[Identifying the Importance of MT-3 Expression for Neuroblastoma Cells]. / Identifikace významu exprese MT-3 pro bunky neuroblastomu.

BACKGROUND: Resistance of cancer cells to cytostatics is caused by a number of mechanisms that are often combined. These include reduced cell entry or increased efflux, increased DNA repair, defects of, apoptotic pathways, increased cytostatic degradation as well as elevated levels of intracellular thiols of glutathione and metallothioneins (MT). It has been reported that high concentrations of thiol groups in the cytoplasm bind platinum alkylation derivatives and chemorezistence is due to the transfer of platinum from the cytostatic to MT, which inactivates them. Because we have shown an increase in MT levels in resistant neuroblastoma (NB) lines, but not in sensitive lines after incubation with platinum cytostatics, we have considered MT-3 for NB cells in our previous studies. METHOD: SiMa NB cell lines transfected with vector containing human MT-3 and GFP or GFP only (control). Expression Microarray Human Cancer 3711 ElectraSense medium density 4 × 2k array slides with 1,609 DNA probes (Custom Array, Bothell, WA, USA), MT-3 expression and most expressed genes validated by real-time polymerase chain reaction. Sensitivity to CDDP (cisplatin) - MTT assay, clonogenicity test, Western blott caspase cleavage and free oxygen radicals fluorescence microscopy after CellROX Deep Red Reagent staining. Levels of MT-3 mRNA in 23 samples of high-risk NB, normal human cortex and bovine adrenal glands were investigated by reverse transcription polymerase chain reaction. RESULTS: Expression microarray showed downregulation 3 and overexpression of 19 genes in MT-3 transfected NB cells. Using gene ontology, over-expressed genes have been shown to drive senescence-induced oncogenes (CDKN2B and ANAPC5), and the genes of glutathione S-transferase M3, caspase 4 and DNAJB6 (chaperone neuronal proteins) were also expressed. We have demonstrated a reduced sensitivity of MT-3 transfected cells to CDDP (24h IC50 of 7.48 ± 0.97 and 19.81 ± 1.2 µg/ml), a higher number of colonies after incubation with CDDP, reduced caspase 3 after incubation with CDDP and lower free oxygen radicals after induction of CDDP. High-grade NB cells expressed MT-3 significantly more than non-tumoral adrenal cells but failed to show a clear relationship to disease course. CONCLUSION: We have demonstrated the relationship between MT-3 and senescence-induced oncogene genes and some other genes relevant to cell fate (glutathione S-transferase M3, caspase 4 and DNAJB6) and a significant proportion of MT-3 on CDDP resistance. High levels of MT-3 in high-risk NB could be one of the causes of frequent relapses in this tumor.Key words: neuroblastoma - metallothionein 3 - chemoresistance The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.This work was supported by AZV CR grant 15- 28334A. Submitted: 17. 2. 2018Accepted: 16. 4. 2018.

[Glycine-N-methyltransferase and Malignant Diseases of the Prostate]. / Glycin-N-metyltransferáza a nádorová onemocnení prostaty.

BACKGROUND: Prostate cancer (PC) constitutes a heterogeneous group of diseases with high prevalence rates that are still increasing, particularly in western countries. Since 1980, prostate specific antigen (PSA) and other diagnostic approaches have been used for PC screening; however, some of these approaches are often deemed painful and cause invasive damage of tissue. Therefore, molecular approaches to PC diagnosis are attracting increasing attention, potentially providing patients with less stressful situations and providing better diagnoses and even prognostic information. Recent metabolomic and genomic studies have suggested that biomolecules can be used as diagnostic or prognostic markers or as targets for the development of novel therapeutic modalities. One of these molecules is glycine-N-methyltransferase (GNMT), an enzyme that plays a pivotal role in the biochemical conversion of glycine to sarcosine. The link between this molecule (encoded by homonymous gene - GNMT) and PC has been confirmed at several levels, and thus GNMT can be considered a promising target for the development of advanced diagnostic and/or prognostic approaches. AIM: The aim of this study was to analyse the physiological role of GNMT and to examine in greater detail its connection with PC at different levels, including gene structure, gene expression, and metabolism, in which GNMT plays an important role, not only in controlling the methylation status of cells, but also the metabolism of folic acid and methionine. Last but not least, we discuss the importance of cellular methylation processes and the link between their aberrations and PC development.Key words: glycine - folic acid - metabolism - methylation - sarcosineThis work was supported by GA CR 16-18917S, League against Cancer Prague (project 2022015) and Czech Ministry of Health - RVO, UH Motol 00064203.The authors declare they have no potential confl icts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 9. 2. 2016Accepted: 20. 3. 2016.

