Differential expression of keratin 19 in normal human epithelial tissues revealed by monospecific monoclonal antibodies

Expression Patterns of Cytokeratins (CK7, CK20, CK19, CK AE1/AE3) in Atypical Endometrial Hyperplasia Coexisting with Endometrial Cancer

Few studies have evaluated cytokeratin's (CK) staining patterns in atypical endometrial hyperplasia (AEH) coexisting with early-stage endometrial cancer (EC). We aimed to assess the staining patterns of selected CKs (CK7, CK19, CK20, CK AE1/AE3) in 74 patients with coexisting AEH and EC by independently analyzing both morphological variables. Specimens were collected from women with AEH and EC who underwent surgical interventions between 2012 and 2019 at the Department of Obstetrics and Gynecology of Vilnius University Hospital "Santaros Klinikos" in Vilnius, Lithuania. Immunostaining was also qualitatively classified as being heterogeneous or intense. The results revealed heterogeneous CK7 expression in all AEH cases and intense staining in 95.95% cases of AEH. The heterogeneous expression of CK7 was detected in all EC specimens. Intense CK7 expression was observed in 95.09% cases of EC G1 and in all G2 ECs. Heterogenous CK19 expression was present in all AEH specimens with intense staining in 92.42% of cases. Heterogeneous CK19 expression was observed in all EC samples with intense expression in 86.27% cases of EC G1 and 100% cases of EC G2. Interestingly, a significant relationship was found when comparing the heterogeneous expression of CK19 between AEH and well-differentiated EC. A significant difference was reported in the intense expression of CK AE1/AE3 (p = 0.031; p = 0.029) between AEH and G2 ECs and in the intense expression of CK AE1/AE3 between G1 and G2 ECs. CK20 staining was not a characteristic feature for AEH and early-stage EC. CK staining is present either in AEH or in early-stage endometrioid-subtype EC in different manners. Heterogeneous CK19 expression was significantly more common in AEH than in EC. CK20 expression was not associated with either AEH nor early-stage EC. An intense expression of CK AE1/AE3 was mainly present in moderately differentiated ECs, whereas the intense reactivity of AE1/AE3 showed a significant difference in well to moderately differentiated uterine tumors. The clinical implication of CK staining may aid in the more accurate diagnosis of AEH and early-stage EC as well as detect micrometastases leading to better oncological outcomes.

Differential distribution of intermediate filament proteins in the bovine and ovine tongues

Intermediate filaments constitute the most heterogeneous class among the major classes of cytoskeletal proteins of mammalian cells. The 40 or more intermediate filament proteins have been classified into five types which show very specific rules of expression in specialized cell types. This study aimed to investigate the immunohistochemical distribution of cytokeratins (CKs) 8, 18, and 19 as well as the intermediate filaments vimentin, laminin, and desmin in bovine and ovine tongues. Immunohistochemical staining was performed for CKs 8, 18, 19, vimentin, laminin, and desmin. Our results revealed similar immunostaining intensity and distribution among various CKs, contrasting with distinct patterns for vimentin, laminin, and desmin. Immunoreactions were primarily localized in serous acini and ductal epithelium for cytokeratins, while vimentin and laminin were evident in connective tissue, endothelium, serous acini, and desmin in striated and smooth muscles. This study highlighted the absence of CKs 8, 18, 19, vimentin, and desmin in the lingual epithelium of bovine and ovine tongues. These findings enabled the classification of epithelial cells based on their specific cytokeratin patterns. Furthermore, vimentin was identified in mesodermal tissues and organs, desmin in muscle tissue, and laminin played crucial roles in basement membrane formation, nerve tissue regeneration, innervation of epithelial taste buds, and tissue separation and connection. Our findings provide essential insights into intermediate filament dynamics at the cellular and tissue levels. They serve as a foundation for future studies using systematic molecular biological techniques in this field.

The role of cytokeratin 19 levels in the determination of endometriosis stages

OBJECTIVE/AIM

Endometrisosis, one of the most common gynecological disease, is characterized by the presence of endometriotic tissue outside of uterine cavity. The development and the validation of a simple blood biomarker specific and sensitive for endometriosis may facilitate the rapid and the accurate diagnosis of the disease and thus early treatment. Cytokeratin expression changes during epithelial differentiation and this expression is important for the modulation and the control of cell cycle regulation, tumor cell motility and apoptosis. Cytokeratin 19 (CK-19) is expressed in most simple epithelial cells and their malignant counterparts. The aim of this study is to investigate serum CK-19 expression levels in patients with endometriosis and to determine the diagnostic role of CK-19 levels in differentiating various stage of endometriosis.

METHODS

Ctytokeratin-19 expression and level were studied in 70 endometriosis patients and 50 volunteers by ELISA and RT-PCR. ROC analysis was performed by comparing all stages with each other and with the control group.

RESULTS

The CK-19 levels were significantly higher in the endometriosis groups than that of the control group by ELISA and RT-PCR. A significant (p < .05) difference was observed in endometriosis patients according to the stages.

CONCLUSION

Based on our data, it suggests that Cytokeratin-19 may have a potential role in the development of endometriosis.

A physiologically relevant, estradiol‐17β [E2]‐responsive in vitro tissue‐engineered model of the vaginal epithelium for vaginal tissue research

Aims

There are many situations where preclinical models of the human vagina would be valuable for in vitro studies into the pathophysiology of vaginally transmitted diseases, microbicide efficacy, irritability testing, and particularly, for assessing materials to be inserted in the vagina for support of the pelvic floor. The aim of this study is to develop a physiologically relevant, low cost, and ethically suitable model of the vagina using sheep vaginal tissue (SVT) to reduce the need for animal testing in gynecological research.

Methods

Tissue‐engineered (TE) vaginal models were developed by culturing primary vaginal epithelial cells and vaginal fibroblasts, isolated from the native SVTs on decellularized sheep vaginal matrices at an air–liquid interface. Morphological analyses of the models were conducted by performing hematoxylin and eosin staining and further characterization was done by immunohistofluorescence (IHF) of structural proteins and cytokeratins.

Results

Histological analysis of the models revealed a gradual formation of a stratified epithelium on our decellularized matrices and cell metabolic activity remained high for 21 days as measured by the resazurin assay. Our models showed a dose‐dependent response to estradiol‐17β [E₂] with an increase in the vaginal epithelium thickness and cellular proliferation under higher E₂ concentrations (100–400 pg/ml). The physiological relevance of these results was confirmed by the IHF analysis of Ki67, and cytokeratins 10 and 19 expression.

Conclusion

In this study, we have developed an estradiol‐responsive TE vaginal model that closely mimics the structural and physiological properties of the native SVT.

Diagnostic and prognostic impact of cytokeratin 19 expression analysis in human tumors: a tissue microarray study of 13,172 tumors

To evaluate cytokeratin 19 (CK19) expression in normal and cancerous tissues, 15,977 samples from 122 tumor types and 608 samples of 76 normal tissue types were analyzed by immunohistochemistry (IHC). In normal tissues, CK19 expression occurred in epithelial cells of most glandular organs but was strictly limited to the basal cell layer of nonkeratinizing squamous epithelium and absent in the skin. CK19 expression in ≥90% of cases was seen in 34% of the tumor entities including the adenocarcinomas of the pancreas (99.4%), colorectum (99.8%), esophagus (98.7%), and stomach (97.7%), as well as breast cancer (90.0%-100%), high-grade serous (99.1%) or endometrioid (97.8%) ovarian cancer, and urothelial carcinoma (92.6%-100%). A low CK19 positivity rate (0.1-10%) was seen in 5 of 122 tumor entities including hepatocellular carcinoma and seminoma. A comparison of tumor versus normal tissue findings demonstrated that upregulation and downregulation of CK19 can occur in cancer and that both alterations can be linked to unfavorable phenotypes. CK19 downregulation was linked to high grade (p = 0.0017) and loss of estrogen receptor- and progesterone receptor-expression (p < 0.0001 each) in invasive breast carcinoma of no special type. CK19 upregulation was linked to nodal metastases in neuroendocrine tumors and papillary thyroid carcinomas (p < 0.05 each) and to poor grade in clear cell renal cell carcinoma (p < 0.05). CK19 upregulation was particularly common in squamous cell carcinomas. We concluded that CK19 IHC might separate primary liver cell carcinoma from liver metastases, seminoma from other testicular tumors, and helps in the detection of early neoplastic transformation in squamous epithelium.

