Peter Vooijs

Tissue distribution of keratin 7 as monitored by a monoclonal antibody

Monoclonal antibody (RCK 105) directed against keratin 7 was obtained after immunization of BALB/c mice with cytoskeletal preparations from T24 cells and characterized by one- (1D) and two-dimensional (2D) immunoblotting. In cultured epithelial cells, known from gel electrophoretic studies to contain keratin 7, this antibody gives a typical keratin intermediate filament staining pattern, comparable to that obtained with polyclonal rabbit antisera to skin keratins or with other monoclonal antibodies, recognizing for example keratins 5 and 8 or keratin 18. Using RCK 105, the distribution of keratin 7 throughout human epithelial tissues was examined and correlated with expression patterns of other keratins. Keratin 7 was found to occur in the columnar and glandular epithelium of the lung, cervix, breast, in bile ducts, collecting ducts in the kidney and in mesothelium, but to be absent from gastrointestinal epithelium, hepatocytes, proximal and distal tubules of the kidney and myoepithelium. Nor could it be detected in the stratified epithelia of the skin, tongue, esophagus, or cervix but strongly stained all cell layers of the urinary bladder transitional epithelium. When applied to carcinomas derived from these different tissue types it became obvious that an antibody to keratin 7 may allow an immunohistochemical distinction between certain types of adenocarcinomas.

The effectiveness of cervical screening: A population-based case-control study

The cervical smear histories of 36 women with invasive cervical cancer were compared to those of 120 age-matched controls, drawn from local registrars offices. Of the cases 47% were screened at least once, while for the controls this figure was 68%. The relative risk of getting invasive cervical cancer for women screened at least once compared to women who were never screened was 0.32. The most important confounding factor was age at first intercourse. Contrary to other studies however, it was found that women who were younger when having first intercourse were screened more often. After correcting the relative risk of screened vs unscreened for age at first intercourse, the relative risk became 0.22. When the length of the interval since the last smear was considered, the relative risk was 0.18 when the smear was made between 2 and 5 years earlier and 0.30 when this smear was made more than 5 years earlier. These results support the assumption that screening is effective in the prevention of invasive cancer of the uterine cervix. Even a screening interval of more than 5 years provides considerable protection.

Antibodies to cytokeratin and vimentin in testicular tumour diagnosis

Thirteen primary and metastatic testicular germ cell tumours, including classical and anaplastic seminomas, and non-seminomatous testicular tumours were examined for their intermediate filament protein (IFP) types. The seminomas were shown to react with a monoclonal and a polyclonal antibody to bovine lens vimentin, while non-seminomatous germ cell tumours were strongly positive for a polyclonal and a monoclonal antibody to cytokeratin. In one case of seminoma with elevated serum levels ofβHCG andαFP, cytokeratin positive tumour cells were found. In the case of teratocarcinoma, several components of the tumour could be distinguished using a combination of antisera in double-label immunofluorescence microscopy. The glandular component of this tumour was positive with the polyclonal antikeratin, but also with the monoclonal cytokeratin antibody specific for glandular epithelia (RGE 53). However, the squamous component was negative with this latter antibody. Strikingly, the spindle cell component showed focal positivity for vimentin, with coexpression of cytokeratin and vimentin in some cells. Our data show that antibodies to cytokeratin and vimentin can be helpful in the diagnosis of testicular germ cell tumours, especially in the differentiation between seminomas and non-seminomatous tumours.

Differential diagnosis of human carcinomas, sarcomas and their metastases using antibodies to intermediate-sized filaments☆

Intermediate filaments (IF) are tissue-specific in so far that epithelial, mesenchymal, muscle and neural tissue types can be distinguished by the use of specific antibodies to keratin, vimentin, desmin and neurofilaments or glial filaments respectively. We have examined the possibility of using these sera in the differential diagnosis of human malignant tumors. Using antisera to human skin keratin and bovine lens vimentin we could differentiate between carcinomas (keratin +) and sarcomas (vimentin +). Furthermore, we could show that when cells become malignant and metastasize they retain their original IF and do not develop additional IF systems. We conclude that antibodies to IF proteins are powerful tools in the hands of a pathologist as an additional method to improve identification of tumors and their metastases.

