0000000000136250
AUTHOR
Werner W. Franke
Establishment and Characterization of Two Merkel Cell Tumor Cultures
Two Merkel cell tumor cultures (MC-MA1, MC-MA2) have been established from metastases of typical Merkel cell tumors. The mestastases in vivo were characterized by co-expression of cytokeratins 8, 18, 19, 20 and neurofilaments, presence of intermediate filament whirls, expression of synaptophysin, neuron-specific enolase, and chromogranin A, rare and weak immunostaining for plakoglobin but absence of cadherins and desmoplakins. Both cultures grow, using supplemented RPMI medium on human irradiated fibroblast feeder layers, as loosely arranged floating small aggregates. Their karyotypes are mostly hyperdiploid. The mean doubling times were about 84 h in the first 8 months and later increased.…
Increased numbers of cytokeratin-positive interstitial reticulum cells (CIRC) in reactive, inflammatory and neoplastic lymphadenopathies: hyperplasia or induced expression?
A total of 291 enlarged lymph nodes showing a range of reactive-inflammatory processes, primary and metastatic neoplasms were studied to determine the distribution and immunoprofile of their cytokeratin-positive interstitial reticulum cells (CIRC) in comparison with normal nodes. In 258/291 nodes (89%), CIRC numbers were distinctly increased in the subcapsular, paracortical and, occasionally, in the medullary zones; often, these increased CIRC formed networks around follicles, sinuses and vessels. CIRC had comparatively small, irregularly shaped bodies and dendritic processes; occasionally, giant forms were noted. CIRC contained cytokeratins (CK) 8 and 18 but not 19, as shown by immunohisto…
The human gene encoding cytokeratin 20 and its expression during fetal development and in gastrointestinal carcinomas
The differentiation of the predominant cell types of the mucosal epithelium of the mammalian gastrointestinal tract is characterized by increasing amounts of an intermediate-sized filament (IF) protein designated cytokeratin (CK) 20 which is a major cellular protein of mature enterocytes and goblet cells. Here we report the isolation of the human gene encoding CK 20, its complete nucleotide sequence and the amino acid sequence deduced therefrom that identifies this polypeptide (mol. wt. 48553) as a member of the type I-CK subfamily. Remarkable, however, is the comparably great sequence divergence of CK 20 from all other known type I-CKs, with only 58% identical amino acids in the conserved …
Intermediate filaments and desmosomal plaque proteins in testicular seminomas and non-seminomatous germ cell tumours as revealed by immunohistochemistry.
Seminomas and non-seminomatous testicular germ cell tumours were studied for the presence of cytokeratin and vimentin filaments and desmosomes using immunohistochemical methods. In the majority of the classical seminomas and in seminomatous areas of mixed tumours most tumour cells appeared to lack cytokeratin filaments. Some seminomas contained a focally variable proportion of cells exhibiting cytokeratin-positive structures while other cases contained only few seminoma cells with a well developed fibrillar cytokeratin network. Gel electrophoresis of cytoskeletal proteins from microdissected regions revealed cytokeratin polypeptides nos. 8 and 18 typical of simple epithelia. In one seminoma…
Synaptophysin expressed in the bronchopulmonary tract: neuroendocrine cells, neuroepithelial bodies, and neuroendocrine neoplasms.
Synaptophysin is an integral membrane glycoprotein with an Mr of 38,000 that occurs in the small, clear vesicles present in neuronal cells and tumors as well as in pancreatic islet cells and various neuroendocrine (NE) carcinomas. We found that synaptophysin is also expressed in normal NE cells of the lungs of newborn rabbits and mice as well as of human fetuses. In bronchial ganglion cells and in nerves, synaptophysin is coexpressed with neurofilament proteins (NFPs), whereas in solitary NE cells and in at least some of the neuroepithelial bodies (NEBs) of the bronchial mucosal lining, synaptophysin coexists with cytokeratins. We also studied a series of NE neoplasms of the lung covering t…
Complexus adhaerentes, a new group of desmoplakin-containing junctions in endothelial cells: II. Different types of lymphatic vessels.
