Diagnostic significance of coexpression of intermediate filaments in fine needle aspirates of human tumors

A study was undertaken of the diagnostic significance of the coexpression of intermediate filaments in fine needle aspirates of human tumors. Three types of coexpression were found: (1) true coexpression, in which tumor cells simultaneously express more than one intermediate filament protein; (2) pseudocoexpression, in which various tumor cell types from histogenetically different parts of a complex tumor show different results; and (3) false coexpression, in which tumor cells with one or two types of intermediate filaments are present together with benign cells expressing a different filament type. True coexpression of vimentin and keratin was documented in renal cell carcinomas, endometrial carcinomas, certain thyroid carcinomas and Hürthle cell adenomas. Coexpression of keratin and neurofilaments was seen in Merkel cell carcinomas, and coexpression of desmin and vimentin was found in leiomyosarcomas. Keratin, vimentin and neurofilament expression was seen in medullary thyroid carcinomas, and keratin, vimentin and glial fibrillary acidic protein expression was observed in pleomorphic adenomas of the salivary gland. Pseudocoexpression was noted in synovial sarcoma, epithelioid sarcoma, benign cystosarcoma phyllodes of the breast, teratocarcinoma, malignant granular cell tumor, progonoma, Wilms' tumor and triton tumor. Sources of false coexpression are also discussed.

Villin, intestinal brush border hydrolases and keratin polypeptides in intestinal metaplasia and gastric cancer; an immunohistologic study emphasizing the different degrees of intestinal and gastric differentiation in signet ring cell carcinomas

Gastric carcinomas have been assayed for the presence of villin and for the small intestinal hydrolases aminopeptidase N and sucrase isomaltase. These proteins seem not to be present in normal stomach epithelium. However intestinal metaplasia in stomach, and tumour cells in the glandular patterns of gastric carcinoma were positive for all three markers, showing characteristic apical positivity. In contrast, in diffuse gastric carcinomas the percentage of signet ring cells positive for these markers varied from 10-100% with each marker showing a similar percentage of positive cells. Testing of gastric carcinomas with antibodies specific for different keratin polypeptides showed that while all 7 tumours were positive for keratins 8 and 18.2 were also positive for keratin 7. In the keratin 7 positive tumours all tumour cells were keratin 7 positive. The keratin 8 antibody also reacted on routinely fixed specimens. Thus gastric carcinomas reveal different degrees of gastric and intestinal differentiation.

Nebulin and titin expression in Duchenne muscular dystrophy appears normal

Monoclonal antibodies which recognize different epitopes on either titin or nebulin show normal staining patterns on frozen sections of three muscle biopsies of Duchenne muscular dystrophy (DMD). Gel electrophoresis and immunoblotting performed on two of these muscle biopsies show the normal pattern of titin and nebulin polypeptides. Since the donor of one of these biopsies has a large deletion of the 5'-region of the DMD gene, our results argue against the recent proposal that nebulin is the gene mutated in DMD.

Actin typing of rhabdomyosarcomas shows the presence of the fetal and adult forms of sarcomeric muscle actin

We analyzed actin expression in two human rhabdomyosarcomas as well as in three rhabdomyosarcomas induced in rats by the injection of nickel sulfide. All five tumors exhibited appreciable amounts of the sarcomeric alpha-actin types, in line with their myogenic differentiation. The level of these actins was particularly high in the rat tumors, which according to morphological criteria, all showed a higher degree of differentiation than the human tumors. Interestingly, in both human tumors and in two of the three rat tumors, the level of the cardiac alpha-actin type was significantly higher than that of adult skeletal muscle alpha-actin. Taken together with the results of recent reports indicating that the cardiac alpha-actin type is a marker of embryonic and fetal skeletal muscle, our findings indicate that rhabdomyosarcomas express the embryonic sarcomeric actin isoform.