[Modern Nanomedicine in Treatment of Lung Carcinomas]. / Moderní nanomedicína v lécbe karcinomu plic.

BACKGROUNDS: Despite the fast development of new effective cytostatics and targeted therapy, the treatment efficiency of lung cancer is still insufficient. The systemic administration of drugs results in a decrease in drug concentrations in tumor site, particularly due to specific extracellular environment in lungs. Nanotransporters could serve as a platform, protecting a drug against these undesired effects, which may enhance its therapeutic index and reduce side effects of a drug. Moreover, nanotechnologies possess the potential to improve the diagnostics of lung cancer, and thus increase a survival rate of oncologic patients. AIM: The presented study is aimed to demonstrate the possibilities provided by nanotechnologies in the field of treatment and diagnostic of lung cancers and discuss the obstacles, which complicate a translation into clinical practice.

Anticancer efficiency of reovirus in normoxia and hypoxia.

Oncolytic viruses infect, replicate in, and lyse tumour cells but spare the normal ones. One of oncolytic viruses is a naturally occurring replication-competent reovirus (RV), which preferentially kills tumour cells with activated Ras signaling pathways. The aim of this study was to survey effects of RV on brain tumour-derived cells in vitro under hypoxic conditions since hypoxia causes resistance to radio- and chemotherapy. This study demonstrates that RV replicates preferentially in tumour cells and that the virus is able to overcome cellular adaptation to hypoxia and infect and kill hypoxic tumour cells. RV can both replicate in hypoxic tumour microenvironment and cause the cytopathic effect, subsequently inducing cell death. We found that a large proportion of cells are killed in hypoxia (1% O2) by caspase-independent mechanisms. Furthermore, we learned that the cell death induced by RV in hypoxic conditions is not caused by autophagy.

[Modern imaging techniques for anthracycline cytostatics -  review of the literature]. / Moderní zobrazovací techniky pro antracyklinová cytostatika -  literární prehled.

Anthracycline cytostatics can be observed at the level of organelles, cells and whole organisms due to their fluorescent properties. Imaging techniques based on detection of fluorescence can be used not only for observation of drug interaction with tumor cells, but also for targeting therapy of tumors with nanoparticles containing anthracycline cytostatics. Doxorubicin and daunorubicin, enclosed in liposomes, as representatives of nanoparticles suitable for targeted therapy, are used in clinical practice. The main advantage of liposomal drugs is to reduce the side effects due to differences in pharmacokinetics and distribution of the drug in the body. Due to the fact that all biological mechanisms of action of anthracycline drugs are not still fully understood, modern imaging techniques offer tool for in vivo studies of these mechanisms.

Neuroblastoma stem cells - mechanisms of chemoresistance and histone deacetylase inhibitors.