Abstract In diverse mammalian species, including (man, cow and rat) the very flat endothelial cells of lymphatic vessels of various organs, including the retothelial meshwork of sinus of lymph nodes, are connected by zonula -like plaque-bearing junctions which differ from the similarly structured junctions of blood vessel endothelia by the presence of desmoplakin or an as yet unknown but closely related plaque protein. These extended junctions, which also contain plakoglobin but none of the presently known desmogleins and desmocollins, are therefore different from the spot-like desmosomes ( maculae adhaerentes ) present in epithelia, myocardium and dendritic reticulum cells of lymphatic fol…
Monoclonal antibodies to various acidic (type I) cytokeratins of stratified epithelia
Abstract We determined the reactivity of two monoclonal antibodies to cytokeratins that are typically expressed in certain stratified epithelia and several human squamous cell carcinomas using immunoblotting techniques and immunofluorescence microscopy. Antibody Ks 8.12 reacted specifically with cytokeratin polypeptides nos. 13 and 16, and stained noncornified squamous epithelia in a rather uniform way. The examination of diverse human carcinomas showed all squamous cell carcinomas to be positively stained with this antibody, whereas all adenocarcinomas were negative. Another antibody, KK 8.60, reacted with polypeptides nos. 10 and 11, and uniformly stained the suprabasal layers of the epid…
Distribution of a special subset of keratinocytes characterized by the expression of cytokeratin 9 in adult and fetal human epidermis of various body sites.
Biochemical analyses have previously shown that palmar and plantar epidermis, unlike the epidermis of other body sites, contain cytokeratin 9 (Mr 64,000), an unusually large acidic (type I) cytokeratin. Guinea-pig antibodies that specifically and selectively react with bovine and human cytokeratin 9 were used for the immunocytochemical identification of cytokeratin 9 in adult and fetal human epidermis from various body sites. In the epidermis of palms and soles, antibodies against cytokeratin 9 stained a high proportion of the keratinocytes in suprabasal locations. These suprabasal cytokeratin-9-positive keratinocytes were often arranged in vertical columns and concentrated around intraepid…
Cytoskeletal differences between human neuroendocrine tumors: A cytoskeletal protein of molecular weight 46,000 distinguishes cutaneous from pulmonary neuroendocrine neoplasms
The cytoskeletons of various human neuroendocrine (NE) tumors were analyzed immunohistochemically using antibodies against intermediate-filament (IF) proteins as well as by two-dimensional gel electrophoresis of proteins from microdissected tissue samples. All of the tumors studied were found to contain cytokeratin filaments and are therefore referred to as 'NE tumors of the epithelial type'. In addition, neurofilaments were found in most cutaneous and some pulmonary NE tumors, as well as in medullary carcinomas of the thyroid and in pancreatic islet cell tumors. The neurofilament staining was frequently concentrated in cytoplasmic IF aggregates. Gel-electrophoretic analyses showed that all…
Expression of glial filament protein (GFP) in nerve sheaths and non-neural cells re-examined using monoclonal antibodies, with special emphasis on the co-expression of GFP and cytokeratins in epithelial cells of human salivary gland and pleomorphic adenomas.
We describe two novel monoclonal antibodies specific for glial filament protein (GFP), i.e., GF12.23 and GF12.24 (both IgG2a]. These cross-react over a broad range of species with epitopes located in the alpha-helical rod domain typical of all intermediate filament (IF) proteins. These monoclonal antibodies were used, in conjunction with other monoclonal GFP antibodies, rabbit antiserum to GFP, and various antibodies to other cytoskeletal proteins, to examine the occurrence of GFP in cells outside of the central nervous system of rodents, cows, and humans. We detected some scattered GFP-containing cells in the neural sheaths in some species but not in others, and we obtained different resul…
Identification of Merkel cells in human skin by specific cytokeratin antibodies:
Merkel cells are special neurosecretory cells which, in adult human skin, are usually very scarce. By immunofluorescence microscopy using antibodies to human cytokeratin polypeptide no. 18, we localized distinct non-keratinocyte cells in the glandular ridges of human fetal and adult plantar epidermis. Using electron and immunofluorescence microscopy, these cells were identified as Merkel cells containing typical neurosecretory granules as well as bundles of intermediate-sized filaments and desmosomes. Two-dimensional gel electrophoresis of the cytoskeletal fractions of microdissected epidermal preparations highly enriched in Merkel cells indicated the presence of cytokeratin polypeptides no…
