Intermediate and fine cytofilaments in cutaneous and subcutaneous leiomyosarcomas.

The expression of fine and intermediate cytofilaments in 10 cutaneous and seven subcutaneous leiomyosarcomas was studied immunohistochemically. All the tumors contained tumor cells which showed a positive immunoreactivity for desmin in formaldehyde-fixed and paraffin-embedded sections, but none of the seven anti-desmin antibodies used alone produced a distinct positive staining in all the tumors. A lack of correspondence in terms of immunoreactivity between tumor cells and the supposed muscle of origin was observed, especially in the subcutaneous leiomyosarcomas. In all cases, antibodies to muscle-specific and smooth muscle-specific actin were found to produce a positive staining in both the tumors and the supposed muscle of origin. Vimentin was detected in 8/10 cutaneous and 4/7 subcutaneous leiomyosarcomas, while the supposed muscle of origin was positive in 3/10 and 7/7 cases, respectively. Four of the cutaneous and three of the subcutaneous leiomyosarcomas contained tumor cells which stained positively for cytokeratins, while the supposed muscle of origin showed no positivity. It thus appears that a phenotypic shift in terms of vimentin and cytokeratin expression occurs in the tumor cells of cutaneous and subcutaneous leiomyosarcomas compared with the supposed muscle of origin. It is recommended that more than one monoclonal anti-desmin antibody is used to characterize these tumor entities. It is also concluded that the immunoreactivity for muscle-specific actins in superficial leiomyosarcomas is more constant, although less specific, than that of desmin and that the demonstration of the simultaneous expression of muscle-specific actins and desmin is helpful.     

Uterine leiomyosarcomas are characterized by high p16, p53 and MIB1 expression in comparison with usual leiomyomas, leiomyoma variants and smooth muscle tumours of uncertain malignant potential

AIMS: It has been suggested that p16 is overexpressed in uterine leiomyosarcomas in comparison with leiomyomas. In this study, p16 immunohistochemical expression was assessed in a variety of uterine smooth muscle tumours, including usual leiomyomas, leiomyoma variants, smooth muscle tumours of uncertain malignant potential (STUMPs) and leiomyosarcomas. The aim was to ascertain whether there are differences in p16 expression between these groups and whether p16 is of potential value in the assessment of problematic uterine smooth muscle neoplasms. p16 expression was also compared with that of p53 and MIB1. METHODS AND RESULTS: Cases of usual leiomyoma (n = 10), leiomyoma variants (n = 27), STUMP (n = 4) and leiomyosarcoma (n = 22) were subject to p16, p53 and MIB1 immunohistochemistry. For p16, cases were evaluated with respect to both staining distribution and intensity. There was a statistically significant difference in p16 distribution (P < 0.001) and intensity (P = 0.001) between leiomyosarcomas and the other groups. There was no difference in p16 expression between usual leiomyomas, leiomyoma variants and STUMPs. There were also statistically significant differences in p53 (P = 0.014) and MIB1 (P < 0.001) immunoreactivity between leiomyosarcomas and the other groups. CONCLUSIONS: p16 is overexpressed in uterine leiomyosarcomas compared with leiomyomas, benign leiomyoma variants and STUMPs, suggesting that p16 may be implicated in the pathogenesis of malignant uterine smooth muscle neoplasms. p16, in combination with p53 and MIB1, may be of value as an adjunct to morphological examination in the assessment of problematic uterine smooth muscle tumours, although further large-scale studies with follow-up are necessary to confirm this.     

Intermediate filaments of human trophoblast and choriocarcinoma cell lines

Summary Human term placenta and two human choriocarcinoma cell lines were studied immunohistochemically and by immunoblotting with monoclonal antibodies to keratin polypeptides and vimentin. Four keratin polypeptides (40, 45, 52, 54 K) were detected in both normal and malignant trophoblastic cells. The presence of the 54 K keratin polypeptide distinguishes the benign and malignant trophoblastic cells from human embryonal carcinoma cells and a yolk sac carcinoma cell line.     