CK19-positive Hepatocellular Carcinoma is a Characteristic Subtype

The heterogeneity of hepatocellular carcinoma (HCC) commonly leads to therapeutic failure of HCC. Cytokeratin 19 (CK19) is well acknowledged as a biliary/progenitor cell marker and a marker of tumor stem cell. CK19-positive HCCs demonstrate aggressive behaviors and poor outcomes which including worse overall survival and early tumor recurrence after hepatectomy and liver transplantation. CK19-positive HCCs are resistant to chemotherapies as well as local treatment. This subset of HCC is thought to derive from liver progenitor cells and can be induced by extracellular stimulation such as hypoxia. Besides being a stemness marker, CK19 plays an important role in promoting malignant property of HCC. The regulatory network associated with CK19 expression has been summarized that extracellular stimulations which transmit into cytoplasm through signal transduction pathways (TGF-β, MAKP/JNK and MEK-ERK1/2), further induce important nuclear transcriptional factors (SALL4, AP1, SP1) to activate CK19 promoter. Novel noncoding RNAs are also involved in the regulation of CK19 expression. TGFβR1 becomes a therapeutic target for CK19-positive HCC. In conclusion, CK19 can be a potential biomarker for predicting poor prognosis after surgical and adjuvant therapies. CK19-pisitive HCCs exhibit distinctive molecular profiling, should be diagnosed and treated as a separate subtype of HCCs.

Muscle Cell Morphogenesis, Structure, Development and Differentiation Processes Are Significantly Regulated during Human Ovarian Granulosa Cells In Vitro Cultivation

Granulosa cells (GCs) have many functions and are fundamental for both folliculogenesis and oogenesis, releasing hormones and communicating directly with the oocyte. Long-term in vitro cultures of GCs show significant stem-like characteristics. In the current study, RNA of human ovarian granulosa cells was collected at 1, 7, 15 and 30 days of long-term in vitro culture. Understanding the process of differentiation of GCs towards different cell lineages, as well as the molecular pathways underlying these mechanisms, is fundamental to revealing other possible stemness markers of this type of cell. Identifying new markers of GC plasticity may help to understand the aetiology and recurrence of a wide variety of diseases and health conditions and reveal possible clinical applications of the ovarian tissue cells, affecting not only the reproductive ability but also sex hormone production. Granulosa cells were the subject of this study, as they are readily available as remnant material leftover after in vitro fertilisation procedures and exhibit significant stem-like characteristics in culture. The change in gene expression was investigated through a range of molecular and bioinformatic analyses. Expression microarrays were used, allowing the identification of groups of genes typical of specific cellular pathways. This candidate gene study focused on ontological groups associated with muscle cell morphogenesis, structure, development and differentiation, namely, “muscle cell development”, “muscle cell differentiation”, “muscle contraction”, “muscle organ development”, “muscle organ morphogenesis”, “muscle structure development”, “muscle system process” and “muscle tissue development”. The results showed that the 10 most upregulated genes were keratin 19, oxytocin receptor, connective tissue growth factor, nexilin, myosin light chain kinase, cysteine and glycine-rich protein 3, caveolin 1, actin, activating transcription factor 3 and tropomyosin, while the 10 most downregulated consisted of epiregulin, prostaglandin-endoperoxide synthase 2, transforming growth factor, interleukin, collagen, 5-hydroxytryptmine, interleukin 4, phosphodiesterase, wingless-type MMTV integration site family and SRY-box 9. Moreover, ultrastructural observations showing heterogeneity of granulosa cell population are presented in the study. At least two morphologically different subpopulations were identified: large, light coloured and small, darker cells. The expression of genes belonging to the mentioned ontological groups suggest the potential ability of GCs to differentiate and proliferate toward muscle lineage, showing possible application in muscle regeneration and the treatment of different diseases.

CYFRA 21-1 and Placental Growth Factor as Screening Markers for Endometriosis

Background

This study evaluated the performance of serum CYFRA 21-1 and placental growth factor (PIGF) as screening markers for endometriosis.

Material/Methods

In this prospective study included 81 female patients who underwent laparoscopy to treat benign ovarian tumors. Serum samples were obtained from all study patients before surgery. Serum marker levels, including CYFRA 21-1, PIGF, cancer antigen (CA)125, CA19-9, and human epididymis protein 4 (HE4) were measured using a fluorescence immunoassay technique.

Results

Forty of the patients were diagnosed with endometriosis (the study group) and 41 women were diagnosed with other benign ovarian tumors (the control group). Mean serum CYFRA 21-1 and PIGF levels were not different between these 2 groups (P=0.179 and P=0.865, respectively). Elevated serum CA125 levels (>35 U/mL) and lower CYFRA 21-1 levels (≤2.29 ng/mL) were more frequently observed in the endometriosis study group than in the control group (P<0.0001, and P=048, respectively). High serum PIGF levels (>14.2 pg/mL) were observed in both groups (P=0.226). Mean serum CA19-9 levels and HE4 levels, as well as the ROMA (risk of ovarian malignancy Algorithm) score were similar between the 2 groups. Sensitivity (95.0%) and negative predictive value (NPV) (80.0%) of CYFRA 21-1 for diagnosing endometriosis were higher than those of CA125 (sensitivity 67.5%, NPV 74.5%) and PIGF (sensitivity 20.0%, NPV 53.6%). However, the specificity (PIGF 90.2%, CA125 92.7%) and positive predictive value (PPV) (PIGF 66.7%, CA125 87.1%) of PIGF and CA125 for diagnosing endometriosis were higher than those of CYFRA 21-1 (specificity 19.5%, PPV 53.5%).

Conclusions

CYFRA 21-1 and PIGF may be promising markers to identify patients with and without ovarian endometriosis.

Cytokeratin 19 Expression by Reverse Transcriptase-Polymerase Chain Reaction in the Peripheral Blood of Prostate Cancer Patients

Aims and background

Sensitive reverse transcriptase-polymerase chain reaction-based techniques for detection of epithelial antigen expression, such as cytokeratin 19, in the peripheral blood mononuclear fraction of prostate cancer patients may allow the detection of tumor progression at A molecular level.

Methods

We studied cytokeratin 19 expression by reverse transcriptase-polymerase chain reaction in peripheral blood mononuclear cell samples of 10 control men and serially in 44 patients with prostate cancer every three months for 18 months.

Results

None of the 10 normal control men expressed cytokeratin 19 in their peripheral blood mononuclear fraction. In the patients, cytokeratin 19 positivity at entry was not associated with age, Gleason score, clinical stage, prostate-specific antigen or alkaline phosphatase. Interestingly, having at least one positive cytokeratin 19 result during follow-up correlated significantly with time to prostate-specific antigen progression (P = 0.049), especially in the subgroup of metastatic patients (P = 0.032).

