Transcription protein STAT1: biology and relation to cancer

Cell homeostasis is controlled and regulated by multiple signalling proteins that operate almost in all cellular compartments. Their common task is to process regulatory signals from both the extracellular and intracellular spaces by triggering a cascade of intracellular events leading to modulation of downstream gene activity. One of the important signalling pathways is represented by the STAT multigene family comprising seven members. In general, various STATs act as potent transcription factors delivering signals of diverse polypeptide ligands (i.e. cytokines and growth factors) into the nucleus. This review summarizes some up-to-date data on the role of STAT1 in maintaining cellular homeostasis with the emphasis on its role in the control of cell growth, proliferation, apoptosis, and immune reactions. Part of the review deals with expression and posttranslational abnormalities of this molecule identified in a variety of human pathological conditions including cancer. The direct or indirect involvement of STAT1 in the process of malignant transformation is highlighted in view of these molecular perturbances that may contribute to oncogenesis and that may be potentially used as novel targets for anticancer therapy.

Lack of STAT 1 phosphorylation at TYR 701 by IFNgamma correlates with disease outcome in melanoma patients

STAT 1, a member of signal transducer and transcription activator family has been implicated as key downstream mediator of interferon (IFN) signaling. Its functional activation requires phosphorylation at Tyr 701 and Ser 727 residues. Various STAT abnormalities have been found in cancer cells but their relation to oncogenesis, tumor behavior and disease outcome remains mostly unknown. We have examined the inducibility of STAT 1 phosphorylation by IFN alpha/gamma in primary cultures established from melanoma lymph node metastases at first progression and correlated our results with disease outcome and overall survival. Forty-four patients at clinical stage I-III at initial diagnosis entered the study. STAT 1 inducibility of phosphorylation by IFNs was assessed in melanoma cell lysates by means of standard immunoprecipitation and Western blotting using polyclonal and monoclonal antibodies. Lack of STAT 1 phosphorylation at Ser 727 after either IFN was recorded in 75% of patients, however, no correlations with disease evolution could be proved. In contrast, STAT 1 phosphorylation response at Tyr 701 after IFNalpha occurred in 13 (29.5%) and after IFNgamma in 32 (73%) patients. Inducibility of STAT 1 activation at Tyr 701 but not at Ser 727 driven by IFNgamma but not by IFNalpha significantly and unfavorably [corrected] influenced disease- free interval and overall survival. In conclusion, these results show that the absence of IFNgamma inducibility of STAT 1 phosphorylation at Tyr 701 positively correlates with disease outcome in malignant melanoma patients and may represent new independent prognostic marker.

Interferon inducibility of STAT 1 activation and its prognostic significance in melanoma patients

STAT 1, a member of latent cytoplasmic proteins, plays a pivotal role in mediating biological effects of interferons. Its transducing, DNA binding and transcriptional activity require phosphorylation at both Tyr 701 (Y 701) and Ser 727 (S 727) residues. Deficient phosphorylation or constitutive activation of the STAT 1 protein were observed in some human malignancies. Using immunoprecipitation and Western blots performed with lysates made of melanoma cells derived from patients with clinical stage II/III and employing specific anti-STAT 1 PS 727/PY 701 immunoprobes, we show that STAT 1 activation response induced by IFN-alpha/-gamma is significantly impaired. On average, three quarters of patients were lacking phosphorylation at S 727. STAT 1 PY 701 was not inducible by IFN-alpha in 63% and by IFN-gamma in 34% of samples. However, these STAT 1 activation defects showed no correlation with the disease outcome and immunotherapy response as indicated by progression-free survival profiles in patients treated with IFN-alpha2b.

Inhibition of adhesion breast cancer cells by anticoagulant drugs and cimetidine

Recent studies suggest that anticoagulant drugs and cimetidine therapy in malignancy may improve cancer survival and inhibit the metastatic process. In this study we investigated and compared the effects of anticoagulant drugs (unfractionated heparin, warfarin, acetylsalicylic acid, low-molecular-weight heparins--nandroparinum, enoxaparinum, dalteparinum and reviparinum), cimetidine and combination of cimetidine with anticoagulants on adhesion of highly invasive breast cancer cells lines - BT 549 and MDA-MB-231 (MDA 231)--in vitro. High antiadhesion effect was observed with cimetidine, warfarin and acetylsalicylic acid. Low-molecular-weight heparins had a small antiadhesion effect in independent use. In combination with cimetidine, a potential effect of cimetidine on the antiadhesion was observed. The antiadhesion effect was dependent on the type of the cancer cell line. Different effects between cell lines BT 549 and MDA 231 were observed. The strongest antiadhesion effect was obtained using the combination of cimetidine with acetylsalicylic acid. In the majority of applications of the drugs and their combinations, a proportional antiadhesion effect was dependent on the concentration and time. We suppose that anticoagulant drugs might have higher antimetastatic effect in combination with cimetidine. The choice of anticoagulants can decrease the adhesion, decrease tumor angiogenesis and cause the shortening of blood clotting time. Cimetidine can decrease the adhesion of cancer cells and increase the activity of NK cells. Indeed, according to our results, application of cimetidine and anticoagulant drugs intensifies the antiadhesion effect together with other antimetastatic effects.