Oral granular cell lesions

Six cases of oral granular cell lesions were studied with respect to intermediate-sized filaments (IF), peanut lectin binding (PNL) and muramidase activity by means of the peroxidase antiperoxidase technique. The tumours included three granular cell myoblastomas of the tongue (GCM) two cases of congenital gingival granular cell tumour (CGGT) and one granular cell ameloblastoma (GCA). Every tumour studied showed intracytoplasmic PNL binding whereas muramidase was negative in all cases. Vimentin expression was demonstrated in the CGGT and to a lesser extent in the GCM, but was absent in the GCA which was positive for keratin. Desmin and glial fibrillary acidic protein (GFAP) were not present in any of the lesions. These data demonstrate that PNL binding might be considered to be a common feature of granular cells regardless of their histogenesis. Lysosomes are supposed to represent the intracellular binding sites for this marker. Moreover it is shown that histomorphological identity between the granular cells of CGGT and GCA does not signify identity in histogenesis since the former are of mesenchymal derivation while the latter, from their intermediate filament protein types appear to originate from epithelium.

Characterization of a hormone-producing ovarian carcinoma cell line

An ovarian carcinoma cell line (OTN 11) was produced from the ascitic fluid of a patient with a moderately to well differentiated papilliferous cystadenocarcinoma of the ovary. The cell line was characterized using electron microscopy karyotyping, immunohistochemical techniques with monoclonal antibodies against keratins as epithelial markers, and the monoclonal antibodies OV-TL 3 and OC 125 as ovarian carcinoma markers. These techniques revealed the epithelial and adenocarcinomatous nature of the cell line and the presence of ovarian carcinoma-related surface markers. The adenocarcinomatous nature of the cell line also became apparent after heterotransplantation of cell suspensions into nude mice and nude rats, in which adenomatous tumor structures were formed. These xenografts had the same ultrastructural and immunohistochemical properties as the cell line. Despite the adenocarcinomatous character of the tumor the cultured cells release estradiol into the culture medium. We may conclude that OTN 11 is an ovarian carcinoma cell line which has retained highly differentiated functions, such as the production of an ovarian hormone.

Cervical cancer survival in Nijmegen region, The Netherlands, 1970–1985

Survival rates were computed for 359 women diagnosed with invasive cervical cancer between 1970 and 1985. The 5-year survival rate for the entire group was 67%. Survival was better in the period 1976-1980. Extension of the tumor and age at diagnosis were important prognostic factors. The effects of clinical stage, age at diagnosis, and year of diagnosis were studied simultaneously with the proportional hazards model. The hazard rate increased with increasing age and increasing clinical stage. Year of diagnosis had effect on survival only in case of IIB tumors. For the other clinical stages there was no significant effect on survival of year of diagnosis.

Changing intermediate-sized filament patterns in metastatic hepatocellular carcinoma cells of the guinea pig.

SummaryHepatocellular 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.

Can keratin 8 and 17 immunohistochemistry be of diagnostic value in cervical cytology

Based on results from evaluation of tissue sections from premalignant lesions of the uterine cervix, the authors examined the hypothesis that immunostaining of Papanicolaou‐stained cytologic smears with monoclonal antibodies to keratins 8 and 17 allows detection of cervical intraepithelial neoplasia (CIN) with progressive potential. They also investigated whether detection of these two keratin subtypes could be of help in the analysis of normal and/or poor quality cytology smears.

Population screening for cervical cancer in the region of Nijmegen, The Netherlands 1976–1985

In this study the results of a 9-year cervical screening program in the region of Nijmegen, The Netherlands are presented. All women aged 35 through 54 were invited every 3 years for a cervical smear. Overall attendance rates were 74%, 67%, and 63% at first, second, and third screening, respectively. The number of histologically confirmed severe epithelial abnormalities discovered in women who were screened for the first time was 3.8 per thousand smears, 1.0 per thousand in women who were screened twice and 0.7 per thousand in women who were screened three times in the program. Three years after the start of the screening program the incidence of invasive squamous cell cancer started to decline in the women aged 35 through 54 years. On the basis of the results of this study we may conclude a screening policy with an interval of 3 years to be a safe procedure. Whether this interval is the most efficient cannot be concluded. We have the impression that an interval of 4 to 6 years may lead to comparable results.