Conclusions

We conclude that cytokeratin 19 expression by reverse transcriptase-polymerase chain reaction in the peripheral blood mononuclear cell fraction of prostate cancer patients correlates with time to prostate-specific antigen progression. Further studies are needed to confirm these findings.

Cytokeratins in the Histological Diagnosis of Malignant Tumors

Cytokeratins, which comprise a multigene family of 20 related polypeptides (CKs 1–20), are constituents of the intermediate filaments of epithelial cells, in which they are expressed in various combinations depending on the epithelial type and the degree of differentiation. Of these, CK 19 (400 amino acids; 44.1 kilodaltons) is an example of a widely distributed CK, being expressed in various epithelia, including many simple epithelia. In contrast, the recently identified CK 20 (424 amino acids; 48.6 kilodaltons) is essentially confined to gastrointestinal epithelia, the urothelium and Merkel cells. The differential expression of individual CKs in various types of carcinomas makes them useful markers for histopathological carcinoma subtyping, providing relevant information concerning the differentiation and origin of carcinomas, especially when tumors first present as metastases. The CKs that are of particular value for differential diagnosis include CK 20, as it is mainly expressed in carcinomas derived from CK 20-positive epithelia; it is also found in bile-tract, pancreatic and mucinous ovarian adenocarcinomas, being absent in most other carcinomas. In certain carcinoma types, the changes in the expression of individual CKs that may occur during tumor progression could be of prognostic relevance. It remains to be established whether the serological detection of fragments of not only widely distributed but also more restrictedly expressed CKs may provide useful serological tumor markers in the future.

Similar Characteristics of Endometrial and Endometriotic Epithelial Cells

Epithelial-mesenchymal transition (EMT) is characterized by the loss of epithelial and acquisition of mesenchymal cell characteristics. Our aim was to assess the epithelial phenotype in the pathogenesis of endometriosis with epithelial and mesenchymal markers. We used 2 structural (keratin-18, -19 [K18, K19]), 1 membrane-associated (mucin-1 [MUC1]), and 2 mesenchymal proteins (vimentin; zinc finger E-box-binding homeobox 1, [ZEB1]) to compare epithelial and mesenchymal characteristics in eutopic endometrium with the 3 endometriotic entities, peritoneal, ovarian, and deep infiltrating endometriosis (DIE). Quantitation showed no differences for K18, K19, and MUC1 between endometrium with and without endometriosis. Also, K18 was not different between endometrium and endometriotic lesions. In contrast, K19 and MUC1 were modestly but significantly decreased in the endometriotic lesions compared to endometrium. However, the maintained expression of epithelial markers in all investigated tissues, regardless of the pathological condition, clearly indicates no loss of the epithelial phenotype. This is further supported by the reduced presence of epithelial vimentin in endometriotic lesions which is in contrast to an increase in stromal vimentin in ectopic endometrium, especially in ovarian endometriosis. The ZEB1 increase in endometriotic lesions, especially in DIE, on the other hand suggests a role of partial EMT in the development of endometriotic lesions, possibly connected with the gain of invasive capabilities or stemness. Taken together, although we found some hints for at least a partial EMT, we did not observe a severe loss of the epithelial cell phenotype. Thus, we propose that EMT is not a main factor in the pathogenesis of endometriosis.

Aberrant keratin 7 and 20 expression in triple-negative carcinoma of the breast

Early studies characterizing the keratin (K) profile of various epithelial tissues indicated that breast carcinoma is K7 positive and K20 negative, but not all breast carcinomas show this profile. Triple-negative carcinoma (TNC) has been characterized by negativity for estrogen receptor (ER), progesterone receptor (PgR), and Her2/neu protein. TNC is more likely to metastasize to the viscera and present as a metastatic poorly different carcinoma. In our study, on the basis of immunohistochemical staining of ER, PgR, and Her2/neu, 75 of the 290 patients with invasive breast carcinoma were judged to have TNC. K20 expression was detected in 6 of 75 patients with TNC, and non-TNC was negative in all 215 cases (P = .0003). K7 expression was also detected in 72 of 75 TNC cases. However, non-TNC was negative in 26 of 215 cases, which was significant (P = .0457). An aberrant profile of K was observed in the TNC group, indicating that caution is needed in determining the site of primary tumors using immunohistochemical algorithms. It should be kept in mind that patients with TNC show highly variable K profiles in practical diagnosis.

The real reason for having a meibomian lipid layer covering the outer surface of the tear film - A review

This review critically evaluates a broad range of literature in order to show the relationship between meibum, tear lipids and the tear film lipid layer (TFLL). The relationship of meibum composition to dry eye syndrome is briefly discussed. The review also explores the interactions between aqueous and the TFLL by examining the correlations between meibomian lipids and lipids extracted from whole tears, and by considering protein adsorption to the TFLL from the aqueous. Although it is clear to the authors that a normal tear film resists evaporation, an emerging idea from the literature is that the main purpose of the TFLL is to allow the spread of the tear film and to prevent its collapse onto the ocular surface, rather than to be an evaporative blanket. Current models on the possible structure of the TFLL are also examined.

CYFRA 21-1 in urine: a diagnostic marker for endometriosis?

Diagnostic workup of endometriosis usually involves laparoscopic inspection and histological examination of biopsies. Unequivocal laboratory parameters for this ailment have not been available in routine diagnostic evaluations thus far. In this study, we examined urine concentrations of cytokeratin 19 (CYFRA 21-1), a structural protein specific for epithelia. We performed immunoassays for CYFRA 21-1 in urine samples from women afflicted with endometriosis throughout their menstrual cycle. We observed a significant increase in CYFRA 21-1 concentrations, corrected by creatinine levels, in the late follicular phase as compared with the level in healthy controls. We conclude that cyclically increased CYFRA 21-1 concentrations in urine could serve as a valuable noninvasive diagnostic parameter in the workup of clinically manifesting endometriosis.

Increases in serum CYFRA21-1 concentration during successful treatment with crizotinib

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Cytokeratin-19 as a biomarker in urine and in serum for the diagnosis of endometriosis--a prospective study

Endometriosis compromises the quality of life of countless women worldwide and is a leading cause of disability. Clinical symptoms of endometriosis can be very heterogeneous leading to a long interval between onset of symptoms and surgical diagnosis. A noninvasive, rapid diagnostic test is urgently needed. In this prospective study, we evaluated the usefulness of Cytokeratin-19 (CK19) as a biomarker for the diagnosis of endometriosis through urine and serum ELISA. 76 reproductive-aged women undergoing laparoscopy for benign conditions were included to this study and divided into two groups by the presence (n = 44) or absence (n = 32) of endometriosis. There was no statistically significant correlation between the concentration of CK19 in urine (p = 0.51) or in serum (p = 0.77) and the diagnosis of endometriosis. Assigning the samples to the proliferative or secretory cycle stage did not sufficiently lower the p values. In this study, the promising data reported in the recent literature about CK19 serving as a sufficient biomarker for endometriosis could not be verified when tested in a larger sample size. Further studies are warranted to explore the usefulness of CK19 in the diagnosis of endometriosis.