Malignant melanoma associates with Th1/Th2 imbalance that coincides with disease progression and immunotherapy response

The immunological dysfunction associated with human cancer is well known phenomenon. It comprises number of pathological changes within immune network including imbalance in cytokines of Th1/Th2 origin. The objectives of our study were (i) to evaluate the abnormalities in serum levels of selected cytokines in malignant melanoma patients with regional lymph node metastases as compared to normal values, (ii) to examine the relationship between postoperative cytokine levels and disease progression and (iii) to correlate cytokine profile changes during IFN-alpha therapy with the disease progression and potential therapeutical response. Nine Th1/Th2 related cytokines and sIL-2R were determined in 26 malignant melanoma patients at clinical stage III prior and during adjuvant immunotherapy. Control group consisted of 26 healthy persons. Patients were treated with rIFN-alpha according to EORTC Melanoma group protocol 18952. Cytokines were quantified in patients sera using commercial ELISA kits. Majority of melanoma patients showed significantly lower values of IL-2 and IFN-gamma and pathologically elevated levels of IL-4, IL-6, IL-10 as compared to healthy subjects what indicates disease associated Th1/Th2 imbalance. In addition increased IL-12 and IL-15 values were noted in some patients (54% and 27%, respectively). All patients who manifested early relapse during immunotherapy had significantly lower pretreatment levels of IL-2 and IL-12 than those remaining without progression and probably benefiting from the treatment. Cytokine changes during immunotherapy disclosed that decreases in IL-2 and IL-12 and raises in IL-6 and IL-10 values occurred at least one month prior to relapse. Moreover, the continuous elevation of TNF-alpha and sIL-2R could be observed in patients who remained without progression during 10 months lasting immunotherapy. Our data illustrate that malignant melanoma associates with Th1/Th2 perturbances which are directed towards extended Th2 responses and that measurement of selected cytokines of Th1/Th2 category may be used as an early signal of disease deterioration and for evaluation of immunotherapy response.

[Risk assessment of irradiation of tissue with metal implants]

Authors examine the influence of metal implants on the distribution of ionizing radiation in tissue. In vivo measurements in a patient are seldom possible. The risk can be assessed with sufficient accuracy on the basis of various experimental dosimetric methods, histological changes in the irradiated volume and the tolerance to the physical stress, published in the available literature. The analysis shows that the risk of significant dose inhomogeneity or the treatment toxicity is minimal if mentioned principles are adhered to. Radiotherapy indications and dosage should not be markedly changed on the basis of the presence of metal in the irradiated volume.

[Radical radiotherapy of prostate carcinoma]

Radiotherapy is an effective treatment modality of prostate carcinoma. Considering the limited radiosensitivity of this tumour it is necessary to use relatively high doses of radiation. Modern technology offers the possibility to perform high-dose radiotherapy with acceptable toxicity. The authors present various options of both external and internal irradiation. They point out that brachytherapy, previously considered less appropriate from the radiobiology aspect, is according to the current views and results a very suitable treatment modality of prostate cancer.

Relation of prenephrectomy CD profiles and serum cytokines to the disease outcome and response to IFN-alpha/IL-2 therapy in renal cell carcinoma patients

Immune parameters, including cytokine levels and CD profiles were determined in 78 renal cell carcinoma patients (RCC) prior to nephrectomy. The values were correlated with the outcome of disease and response to cytokine-based treatment during a 3-year follow-up. Significantly lower frequency of progressions and higher proportion of survivors were recorded in 24 treated patients compared to 43 untreated ones (22.9% vs. 53.5% and 82.9% vs. 55.8%) illustrating the beneficial effect of immunotherapy on the course of RCC at localized stage. RCC-related immune changes are demonstrated by reduced proportion of CD19+, CD28+, HLA-DR+, CD19+/80+ and CD8+/28+ subsets, by increased serum levels of IL-6, sIL-2R, CRP and by impaired production of IL-2 and TNF-alpha released by in vitro stimulated PBMC. Only increased CRP, IL-6 serum values, decreased CD8+ and increased CD122+ were significantly related to patients' prognosis. Comparisons of preoperative CD profiles and cytokine values with the response to IL-2/IFN-alpha based therapy disclosed significant correlation in only CD80+ and CD19+/80+ subsets. Treated patients who relapsed during the 3-year follow-up exhibited at the diagnosis significantly reduced proportion of CD80+ and CD19+/80+ cells (CD80+ means - 0.79 vs. 1.69 and CD19+/80+ means - 0.32 vs. 0.61) comparing to those surviving disease-free. In addition initial proportion of CD3+, CD8+ and CD19+ cells was reduced in treated patients who manifested progression but statistical difference from those remaining disease-free was not proved.