Cancer stem cells (CSCs) form a small proportion of tumor cells that have stem cell properties: self-renewal capacity, the ability to develop into different lineages and proliferative potential. The interest in CSCs emerged from their expected role in initiation, progression and recurrence of many tumors. They are generally resistant to conventional chemotherapy and radiotherapy. There are two hypotheses about their origin: The first assumes that CSCs may arise from normal stem cells, and the second supposes that differentiated cells acquire the properties of CSCs. Both hypotheses are not mutually exclusive, as it is possible that CSCs have a diverse origin in different tumors. CD133+ cells (CD133 is marker of CSC in some tumors) isolated from NBL, osteosarcoma and Ewing sarcoma cell lines are resistant to cisplatin, carboplatin, etoposide and doxorubicin than the CD133- ones. Being resistant to chemotherapy, there were many attempts to target CSCs epigenetically including the use of histone deacetylase inhibitors. The diverse influence of valproic acid (histone deacetylase inhibitor) on normal and cancer stem cells was proved in different experiments. We have found an increase percentage of CD133+ NBL cells after their incubation with VPA in a dose that does not induce apoptosis. Further researches on CSCs and clinical application for their detection are necessary: (i) to define the CSC function in carcinogenesis, cancer development and their role in metastasis; (ii) to find a specific marker for CSCs in different tumors; (iii) to explain the role of different pathways that determine their behavior and (iv) to explain mechanisms of chemoresistance of CSCs.

Evaluation of alpha-methylacyl-CoA racemase, metallothionein and prostate specific antigen as prostate cancer prognostic markers.

Current diagnostic techniques are inefficient in distinguishing latent and low-risk forms of prostate cancer from high-risk forms. The present study is focused on determination of putative tumor markers of aggressive high-grade forms of prostate cancer. Potential markers were determined in blood sera of 133 patients (82 cases and 51 controls) and in cell lines (Gleason score 9-derived 22Rv1 and normal tissue derived PNT1A) on mRNA and protein levels. Alpha-methylacyl-CoA racemase (AMACR), metallothionein classes 1A and 2A (MT1A and MT2A) were determined and compared to prostate specific antigen (PSA) levels. On mRNA level, significantly increased expression of MT2A (2.4-fold), PSA (2.6-fold) and AMACR (8.4-fold) and insignificantly (1.9-fold) elevated MT1A in 22Rv1 compared to non-tumor PNT1A were determined. On protein level, significant enhancement of free PSA and total PSA in tumor cell line was evident. AMACR protein was 1.5-fold elevated in tumor line (below the level of significance). Contrary to mRNA, significantly (p = 0.01) reduced level of MT protein in tumor lines was determined. In the case of serum level, significantly enhanced MT level (4.5-fold) in patients' sera was found. No significant changes were observed in the case of AMACR. These findings indicate possible alternative role of MT to PSA prostate cancer marker. In addition, level of AMACR is distinctly higher in the Gleason score 9 in serum of patients and MT shows a descending trend in relation to Gleason score.

Clinical importance of matrix metalloproteinases.

This review gives a brief summary on clinical applications of MMPs and their determination. Primarily, the activity of MMPs in cancer formation, development and metastasis is discussed. Further, survey on methods including fluorimetric methods, zymographies, Western-blotting, immunocapture assay, enzyme-linked immunosorbent assay, immunocytochemistry and immunohistochemistry, phage display, multiple-enzyme/multiple-reagent system, activity profiling, chronopotentiometric stripping analysis and imaging methods for detection and determination of MMPs follows (Fig. 3, Ref. 100).

In vitro and in vivo effects of reovirus on HPV16-transformed mice cells.

UNLABELLED: Oncolytic viruses are examined to serve as anticancer therapeutics. It is expected that in addition to direct oncolytic effect their action will also help eliciting a solid antitumor immunity. In presented series of experiments we have employed two HPV16-transformed mouse (strain C57/B6) cell lines, TC-1 and MK16/III/ABC (MK16), and reovirus type 3, strain Dearing (RV). Both cell lines are highly susceptible to RV and produce large amounts of infectious virus in vitro while normal human are not susceptible to RV. Still, some differences were encountered. TC-1 cells produced moderately lesser amounts of infectious virus, but, paradoxically, were more efficient producers of delta1 antigen of RV and as a consequence of virus infection died more rapidly than simultaneously infected MK16 cells. Minor differences between the cell lines were observed in the percentage of cells arrested in theG2/M phase of the cell cycle and in some markers of apoptosis. When inoculating high doses (5x106) of infected cells (MOI 10 PFU/cell) into syngeneic animals their oncogenic activity was strongly suppressed, nearly completely in the case of MK16 cells and somewhat less efficiently in the case of more oncogenic TC-1 cells. Immunizing experiments in which non-oncogenic doses (106) of RV infected TC-1 cells were tested in parallel with the same doses of irradiated cells brought surprising results. When immunized animals were challenged with TC-1 cells, the irradiated cells proved to be a much better immunogen that the infected cells. However, when challenged with MK16 cells the opposite was true. It is believed that this difference was associated with the different biological properties of the cell lines tested. KEYWORDS: reovirus type 3, HPV16-transformed mouse cell lines, apoptosis, cell cycle, immunization/challenge experiments.