An immunohistochemical analysis of stathmin 1 expression in uterine smooth muscle tumors: differential expression in leiomyosarcomas and leiomyomas

The oncogenic phosphatidylinositol 3-kinase-AKT-mammlian target of rapamycin pathway (PI3K-AKT-mTOR) pathway is known to be activated in uterine smooth muscle tumors, and Stathmin 1 (STMN1) expression has been identified as a marker of PI3K-AKT-mTOR pathway activation. We hypothesized that STMN1 may have some diagnostic utility and explored how well STMN1 expression correlated with histologic classifications of uterine smooth muscle tumors into benign and malignant groupings. 84 smooth muscle tumors were assessed for STMN1 expression by immunohistochemistry. These included spindle cell leiomyosarcoma (n = 32), conventional spindle cell leiomyomas (n = 30), atypical (symplastic) leiomyoma (n = 5), cellular leiomyoma (n = 7), smooth muscle tumor of uncertain malignant potential (n = 4), mitotically active leiomyomas (n = 2), benign metastasizing leiomyoma (n = 3), and cotyledonoid dissecting leiomyoma (n = 1). All spindle cell leiomyosarcomas were positive (32/32 positive; 100%) as compared with conventional leiomyomata (11/30; 37%) (P < 0.0001). The average immunohistochemical score (0-12+, reflective of intensity and extent) for leiomyosarcomas was 8.7 (± 1.43) whereas the conventional leiomyomata average score was 1.6 (± 1.07) (P < 0.0001). This difference in scores was reflected in the patterns of expression: leiomyosarcomas were predominantly strongly and diffusely positive whereas leiomyomata were predominantly weakly, albeit diffusely positive when expression was present. The sensitivity of STMN1 expression for leiomyosarcomas was 100%. However, the specificity was found to be only 55% (CI = 43-68%). The negative and positive predictive values for leiomyosarcomas were 100% and 52% respectively. The odds ratio (OR) for any STMN1 expression in predicting a spindle cell leiomyosarcoma diagnosis from this dataset was highly significant (OR = 144, P = 0.0006). Thirteen non-smooth muscle tumors that involved the uterus all showed at least focal STMN1 immunoreactivity. In summary, STMN1 is a highly sensitive marker for leiomyosarcoma but is suboptimally specific for diagnostic purposes. The 100% negative predictive value for leiomyosarcoma may offer some diagnostic utility in a small sample, since the absence of STMN1 immunoreactivity in a putative leiomyosarcoma is a strong argument against this diagnostic possibility.     

Lack of CD34 positive stromal cells within angiomyomas (vascular leiomyomas)

AIMS: To investigate the role of CD34 positive stromal cells in the morphogenesis and tumour growth regulation of angiomyomas (vascular leiomyomas). METHODS: Histochemical analysis using monoclonal antibodies to CD34 and CD31 was performed in 10 angiomyomas and their adjacent soft tissue. RESULTS: CD34 positive stromal cells were not seen within the tumour tissue; the thick walled vessels within the tumours lacked CD34 positive stromal cells. In contrast, bundles of CD34 positive stromal cells were detected at the tumour border of all of the angiomyomas and in the adventitial tissue of the surrounding normal vessels. CONCLUSIONS: The lack of CD34 positive stromal cells within an angiomyoma is associated with the characteristic morphology of an angiomyoma.     

Intermediate filaments as differentiation markers of normal pancreas and pancreas cancer.