Rare somatic p53 mutation identified in breast cancer: a case report

Most p53 mutations occur in the central part of the p53 gene that codes for the DNA-binding domain. Missense mutations are prevalent. However, 10-25% of all mutations occur outside exons 5-8 and include a prevalence of frameshift, nonsense and splice site mutations. Functional analysis of p53 transactivation ability in yeast (FASAY) was used to screen for p53 mutations in tumors and a mutant p53 protein retaining partial activity was identified. We characterized this somatic p53 mutation in codon 337: transition C-->T, changing codon CGC to TGC and causing substitution of arginine for cysteine in exon 10, which codes for the tetramerization domain of p53. We detected high accumulation of this mutant p53 protein within the tumor tissue and found that it cannot be immunoprecipitated by either a wild-type p53-specific antibody (PAb1620) or by a mutant p53-specific antibody (PAb240). We confirmed the somatic origin of the mutation by analysis of p53 status in peripheral leukocytes.

Metastatic MHC class I-negative mouse cells derived by transformation with human papillomavirus type 16

In the endeavour to develop a model for studying gene therapy of cancers associated with human papillomaviruses (HPVs), mouse cells were transformed with the HPV type 16 (HPV16) and activated H-ras oncogenes. This was done by cotransfection of plasmid p16HHMo, carrying the HPV16 E6/E7 oncogenes, and plasmid pEJ6.6, carrying the gene coding for human H-ras oncoprotein activated by the G12V mutation, into secondary C57BL/6 mouse kidney cells. An oncogenic cell line, designated MK16/1/IIIABC, was derived. The epithelial origin of the cells was confirmed by their expression of cytokeratins. No MHC class I and class II molecules were detected on the surface of MK16/1/IIIABC cells. Spontaneous metastases were observed in lymphatic nodes and lungs after prolonged growth of MK16/1/IIIABC-induced subcutaneous tumours. Lethally irradiated MK16/1/IIIABC cells induced protection against challenge with 10(5) homologous cells, but not against a higher cell dose (5 x 10(5)). Plasmids p16HHMo and pEJ6.6 were also used for preventive immunization of mice. In comparison with a control group injected with pBR322, they exhibited moderate protection, in terms of prolonged survival, against MK16/1/IIIABC challenge (P < 0.03). These data suggest that MK16/1/IIIABC cells may serve as a model for studying immune reactions against HPV16-associated human tumours.

[Papillomaviruses and human tumors]

The report summarizes the main results obtained in the course of our research project. The results of immunological and epidemiological studies provide further proofs that human papillomaviruses (HPV) are the etiological agents in cervical neoplasia. In addition, they raise hopes that immunological methods may be utilized in diagnostics of cervical cancer and for monitoring the clinical course of this disease in the near future. Since the etiological relationship between HPV and cervical carcinoma seems to be proven beyond reasonable doubt, the development of prophylactic and therapeutic vaccines has become the dominant of the contemporary HPV reseach. For studying immune reactions against HPV-induced tumours we developed a model of HPV16-transformed rodent cells.

Longitudinal follow-up of antibody response to selected antigens of human papillomaviruses and herpesviruses in patients with invasive cervical carcinoma

A group of 21 cervical-carcinoma patients was followed longitudinally. All patients had undergone intensive radiotherapy. In the course of a more than 5-year observation period, 2 patients died of cervical cancer, 1 from other causes, 3 were lost from follow-up, and 15 survived without any signs of the disease. Sera taken before, up to 17 months after and more than 5 years after the start of therapy, were tested by ELISA for IgG antibodies reactive with a broad spectrum of HPV-derived antigens, glycoprotein G of HSV 2, whole virion antigen of HCMV, and a synthetic peptide corresponding to the immuno-dominant region of EBNA 1. The therapy was associated with a marked decrease in E2 and E7 antibodies in nearly all patients possessing pre-existing antibodies; the changes in VLP antibody levels in the treated women were more rare and less pronounced. In the course of the observation period, seroconversion to gG HSV2 positivity was seen in 5 patients, while, a marked increase in pre-existing gG HSV2 antibodies was observed in 5 out of 7 originally seropositive patients. At enrollment, only 2 patients were free of HCMV antibody and only 1 was free of EBNA1 antibody; no seroconversion relative to either antigen was seen during the observation period.

p53 status in breast carcinomas revealed by FASAY correlates well with p53 protein accumulation determined by immunohistochemistry

The prognostic and predictive value of p53 mutation in breast cancer is still conflicting. The choice of the p53 status detection method may account for some discrepancies. In this pilot study we compared two differently-based methods for detection of p53 alteration in 32 breast carcinoma samples: the immunohistochemical method using Bp53, DO1 and DO11 monoclonal antibodies for analysis of the p53 protein accumulation in cell nuclei and the functional method FASAY. FASAY - functional analysis of the separated alleles in yeast - tests the capability of the human p53 to transactivate a reporter with a p53 binding site RGC driving the ADE2 gene in yeast. In our group the percentage of breast cancers with accumulated p53 protein was 50%, as well as percentage of mutant p53 scored by FASAY was 50%. Although the agreement of both methods, when comparing the results of individual patients was high (94%), our results show that immunohistochemistry does not reflect the p53 status quite exactly.

