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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vimentin was isolated and purified from the pig eye lens by homogenization, ultracentrifugation, extraction in urea buffer and preparative electrophoresis. It was identified with SDS-PAGE and rabbit anti-vimentin was raised against the purified vimentin. The specificity of anti-vimentin was examined with immunohistochemical technique and double immune diffusion. Results showed that the vimentin antibody possessed good specificity for mesenchyme-derived cells. Tumor tissue sections from 151 cases were stained with anti-vimentin, anti-keratin, anti-desmin, anti-S-100 protein, anti-Factor-FVIII released antigen, and anti-lysozyme. Positive staining was obtained in mesenchyme-derived cells, while the epithelial tumor cells did not react with anti-vimentin. It indicated that vimentin antibody is effective for tumor differential diagnosis in surgical pathology.
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PMID:[Vimentin and tumor diagnosis]. 239 Jul 90

The distribution of cytokeratins, desmosomal-plaque proteins (desmoplakins), and vimentin in nephroblastoma tissue was studied by immunofluorescence microscopy using specific antibodies. In undifferentiated blastema cells, desmosomes, as revealed by antibodies to desmoplakins, preceded the advent of significant amounts of cytokeratins, indicating that desmosomes are early and sensitive markers of epithelial differentiation. Cytokeratin-positive tumor cells were seen in the following distribution patterns: groups of loosely arranged and scattered cells containing only scant cytokeratin fibrils surrounded by negative stroma cells; focal accumulation of cytokeratin-positive cells with cytokeratin-specific cytoplasmic fibril meshwork staining; rosettes of cytokeratin-positive cells without formation of distinct lumina, showing concentration of cytokeratin staining in the center; tubules with distinct lumina made up of cytokeratin-positive cells, with cytokeratin staining concentrated in the subapical cell portions. In cytokeratin-positive cells, the numbers of desmoplakin-positive dots were generally increased; in well-formed tubules, enrichment of desmoplakin-positive spots, corresponding to the subapical skeletal disks, was most conspicuous. Vimentin was demonstrated in stromal areas, but also in blastema cells showing coexpression of desmosomes and vimentin filaments. Moreover, in certain blastema cells, an overlap of cytokeratin and vimentin immunostaining was observed. Epithelial cells of nephroblastoma tubules did not react with vimentin antibodies. Our results show that the appearance of desmosomal plaques, as demonstrated by antibodies to desmoplakins, may be a very early feature of epithelial differentiation, and they also emphasize the value of antibodies to desmoplakins in tumor cell typing and diagnosis.
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PMID:Distribution of vimentin, cytokeratins, and desmosomal-plaque proteins in human nephroblastoma as revealed by specific antibodies: co-existence of cell groups of different degrees of epithelial differentiation. 241 Mar 18

The cytoskeleton (CSK) of eukaryotic cells is composed of a complex interconnected network of filaments which is important in a wide variety of cellular functions including changes in cell shape, cell motility, mitosis, anchorage-dependent growth, and the localization of cellular organelles such as mitochondria, polyribosomes, and secretory granules. The various proteins comprising the cytoskeleton include actin in microfilaments, tubulin in microtubules, and the heterogeneous group of intermediate filament proteins that are associated with different cell types (keratin in epithelial cells, vimentin in fibroblasts, desmin in muscle cells, glial filament protein in glial cells, and the neurofilament protein subunits in neural tissue). Many other proteins in glial cells, and the neurofilament protein subunits in neural tissue). Many other proteins are closely associated with the cytoskeleton and influence its organization. In neoplastic cells, the expression of these different CSK proteins, especially the intermediate filament proteins, reflects their morphologic and functional differentiation. The carcinomas contain keratin; identification of individual keratin components may allow further sub-classification of carcinomas which is consistent with their tissue of origin. The sarcomas of muscle origin contain desmin. Vimentin is found primarily with cells of mesenchymal origin, but may coexist with other intermediate filament proteins in other tumors. One example is the coexistence of keratin and vimentin in tumors, such as mesotheliomas, which are derived from epithelial cells of embryonic origin. Glial fibrillary acidic protein is the most specific marker for glial tumors. Tumors of neural origin are characterized by the presence of neurofilament subunits. Therefore, analysis of CSK composition would be useful in diagnosis of clinical specimens and aid in studies of lineage relationships of neoplasms. Although no consistent differences in cytoskeletal structure between neoplastic and normal cells have been identified so far, the presence of more subtle biochemical alterations in the cytoskeletal structure of neoplastic cells that contributes to malignant behavior has not been ruled out. Since the cytoskeletal network plays an important role in cell shape and cell locomotion, which in turn are thought to be involved in growth control, invasion, and metastasis, further work is directed at identifying the various alterations in cytoskeletal architecture that may influence the malignant behavior of neoplastic cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Cytoskeleton-associated proteins: their role as cellular integrators in the neoplastic process. 241 18