Cytoskeletal components of lymphoid organs
Using light and electron microscopic immunolocalization with antibodies to cytoskeletal proteins, we have characterized the nonlymphoid cells of various human lymphoid organs (lymph nodes, tonsils, spleen). In all these tissues, the lymphoid follicles contain a three-dimensional meshwork of "dendritic reticulum cells" which are characterized by the presence of desmosomal junctions, as demonstrated by positive punctate staining with antibodies to the desmosome-specific proteins desmoplakin I and desmoglein, and by intermediate-sized filaments (IFs) of the vimentin type only. In contrast, the extrafollicular regions are characterized by an extended meshwork of other types of reticulum cells, …
Different patterns of cytokeratin expression in the normal epithelia of the upper respiratory tract
The distribution and type of cytokeratins present in the normal human epithelia of the nasopharynx, oropharynx, tongue, palatine tonsil, epiglottis, vocal cord, and laryngeal ventricle were studied using immunohistochemical techniques and by gel electrophoresis of cytoskeletal proteins microdissected from frozen tissues. Noncornifying stratified epithelia covering the oropharynx, tongue, surface of the palatine tonsil, pharyngeal surface of the epiglottis, and vocal cord were all found to contain cytokeratins nos. 4, 5, 6, 13, 14, and 15, together with minor amounts of cytokeratin no. 19, i.e., a pattern similar to that previously reported for esophageal epithelium. The immunohistochemical …
Patterns of expression of trichocytic and epithelial cytokeratins in mammalian tissues
Abstract Cells forming hair and nail material are characterized by the synthesis of members of a particular group of α-keratin polypeptides (trichocytic cytokeratins, “T cytokeratins”) different from epithelial cytokeratins (“E cytokeratins”). As the precursor cells to trichocytes are derived from fetal epidermal keratinocytes expressing only E cytokeratins, we have studied the patterns of expression of both T and E cytokeratins in developing human hair-and nailforming tissues of different fetal stages, by immunocyto-chemistry using antibodies specific for certain T or E cytokeratins and by two-dimensional gel electrophoresis and immunoblotting. In developing hair follicles up to the early …
Contactus adherens, a special type of plaque-bearing adhering junction containing M-cadherin, in the granule cell layer of the cerebellar glomerulus.
In the glomeruli of the granule cell layer of mammalian cerebellum, neuronal extensions are interconnected by numerous small, nearly isodiametric (diameters up to 0.1 micron), junctions previously classified as puncta adherentia related to the vinculin-containing, actin microfilament-anchoring junctions of the zonula adherens of epithelial and certain other cells. Using immunofluorescence and immunoelectron microscopy, we have found, however, that these junctions are negative for E- and VE-cadherin, for desmosomal cadherins, and also for vinculin, alpha-actinin, and desmoplakin, but they do contain, in addition to the protein plakoglobin common to all forms of adhering junctions, the plaque…
Patterns of Expression and Organization of Cytokeratin Intermediate Filaments
Cytokeratins are a large multigene family comprising two polypeptide types, i.e. acidic (type I) and basic (type II) ones, which are distinguished on the basis of immunological, peptide mapping, mRNA hybridization, and primary amino acid sequence data. The acidic (type I) cytokeratins can be subdivided into at least two different subtypes on the basis of their carboxy-terminal sequences. Considerable interspecies conservation of sequences exists, even extending to the 3'-non-coding mRNA regions. Different pairs of type I and II cytokeratins show different resistance to dissociation in urea. Sequence differences of the type I cytokeratins containing functional domains may be an explanation o…
Intermediate filament protein profiles of human testicular non-seminomatous germ cell tumors: correlation of cytokeratin synthesis to cell differentiation
Abstract The patterns of cytoskeletal differentiation were studied in 20 testicular non-seminomatous germ cell tumors by immunohistochemistry, using diverse monoclonal antibodies specific for different intermediate filament (IF) proteins and for desmoplakin. Immuno-fluorescence and immunoperoxidase methods on both formalin-fixed and frozen tissues were applied, in some cases together with a gel electrophoretic analysis of IF proteins. The tumors examined included embryonal carcinoma (EC), endodermal sinus tumor (EST), choriocar-cinoma and teratoma. Nine of the tumors were composed of only one histological type, the others showed mixed components. Cytokeratins 8 and 18 were identified in all…
Loss of desmoglein 2 suggests essential functions for early embryonic development and proliferation of embryonal stem cells.