Renal cell carcinoma-associated immune impairment that may interfere with the response to cytokine therapy

This prospective study was carried out to explore cytokine-related immune alterations in 69 renal cell carcinoma patients (RCC) and to look for changes which might potentially serve as a reliable predictors of response to cytokine-based therapy. Interleukin-2 (IL-2), its soluble receptor (sIL-2R) and tumor necrosis factor (TNF-alpha) levels produced in vitro by PHA activated and intact mononuclear cells (PBMC) were determined. Concentrations of IL-2, IL-4, IL-6, sIL-2R, TNF-alpha and CRP were measured in sera. Cytokine level was evaluated by enzyme-linked immunoadsorbent assay (ELISA) and CRP was determined by means of turbidimetric method. All measurements were performed in patients without any prior treatment. PHA activated PBMC of RCC patients were significantly defective in producing IL-2 and TNF-alpha comparing to controls (p < 0.03 and p < 0.001). The difference of sIL-2R was noted in metastatic stage only (p < 0.03). Unstimulated PBMC manifested decrease in IL-2 (p < 0.03) and increased level of TNF-alpha in advanced disease (p < 0.02). This impairment reflected tumor size and differentiation stage. Serum concentrations of IL-2, sIL-2R and TNF-alpha were within normal range. However, in relation to the clinical stage, significantly increased serum IL-2 was noted in combined Stage I and II as compared to controls (p = 0.012). IL-6 and CRP showed markedly elevated levels with a significancy which allowed to distinguish samples from metastatic patients. In conclusion careful comparisons of these data with clinical course of cytokine treated patients will disclose which of those tests may possess predictive power in the individual patients who are likely to respond to cytokine-based treatment.

[Prenatal diagnosis and therapy of congenital diaphragmatic hernia]

The diagnosis and treatment of congenital diaphragmatic hernia, CDH, is an interdisciplinary problem. The patient concentration with prenatally diagnosed CDH for comprehensive examination with subsequent decision on the type of delivery improves the prognosis of patients with CDH. Introduction of corticoid therapy in prenatally assessed CDH reduces dysfunction and surfactant deficiency and can reduce the degree of respiratory failure during delivery. In very early prenatally assessed CDH it is possible to consider the possibility of combined corticoid and TRH (thyroxin releasing hormone) treatment of CDH. The authors submit also contemporary possibilities of prenatal intervention treatment of CDH (indication criteria for reconstruction operations of foetal surgery, intrauterine closure of the trachea and artificial laparoschisis). The concentration of patients with postnatally diagnosed CDH and a severe grade of acute respiratory insufficiency in a department with conventional and non-conventional artificial pulmonary ventilation incl. inhalation of NO oe extracorporeal membrane oxygenation, ECMO, is a further step towards optimation of treatment. Continuous evaluation of parameters of pulmonary functions during the pre- and postoperative period may prove that a therapeutic protocol with delayed surgery is useful.

Prognostic value of bone marrow biopsy in operable breast cancer patients at the time of initial diagnosis: Results of a 20-year median follow-up

From May 1975 until May 1980,128 operable breast cancer patients, clinical stage I-II, had a core bone marrow biopsy (BMB) from the posterior iliac crest as a part of the routine diagnostic work-up at the time of initial diagnosis. The mean age of the patients was 56 years, range 26-93. In a previous study on this material, 10 patients (7.8 per cent) were positive for tumor cells and 118 negative by conventional histopathology of BMB [1]. In 1996 we reexamined all BMB separately at two laboratories, using monoclonal antibodies against cytokeratins AE1-AE3, KL1, CAM 5-2 (DOP), and DC10, BA17 (MCI). The number of extrinsic cells in the bone marrow was graded positive for micrometastases when > or = 5 cells or suspicious when 1-4 cells per approximately 2 x 10(6) bone marrow cells were found, using high power field magnification. Micrometastases were detected in 17 patients (13.3 per cent) and another 8 patients were classified as suspicious. The presence of micrometastases was correlated to the axillary lymph node stage and primary tumor location. Median follow-up was 20 years. All 17 micrometastatic patients relapsed and died within 6 years of disease progression with evident osseous metastases. There was one disease-free survivor of the 8 patients with suspicious BMB after 17 years of follow-up. The median overall survival was significantly shorter in tumor-cell positive patients, being 1.9 years compared to 11.7 years in the BMB negative and BMB suspicious groups (p < 0.0001). Immunohistochemical analysis of core BMB taken postoperatively may be useful in predicting the prognosis in patients with breast cancer clinical stage I-II.

Epitope analysis of the human p53 tumour suppressor protein

Using a set of overlapping peptides of the human p53 protein, we have performed an accurate mapping of the p53 antigenic sites, recognized by a panel of 19 monoclonal antibodies from the Bp53 series. The results show that most of the antibodies recognize determinants localized in the amino-terminal domain of the protein. Several antibodies reacted with peptides which correspond to the antigenic determinants localized in the carboxy terminus of p53. None of these antibodies reacted with peptides in the central DNA-binding domain of p53 protein.