The expression of vimentin in pulmonary carcinomas was studied in 285 cases of surgically resected lung cancer from our hospital files. Formalin fixed, paraffin-embedded sections were studied by immunoreactive staining techniques using two monoclonal antibodies against vimentin. Cases demonstrating vimentin positivity by the avidin-biotin-peroxidase method included 11 of 129 adenocarcinomas studied (8.5%), and 15 of 61 large cell carcinomas studied (24.6%). Vimentin expression was not seen in any of the 51 squamous cell carcinomas or 35 small cell carcinomas in our series. The positive cases of adenocarcinoma were in moderately and poorly differentiated cancers. Four of the eight giant cell carcinomas (50%) demonstrated vimentin expression. All cases that exhibited vimentin positivity were studied for cytokeratin expression. Coexpression of vimentin and cytokeratin was demonstrated not only within the same tumor but also within the same cells in some cases stained by double antibody technique, including both adenocarcinomas and large cell carcinomas. Similar immunoreactive methods were also applied to sections from human lung cancer transplants grown in the nude mouse. Of 28 tumors studied, four of 11 adenocarcinomas (36%) and all 4 large cell carcinomas demonstrated coexpression of vimentin and cytokeratin, while none of the five squamous cell carcinomas or eight small cell carcinomas expressed vimentin.
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PMID:Expression of vimentin in surgically resected adenocarcinomas and large cell carcinomas of lung. 242 81

Hepatocellular carcinoma cells obtained from ascitic fluid after diethylnitrosamine treatment of Sewall Wright strain-2 guinea pigs produce solid (primary) tumors, lymph-node metastases and malignant ascites when reinjected into animals of the same strain. When brought into culture the cells settle, form multilayer cultures and can be maintained in passage. In addition to epithelium-specific cytokeratin intermediate filaments (IF), these latter cells, like most cultured cells, also contain vimentin. Hepatocellular carcinoma cells in solid tumors and in metastatic tumors retain their original keratin IF and in general do not have an additional vimentin-IF system. When the tumor cells are present in ascites they develop vimentin-IF in addition to cytokeratin filaments. Vimentin is gradually lost when these cells sediment onto the peritoneal surface and proliferate continuously to form papillary projections, or when they are detected as circumscribed metastases. It seems likely, therefore, that in this system the synthesis of an additional vimentin cytoskeleton is related to reduced cell-to-cell contact and to the ability of the cells to survive individually or as cell clusters in body fluids, without being part of a cohesive tissue.
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PMID:Changing intermediate-sized filament patterns in metastatic hepatocellular carcinoma cells of the guinea pig. 242 67

Two cases of malignant rhabdoid tumor of the kidney (MRT) and two cases of bone metastasizing renal tumor (BMRT) were studied using electron microscopy and immunohistochemistry, in an attempt to evaluate the histogenetic relation to classical Wilms' tumor (2 cases). The two cases of MRT showed ultrastructural features of intermediate filament clusters in the cytoplasm. Vimentin, keratin, laminin, and peanut (PNA) lectin were immunohistochemically demonstrated in two cases of MRT. Tissue polypeptide antigen (TPA) was detected in one case. As for BMRT, the metastatic lesion exhibited numerous rosette-like structures of tumor cells. Vimentin was immunohistochemically demonstrated in one case, but no other antibodies were stained in two cases. Two cases of classical Wilms' tumor immunohistochemically demonstrated vimentin, keratin, PNA lectin, and TPA. MRT and BMRT fall within the broad spectrum of Wilms' tumors from the histogenetic aspect, but their clinical behavior is distinct.
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PMID:Sarcomatous variants of Wilms' tumor. Immunohistochemical and ultrastructural comparison with classical Wilms' tumor. 243 3

Vimentin has been regarded as the intermediate filament characteristic of normal and neoplastic mesenchymal cells and keratins as typical of epithelial cells and the neoplasms derived from them. However, many epithelial cells in tissue culture or in effusion, as well as cells in some solid epithelial neoplasms such as renal, endometrial, ovarian, pulmonary, and thyroid adenocarcinomas, have been shown to coexpress vimentin and keratin. The recent availability of monoclonal antibodies that work reasonably well in paraffin-embedded tissue led us to carry out a comprehensive immunohistochemical study on formalin- and alcohol-fixed specimens of neoplasms in which we used monoclonal antibodies against vimentin. These results were compared with our previous study in which the same tumor tissues were investigated using antibodies against keratin. The antigenicity of vimentin was found to be preserved in all alcohol-fixed specimens and in 63% of formalin-fixed tissues. Vimentin was the sole intermediate filament present in virtually all sarcomas, meningiomas, schwannomas, and melanomas. In addition, variable percentages (10-57%) of carcinomas, neuroendocrine carcinomas, neuroblastomas, thymomas, and mesotheliomas were positive for vimentin, which, except in the neuroblastomas, was coexpressed with keratins. Among the adenocarcinomas, more than 50% of papillary carcinomas of the thyroid, as well as renal, endometrial, ovarian, and lung carcinomas, coexpressed keratins and vimentin. A distinctive paranuclear and basal localization of vimentin was observed in the cells of many of these tumors, in contrast to the predominantly apical distribution of the keratins. The authors conclude that coexpression of vimentin and keratin is more widespread than previously reported and that antibodies to vimentin, by themselves, are of limited value for the differentiation of epithelial from mesenchymal neoplasms.
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PMID:The distribution of vimentin and keratin in epithelial and nonepithelial neoplasms. A comprehensive immunohistochemical study on formalin- and alcohol-fixed tumors. 244