[Treatment results in patients treated from 1980 to 2004 for Wilms' tumour in a single centre]. / Lécebné výsledky pacientu lécených v letech 1980-2004 na jediném pracovisti pro nefroblastom.

BACKGROUNDS: The principle behind the treatment of nephroblastoma has been similar for at least 4 decades, based on vincristine and dactinomycine, radiotherapy in selected stages. The last three decades have been characterised by the aim to reduce the intensity and length of treatment. DESIGN: To retrospectively compare survival rates and treatment success in a cohort of patients aged under 19 years, treated from 1980 to 2004 at a single centre by five consecutive treatment protocols. MATERIALS AND METHODS: The outcome was evaluated in patients treated consecutively by two protocols established at the centre before 1980 and modified in 1986, and from 1988 consecutively by three accepted protocols, SIOP9, SIOP93 and SIOP2001. RESULTS: Overall survival as well as event-free survival rates were evaluated by Kaplan-Meier functions in 315 patients (52.7% women). The average age at diagnosis was 3.9 +/- 2.9 years, median 3.3, range 0.01-17.2 years. Age over 12 years in 2.2% patients. The average follow-up time was 13.1 +/- 7.8, median 13.6, range 0.2-27.8 years. The original 104 weeks of protocol KDO86 treatment had a 10-year overall survival rate of 91.9 +/- 3.2%. Overall survival significantly fell with radiotherapy reduction in lower clinical stages and treatment diversification in protocols with substantial treatment length reduction. Overall survival returned to the original value of KDO86 only in 1994, when SIOP93 was accepted with a 10-year overall survival rate of 92.47 +/- 3.0% and event-free survival 85%, with similar trends in the latest protocol, SIOP2001. In the entire cohort two coincident malignancies (tumour duplicities) were found: one B-lymphoma, one neuroblastoma. A second malignancy occurred in one patient--superficial spreading melanoma. CONCLUSION: from the retrospective view the accepted SIOP9 protocol has a significantly worse outcome in both the overall survival and in event-free survival rate compared with the original therapy. Only the SIOP93 and SIOP2001 protocols accepted after 2003 have an acceptable 10-year overall survival rate (around 92%) as well as event-free survival (85%) with substantially reduced length and intensity of treatment, lowering the risk of late effects.

Changes of blood count, lymphocyte subpopulations and immunoglobulin levels in nephroblastoma long term survivors.