Coexpression of keratin and vimentin in damaged and regenerating tubular epithelia of the kidney

Most renal cell carcinomas coexpress vimentin and keratin, while renal tubular epithelia express only keratin. Investigation of the intermediate filament composition of tubular epithelia in diseased rat and human kidneys now shows that altered tubular epithelia unequivocally coexpress keratin and vimentin. In rats, pronounced coexpression of vimentin and keratin was observed in chronic nephrosis induced by daunomycin, and the extent of coexpression seemed to increase with the incidence of altered collapsed and cystically dilated tubules and with the degree of tubular epithelial proliferation. It was also seen during tubular regeneration after acute tubulotoxic injury induced by mercury chloride poisoning, with vimentin expression being lost in fully regenerated tubular epithelium. In man, expression was seen in chronically and irreversibly damaged kidneys. Thus, vimentin can be expressed temporarily in acutely and reversibly damaged kidneys and chronically in irreversibly damaged kidneys. Vimentin could perhaps be regarded as an indicator of the regenerating and proliferating activity of tubular lesions.

Intermediate filaments in cytological specimens of thyroid tumors

Cytological specimens of thyroid carcinomas and follicular adenomas obtained by fine-needle aspiration biopsies or touch imprints were investigated with antibodies to keratin, vimentin, and neurofilaments. All tumors were keratin positive. In follicular adenomas as well as in papillary thyroid carcinomas, a coexpression of keratin and vimentin was detected; in follicular carcinomas, only some tumors showed coexpression of keratin and vimentin; and in medullary thyroid carcinomas, positive staining of all six tumors studied was seen with the keratin and neurofilament antibodies, with some tumors also showing coexpression of vimentin. The mechanisms of such coexpression is unclear.

Keratin polypeptides in malignant epithelial liver tumors. Differential diagnostic and histogenetic aspects

Five monoclonal antibodies recognizing different keratin polypeptides in immunoblotting or different epithelial cell types in complex tissues were studied for their suitability as reagents for the differential diagnosis of primary and secondary malignant epithelial liver tumors. The broad specificity keratin antibodies lu-5 and KL-1 stained all epithelial liver neoplasms. In contrast the antibodies CK-7 (Ker-7-specific), CK-2 (Ker-18-specific) and KA-4 (Ker-19-specific in liver) allow these neoplasms to be divided into three groups: Hepatocellular carcinomas were CK-2-positive and CK-7-negative. Cholangiocellular carcinomas, liver metastases of extrahepatic bile duct carcinomas, liver metastases of a ductal carcinoma of breast, and a follicular thyroid carcinoma were stained positively by CK-2, CK-7, and KA-4. In 1 of 6 hepatocellular carcinomas neoplastic hepatocytes were focally labeled by KA-4. In a focal nodular hyperplasia of the liver modified hepatocytes were decorated not only by CK-2 but also by CK-7 and KA-4. Liver metastases of colorectal adenocarcinomas and of a carcinoid tumor were stained positively by CK-2 and KA-4 but not by CK-7.

[Immunohistological demonstration of the intermediate filaments in a laryngeal carcinosarcoma: considerations on its histogenesis]

A carcinosarcoma of the larynx was analysed by means of a light microscope and by immunohistological staining technique using antibodies against various intermediate filament proteins. Whereas tumour areas of an epithelial character reacted with antibodies against keratin, the spindle cells demonstrated a positive immunofluorescence with vimentin antibodies. Inside some tumour cells a coexpression of keratin and vimentin (intermediate filaments of mesenchymal cells) could be demonstrated. It is likely that these double stained cells represent the primitive stem cell of the carcinosarcoma, differentiating during further development either into epithelial or mesenchymal tumour cells.

Decisive role of intermediate filament typing of tumor cells in the differential diagnosis of difficult fine needle aspirates

Thirty-six diagnostically difficult fine needle aspirates from enlarged lymph nodes and malignant soft tissue tumors, containing tumor cells with scanty or no obvious light microscopic features indicative of their differentiation, were assessed by a panel of six cytopathologists. Their diagnoses were recorded and then compared with the definitive diagnosis established by combining the cytologic findings with the results of intermediate filament typing of tumor cells in the smears using monoclonal antibodies specific for each filament type. The results show that use of these antibodies can markedly improve the accuracy of the cytologic diagnosis of tumor type as well as revise or prevent erroneous cytologic diagnoses in difficult cases. This pertains especially to the differential diagnoses of carcinoma versus malignant lymphoma, carcinoma versus malignant melanoma, carcinoma versus sarcoma and squamous carcinoma versus carcinoma of simple epithelia. Intermediate filament typing of tumor cells in aspirates as an objective histogenetic criterium makes the differential diagnosis of the difficult aspirates much more reliable and reproducible, provided that appropriate questions are asked, monoclonal antibodies with well-defined specificities are used and the antigenicity of the intermediate filaments in smears is preserved.