[Practical results of monitoring pregnancy in women with systemic lupus erythematosus]

BACKGROUND

The authors dealt with the urgent problem under what conditions it is possible to achieve in a woman with systemic lupus erythematosus (SLE) or another collagenosis, or secondary antiphospholipid syndrome (APS) a favourable outcome of pregnancy and the delivery of a healthy infant.

METHODS AND RESULTS

The investigation comprised 23 women incl. 20 with SLE, two with the mixed form of a diffuse connective tissue disease (MCTD) and one with Sjögren's syndrome of the primary type. From the total number of 20 pregnancies six were consulted in advance with a doctor (group I-s-called planned pregnancies) and all terminated by a successful delivery. Of 11 pregnancies which were not consulted with a doctor in advance (group II-so-called unplanned pregnancies) 9 were terminated in term, however, only 5 with a successful delivery (55.5%), two women are still pregnant. Exacerbation of the basic disease during pregnancy was recorded only once and did not lead to discontinuation of the pregnancy.

CONCLUSIONS

The authors provide evidence that desired pregnancy of informed women suffering from SLE or another collagenosis when assisted by a specialized medical team can lead to a successful delivery of an infant.

A constitutional de novo mutation in exon 8 of the p53 gene in a patient with multiple primary malignancies

We report a constitutional point mutation of codon 278 in exon 8 of the TP53 gene that has not yet been described as a germ-line mutation. A 52-year-old female developed multiple primary malignancies (liposarcoma, breast cancer, malignant histiocytoma, occult adenocarcinoma). The mutation found in her tumour and peripheral blood lymphocyte DNA is a cytosine to thymine transition at the second position of codon 278 resulting in an amino acid exchange from proline to leucine in the DNA-binding domain. Evaluation of the patient's family revealed that both of her sons were affected by the same mutation. Although the patient's mother had died already, we were able to demonstrate by polymorphic microsatellite analysis that the defective allele originated from the maternal side. As four brothers and one sister had inherited the same allele, which however was wild type, we were able to show that the mutation must have occurred in the germ cells of the patient's mother and that it may therefore be called de novo. This explains the lack of a high cancer incidence in the family history. All tumours tested showed positive immunohistochemical staining for p53. Loss of heterozygosity was found in five of seven tumours, one showing chromosome 17 monosomy.

[The quality of documentation in patients after conservative surgical procedures in breast carcinoma and its effect on subsequent therapy]

The quality of data was evaluated in 50 patients referred for adjuvant treatment to the Department of Radiotherapy and Oncology, University Hospital "Královské Vinohrady" after conservative surgery for breast cancer. The authors suggest improving the cooperation between surgeon and radiation oncologist. The purpose of this study is to establish the criteria for conservative surgery of breast carcinoma and to evaluate, if the data provided by surgery and pathology departments are sufficient for radiation oncologist to complete high quality postoperative radiotherapy.

p53 protein alterations in human testicular cancer including pre-invasive intratubular germ-cell neoplasia

Expression of the p53 oncoprotein was examined in a wide range of primary human testicular germ-cell tumours using a new mouse monoclonal antibody (MAb) BP53-11 raised and characterized in this study, in parallel with a polyclonal rabbit antiserum CM-1. Immunohistochemistry on paraffin sections showed positive nuclear reaction in at least a fraction of malignant cells in 90 (84%) out of 107 cases studied. Aberrant accumulation of the p53 protein was found among testicular tumours of all major histological types, although generally a higher percentage of positive cases and a higher proportion of p53 over-expressing nuclei within individual lesions was observed in embryonal carcinomas when compared with seminomas. The typical heterogeneous staining pattern characteristic of histological specimens was also found in a cultured cell line derived from a human embryonal carcinoma. In contrast to immunohistochemically undetectable levels in normal testes and morphologically normal tissue areas in the tumour-bearing testes, the accumulation of the p53 protein was clearly identified in a high proportion (59% of cases) of the pre-invasive lesions with positive atypical intratubular germ cells often found in the tissue adjacent to invasive tumours. Altered expression of the p53 protein is therefore a unifying feature of the majority of invasive male germ-cell tumours and the change resulting in high levels of p53 appears to be a relatively early step in the human testicular cancer pathogenesis.

Aberrant expression of the p53 oncoprotein is a common feature of a wide spectrum of human malignancies

Accumulation of the p53 protein was analysed in 212 human malignant lesions. Immunohistochemical staining with new polyclonal (CM-1) and monoclonal antibodies (BP 53-12 and BP53-24) to p53 on methacarn-fixed paraffin sections showed positive staining in 161 (76%). The positive tumours were found across a wide range of human malignancies including breast, colon, stomach, bladder and testis carcinomas, soft-tissue sarcomas and melanomas. The staining was always confined to the malignant lesion. Immunoprecipitation and quantitative ELISA assays established that the positive staining was associated with accumulation of the protein and that the protein was frequently in a mutant conformation. Accumulation of mutant p53 protein is therefore a common feature of human malignant disease.