Overexpression of aldolase A and cytokeratin 19 in ovine pulmonary adenocarcinoma

Ovine pulmonary adenocarcinoma (OPA) is a transmissible lung cancer of sheep caused by jaagsiekte sheep retrovirus (JSRV). In the present study the protein profiles of five neoplastic and three non-neoplastic sheep lung tissues were examined for the identification of proteins overexpressed in ovine pulmonary adenocarcinoma. Lung sections of the experimental group of sheep were collected during necropsies for proteomic and immunohistochemical examination. Two dimensional electrophoresis (2DE) was performed using gel strips with immobilized pH gradient 3-10. As a result of 2DE gel analysis 14 spots characterized by over 2-fold higher expression in tumour proteomes were selected for mass spectrometry. In eleven spots more than one polypeptide was identified indicating overlapping of proteins in gels. In two spots demonstrating over 3-fold higher expression in OPA proteomes, single proteins: cytokerarin 19 (CK19) and aldolase A were identified. Immunohistochemical studies revealed that CK19 and aldolase A were expressed in the cytoplasm of epithelial cells of bronchioles in non-neoplastic lung sections, as well as epithelial cells of bronchioles and neoplastic cells in lung sections of OPA affected sheep. The results indicate that the overexpression of the two proteins reflects the presence of neoplastic cells in the lungs of OPA affected sheep.

A gene expression atlas of the domestic pig

BACKGROUND

This work describes the first genome-wide analysis of the transcriptional landscape of the pig. A new porcine Affymetrix expression array was designed in order to provide comprehensive coverage of the known pig transcriptome. The new array was used to generate a genome-wide expression atlas of pig tissues derived from 62 tissue/cell types. These data were subjected to network correlation analysis and clustering.

RESULTS

The analysis presented here provides a detailed functional clustering of the pig transcriptome where transcripts are grouped according to their expression pattern, so one can infer the function of an uncharacterized gene from the company it keeps and the locations in which it is expressed. We describe the overall transcriptional signatures present in the tissue atlas, where possible assigning those signatures to specific cell populations or pathways. In particular, we discuss the expression signatures associated with the gastrointestinal tract, an organ that was sampled at 15 sites along its length and whose biology in the pig is similar to human. We identify sets of genes that define specialized cellular compartments and region-specific digestive functions. Finally, we performed a network analysis of the transcription factors expressed in the gastrointestinal tract and demonstrate how they sub-divide into functional groups that may control cellular gastrointestinal development.

CONCLUSIONS

As an important livestock animal with a physiology that is more similar than mouse to man, we provide a major new resource for understanding gene expression with respect to the known physiology of mammalian tissues and cells. The data and analyses are available on the websites http://biogps.org and http://www.macrophages.com/pig-atlas.

Discovery of a novel biomarker in the urine in women with endometriosis

OBJECTIVE

To investigate whether proteins secreted in urine differ between women with and without endometriosis.

DESIGN

Laboratory study using human urine.

SETTING

University-based laboratory.

PATIENT(S)

Women with and without endometriosis undergoing laparoscopy, hysteroscopy and curettage.

INTERVENTION(S)

Urine collection from women with and without endometriosis.

MAIN OUTCOME MEASURE(S)

Proteomic techniques and mass spectrometry to identify proteins secreted in the urine of women with and without endometriosis.

RESULT(S)

On average, 133 proteins were significantly different between women with and without endometriosis. Cytokeratin-19 was highly up-regulated in the urine of women with endometriosis.

CONCLUSION(S)

Cytokeratin-19 may be a valuable urinary biomarker for endometriosis.

Detection of circulating tumor cells in prostate cancer patients: methodological pitfalls and clinical relevance

Disseminated malignancy is the major cause of prostate cancer-related mortality. Circulating tumor cells (CTCs) are essential for the establishment of metastasis. Various contemporary and molecular methods using prostate-specific biomarkers have been applied to detect extraprostatic disease that is undetectable by conventional imaging techniques, assessing the risk for disease recurrence after therapy of curative intent. However, the clinical relevance of CTC detection is still controversial. We review current literature regarding molecular methods used for the detection of CTCs in the peripheral blood and bone marrow biopsies of patients with prostate cancer, and we discuss the methodological pitfalls that influence the clinical significance of molecular staging.

The human keratins: biology and pathology

The keratins are the typical intermediate filament proteins of epithelia, showing an outstanding degree of molecular diversity. Heteropolymeric filaments are formed by pairing of type I and type II molecules. In humans 54 functional keratin genes exist. They are expressed in highly specific patterns related to the epithelial type and stage of cellular differentiation. About half of all keratins—including numerous keratins characterized only recently—are restricted to the various compartments of hair follicles. As part of the epithelial cytoskeleton, keratins are important for the mechanical stability and integrity of epithelial cells and tissues. Moreover, some keratins also have regulatory functions and are involved in intracellular signaling pathways, e.g. protection from stress, wound healing, and apoptosis. Applying the new consensus nomenclature, this article summarizes, for all human keratins, their cell type and tissue distribution and their functional significance in relation to transgenic mouse models and human hereditary keratin diseases. Furthermore, since keratins also exhibit characteristic expression patterns in human tumors, several of them (notably K5, K7, K8/K18, K19, and K20) have great importance in immunohistochemical tumor diagnosis of carcinomas, in particular of unclear metastases and in precise classification and subtyping. Future research might open further fields of clinical application for this remarkable protein family.

Neuronal-epithelial interactions in mammalian gustatory epithelium

There are two neurally controlled morphogenetic programmes in the fungiform papillae of the rodent tongue. When gustatory axons are present they not only promote the expression of taste receptor cells but also simultaneously suppress the outgrowth of an ectopic filiform spine. Innervation during development is essential for the initial formation of taste buds. Consequently, denervation during development irreversibly prevents the establishment of a permanent line of stem cells for taste buds, in contrast to the reliable re-emergence of taste buds after the reinnervation of denervated adult gustatory epithelium. Monoclonal antibodies to keratins selectively recognize cells in particular differentiated states and may contribute to an understanding of the cell lineages and cell-cell interactions that lead to taste buds and filiform spines. Regeneration may recapitulate the late steps in taste development but not the early steps, which are slower and subject to irreversible alteration with denervation. Arguments are set forth that the nerve dependence of taste buds and some other cutaneous receptor cells provides an important selective advantage. Nerve dependence ensures that a more protective integumental covering will replace any superficial, secondary sensory cells rendered useless by denervation.

The human type I keratin gene family: characterization of new hair follicle specific members and evaluation of the chromosome 17q21.2 gene domain

In general concurrence with recent studies, bioinformatic analysis of the chromosome 17q21.2 DNA sequence found in the EBI/Genebank database shows the presence of 27 type I keratin genes and five keratin pseudogenes present on 8 contiguous Bacterial Artificial Chromosome (BAC) sequences. This constitutes the 970 kb type I keratin gene domain. Inserted into this domain is a 350 kb region harboring 32 previously characterized keratin-associated protein genes. Of the 27 keratin genes found in this region, six have not been characterized in detail. This study reports the isolation of cDNA sequences for these keratin genes, termed K25irs1-K25irs4, Ka35, and Ka36, as well as cDNA sequences for the previously reported hair keratins hHa3-I, hHa7, and hHa8. RT-PCR analysis of 14 epithelial tissues using primers for the six novel keratins, as well as for keratins 23 and 24, shows that the six novel keratins appear to be hair follicle associated. Previous expression data, coupled with evolutionary analysis studies point to K25irs1-K25irs4 probably being inner root sheath specific keratins. Ka35 and Ka36 are, based on their exon-intron structure and expression characteristics, hair keratins. In contrast, K23 and K24 appear to be epithelial keratins associated with simple/glandular or stratified, non-cornified epithelia, respectively. A literature analysis coupled with the data presented here confirms that all of the 27 keratin genes found on this domain have been characterized at the transcriptional level. Together with K18, a type I keratin gene found on the type II keratin domain, this seems to be the entire complement of functional type I keratins in humans.