Expression of intermediate filaments (IF) is regulated during development and differentiation. The authors have studied the expression of vimentin and cytokeratins (CK) 4, 7, 8, 13, 18, 19 in normal pancreas, chronic pancreatitis, and pancreas cancer using monoclonal antibodies. Immunohistochemical assays were performed on fresh frozen tissue sections and on cultured pancreas cancer cells using the streptavidin-peroxidase method. In normal pancreas, acinar cells expressed CK 8 and 18, whereas ductal cells expressed CK 7, 8, 18, and 19. CK 4 was expressed by 5-10% of pancreas duct cells in all specimens of normal pancreas. CK 13 was not detected in any epithelial cells of normal pancreas or pancreatitis. CK 7, 8, 18, and 19 were homogeneously expressed in all pancreas cancers, whereas CK 4 was expressed only in 5-50% of cells in 10/16 tumors. Foci of squamous metaplasia expressed CK 13 but showed partial loss of expression of CK 7, 8, 18, and 19. Thirteen pancreas cancer cell lines examined showed homogeneous expression of CK 7, 8, 18, and 19; 2/11 lines expressed CK 4 weakly, and 6/11 expressed vimentin. CK 13 was not detected in any of the lines. These results indicate that pancreas cancer cells consistently express cytokeratin polypeptides characteristic of ductal epithelial cells and that this phenotype is retained in pancreas cancer cell lines. In addition, squamous metaplasia is associated with a coordinate change in the expression of CK polypeptides.     

Different karyotypic abnormalities, t(1;6) and del(7), in two uterine leiomyomas from the same patient

Cytogenetic studies of two uterine leiomyomas from the same patient revealed different karyotypic changes. Both tumors showed only a single chromosome abnormality; one had t(1;6)(q23;p21) and the other del(7)(q21.2q31.2). These findings support the view that multiple leiomyomas of the uterus arise independently.     

The fine structure and innervation of the cushion veins of the human nasal respiratory mucosa

Cushion veins of the human nasal lining were studied in eight patients of both sexes ranging in age from 11 to 59 years. It was found that the subendothelial cushions were part of the tunica media and consisted of smooth muscle cells, collagen and elastic fibers and occasional fibrocytes. The muscle fibers of the cushion nearest to the endothelium were circular. They extended processes towards the endothelium through gaps in the endothelial basement membrane and formed appositional junctions with the endothelial cells. The rest of the cushion consisted of longitudinal muscle fibers. The sarcoplasm of the muscle cells was characterized by large areas filled with vesicles of various sizes. In addition, these cells possessed cytoplasmic processes which were devoid of a basement membrane and which did not show the regular structure of sarcoplasm. The subendothelial cushion possessed a rich, intrinsic nerve supply of adrenergic and cholinergic axons. It is suggested that the cushion veins regulate the drainage of the cavernous tissue and are under nervous and humoral control. The increase in girth of the subendothelial cushion is effected by contraction of the longitudinal muscle cells and probably by uptake of extracellular fluid by means of the specialized cytoplasmic processes. The single layer of circular muscle cells situated between the endothelial lining and the longitudinal musculature, may provide protection to the endothelium against distension when the cushion expands.     

Morphogenesis and fine structure of Eel Virus (Berlin), a member of the proposed birnavirus group

Summary Eel Virus (Berlin) is associated with the occurrence of skin tumors in European eels. The genome of the virus consists of two segments of double-stranded (ds) RNA. The agent is assembled exclusively in the cytoplasm. Isometric particles with a diameter of 61 nm and in addition tubular structures and smaller particles were observed. The virion has a single shell: its capsid is composed of 132 interconnected morphological units with T=13 dextro symmetry. According to particle size and bipartite nature of the genome, this virus has to be assigned to the tentatively proposed group of bisegmented ds RNA animal viruses.With 6 FiguresDedicated to Professor Dr. G. Henneberg on occasion of his 75th birthday.     