A series of 14 new monoclonal antibodies to keratins: characterization and value in diagnostic histopathology

A series of 14 new mouse monoclonal antibodies (MAbs) to keratins is described and the data suggesting their potential value in the differential diagnosis of human tumours are reported. The specificities of individual MAbs of the 'C-series' presented here range from monospecificity for keratin No. 7 (MAbs C-18, C-35, C-62, and C-68), keratin No. 8 (MAbs C-15, C-43, and C-15), and keratin No. 18 (MAbs C-04 and C-08) up to the broadly reacting 'pan-keratin' MAb C-11, with the target epitopes of the remaining four MAbs being shared by different pairs of keratin polypeptides. The results of the biochemical characterization of the MAbs, together with their immunohistochemical staining patterns on frozen as well as on paraffin sections of normal human tissues, suggest that they represent a significant contribution to the growing list of anti-keratin MAbs applicable in both research and routine diagnostic pathology. The immunohistochemical examination of a wide range of human neoplasms with the new MAbs not only confirmed their value in making distinctions between carcinomas, on the one hand, and lymphomas, and gliomas, on the other, but also verified the possibility of more subtle subdivisions within the group of adenocarcinomas and their metastases. Furthermore, the identification of small subsets of breast carcinomas with decreased levels or apparent loss of the keratin No. 7 polypeptide and some cases of stomach carcinoma with apparently induced expression of this keratin suggests that such 'exceptions' must be considered when using keratin spectra as one of the criteria in differential diagnosis.

Patterns of expression of the p53 tumour suppressor in human breast tissues and tumours in situ and in vitro

An extensive series of histological sections reflecting the various states of normal breast tissue, and a range of benign and malignant lesions, were examined for the expression of the p53 protein using a panel of anti-p53 antibodies. In 2 separate series the results of using frozen or methacarn-fixed, paraffin-embedded sections were compared. Strong positive staining for p53 was detected in over 50% of the malignant lesions when frozen sections were used. This number fell to just over 20% when methacarn-fixed sections were examined. In neither series was any p53 staining seen in normal breast or in the benign lesions. Studies by Western blotting on breast cell lines confirmed that this histological signal is due to a pronounced over-expression of the p53 protein. Earlier studies show that this over-expression is associated with mutation of the p53 gene. Mutation of the p53 gene with over-expression of the mutant protein is therefore one of the most frequent specific genetic changes in malignant breast cancer.

[Personal experience with strain-induced diseases--neurologic aspects]

The author summarizes his experience with diseases of the locomotor system of the extremities caused by long-term, excessive unilateral overload (item 29 of the Czechoslovak "List of occupational diseases") assembled during the period 1976 to 1987. In the department for occupational diseases of the District Institute of National Health Pardubice 349 subjects were examined where the disease was suspected, in 93 workers the occupational affection was notified. From a total of 2,294 notified occupational during the above period disease due to overload accounted for 4.1%. The cause of the affection was most frequently bursitis (32x), epicondylitis (25x) and carpal tunnel syndromes (24x), other affections being less frequent. The author analyzed the results with regard to sex, age, period of exposure, occupation. Special attention was devoted to glass workers who accounted for 51.6% of all affected subjects. The author discusses possible neurological affections, i. e. damage of the peripheral nerves. In the assessment of disease caused by overload the authors emphasized the importance of close cooperation of specialists for occupational diseases, neurologists, orthopaedists, physiologists and specialists in hygiene of work.

Secretory component in differentiating normal epithelium, benign lesions and malignancy in the human breast as monitored by monoclonal antibodies

An immunohistochemical study of the expression of the secretory component (SC) in human mammary gland epithelium at various stages of differentiation, as well as in benign and malignant breast tumours, was undertaken using three mouse monoclonal antibodies. Antibody RICEO-SC-05 (SC-05), raised against a partially purified preparation of human SC, and reacting with a reduction-resistant epitope present in both free and polymeric immunoglobulin-bound SC, was compared in immunoperoxidase and immunofluorescence studies on a diverse range of normal tissues, to 2 reference anti-SC antibodies (LICR-LONLC28 and RICEO-MFG-12). All three antibodies reacted with secretory epithelia only, consistent with known patterns of expression of SC in tissues, although there was an unexpected reaction by all anti-SC antibodies with some Hassal's corpuscles of the thymus. Staining patterns seen in the normal resting, pregnant, lactating and regressing (after weaning) breast provide evidence for differentiation-associated changes in the production of SC, and support the concept of terminal ductal lobular units (TDLUs) as functional compartments of the mammary gland. SC was detected in all but one benign breast lesion (n = 53) as compared to only 24% positive cases with heterogeneous expression of SC found among 176 primary and metastatic breast carcinomas examined. In a series of 40 primary breast carcinomas and their corresponding lymph node metastases, a good overall correlation was found between the expression of SC in the matched specimens; aside from 3 heterogeneously SC-positive carcinomas whose metastatic counterparts were SC-negative. Our results demonstrate a potential application for monoclonal antibodies to SC in the study of human mammary gland differentiation, but suggest that the value of an assay for SC in the diagnosis of breast carcinomas is questionable due to the generally low expression of SC by either primary or metastatic breast lesions.