DNA methylation control of tissue polarity and cellular differentiation in the mammary epithelium

Alterations in gene expression accompany cell-type-specific differentiation. In complex systems where functional differentiation depends on the organization of specific cell types into highly specialized structures (tissue morphogenesis), it is not known how epigenetic mechanisms that control gene expression influence this stepwise differentiation process. We have investigated the effect of DNA methylation, a major epigenetic pathway of gene silencing, on the regulation of mammary acinar differentiation. Our in vitro model of differentiation encompasses human mammary epithelial cells that form polarized and hollow tissue structures (acini) when cultured in the presence of basement membrane components. We found that acinar morphogenesis was accompanied with chromatin remodeling, as shown by alterations in histone 4 acetylation, heterochromatin 1 protein, and histone 3 methylated on lysine 9, and with an increase in expression of MeCP2, a mediator of DNA-methylation-induced gene silencing. DNA hypomethylation induced by treatment with 5-aza-2' deoxycytidine during acinar differentiation essentially prevented the formation of apical tissue polarity. This treatment also induced the expression of CK19, a marker of cells that are in a transitional differentiation stage. These results suggest that DNA methylation is a mechanism by which mammary epithelial differentiation is coordinated both at the tissue and cellular levels.

Different proliferative activity of the glandular and myoepithelial lineages in benign proliferative and early malignant breast diseases

The aim of the present study was to explore cell biological characteristics of normal breast, benign proliferative breast diseases and noninvasive breast malignancies based on the recently published adult progenitor cell concept from our group. Here, we investigated the proliferative activity of CK5/14(+), CK8/18/19(+) and alpha-smooth muscle actin(+) cellular phenotypes encountered in normal mammary gland, in a series of usual ductal hyperplasias and early malignant breast diseases, such as atypical ductal and lobular hyperplasias, as well as ductal and lobular in situ carcinomas. Immunohistochemical double labeling was performed on frozen sections from diagnostic breast biopsies by using antibodies to basal cytokeratins (CK5/14), glandular cytokeratins (CK8/18/19), smooth muscle actin and the Ki-67 antigen (MIB1). Normal breast tissues and usual ductal hyperplasias were characterized by a heterogeneous cellular composition of the growth fraction. The proliferative cell compartment consisted of CK8/18/19(+) glandular and, in a variable proportion, CK5/14(+) progenitor phenotypes. In contrast, noninvasive breast malignancies were composed of a monotonous proliferation of CK 8/18/19(+) neoplastic glandular cells. These findings indicate a significant role of progenitor cells in the development of benign proliferative breast diseases and lend support to the view that malignant transformation in the human breast usually occurs in a cell committed to the glandular lineage. Our results provide cell kinetic support to the functional progenitor cell hypothesis, and we propose this concept as an operative model for understanding benign proliferative and malignant breast diseases.

Simultaneous segmental obstruction of bile duct and portal vein markedly changes a population of biliary and hepatic cells in human liver

BACKGROUND AND AIMS

No studies have investigated histologic changes caused by simultaneous segmental obstruction of the bile duct and portal vein in human liver.

PATIENTS/METHODS

Liver tissues with simultaneous obstruction of the segmental bile duct and portal vein (O(+/+) liver), with segmental bile duct obstruction alone (O(+/-) liver), and without obstruction (O(-/-) liver) were obtained from patients who underwent hepatectomy, and studied morphologically and immunohistochemically.

RESULTS

In O(+/+) liver, the proportional area consisting of hepatocytes was significantly less (31.0+/-25.8%) than in O(+/-) liver (78.4+/-18.9%) or O(-/-) liver (86.5+/-9.2%). In contrast, the proportional area consisting of biliary epithelial cells was significantly higher in O(+/+) liver (9.1+/-6.1%) than in O(+/-) liver (1.6+/-1.5%) or O(-/-) liver (0.7+/-0.6%). The proportional area consisting of fibrous tissue also was significantly higher in O(+/+) liver than in the other two groups. In O(+/+) liver, some cells located at the periphery of hepatocyte areas were immunoreactive for both hepatocyte and biliary epithelial cell markers.

CONCLUSION

Simultaneous segmental obstruction of the bile duct and portal vein induces a marked ductular increase, periportal fibrosis, and a reduction in the number of hepatocytes in human liver tissue.

Stimulation of human colonic epithelial cells by leukemia inhibitory factor is dependent on collagen-embedded fibroblasts in organotypic culture

The colonic epithelium undergoes a continuous cycle of proliferation, differentiation, and apoptosis. To characterize factors important for colonic homeostasis and its dysregulation, human fetal colonic epithelial cells were isolated and seeded on a collagen type I matrix with embedded colonic fibroblasts. The epithelial cells rapidly spread from clusters and proliferated, and within 3 days, a columnar layer of polarized epithelium surrounded the surface of the constricted collagen matrix. The polarized enterocytes developed brush borders, tight junctions and desmosomes, and goblet and enteroendocrine cells were present. A balance of growth and differentiation was maintained for several weeks in the presence of collagen-embedded fibroblasts and a complex mixture of growth factors. Leukemia inhibitory factor (LIF) was critical for proliferation of enterocytes and inhibited expression of the differentiation marker carbonic anhydrase II. In the presence of LIF, the relative number of goblet cells remained stable, whereas enteroendocrine relative cell number declined. LIF-stimulated epithelial cells remained dependent on the presence of fibroblasts in the matrix. In combination with stem cell factor and endothelin 3, LIF induced formation of disorganized structures of stratified and semi-stratified cells, suggesting that the homeostatic balance in the normal human colon requires cooperation with differentiation-inducing factors.

Sensitive periods for the effect of dietary sodium restriction on intact and denervated taste receptor cells

Unilateral chorda tympani nerve (CT) section combined with dietary sodium restriction leads to striking alterations in sodium taste function. The regenerated rat CT exhibits deficits in sodium sensitivity, and surprisingly, there are also functional alterations in the intact, contralateral nerve. The studies presented here describe the functional "sensitive periods" for these aberrations and the number of taste buds present during corresponding stages. The regenerated CT is sensitive to dietary sodium restriction during the first 2 wk after denervation, whereas the intact CT is sensitive to dietary manipulation during the first week postsection. Therefore, distinct mechanisms are responsible for the effects of sodium restriction combined with denervation, because separate sensitive periods exist for the regenerated and intact CT nerves. Identification of mature taste buds with an antibody directed at anti-keratin 19 revealed that there is a loss of ~85% of taste buds on the denervated side of the tongue under control and low-sodium diets within the first week postsection. Thus, sodium restriction does not differentially affect the loss of taste buds following denervation.

[CYFRA 21.1 cytosol levels in lung adenocarcinomas. Correlation with other clinico-biological parameters]

INTRODUCTION

Cyfra 21.1 are soluble cytokeratin 19 fragments present in several biological fluids. The aim of this work was to study cyfra 21.1 cytosolic levels in lung adenocarcinomas and their possible correlation with other clinical-biological parameters.

PATIENTS AND METHODS

Cyfra 21.1 was determined, using an immunoradiometric assay (CIS BioInternational. France), in 58 tissue samples of lung adenocarcinomas patients. Other parameters included in the study were the following: clinical stage, histological grade, ploidy, S-phase cellular fraction, as well as cathepsin D, CA 125 and hyaluronic acid levels in cytosols. Likewise, AH, erbB2 oncoprotein, CD44s, CD44v5 and CD44v6 levels in cell surfaces were assayed.

RESULTS

Cyfra 21.1 cytosolic levels oscillated between 24.8 and 6,774 ng/mg prot. (median 1,147.5) and were higher (p:0.00074) than those observed in 16 normal lung samples of the same patients. We did not observe any statistically significant differences in cyfra 21.1 values when clinical stage, ploidy, S-phase and histological grade were considered. When lung adenocarcinomas were classified according to cyfra 21.1 positivity, using 1,499 ng/mg prot. as cut-off, which represents the 75th percentile of the whole group, we noted that positive cases had higher levels of cathepsin D (p:0.00218), cytosolic hyaluronic acid (p:0.02947), erbB2 protein (p:0.06272) and CA 125 (p:0.07243) than negative carcinomas.