Neuroendocrine (Merkel-cell) carcinoma of the skin. Cytology, intermediate filament typing and ultrastructure of tumor cells in fine needle aspirates

The light and transmission electron microscopic findings and the intermediate filament typing of tumor cells from fine needle aspirates of primary, recurrent and metastatic neuroendocrine (Merkel-cell) carcinoma of the skin are described. The tumor cells in the smears coexpressed keratins and neurofilaments and were characterized by "intermediate filament buttons," i.e., buttonlike fragments of cytoplasm of tumor cells, which could be observed either by staining with intermediate filament-specific antibodies using immunofluorescence or by their appearance in hematoxylin-and-eosin-stained smears. These features may help in the differential diagnosis of fine needle aspirates of neuroendocrine carcinomas of the skin.

Cytoplasmic intermediate filament proteins and the nuclear lamins A, B and C share the IFA epitope

The murine monoclonal antibody IFA isolated by Pruss et al. (Cell 27 (1981) 419) reacts with all major proteins of the cytoplasmic intermediate filament family (IF) albeit with different affinities but leaves the nucleus undecorated in standard immunofluorescence microscopy. Here we show that IFA reacts with all three nuclear lamins from rat and man in immunoblotting. This is most easily demonstrated in a cell line in which most cells lack cytoplasmic IFs. Thus the rather minor but ubiquitous 66 kD polypeptides identified by Pruss et al. as IF-associated proteins reflect the lamin triplet. While surprising at first, these results are in agreement with the approximate location of the IFA epitope on IF molecules and the recently discovered sequence homology along the rod domain between lamins A and C and IF proteins. Our results extend this relation to lamin B in spite of its unique behaviour during mitosis.

Keratin filament disruption in interphase and mitotic cells--how is it induced?

We have studied the lability of keratin intermediate filaments in epithelial cell lines to try to understand the molecular mechanism that cause the ultrastructural transition from 10 nm filaments to the ball-like aggregates containing 2 to 3 nm filaments. Our results suggest that different growth conditions used in different laboratories may explain some but not all of the discrepancies in the literature on mitotic keratin filament disruption. Such disruption is not only cell type, but also subclone dependent and can be manipulated in one instance by altering the NaHCO3 concentration of the growth medium. An apparently similar filament to aggregate transition can be induced in interphase cells of some epithelial cell lines by incubation in a cold hypotonic buffer, or when cells are pretreated with phorbol ester and then incubated in cold physiological saline. A putative dialyzable and heat-stable factor present in medium conditioned by the growth of particular epithelial cell types may be required for disruption. Keratin polypeptide phosphorylation may play a role in filament labilization.

Psychiatric disorder and gynaecological symptoms in middle aged women: a community survey

In a community survey 521 women aged 35-59 were selected at random from all patients registered in two groups practices. They were interviewed at home and assessed by means of standardised psychiatric measures and detailed gynaecological inquiry. Levels of psychiatric morbidity were found to be within the expected range for such a sample. Both psychiatric morbidity and the personality dimension of neuroticism were significantly associated with gynaecological symptoms, including dysmenorrhoea and premenstrual tension, some symptoms of excessive menstruation, and flushes and sweats but not disappearance of menstruation for over six months. Current psychiatric state was significantly associated with recent adverse life events and with indices of psychiatric vulnerability (neuroticism and previous psychiatric history), suggesting possible aetiological links with gynaecological symptoms. The findings of this study have implications for the management of gynaecological complaints in general practice.