Monoclonal antibodies against individual cytokeratins in the detection of metastatic spread

A panel of 17 monoclonal antibodies (MAbs) recognizing various keratin polypeptides has been used to define their binding on non-epithelial elements in 28 bone-marrow samples and 14 lymph nodes, in order to establish their limitations for use as a possible tool for immunodiagnosis of carcinoma spread. Immunocytochemical studies have shown that only 8 antibodies consistently exhibited no false-positive staining of marrow cells. All the remaining MAbs labelled (mostly in a non-specific manner) a few cells of marrow samples derived from patients with either haematological disorders or malignant lymphomas. Fine granules and droplet-like cytoplasmic inclusions were predominant patterns of positive reactions. Homogeneous cytoplasmic staining reminiscent of specific keratin immunolabelling was occasionally seen as well. The positive cells could be also identified in some lymph nodes free of tumour infiltration. All antibodies visualized cytoplasmic droplets in scattered cells of lymph nodes taken from a patient with non-Hodgkin lymphoma. This type of positivity was mostly associated with positive histochemical reactions for iron. Quite significant was the detection of fibrillar positivity in the extrafollicular reticular cells in all nodes examined. Such a specific type of staining was exclusively induced by antibodies directed against epitopes of keratin 8 and 18, whereas those MAbs recognizing keratin 7 and 19 always gave negative results. Our data indicate that caution is required when such MAbs, considered as markers of specific cell types, are being used as an immunodiagnostic tool to identify single carcinoma cells. A series of criteria, including morphological ones, must be utilized in order to obtain meaningful results.

HLA-DR antigens on differentiating human mammary gland epithelium and breast tumours

The staining pattern of a monoclonal antibody directed to the monomorphic determinant of HLA-DR antigens was examined on sections of human mammary gland tissues at various stages of differentiation as well as on 50 benign and 72 malignant breast lesions. Normal resting breast epithelium lacked HLA-DR, whereas late-pregnant and lactating epithelia expressed high levels of HLA-DR antigens, followed by a decline in the post-weaning regression period. Most benign breast lesions revealed heterogeneous staining ranging from very few up to 20-25% positive epithelial Greater variability was observed among carcinomas, where a small group (approximately 7%) of cases showing 40-95% positive tumour cells was found, in addition to negative tumours and those with the minority of HLA-DR expressing carcinoma cells. The density of the leukocytic infiltrate was higher in carcinomas than in either normal breast tissue or benign lesions, the HLA-DR phenotype of the mononuclear infiltrating cells lacking any obvious correlation with the HLA-DR status of the epithelial component. Immunoblotting analyses of whole-tissue lysates separated by SDS-PAGE confirmed the immunohistochemical data and demonstrated the reactivity with only one protein band predicted for HLA-DR alpha-chain. The combination of immunohistochemistry and autoradiography on sections of human reduction mammoplasty organoids cultured in collagen gels and labelled with tritiated thymidine revealed a lack of HLA-DR expression on proliferating breast epithelial cells suggesting factors other than cell kinetics must be responsible for induction of HLA-DR antigens seen in pregnant and lactating breast epithelium and some tumours.

Lack of beta-casein production by human breast tumours revealed by monoclonal antibodies

An immunohistochemical study with four monoclonal antibodies to human beta-casein was carried out to examine the expression of this milk protein in a wide range of normal tissues, in 127 breast tumours and in a heterogeneous panel of 42 malignancies of other histogenesis. The only normal tissue stained positively by the antibodies was the mammary gland in late pregnancy, during lactation and in the post-lactational regression period. None of the tumours of non-mammary origin showed any staining. Furthermore, only two of 40 benign breast lesions and one anaplastic primary carcinoma with its metastasis (among 87 breast carcinomas) showed any reactivity. The immunohistochemical results were supported by immunoblotting data and suggested beta-casein expression has no role to play as a marker in the diagnosis or monitoring of human breast cancer.

Is cancer a macrophage-mediated autoaggressive disease?

As part of their physiological functions macrophages secrete various products that influence tissue environment. They can also secrete tumour growth promoting substances and it is highly probable that they help to establish tumour supporting fibrovascular stroma. Macrophages may fuse with other cells (including neoplastic cells) and many malignant properties of these hybrids or of their progeny may be maintained by the macrophage genome. In addition processes that occur after fusion might be important in inducing malignant transformation, especially when fusion has occurred with initiated cells. Superficial spreading melanoma is an example that is in keeping with the hypothesis of cell fusion.

Expression of HLA-DR antigens on tumour cells does not contribute to skin reactivity to autologous cholesteryl hemisuccinate (CHS)-treated tumour cells in patients with metastatic melanoma

Skin tests with autologous cholesteryl hemisuccinate (CHS)-treated and untreated cells were performed in ten metastatic melanoma patients. In the majority of cases evident reaction was noted with CHS-treated cells (9/10) while the reaction with untreated cells was mostly negative (7/10). Tumour cell suspensions used for skin tests were characterized for reactivity with monoclonal antibody TAL 1B5 detecting the HLA-DR alpha chain. There were no differences between CHS-treated and untreated cells with respect to HLA-DR expression and no correlation was found between grade of skin reaction to CHS-treated cells and the proportion of HLA-DR positive cells in the injected cell sample.