CONCLUSIONS

These results suggest the possibility that high cytosolic cyfra 21.1 levels could be associated with a poor outcome in lung adenocarcinomas.

Hair follicle predetermination

Recent genetic and molecular studies of hair follicle (HF) biology have provided substantial insight; however, the molecular data, including expression patterns, cannot be properly appreciated without an understanding of the basic cellular rearrangements and interactions that underpin HF cyclic transformations. We present a novel interpretation of the major cellular processes that take place during HF cycling – the hypothesis of hair follicle predetermination. This hypothesis is an extension of previous models of HF cellular kinetics but has two critical modifications: the dual origin of the cycling portion of the HF, and the timing of the recruitment of stem cells. A compilation of evidence suggests that the ascending portion of the HF (hair shaft and inner root sheath) arises not from bulge-located HF stem cells that contribute to the formation of only the outer root sheath (ORS), but instead from the germinative cells localized in the secondary hair germ. In middle anagen, upon completion of the downward growth of the HF, cells derived from the bulge region migrate downward along the ORS to reside at the periphery of the HF bulb as a distinct, inactive cell population that has specific patterns of gene expression - ‘the lateral disc’. These cells survive catagen-associated apoptosis and, under the direct influence of the follicular papilla (FP), transform into the hair germ and acquire the ability to respond to FP signaling and produce a new hair. Thus, we propose that the specific sensitivity of germ cells to FP signaling and their commitment to produce the ascending HF layers are predetermined by the previous hair cycle during the process of transformation of bulge-derived lateral disc cells into the secondary hair germ.

Bromodeoxyuridine increases keratin 19 protein expression at a posttranscriptional level in two human lung tumor cell lines

Keratins form the largest subfamily of intermediate filament proteins and show strict lineage- and differentiation-associated expression in epithelial cells. Little is known about the mechanisms that control keratin protein synthesis in these cells. We have examined the effect of the differentiation-modulating agent, 5'-bromo-2'-deoxyuridine (BrdU), on keratin 19 (K19) expression in two human lung carcinoma cell lines, DLKP and A549. Treatment of both cell lines with 10 microM BrdU for 7 d induced the expression of K19 protein in keratin-negative DLKP cells, and significantly increased K19 protein expression in A549 cells. K19 messenger ribonucleic acids (mRNAs) were detected by Northern blot and reverse transcriptase-polymerase chain reaction analyses in both cell lines, but no increase in K19 mRNA levels was detected in either cell line, even with treatment with BrdU for up to 21 d. This suggests that K19 protein synthesis is normally blocked at a posttranscriptional level in DLKP cells, and BrdU can somehow reverse this block, resulting in the induction of K19 protein synthesis. Treatment of HL60, a leukemic cell line, with BrdU, resulted in noninduction of K19 protein synthesis, and no K19 mRNA transcripts were detected before and after BrdU treatment, possibly suggesting that BrdU is acting in an epithelial-specific manner to reverse a block in K19 protein synthesis in DLKP keratin-negative lung cancer cells. Therefore, DLKP (and A549) may be useful cellular models to investigate if this represents a regulatory step in early lung development or a mechanism whereby tumor cells possess the ability to down-regulate the expression of a more-differentiated phenotype.

Anti-cytokeratin antibodies in sera of the patients with autoimmune hepatitis

Antibodies to cytokeratin (CK) are found in some patients with autoimmune hepatitis (AIH). We hypothesized that serum antibodies to CK8, CK18 and CK19 may be formed in patients with AIH. We established an enzyme-linked immunosorbent assay (ELISA) to quantify anti-CK8, anti-CK18 and anti-CK19 antibodies in sera of patients with AIH. In addition, we quantified circulating CK8:anti-CK8 antibody as well as CK18:anti-CK18 antibody immune complexes in patients' sera, by an enzyme-linked immunosorbent assay (ELISA). Furthermore, to evaluate the expression of CK8, CK18 and CK19 in liver tissue, immunohistochemical stainings were performed. Significantly high levels of anti-CK8, anti-CK18 and anti-CK19 antibodies were demonstrated in patients with AIH compared with normal volunteers and patients with chronic active hepatitis C (CH-C). In addition, these antibodies were significantly decreased after steroid treatment. Levels of CK8:anti-CK8 and CK18:anti-CK18 immune complexes in sera of patients with AIH were significantly high compared with those of patients with CH-C and normal volunteers. Immunohistochemically, CK8 or CK18 were absent from some hepatocytes of AIH. CK19 was aberrantly expressed in periportal hepatocytes in patients with AIH, but not CH-C. This is the first study to quantify anti-CK8, anti-CK18, anti-CK19 antibodies and immune complexes in patients with AIH. The clinical significance of anti-CK antibodies and their immune complexes of AIH is also discussed.

The keratin 19 promoter is potent for cell-specific targeting of genes in transgenic mice

BACKGROUND & AIMS

Keratins are intermediate filaments that are critical in cytoskeletal organization. Their roles in cellular processes are underscored by inherited human diseases in which germline mutations of keratins are found, as well as by transgenic and knockout mouse models that recapitulate those diseases. Keratin 19 (K19) has unique structural properties and developmental and spatial expression patterns. This suggests that K19 expression may correlate with important cell fate decisions in gastrointestinal tract epithelia.

METHODS

We used mouse K19 5' untranslated region and promoter sequences and fused it to the lacZ reporter gene in a transgene construct. Characterization was by beta-galactosidase expression and X-gal histochemistry in gastrointestinal epithelia. Because endogenous K19 protein is transcriptionally regulated by the Kruppel-like transcription factor 4 (KLF4), we determined the spatial expression patterns of KLF4 and K19 in relationship to the lacZ reporter gene product.

RESULTS

K19-lacZ transgenic mice were found to have reporter gene expression in an epithelial-specific pattern. Expression was restricted to ductal epithelial cells in the pancreas, surface colonocytes, small intestinal villi, and gastric isthmus cells. Transgene expression correlated with K19 and KLF4 protein expression in the pancreas and stomach and was overlapping in the small and large intestine.

CONCLUSIONS

The K19 promoter may be a useful tool to study epithelial cell biology and subsequent transdifferentiation programs, particularly the pancreas and stomach.

Immortalization of rat middle ear epithelial cells by adeno 12-SV40 hybrid virus

Rat middle ear epithelial cells were infected with the adeno 12-SV40 hybrid virus. The cell line thus obtained displays features of primary cultured epithelial cells in both light microscopic and ultrastructural examinations. The immortalized cells have been in continuous proliferation for 40 passages and more than 17 months. Immunohistochemical analysis of the immortalized cells was positive for the SV40 T antigen and the tumor suppressor protein p53. The cells also stained positive for cytokeratin, an epithelial cell marker, and negative for vimentin, a fibroblast marker. These results, together with karyotype analysis, indicate that this cell line originated from rat middle ear epithelial cells and retains the characteristics of epithelial cells. This cell line will be useful for studying the normal cellular biology of middle ear epithelial cells, as well as the cellular and molecular mechanisms involved in the bacteria-middle ear epithelial cell interaction.

Elevation of cytokeratin 19 fragment in serum in patients with hepatoma: its clinical significance

OBJECTIVES

Cytokeratin 19 fragment (CK19) levels in serum have already been documented as a useful tumour marker for lung cancer. In the present study, we hypothesize that CK19 may be increased in serum from patients with hepatoma.