Summary Desmoglein 2 (Dsg2) is a Ca 2+ -dependent adhesion molecule of desmosomes and is synthesized in all desmosome-bearing tissues from their earliest appearance onward. To examine the function of Dsg2, its gene was inactivated by homologous recombination in embryonal stem (ES) cells for the generation of knockout mice. DSG2 −/− mice and a considerable number of DSG2 +/− mice died at or shortly after implantation. On the other hand, DSG2 −/− blastocysts developed an apparently normal trophectoderm layer, the first tissue known to produce desmosomes, and hatched properly. Immunofluorescence analyses of these blastocysts showed, however, that the distribution of the desmosomal plaque prote…
Immunocytochemical study of an endometrial diffuse clear cell stromal sarcoma and other endometrial stromal sarcomas
Intermediate filament composition was studied in the following endometrial stromal tumors: low-grade stromal sarcoma (endolymphatic stromal myosis), high-grade stromal sarcoma with an associated adenocarcinoma (collision tumor), diffuse clear cell stromal sarcoma and a mesodermal mixed tumor (carcinosarcoma). The tumor cells of the stromal tumors as well as the mesenchymal elements of the mixed mesodermal tumor were decorated exclusively with antibodies to vimentin. Desmin was not demonstrated in these tumor cells. A biochemical study of the cytoskeletal filaments present in the low-grade stromal sarcoma revealed, in addition to vimentin, beta and gamma actin as seen in normal endometrial s…
Formation of Epidermal and Dermal Merkel Cells During Human Fetal Skin Development
The origin of Merkel cells is still a matter of debate, specifically the question of whether they are derived from epithelial cells of the epidermis or from immigrated neural crest cells. As an argument for the latter hypothesis the occurrence of dermal, nerve-associated Merkel cells in human fetal skin has often been mentioned. Therefore, we analyzed the distribution of Merkel cells in epidermis and dermis of plantar skin of human embryos and fetuses, ranging in gestational age between 7 and 17 weeks. Merkel cells were identified by immunocytochemistry on frozen sections using antibodies against simple epithelium-type cytokeratins and by electron microscopy. In the 17-week-old fetus, 17% o…
Cytokeratins in normal lung and lung carcinomas
The various epithelial cells of the lower respiratory tract and the carcinomas derived from them differ markedly in their differentiation characteristics. Using immunofluorescence microscopy and two-dimensional gel electrophoresis of cytoskeletal proteins from microdissected tissues we have considered whether cytokeratin polypeptides can serve as markers of cell differentiation in epithelia from various parts of the human and bovine lower respiratory tract. In addition , we have compared these protein patterns with those found in the two commonest types of human lung carcinoma and in several cultured lung carcinoma cell lines. By immunofluorescence microscopy, broad spectrum antibodies to c…
Intraepidermal formation of Merkel cells in xenografts of human fetal skin.
An experimental transplantation model using human fetal skin was applied to approach the question of the embryologic origin of human Merkel cells. Palmar and plantar skin from five fetuses, between 8 and 11 weeks of estimated gestational age (EGA), was xenografted to subcutaneous beds of nude mice. After 4 or 8 weeks of growth, biopsies were taken from these xenografts and examined for the presence of Merkel cells, using immunocytochemistry with antibodies specific for simple epithelial-type cytokeratins and neuron-specific enolase (NSE) as well as using electron microscopy. Skin from the same fetuses at the time of transplantation was screened in the same way. In all fetuses, no (or very s…
Heterogeneity of intermediate filament expression in human testicular seminomas.
Testicular seminoma has in the past been considered to represent a germ cell tumor incapable of further differentiation. In recent years this view has been challenged on the basis of morphologic and chromosomal studies. Moreover, studies of intermediate filaments (IF) of seminoma cells have provided evidence of the capability of seminoma cells to differentiate in different directions. In the present study of the IF protein profile of 26 human testicular seminomas, using frozen as well as formalin-fixed, paraffin-embedded tissues, we report evidence of a heterogeneous differentiation potential inherent in these neoplasms. Thus, in 4 of the seminomas neither cytokeratins nor vimentin were det…