The aim of this study was to investigate the frequency of blood count, lymphocyte subpopulations, and immunoglobulin levels alterations in a group of healthy nephroblastoma long-term survivors. The group included 122 nephroblastoma longterm survivors who were at least five years post anticancer therapy and free of any sign of recurrence The proportion of lymphocyte subpopulations was analyzed by flow cytometry using antibodies anti CD45 FITC/CD14 PE, anti CD3 FITC/ CD16+CD56 PE, anti CD4 FITC/ CD8 PE and anti CD20 FITC. Immunoglobulin G, A, and M levels were evaluated by immunoturbidimetry. Total blood count was also examined. The occurrence of decreased immunoglobulin levels, leukocytes, lymphocytes, and granulocytes count, proportion of T lymphocytes and their CD4+ subpopulation are not frequent. The most frequently decreased lymphocyte subpopulation was CD8 (15.5%). The most frequent abnormal findings were increased proportion of NK cells (38.5 %), B lymphocytes (38,52 %), decreased number of erythrocytes (25.2 %), hemoglobin levels (41.7 %) and hematocrit (13.9 %). The only significant differences between results of immunological examination and course of the disease were more frequently decreased proportion of CD4+ lymphocytes in recurrent disease survivors and lower IgA levels in survivors after radiotherapy. We found decreased at least one immunological parameter in one fifth of the survivors. The most frequently altered parameter was hemoglobin, which was decreased in 41.7 % of survivors. Decraesed hemoglobin may worsen quality of survivors life. Key words: nephroblastoma long-term survivors, blood count, lymphocyte subpopulations, immunoglobulin G, A, M serum levels.

Metallothionein--a promising tool for cancer diagnostics.

The latest research outcomes indicate that metallothionein (MT) levels in peripheral blood and serum from cancer patients can provide many interesting information about type or clinical stage of the disease, or response to therapy. MT plays a key role in transport of essential heavy metals, detoxification of toxic metals and protection of cells against oxidation stress. Serum MT levels of cancer patients are three times higher than control patients (0.5 microM). The elevated MT levels in cancer cells are probably related to their increased proliferation and protection against apoptosis. Automated electrochemical detection of MT allows its serial analysis in a very small volume with excellent sensitivity, reliability and reproducibility and therefore it can be considered as a new tool for cancer diagnosis (Fig. 4, Ref. 55). Full Text (Free, PDF) www.bmj.sk.

[Utilization of MLPA to detection of genetic changes in neuroblastoma]. / Vyuzití MLPA techniky k prukazu genetických zmen u neuroblastomu.

Neuroblastoma (NB) is a childhood cancer derived from neural crest cells, with a highly variable clinical course and biologic behavior. Several genomic imbalances correlate to prognosis in NB, with structural rearrangements, including MYCN amplification, in a near-diploid setting typically signifying high-risk tumours and numerical changes in a near-triploid setting signifying low-risk tumours. At present, many different techniques are used for detection of these copy number changes including standard chromosome karyotyping, comparative genomic hybridization (CGH), fluorescent in situ hybridization (FISH) and array CGH. Now, a new methodology called multiplex ligation dependent probe amplification (MLPA) has been developed. This new approach is based on polymerase chain reaction (PCR) amplification of ligated probes hybridized to target DNA sequences. MLPA is a highly sensitive, a rapid, accurate, reliable, and cost-effective. ENAQUA use neuroblastoma MLPA kit as a standard for detection genetic changes in neuroblastoma. We found high level concordance in FISH, CGH and MLPA investigations.

Expression of glutamate carboxypeptidase II in human brain.

Glutamate carboxypeptidase II (GCPII) is a transmembrane glycoprotein expressed in various tissues. When expressed in the brain it cleaves the neurotransmitter N-acetylaspartylglutamate (NAAG), yielding free glutamate. In jejunum it hydrolyzes folylpoly-gamma-glutamate, thus facilitating folate absorption. The prostate form of GCPII, known as prostate specific membrane antigen (PSMA), is an established cancer marker. The NAAG-hydrolyzing activity of GCPII has been implicated in a number of pathological conditions in which glutamate is neurotoxic (e.g. amyotrophic lateral sclerosis, Huntington's disease, Alzheimer's disease, epilepsy, schizophrenia, and stroke). Inhibition of GCPII was shown to be neuroprotective in tissue culture and in animal models. GCPII is therefore an interesting putative therapeutic target. However, only very limited and controversial data on the expression and localization of GCPII in human brain are available. Therefore, we set out to analyze the activity and expression of GCPII in various compartments of the human brain using a radiolabeled substrate of the enzyme and the novel monoclonal antibody GCP-04, which recognizes an epitope on the extracellular portion of the enzyme and is more sensitive to GCPII than to the homologous GCPIII. We show that this antibody is more sensitive in immunoblots than the widely used antibody 7E11. By Western blot, we show that there are approximately 50-300 ng of GCPII/mg of total protein in human brain, depending on the specific area. Immunohistochemical analysis revealed that astrocytes specifically express GCPII in all parts of the brain. GCPII is enzymatically active and the level of activity follows the expression pattern. Using pure recombinant GCPII and homologous GCPIII, we conclude that GCPII is responsible for the majority of overall NAAG-hydrolyzing activity in the human brain.