Intermediate filaments of the cytoskeleton in glandular cells of the rat fundic mucosa: immunofluorescence and electron microscopy study

The organization of intermediate filaments (IF) in cells of the rat fundic mucosa was studied by electron microscopy and immunofluorescence microscopy using specific antiprekeratin antibodies on frozen sections and isolated cells. Our results suggest that mucous cells lining the gastric surface and the gastric pits, which appeared strongly decorated, are the most rich in IF. These cells displayed coarse bundles of IF oriented in all directions as well as desmosome-attached tonofibrils. Mucous neck cells contained fewer bundles of IF located preferentially toward the apical region. Zymogen cells showed a strong staining along the contour of the luminal border, together with a faint decoration of a fine meshwork extending throughout the cytoplasm. A poorly defined fibrillar cortex present underneath the secretory plasma membrane and sparse bundles of IF among the elements of the rough endoplasmic reticulum were seen in thin sections. In contrast, parietal cells appeared brightly stained and the prekeratinlike material formed a cortical polygonal meshwork especially visible in isolated cells. A developed system of IF formed by conspicuous bundles located underneath the secretory canaliculi, among the mitochondria and in the vicinity of the basal plasma membrane, was observed in the electron microscope.     

Modulation of vascular tone and reactivity by nitric oxide in porcine pulmonary arteries and veins

Isolated porcine pulmonary vessels were studied in order to evaluate the role of nitric oxide in arteries and veins. Leukotriene C4 and noradrenaline contracted porcine pulmonary arteries but induced only negligible contractions of porcine pulmonary veins. After treatment with the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine (L-NOARG), significant contractions to leukotriene C4 and noradrenaline were uncovered in pulmonary veins. In arterial preparations, L-NOARG caused a less marked potentiation of noradrenaline-induced contractions and did not alter leukotriene C4-induced contractions. Endothelium-dependent relaxations to acetylcholine were greater in veins compared with arteries whereas the endothelium-independent relaxations to the nitric oxide donor sodium nitroprusside (SNP) and the cyclic nucleotide analogue 8-bromo-cGMP were similar in the two preparations. Taken together these data suggest that the apparent insensitivity of porcine pulmonary veins to leukotriene C4 and noradrenaline was because of release of nitric oxide. The effect of nitric oxide synthase inhibition was less pronounced in porcine pulmonary arteries, suggesting a preferential functional role of nitric oxide in porcine pulmonary veins, originating in a greater production of nitric oxide by veins as opposed to arteries.     

Intermediate filaments of normal and neoplastic tissues of the female genital tract with emphasis on problems of differential tumor diagnosis

Cytokeratins of normal epithelia and of some neoplasms of the female genital tract were studied by immunofluorescence microscopy of frozen sections and by two-dimensional gel electrophoresis of cytoskeletal proteins from microdissected tissues. All normal epithelia were stained with the monoclonal cytokeratin antibody KG 8.13 whereas certain monoclonal antibodies stained only simple epithelia. As revealed by gel electrophoresis the normal epithelia of the ovarian surface, oviduct, endometrium and endocervix contained cytokeratin polypeptides Nos. 7, 8, 18 and 19. In contrast, stratified exocervical epithelium showed a much more complex pattern (polypeptides No. 1, 2, 4, 5, 6, 11, 13, 14, 15, 16, 17 and 19). A similar pattern was found in the vagina. All epithelial neoplasms studied, regardless of the degree of histologic differentiation, were stained with antibody KG 8.13 as well as with conventionally obtained guinea pig antibodies to bovine muzzle prekeratins. The ovarian, endometrial and endocervical epithelial tumors maintained the pattern of their cells of origin, i.e. they expressed only cytokeratins Nos. 7, 8, 18 and 19. In one type of endocervical adenocarcinoma an additional cytokeratin polypeptide (No. 17) was detected. In contrast, the epithelial tumors of the lower genital tract showed a more complex pattern which also showed some differences with respect to that described for the corresponding normal tissue. Thus, in non-keratinizing squamous cell cervical carcinomas, cytokeratins Nos. 5, 6, 7, 8, 13, 14, 15, 16, 17, 18 and 19 were present, whereas the keratinizing cervical cancers showed polypeptides Nos. 5, 6, 13, 14, 16, 17 and 19.(ABSTRACT TRUNCATED AT 250 WORDS)     

