining patterns of feline tissues are basically similar with respect to that of corresponding tissues in other mammalian species for each of the four intermediate filament proteins studied, but some differences have been also noticed. This study confirms the broad interspecies cross-reactivity of intermediate filament proteins antisera and demonstrates their capability to differentiate particular types of feline cells and tissues.

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.

Effects of lymphocytes and fibroblasts on the growth of human mammary carcinoma cells studied in short-term primary cultures

Breast carcinomas commonly contain varying amounts of fibrous stroma and infiltrates of lymphoid cells. Dickson and Lippman (Endocrine Rev., 8,29, 1987) have proposed a model of growth regulation in breast cancer involving interactions between stroma and carcinoma cells. This model is based on results obtained with established cell lines. In an effort to bring experimentation closer to the clinical situation we have used short-term primary cultures from human breast cancer in co-cultures with lymphocytes and fibroblasts. Cultures were established in a chemically defined serum-free medium (CDM3). Cell types were characterized on the basis of live morphology and expression of vimentin and keratin 18. A semi-quantitative system was developed for measuring growth of epithelial cells, thus defining two indices: maximal growth index (GI-max) and growth rate (GR). Moderate-to-good growth was obtained from 34 out of 46 carcinoma samples (74%) and 30 out of 38 parallel samples of non-cancerous tissue (79%). Success in culture was negatively correlated with the amount of hard stroma but unrelated to age of patient or clinical status. Malignant epithelium was clearly identified in 12 out of 34 (35%) carcinoma samples. For the evaluation of responses of epithelial cells in co-cultures, the cultures from each sample were ranked according to GI-max.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemistry with keratin, vimentin, desmin, and alpha-smooth muscle actin monoclonal antibodies in canine mammary gland: normal mammary tissue

Normal canine mammary gland tissue was studied immunohistochemically with monoclonal antibodies (MoAbs) directed against various human keratin types, vimentin, desmin, and alpha-smooth muscle actin. Both ductal and alveolar luminal cells were immunoreactive with MoAbs recognizing respectively human keratins no. 7, 8, 18 and 19. In addition, some ductal luminal cells were labelled with a keratin 4 and a keratin 10 MoAb. Basal/myoepithelial cells were immunoreactive only with MoAbs directed against keratin 14, keratins 14 and 17, and alpha-smooth muscle actin. The vimentin MoAb merely labelled solitary loose intraluminal cells representing macro-phages or sloughed epithelial cells. These findings correspond largely to observations made in human breast tissue.

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.