Chlamydia trachomatis and reactive arthritis: the missing link

Reactive inflammatory arthritis is a common sequel to sexually acquired non-gonococcal genital-tract infection. Approximately 50% of cases are associated with Chlamydia trachomatis infection in the genital tract, although conventional cultures of joint material are sterile. Synovium, synovial-fluid cells, or both, from eight patients with sexually acquired reactive arthritis (SARA) and eight with knee effusions associated with other rheumatic diseases were examined by means of a fluorescein-labelled monoclonal antibody to C trachomatis ('Micro Trak'; Syva). Typical chlamydial elementary bodies were seen in joint material from five patients with SARA but in none of the controls. An inclusion-like cluster of elementary bodies was seen in one synovial biopsy sample. All five patients had high titres of serum chlamydial antibody. It is likely that the synovitis of SARA results directly from the presence of chlamydial elementary bodies in the joint.

Intermediate filament expression in human vascular smooth muscle and in arteriosclerotic plaques

Different regions of human aorta and of other human arteries obtained at autopsy were analyzed with regard to their topography and to the different stages of arteriosclerosis. Material was studied by immunocytochemical techniques with antibodies specific for either desmin (D) or for vimentin (V), the two types of intermediate filament proteins present in vascular smooth muscle cells. In normal arteries endothelial cells as well as the adjacent intimal cells were D-V+. In the media D+V+ as well as D-V+ cells were present, with the relative numbers of each cell type dependent on the particular blood vessel. When cells in arteriosclerotic plaques at different stages of development were examined an occasional plaque showed cells of the D+V+ type. In the majority of plaques however the cells were V-D+. In plaques where severe ulceration and necrotic material was present D-V+ cells were found at the border of the lesion: foam cells when they could be identified appeared to be D-V+.

Keratin polypeptide distribution in benign and malignant breast tumors: subdivision of ductal carcinomas using monoclonal antibodies

Monoclonal antibodies which recognize one or only a few keratin polypeptides have been used to study the distribution of different keratins in benign and malignant breast lesions by immunocytochemical methods. Seven monoclonal antibodies which recognized either different keratin polypeptides by immunoblotting techniques, or identified different epithelial cell types in complex tissues were used. In two mastopathies and three fibroadenomas the antibody lu5 stained luminal cells as well as myoepithelial cells. In contrast the antibodies CK7, Troma 1, CK2 and KA4 labeled only luminal cells, whereas antibody CKB1 decorated only myoepithelial cells. All 15 ductal carcinomas showed a uniform staining of tumor cells with the antibodies Troma 1, CK2, KA4 and lu5. The antibody CK7 also stained all ductal carcinomas, but in two specimens the staining was heterogeneous. The antibody CKB1 decorated only the pre-existing myoepithelial cells in 11 of 12 ductal carcinomas but in the remaining specimen the tumor cells were also strongly positive. Tumor cells in lobular carcinomas were labeled by antibodies CK7, Troma 1, CK2, KA4, bu not by CKB1. The antibody CKS1 showed no staining of any of the benign and malignant breast lesions.

Immunohistochemistry of cytoskeletal filaments in the diagnosis of soft tissue tumors

There is abundant evidence that intermediate filaments can be used as cell type specific markers both for normal tissue and for tumors. The results of intermediate filament typing in soft tissue tumors and its diagnostic relevance is shown. This system can also be used to solve other problems in surgical pathology. One of the most useful applications of intermediate filament typing is to differentiate the round cell tumors of children; thus, rhabdomyo-sarcomas are desmin positive, malignant lymphomas contain only vimentin, and neuroblastomas show positivity for neurofilaments.