Expression of monoclonal antibody-defined epitopes of keratin 19 in human tumours and cultured cells

The monoclonal antibodies BA16 and BA17, reacting specifically with human keratin 19 (40 kD) have been tested by immunohistochemical staining methods for their reaction with a wide range of human tumours and cultured cells. Primary adenocarcinomas and their metastases showed a homogeneously positive reaction with greater than 95% of the tumour cells staining. Non-epithelial tumours, basaliomas and squamous cell carcinomas were unstained, while benign breast lesions and a thyroid adenoma show a mosaic pattern of stained and unstained (5-40%) cells. These three staining patterns were also seen in cultured cells. Positive homogeneous staining was seen in all breast cancer cell lines examined with the exception of PMC42, which exhibits stem cell characteristics, and which showed the heterogeneous pattern of staining seen in milk cell cultures. Non-epithelial lines and strains, two cell lines from cervical carcinomas and three SV40 transformed breast epithelial lines were unstained. The antibodies BA16 and 17 are potentially useful reagents for distinguishing adenocarcinomas (and their metastases) from non-epithelial tumours and from squamous carcinomas. They may also discriminate between benign and malignant breast lesions, and identify a specific differentiation phenotype in the secretory cell lineage.

Differential expression of keratin 19 in normal human epithelial tissues revealed by monospecific monoclonal antibodies

Three monospecific monoclonal antibodies (BA16, BA17 and A53-B/A2) recognizing different epitopes of the human keratin 19 were used to determine tissue distribution of this 40 kDa keratin polypeptide. Immunohistochemical methods revealed four different staining patterns among normal human epithelial tissues: firstly, complete negativity of the epidermis, sebaceous glands, hepatocytes and other tissues; secondly, homogeneous positivity as seen for example in the gall bladder and urinary bladder epithelium, endometrium and many other epithelia; thirdly, a mosaic of positive and negative cells among mammary gland luminal cells, prostate epithelia and some other epithelia and fourthly, a more complex heterogeneous pattern found in non-keratinizing squamous epithelia and hair follicles with generally the basal layer being the most strongly or sometimes exclusively stained. The pattern seen in non-keratinizing squamous epithelia varied considerably according to the fixation method and the antibody used as well as among different donors and in different areas of the same organ. The other three staining patterns were on the other hand nearly identical with all three antibodies on both frozen sections and sections of methacarn-fixed paraffin-embedded tissues. Our results provide evidence for differential expression of the human keratin 19 at the single cell level, an observation which could be exploited in the study of epithelial differentiation and pathology.

Frequency of foetal growth deviations diagnosed by ultrasonic measurement and analysis of their causes

In a population sample, whose congruity with the country-wide population was verified, the birthweight, menstrual age and gestational age (assessed by repeated ultrasonic foetometry in the course of pregnancy) were mutually correlated. A group of 80% of newborns out of the total population sample, in whom no disturbance of foetal growth rate was found throughout the course pregnancy, served as the basis for preparation of the standard of normal foetal growth. In the interval from the 36th to the 42nd week of pregnancy a highly significant linear relationship between gestational age and birthweight was found, without terminal flattening of the "normal foetal growth curve". In the remaining 20% of the population there was a twofold predominance of growth retardation over growth acceleration.

Leukocyte adherence inhibition responses obtained with various tumor extracts in breast cancer patients

Leukocyte adherence inhibition (LAI) assay was employed to detect cell-mediated immune response in breast cancer patients of clinical stages I and II. Twenty-one breast cancer extracts were screened in 232 breast cancer patients and 343 healthy persons. The activity of individual extracts differed remarkably. Overall, LAI response was 58.6% (136/232) correct and 18.9% (65/343) false positive. Fifteen extracts were not suitable from the clinical point of view. Only two extracts gave a constantly high rate of tumor-specific LAI-positive values in breast cancer patients, ie, 83.3% (25/30) and low percentage of false positive results in controls, ie, 4% (2/50). A further study dealt with the possible relation between the activity of extracts (expressed in percentage of positive LAI results in the tumor group) and histology of primary tumor of patients whose tumor tissue was used for extraction. This relationship could not be proven statistically. We investigated also whether the percentage of correct LAI responses in breast cancer patients could be affected by histological agreement or disagreement (grading and node involvement) between primary tumor of extract donor and primary tumor of patients tested. No significant relationship was found in this respect.

Variability of mitotic activity in chicken embryo tissues

On testing antimitotic substances in chicken embryos the authors encountered considerable changes in the mitotic activity which were difficult to explain. Mitotic indexes (MI) of several tissues sampled during a 24 hour period were measured and compared. The statistical significance of the results was verified by the U- and t-tests. Marked changes in mitotic activity dependent on daytime were found in all cases. Maximum MI values were measured around the 12th, minimum between the 2nd and 6th hours. These variations cannot be explained by the facts known so far. The question arises whether this time regulation of mitotic activity is typical only for embryonic or bird tissues, or whether it may be a general biological phenomenon.