Abdominal diffuse malignant mesotheliomas develop in rats administered asbestos by the intraperitoneal route. A latency period of 6 to 24 months precedes tumor development; the biological and morphological features of these tumors resemble mesotheliomas in humans. Using one- and two-dimensional gel electrophoresis and immunoblotting, rat mesotheliomas (n = 24) were shown to express two classes of intermediate filament (IF) proteins. The tumors contained both vimentin and at least one of six keratins (p40, Mr 40,000; Dm, Mr 50,000; p53, Mr 53,000; Bm, Mr 53,000; Cm, Mr 54,000; Am, Mr 54,000). Vimentin predominated in 15 of 16 tumors exhibiting either sarcomatous or mixed (epithelial and mesenchymal) appearance. One of eight mixed lesions and six of eight epithelial tumors had a complement of IF proteins in which cytokeratins predominated. A similar pattern has been reported in mesotheliomas in humans (Blobel et al., Am. J. Pathol. 121: 235, 1985). Epithelial tumors often contain comparable amounts of vimentin and low molecular weight cytokeratins, while vimentin is the most actively expressed IF protein in sarcomatous tumors. Thus, tumors induced by asbestos in the rat peritoneum express IF proteins in a manner that resembles human mesotheliomas, supporting the notion that these lesions are appropriate models of human mesothelioma.
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PMID:Intermediate filament proteins in asbestos-induced mesotheliomas of the rat. 244 39

Among 284 cases of carcinoma of the gallbladder, 21 were identified as undifferentiated carcinoma (UC), with little glandular or other specific epithelial differentiation. These tumors were classified into three histologic types according to the components: (1) small cell type (eight cases); (2) pleomorphic cell type (eight cases); and (3) spindle cell or pseudosarcomatous type (five cases). Histochemical and immunohistochemical study by the immunoperoxidase technique revealed that most of the tumors (13/21) contained mucosubstances, and that all examples of the UC were immunoreactive for epithelial membrane antigen (EMA), keratin, and carcinoembryonic antigen (CEA), thereby indicating the epithelial nature of the neoplastic cells. Vimentin immunoreactivity was found in nine tumors. In 19, the tumor contained various neoplastic endocrine cells, including somatostatin-immunoreactive (14/19), gastrin-immunoreactive (14/19), human chorionic gonadotropin (HCG)-immunoreactive (9/19), pancreatic polypeptide-immunoreactive (4/19), and serotonin-immunoreactive cells (4/19). The prognosis of patients with UC of the gallbladder was poorer than that of patients with differentiated adenocarcinoma.
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PMID:Undifferentiated carcinoma of the gallbladder. A clinicopathologic, histochemical, and immunohistochemical study of 21 patients with a poor prognosis. 245 57

We applied a panel of antibodies to formalin-fixed, paraffin-embedded sections of 55 renal cell carcinomas using a three-stage immunoperoxidase technique. The antibody panel included two anti-keratins, AE1 and CAM5.2, anti-epithelial membrane antigen (EMA), anti-vimentin, anti-S100 protein, and the anti-leukocyte marker PD7/26. Forty-eight of 55 renal cell carcinomas expressed keratins. CAM5.2 stained 46 tumors (84%) and AE1 stained 37 neoplasms (67%). AE1 reacted with two CAM5.2-negative tumors. EMA was expressed by 35 carcinomas (64%), including three of the CAM5.2-negative neoplasms. Therefore, using all three antibodies, 50 neoplasms (91%) expressed antigens of epithelial differentiation. Anti-EMA and AE1 were complementary to each other; the combination stained 46 of the carcinomas, comparable with CAM5.2 alone. Vimentin was expressed by 26 tumors (47%), and S100 was expressed by one. PD7/26 did not stain any of the cases. Vimentin expression correlated with nuclear grade; low nuclear grade neoplasms infrequently expressed vimentin, while the converse was true for high nuclear grade tumors. Keratin expression was related to tumor cell type and histologic pattern, as fewer neoplasms of clear cell type and with a solid pattern expressed keratins. In contrast, all papillary and eight of nine (89%) spindled carcinomas expressed keratins.
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PMID:An immunoperoxidase study of renal cell carcinomas: correlation with nuclear grade, cell type, and histologic pattern. 245 80


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