Heterogeneous expression of endothelial connexin (Cx) 37, Cx40, and Cx43 in rat large veins

Gap junctions are clusters of transmembrane protein channels for intercellular communication and are composed of connexin (Cx). The vascular endothelial cells express Cx37, Cx40, and Cx43. We herein examined the spatial distribution of the endothelial connexins Cx37, Cx40, and Cx43 in rat large veins including the cranial vena cava, thoracic section of the caudal vena cava, and abdominal section of the caudal vena cava. We also examined the mean size of the endothelial cells and quantified the protein expression levels of the endothelial connexins. We found that the large veins heterogeneously expressed Cx37, Cx40, and Cx43 as follows: Cx40 > Cx37 > > Cx43 in the cranial vena cava, Cx37 > Cx43 > > Cx40 in the thoracic section of the caudal vena cava, and Cx40 > Cx43 > > Cx37 in the abdominal section of the caudal vena cava. Double immunostaining of two of the endothelial connexins revealed that the gap-junction plaques were composed of various combinations of endothelial connexins. The mean size of the endothelial cells was large, moderate, or small in the cranial vena cava, the abdominal section of the caudal vena cava, or the thoracic section of the caudal vena cava, respectively. The heterogeneity of the endothelial cells of the rat large veins in terms of the connexin expression suggests that the endothelial cells are differently coupled in the large veins. The present data are useful for investigating, for example, disease-related alterations in expression of endothelial connexins in large veins.     

Intermediate filaments in normal tissues and lymphomas of northern pike, Esox lucius L., from the Aland Islands of Finland

A battery of polyclonal and monoclonal antibodies directed against cytokeratins, desmin, vimentin, glial fibrillary acidic protein and neurofilament proteins of mammalian species was used to demonstrate intermediate filament (IF) expression in normal and lymphoma tissues of northern pike by indirect immunofluorescence microscopy. Frozen sections of pike intestine, skin, skeletal muscle, heart, liver, testis, head-, mid-, and posterior kidney and brain demonstrated IF in a manner which strengthens the idea that they are evolutionarily highly conserved. The results also confirm the IF-subclass specificities for different types of tissues, as noted by others in other species. Pike lymphoma cells showed morphological resemblance to head kidney cells; immunofluorescence microscopy and immunoblotting revealed vimentin expression, suggesting that the Aland pike lymphoma is a true mesenchymal neoplasm and is derived from haemic cells. The significance of these studies in relation to similar work with other species and to the possible use of IFs in the classification of normal and diseased tissues in fish is discussed.     

Assessment of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status in the fine needle aspirates of metastatic breast carcinomas

The assessment of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2) status in the fine needle aspirates of metastatic breast carcinomas has prognostic and therapeutic implications. In this study, expression of ER, PR, and HER2 was assessed by immunohistochemical study in 70 cases of metastatic breast carcinomas and HER2 gene amplification was further evaluated by fluorescence in situ hybridization (FISH) in 38 (54%) cases. Positive expression of ER and PR was seen in 42 (60%) and 16 (23%) cases of metastatic breast carcinomas, respectively. HER2 immunoreactivity was scored as 0/1+ in 39 (56%), 2+ in 10 (14%), and 3+ in 21 (30%) cases. HER2 gene amplification was seen in 20% of HER2 2+ and 64% of HER2 3+ cases. ER, PR, and HER2 status in primary breast cancers were available to comparison in 31 cases (44%). The concordance rates between metastatic and primary breast carcinomas were 81% for ER, 65% for PR and 71% for HER2. Our study demonstrates that ER, PR, and HER2 status can be assessed in the fine needle aspirates of metastatic breast carcinomas and ER has a higher concordance rate between metastatic and primary breast carcinomas than PR and HER2. The addition of HER2 gene amplification FISH test helps in accurate assessment of HER2 status in metastatic breast carcinomas.