METHODS

We measured the CK19 levels in serum from patients with hepatoma and evaluated the correlation between CK19 level and each clinical parameter. We studied 70 patients diagnosed with hepatoma, and used 14 patients with chronic hepatitis C and 45 patients with liver cirrhosis as controls.

RESULTS

In 33 of 70 patients (47.1%) with hepatoma, the serum CK19 level was elevated to above the normal range. CK19 levels in serum from patients with hepatoma were significantly correlated with levels of alpha-fetoprotein and prothrombin induced by vitamin K absence for factor II (PIVKA-II). In 57 patients with hepatoma in whom both CK19 and alpha-fetoprotein were measured, only CK19 was elevated in seven patients (12.3%). Immunohistochemical studies using hepatoma tissues demonstrated that hepatoma cells were stained by anti-human CK19 antibody. We also demonstrated that the HepG2 cell line expressed CK1 9.

CONCLUSIONS

Our data demonstrate that hepatomas aberrantly express CK19, and that measurement of CK19 might be a useful tumour marker in diagnosing hepatoma.

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.

The tissue-dependent keratin 19 gene transcription is regulated by GKLF/KLF4 and Sp1

Keratins play critical roles in cellular differentiation and cytoskeletal organization. Keratin 19 (K19) is unique because it has been implicated as a marker of stem cells in some tissues, such as the hair follicle in the skin. It is also associated with malignant transformation in esophageal and pancreatic cancers. Here, we show that the K19 promoter is active in a subset of gastrointestinal cancer cells derived from esophageal and pancreas but inactive in other contexts. This activity was mapped to a short region containing an overlapping binding site for gut-enriched Krüppel-like factor (GKLF/KLF4) and Sp1. GKLF has a higher binding affinity and is the predominant binding factor in cells with low Sp-1 protein levels. Pancreatic acinar cells normally do not express K19, but overexpression of GKLF and Sp1 in these cells leads to aberrant expression, similar to what is observed in pancreatic cancer. These results demonstrate the functional interaction of ubiquitous and tissue-restricted transcription factors in determining tissue- and neoplasm-specific patterns of gene expression.

Structural and cell surface antigen expression in the rete ovarii and epoophoron differs from that in the Fallopian tube and in endometriosis

AIMS

We compared the immunohistochemical profiles of the rete ovarii and endometriosis in order to identify a panel which distinguishes between these structures. The immune profiles of the epoophoron, Fallopian tube and ovarian surface epithelium were also studied.

MATERIALS AND METHODS

Twenty-four women with no evidence of endometriosis and seven who had endometriosis in the uterine adnexae were studied using nine antibodies to intermediate filament proteins and cell surface markers. None of the structures studied shared an identical profile of immunohistochemical reaction. The immunoprofile of endometriosis showed some similarities to that of the Fallopian tube, but differed from that of the rete ovarii, epoophoron and ovarian surface epithelium

CONCLUSIONS

A panel including Ca-125, epithelial membrane antigen and the epithelial glycoprotein BerEp4 would permit the distinction between endometriosis and the rete ovarii in problematic cases. The study showed some commonality in reaction between endometriosis and the Fallopian tube which indicates that they may share a common (paramesonephric) origin. There was little commonality in the immunoprofile of endometriosis and the ovarian surface epithelium implying that endometriosis is unlikely to develop as a result of serosal metaplasia.

Phenotypic and genotypic characterization of commonly used human prostatic cell lines

OBJECTIVE

To investigate and catalogue systematically the phenotypic and genotypic characteristics of the commonly used prostatic cell lines using immunocytochemistry and polymerase chain reaction (PCR) of hypervariable sequences within the genome to provide a 'fingerprint' characteristic of each cell line. Materials and methods Malignant (LNCaP, LNCaP-r, PC-3, DU-145) and benign immortalized prostatic cell lines (PNT-1A, PNT-1B, BPH-1) were grown on four-well slides, fixed and subjected to indirect streptavidin-biotin immunocytochemistry. Twenty-three antibodies were used in the following groups: cytoskeletal elements: cytokeratins (CK)-5, -7, -8, -14 (two), -16, -18, -19 (three), -20, vimentin and desmin; MUC1 (three); cell adhesion molecules (E-cadherin, alpha-beta-and gamma-catenin); and prostatic associated proteins: prostate specific antigen (PSA), prostatic acid phosphatase (PAP) and androgen receptor (AR). For the PCR, genomic DNA was extracted from the cell lines and from SKOV3 and MCF7 (positive controls). PCR was performed on three variable regions which were then sequenced: AR exon 1 (CAG repeat polymorphism), and two areas of microsatellite instability (MSI): AR exon 8 and hypoxanthine-guanine phosphoribosyl transferase (HPRT) exon 3.

RESULTS

All cell lines were CK-8/18 positive and most also expressed CK-7 and -19. Heterogeneous CK-20 expression was detected for the first time in prostatic cell lines. All lines were positive for vimentin and negative for desmin. MUC1 was expressed in one malignant (DU-145) and all immortalized cell lines. E-cadherin expression was low or absent in three lines: PNT1A, 1B and PC-3. Only PC-3 failed to express alpha-catenin; beta- and gamma-catenin were expressed by all lines. PSA, PAP and AR were only expressed by LNCaP and LNCaP-r. On PCR, the CAG repeat lengths in exon 1 of the AR ranged from 19 to 27. Three pairs of cell lines had the same exon 1 CAG repeat length: LNCaP/PC-3 (26 repeats), BPH-1/DU-145 (19 repeats) and PNT1 A/1B (20 repeats). Exon 8 sequences were identical except for LNCaP, which showed a single base mutation, and HPRT exon 3 sequences were all identical. There was no evidence of generalized MSI in any of the cell lines examined.

CONCLUSIONS

The cell lines studied fell into three broad groups according to their phenotypic characteristics: (i) prostatic marker positive (LNCaP and LNCaP-r); (ii) high expression of most antigens (DU-145, PC-3 and BPH-1); and (iii) low or absent expression of most antigens (PNT1 A and 1B). Each of the cell lines derived from PC could be identified on the basis of exon 1 and 8 AR sequence variability. DU145 and BPH-1 had identical profiles of the three areas studied, but these cell lines are easily distinguished by their different phenotypic characteristics. PNT1A and 1B had identical genetic and similar phenotypic profiles, which is unsurprising given that they are subclones derived from the same parental line. Even so, these were separable on the basis of CK-19 immunostaining. Using a combination of geno- and phenotypic markers it was possible to derive a 'fingerprint' for each of the cell lines assessed, which will allow meaningful comparison between similar cell lines held in other laboratories.

Immortalization of chinchilla middle ear epithelial cells by adenovirus 12-simian virus 40 hybrid virus

In order to study the cellular and molecular mechanisms of the pathogenesis of otitis media, a chinchilla middle ear epithelial cell line (CMEE-1) with differentiated cell characteristics was established by infection of a primary culture with the adenovirus 12-simian virus 40 (Ad12-SV40) hybrid. This cell line has been in continuous culture for 42 passages, whereas the parent cells underwent senescence and died at the 8th passage. The cell line also retains epithelial morphology and expresses cytokeratin polypeptides 4, 7, and 18, characteristic markers for epithelia. In Western blots of cell proteins, bands at 94 and 53 kd were labeled after binding antibodies against SV40 large T antigen and p53, respectively. Karyotype analysis showed that the cell line is derived from chinchilla epithelial cells. These findings confirm that the cell line is a chinchilla epithelial cell immortalized by the hybrid virus.