Reactivity of a panel of neurofilament antibodies on phosphorylated and dephosphorylated neurofilaments

The work of the Sternbergers and their colleagues has shown that monoclonal antibodies reactive with neurofilament subunit proteins may be sensitive to the state of phosphorylation of these proteins. We therefore examined the ability of our previously described panel of monoclonal and polyclonal neurofilament antibodies to bind to normal and to enzymatically dephosphorylated neurofilament subunits. All the monospecific antibodies, both mono- and polyclonal, which we had previously documented as reactive with neurofilament H protein proved to bind only to the phosphorylated form of this protein, and H antibody staining of neurofilamentous profiles in frozen sections could be abolished by appropriate pretreatment of sections with alkaline phosphatase. In contrast, all monospecific antibodies, both mono- and polyclonal, reactive with native M and L proved to bind with apparently undiminished affinity following enzymatic dephosphorylation of the appropriate antigen, either in frozen sections or on Western blots. The class of monoclonal antibodies which react with both H and M were variable in their response to dephosphorylated neurofilaments; some completely lost their reactivity whilst others were partially or wholly unaffected. We stained frozen sections of nervous tissues from various mammalian species with the panel of antibodies, and observed filamentous staining of the perikarya and dendrites of a variety of different types of neuron with all antibodies, both mono- and polyclonal, directed against L and M. Antibodies with strong reactivity for phosphorylated H always failed to stain neurofilamentous dendritic and perikaryal profiles. We further describe the isolation and characterization of a new monoclonal antibody, which recognizes both phosphorylated and enzymatically dephosphorylated forms of H.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical investigations on the epimyoepithelial islands in lymphoepithelial lesions. Use of monoclonal keratin antibodies

The histogenetic origin of cells in the epimyoepithelial islands occurring in patients with Sjoegren's syndrome has been investigated by using different monoclonal antibodies. The majority of cells in these islands reacted with broad specificity antibodies against keratins. The same cells are stained by a monoclonal antibody CKB1 which detects myoepithelial (basket) cells and basal cells (around the ducts) in normal salivary gland tissue, but which does not stain ductal epithelial cells. Conversely, the cells are not stained by the antibody CK5 which stains ductal epithelial cells in normal salivary gland tissue. The relation of the epimyoepithelial islands to the myoepithelial/basal cell system is thus demonstrated. Certain implications for practical use in surgical pathology are discussed.

Differential diagnosis of gastrointestinal carcinomas by using monoclonal antibodies specific for individual keratin polypeptides

Monoclonal antibodies which recognize particular keratin polypeptides have been used to analyze normal human tissues including pancreas, stomach, colon, gall bladder, and liver as well as tumors of the gastrointestinal tract by immunohistological techniques. Broad specificity (lu5), ker 8 (Troma 1) and ker 18 (CK2) antibodies were positive while a ker 14 specific antibody (CKB1) was negative on all specimens tested. Differential staining patterns were seen with a ker 7 (CK7) and a ker 19 (KA4) antibody. Both antibodies stained gall bladder epithelium, pancreatic ducts but not acinar cells, as well as pancreatic ductal adenocarcinomas. KA4 but not the CK7 antibody stained adenocarcinomas of the stomach and large bowel. Both antibodies stained bile ducts and cholangiocellular carcinoma of the liver but did not stain hepatocytes or hepatocellular carcinomas. The results with keratin monoclonal antibodies compare well with those obtained by others using two dimensional gel electrophoresis and they further support the idea that monoclonal antibodies specific for particular keratin polypeptides will find applications in routine pathological diagnosis.

Villin--a marker of brush border differentiation and cellular origin in human renal cell carcinoma

Expression of villin, a 95-kd F-actin bundling and severing protein, is restricted in animal tissues to epithelial cells with a brush border. Thus, the enterocytes of the intestine and epithelial cells of proximal but not distal tubules of the kidney are strongly positive. Here we report a similar staining pattern for human intestine and kidney. In four human colon adenocarcinomas villin expression was seen in tubular and glandular structures but not in the undifferentiated parts. Fourteen human renal carcinomas (9-Grade I and 5 Grade II) were villin-positive, and 2 sarcomatous renal carcinomas (Grade III) were villin-negative. The percentage of tumor cells that were villin-positive varied from 10-90% for the Grade I and II types. Our results indicate that villin may be a grading marker that deserves further study in renal carcinoma. They also raise the question whether the majority of renal carcinomas are derived from the proximal tubular epithelium rather than from the distal epithelium.