Clinical, pathological and molecular characteristics of newly diagnosed breast cancers.

Selection of breast carcinoma therapy is based on standard prognostic markers, such as tumor size, infiltration of regional lymph nodes, tumor grade, and expression of hormonal receptors. Insufficient treatment results stimulate a search for new markers which may lead to a more precise characterization of these tumors and to a more effective treatment. In our study we determined essential clinical and histopathological characteristics of non-metastasizing breast cancer - primary tumor size, involvement of the regional lymph nodes, expression of hormonal receptors and a status of ERBB-2 protein (HER-2), DNA ploidy, and their possible inter-correlation. In this study 77 patients were analyzed. The mean age was 59.3 years. Tumor stage T1 was found in 53%, T2 in 39%, T3 in 5% of patients. 57% of patients did not show any metastases in the axillary lymph nodes. A higher tumor grade 3 was seen mainly in larger tumors, in 62% of T2 and 66% of T3 tumors; 77% of carcinomas expressed hormonal receptors. HER-2 expression was shown in 21 T1 tumors, 13 T2 tumors, and 1 T3 tumor. 47 tumors were diploid. 13 T1 tumors, 14 T2 tumors, and 2 T3 tumors were aneuploid. Any significant correlation among staging T, N and ERBB-2 expression, hormonal receptors expression, tumor grade and DNA ploidy was found.

Reovirus - possible therapy of cancer.

Oncolytic viruses infect, replicate in, and eventually lyse tumor cells but spare normal ones. In addition to direct lysis, a result of viral replicative cycle, viruses also mediate tumor cell destruction by inducing nonspecific and specific antitumor immunity. Some viruses express proteins that are cytotoxic to tumor cells. Viruses recognized as oncolytic agents can therefore be divided into three categories: 1/ naturally occurring viruses (e.g. Newcastle disease virus, vesicular stomatitis virus, autonomous parvoviruses, some measles virus strains, reovirus) that selectively replicate in tumor cells, in some instances owing to their relative resistance to interferon action; 2/ virus mutants in which some genes essential for replication in normal cells but evitable in cancer cells have been deleted (e.g.adenovirus ONYX 015 that replicates only in cells with defected p53 or herpes virus G207 which exacts the presence of ribonucleotide reductase); 3/ virus mutants modified by the introduction of tissue-specific transcriptional elements that drive viral genes (e.g.adenovirus CV706 that has PSA restricted expression of E1A and E1B and adenovirus adMycTK that binds selectively on myc protein). Reovirus is prevalent in the human population but not associated with any known human disease. Studies have shown that reovirus multiplicate preferentially in tumor cells with activated gene of ras family or ras-signaling pathway while sparing normal cells. Activated ras or its pathway could be found in as many as 60-80% of human malignancies. In our studies we used cell lines that demonstrably express activated ras. We showed the cytopathic effect of reovirus (serotype 3 strain Dearing) on medulloblastoma cell lines and compared it with its acting on normal human fibroblasts. Oncolytics Biotech Inc. is currently guiding three Phase I or Phase I/II Reolysin studies, and has completed two clinical studies and concluded enrolment in a third one.

Characterization of drug-resistant neuroblastoma cell lines by comparative genomic hybridization.