Blood-group-related carbohydrates are expressed in organotypic cultures of human skin and oral mucosa

Cellular maturation and migration are usually associated with changes in cell-surface carbohydrates, but the relationship between these changes and cell behaviour is at present largely unknown. To investigate whether an organotypic culture system can be used as an in vitro model to study the function of cell-surface carbohydrates, we established organotypic cultures of skin and buccal mucosa. In these cultures, keratinocytes are grown at the air-liquid interface on a supporting matrix consisting of homologous fibroblasts embedded in a collagen type I gel. We examined the expression of blood-group-related carbohydrate structures, including Lewis x, sialylated Lewis x, Lewis y, Lewis a, and Lewis b, on the surface of epithelial cells in the cultures. We compared the results with the expression of more well-established markers, including cytokeratins, integrins, bullous pemphigoid antigen and laminin, in the same cultures. The organotypic skin and oral mucosa cultures showed a histological differentiation pattern analogous to that of normal skin and buccal mucosa, and a tissue-specific expression of carbohydrate structures and cytokeratins. However, both types of organotypic cultures also expressed markers which are normally seen during wound healing, including Lewis y, cytokeratin 16, and cytokeratin 19. We conclude that the organotypic cultures of oral mucosa and skin are suitable models for future studies of the function of cell-surface carbohydrates, although the expression of wound healing markers has to be taken into consideration.

Multi-layered periodontal pocket epithelium reconstituted in vitro: histology and cytokeratin profiles

BACKGROUND

In order to study inter-individual differences in bacterial adhesion/invasion of periodontal tissues, an in vitro model for culturing multi-layered pocket epithelium without feeder layers or stromal equivalents (including the evaluation of their cytokeratin profiles) was developed.

METHODS

Pocket epithelium was collected and grown until confluent in Falcon flasks using keratinocyte-serum free medium (KSFM), without a feeder layer. In the second passage, oral keratinocytes were re-grown in a 2 compartment system using either a clear polyester (transwell-clear [TCL]) or a collagen (transwell-col [TCO]) membrane as culture surface. After the first week, the calcium concentration was raised to 1.2 mM and in half the wells, the KSFM was supplemented with 10% fetal calf serum (FCS). Histology and immunohistochemistry were performed after 1, 2, and 3 weeks of additional growth.

RESULTS

In general, all conditions resulted in a structured epithelium consisting of 3 to 5 layers, but important differences were observed between the membrane types and between the media. CK4 was rarely and only lightly expressed while CK18 and 19 (characteristic of junctional epithelium) were very strongly expressed in the older (2 and 3 weeks) cultures. CK13 and 14 (characteristic of any stratifiable epithelial cell) also tended to increase over time; CK13 seemed to be stronger in KSFM with FCS while the contrary was true for CK14. The multi-layer created by the combination TCL/KSFM + 10% FCS resembled a junctional epithelium most, while that grown on TCO without FCS mimicked the sulcular epithelium.

CONCLUSIONS

It seems possible to create a histiotypic culture resembling either periodontal pocket or junctional epithelium without the use of stromal equivalents or feeder layers which make this approach more cumbersome. This multi-layered culture offers a model to investigate the permeability of pocket epithelium and the adhesion and penetration of bacteria under well-defined environmental conditions.

Coordinate expression of cytokeratins 7 and 20 in feline and canine carcinomas

Forty-seven feline and 60 canine epithelial tumors were studied to test the coordinate expression of cytokeratin 7 (CK 7) and cytokeratin 20 (CK 20) using commercially available monoclonal antibodies and an avidin-biotin immunoperoxidase staining technique. Previously, the distribution of both cytokeratins was examined in normal tissues from 4 cats and 4 dogs. The pattern of distribution of CK 7 in normal tissues was similar, with minor differences, to that described in humans, whereas the reactivity pattern of CK 20 in cats and dogs was wider than that in humans. The subset of tumors strongly expressing CK 7 and CK 20 included pancreatic adenocarcinomas (100%), transitional cell carcinomas (75%), and endometrial carcinomas (67%) in the cat. None of the canine tumors had this immunophenotype. Feline (50%) and canine (56%) mammary gland carcinomas and canine cholangiocarcinomas (67%) were the only tumors presenting the CK 7 +/CK 20- immunophenotype, whereas the CK 7-/CK 20+ immunophenotype included thyroid carcinomas (100%), intestinal adenocarcinomas (60%), bronchioloalveolar carcinomas (50%), and renal carcinomas (50%) in the cat and intestinal adenocarcinomas (56%), gastric adenocarcinomas (50%), and ovarian carcinomas (50%) in the dog. The CK 7-/CK 20- immunophenotype included the rest of the analyzed tumors. The immunohistochemical evaluation of coordinate expression of both CK 7 and CK 20 in feline and canine carcinomas using monoclonal antibodies provides important information that can help to discriminate among carcinomas from different primary sites and could be particularly helpful in the determination of the primary site of origin of carcinomas presenting as metastatic disease.

Expression of the intermediate filament keratin gene, K15, in the basal cell layers of epithelia and the hair follicle

The intermediate filament keratin, K15, is present in variable abundance in stratified epithelia. In this study we have isolated and characterized the sheep K15 gene, focusing on its expression in the follicles of sheep and mice. We show that K15 is expressed throughout the hair cycle in the basal layer of the outer root sheath that envelops the follicle. Strikingly, however, in large medullated wool follicles, a small group of basal outer root sheath cells located in the region thought to contain hair follicle stem cells are K15-negative. In the follicle bulb K15 is expressed in cells situated next to the dermal papilla but not in the inner bulb cells. Elsewhere, K15 is expressed at a low, variable level in the basal layer of the epidermis and sebaceous gland, often in a punctate pattern. In the esophagus of the sheep K15 expression is restricted to the basal layer, in contrast to human esophagus where it is expressed throughout the epithelium. Transgenic mouse lines established with a 15-kb sheep K15 gene construct exhibited faithful expression and showed no phenotypic consequences of K15 overexpression. An investigation of transgene expression showed that K15 is continuously expressed in outer root sheath cells during the hair cycle. Given its expression in the mitotically active basal cell layers of diverse epithelia and the follicle, K15 expression appears to signal an early stage in the pathway of keratinocyte differentiation that precedes the decision of a cell to become epidermal or hair-like.

Cellular characterization and successful transfection of serially subcultured normal human esophageal keratinocytes

BACKGROUND

In vitro cell culture models can provide unique insights into squamous epithelial proliferation, differentiation, and neoplastic transformation. Cultures of human esophageal keratinocytes could be advantageous for the study of these processes.

METHODS

Normal human esophageal keratinocytes were cultivated on 3T3 fibroblast feeder layers in vitro and expanded through four serial subcultivations. Confluent tertiary cultures were analyzed by morphological and immunohistochemical techniques to define their basic properties. The ability to transiently transfect cultured esophageal epithelium was tested using a Rous sarcoma virus-luciferase reporter gene by the calcium phosphate and lipofection methods.

RESULTS

Postconfluent cultures displayed a predominantly basal cell phenotype with limited stratification, widespread expression of keratins 5 and 14, and production of attachment specialization proteins such as alpha6beta4 integrin and collagen VII. Terminal differentiation markers (involucrin and transglutaminase) were prematurely expressed. The cells expressed growth factors important in proliferation and differentiation, such as transforming growth factor-beta and interleukin-1beta. Tertiary cultures were successfully transiently transfected with a Rous sarcoma virus-luciferase reporter gene construct.

CONCLUSION

Normal human esophageal cells can be serially passaged through extended numbers of cell generations and transfected by standard methods. This in vitro system may be useful in the study of fundamental cellular processes governing proliferation and differentiation in the esophageal epithelium.