Three parental neuroblastoma cell lines and nine derived lines resistant to Vincristin, Doxorubicin and Cisplatin, respectively, using CGH were studied. CGH profiles of all three parental cell lines were obtained using DNA from a healthy volunteer as reference DNA. Labeled DNA from each of the drug resistant daughter cell lines and labeled DNA from their parental sensitive cell lines were hybridized to obtain a comparison of gains and losses that accompanied the development of resistance for that particular drug. All three parental cell lines were characterized by typical findings for high risk neuroblastoma: N-myc amplification, gain of 17q, and loss of 1p36.2-36.3. Acquired drug resistance in the neuroblastoma cell lines appeared to be accompanied by a large array of DNA sequence copy number changes. The regions frequently affected in chemo-resistant cell lines included gains of 13q14.1-32, and 7q11.2-31.3, 4 q. Amplifications were seen at 7q 21.1 consistent with MDR1 amplification in UKF-NB-2 VCR, UKF-NB-3 DOXO, UKF-NB-4 VCR, and UKF-NB-4 DOXO, but not in any Cisplatin resistant line. All Cisplatin and Doxorubicin and two Vincristin resistant line (UKF-NB-2 VCR and UKF-NB-4 VCR) had a deletion of part of 19q or the whole 19 chromosome. All lines resistant to Vincristin or Doxorubicin and two Cisplatin resistant lines (UKF-NB-2 CDDP and UKF-NB-4 CDDP) had a deletion of at least part of 17q, UKF-NB-4 DOXO had deletion of the whole chromosome 17. The loss of 17q may cause chemoresistance by deletion of topoisomerase IIalpha gene. Deletion of 19 q in all but one chemo-resistant lines may influence of cytochromes P450 genes which are located on 19q13.2. Also gains of 15q 22, which were detected in UKF-NB-4 VCR, UKF-NB-2 DOXO and UKF-NB-4 DO X O, may affect other cytochromes P450 genes.

Acyclic nucleotide analogues suppress growth and induce apoptosis in human leukemia cell lines.

Acyclic nucleotide analogues perturb DNA replication by terminating the growing DNA chain. The analogues selected for testing on human leukemia cell lines, namely 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA), 9-[2-(phosphonomethoxy)ethyl]-2,6-diaminopurine (PMEDAP), and 9-[2-(phosphonomethoxy)ethyl]guanine (PMEG) exhibited growth-inhibiting activity at low concentrations, and apoptosis-inducing activity at high concentrations. A common feature was a reduction of the proportion of G1 cell cycle phase. Activities of the analogues increased in the order PMEA

Congenital-infantile fibrosarcoma: a clinicopathological study of five patients entered on the Prague children's tumor registry.

Five children with congenital-infantile fibrosarcoma are analyzed. The tumor was found at birth in four children: in one patient it was recognized at the age of 7 months. In three children the tumor affected the lower extremity. In one patient the inguinal region was the primary site, in another the abdominal wall. The morphology was that of a highly cellular spindle cell sarcoma with cells arranged in a fascicular pattern. Variations of this common pattern such as a cartwheel arrangement, and foci of small oval cells were observed. The immunohistochemistry revealed positivity of vimentin in four investigated tumors and muscle specific actin in three. Desmin, sarcomeric actin and myoglobin were all negative. There were scattered cells positive with KP1 (CD68), MAC 387, and in one case, with factor XIIIa antibodies which were considered to be reactive rather than tumor cells. The flow cytometry study showed DNA content in three tumors within diploid range; one tumor was hyperdiploid with the DNA index 1.2. Three children are disease-free from nine to 21 years after the diagnosis. One of them had the tumor preoperatively irradiated, and the subsequent histological examination revealed an almost complete tumor necrosis. In one patient there were six recurrences (treated by surgery only), and the child is well 25 months after the last recurrence. In one child the disease had an unusually aggressive course, and the patient died of widespread metastases to the lungs, lymph nodes and bones.

Immunoglobulin levels in children treated for malignant tumors.

IgG, IgA and IgM levels were examined in children treated for different malignant tumors. Chemotherapy decreased IgG and mainly IgM. There was increased incidence of infectious complications in IgG deficiency.