Potentiated antitumor effects of interleukin 12 and interferon alpha against B16F10 melanoma in mice.

Systemic administration of cytokines has not found broad application in cancer immunotherapy due to its toxicity and lack of effectiveness in a broad spectrum of tumors. Among the most promising cytokines used often in pre-clinical and clinical trials are interferon alpha and interleukin 12. We have shown in our study that combining IL-12 with IFN-alpha in a dose which alone does not show antitumor activity results in potentiated antitumor effects without inducing toxicity.

Comparison of methods used to study cell death in an adherent tumoral cell line with moderate clonogenic radiosensitivity.

Our objective was to compare different methods for studying programmed cell death in adherent H460 non-small lung cancer cells of moderate clonogenic radiosensitivity. The major effect of gamma-radiation was found to be the release of cells from the substratum. The different methods gave complementary and unexpected information: a) with the TUNEL method, a few non-apoptotic cells were found in the culture medium; b) with the flow cytometry after propidium iodide labeling, some hypodiploid cells which remained attached to the substratum were apoptotic, as demonstrated by the effect of a caspase inhibitor; c) with the annexin V labeling, the detached cells were demonstrated either necrotic or very late apoptotic; d) the mitochondria transmembrane potential (deltapsim), measurements demonstrated that the mitochondria were implicated in cell death induced by gamma-radiation. These data illustrate the need to use several complementary methods in the study of apoptosis in adherent cells exposed to gamma-radiation.

AgNOR pattern and PCNA analysis in fine needle biopsies of liver cell carcinoma.

The aim of this study was to evaluate the prognostic and diagnostic value of AgNOR and PCNA staining mainly in fine needle biopsies of 34 liver cell carcinomas using an image analyzing system. The AgNOR number per nucleus and the relative AgNOR area, but not the PCNA index, showed a significant correlation with the histological tumor grade according to the classical and the modified Edmondson-Steiner's classification. Regarding univariate survival, only the grade of the classical Edmondson-Steiner's classification was of prognostic significance. The parameters sex, age, maximum tumor diameter, mean AgNOR number, total nuclear area and relative AgNOR area, nuclear area, PCNA index or the grade of the modified Edmondson-Steiner's classification did not reach statistical significance regarding survival. By a factor analysis, two factors could be created, which could explain together 72% of the variance of all parameters included in the study. In a linear discriminant analysis, the AgNOR variables could separate between normal liver cells and cells from high grade or low grade carcinomas in 83.7% of the cases. Therefore, we think that the AgNOR technique can be usefully applied in needle biopsies of liver carcinomas for the differential diagnosis and tumor grading.

Comparison of two different methods for CD34+ selection and T cell depletion in peripheral blood stem cell grafts--our experiences with CellPro, E rosetting and CliniMACS technique.

The aim of this study was to establish a suitable method for in vitro T cell depletion in peripheral blood stem cell grafts for mismatched/haploidentical transplantation in children and adults with severe hematological disorders and for autologous transplantation in patients with autoimmune diseases refractory to conventional immunosuppressive treatment. Two different selection techniques have been used: CD34+ selection using immunoaffinity columns (CellPro Ceprate) followed by T cell depletion by E-rosetting or CD34+ selection using submicroscopic paramagnetic beads (CliniMACS device) with T cell depletion in a one step procedure. The mean purity and recovery of CD34+ cells and efficiency of T cell removal in the final product were compared. From March 1995 to December 1998 we prepared twelve allografts using Cell Pro system for eight children with high-risk hematological malignancies and six autografts for six patients with severe autoimmune diseases. From January 1999 to October 2000 we prepared fifteen allografts using CliniMACS system for ten children with high-risk hematological diseases and inborn metabolic disorders or primary immunodeficiences, five allografts for three adult patients with high-risk hematological malignancies and two autografts for two patients with autoimmune diseases. In allogeneic transplantation the median purity of CD34+ cells in the final products after CellPro and E-rosetting was 85.6% (55.3%-95.7%); median recovery was 24.8% (17%-35%), median transplanted doses of T cells per kilogram of body weight were 0.66x10(4) (0-2.8); in autologous transplantation the median purity of CD34+ was 92.6% (55.6%-96%), median recovery was 28% (22%-46.2%), median transplanted doses of T cells per kilogram of body weight were 0.39x10(4) (0.0-3.6). After CliniMACS technique the median purity of CD34+ cells was 94.87% (69.15%-99%),medianrecoverywas 58% (30%-79.6%), median transplanted doses of T cells per kg of body weight were 0.254x10(4) (0-14.15); in autologous transplantation the median purity of CD34+ was 94% (94%-94%, median recovery was 97.4% (95%-99.8%), median transplanted doses of T cells per kilogram of body weight were 0.87x10(4) (0.49-1.24). We consider both methods of CD34+ selection and T cell depletion suitable for peripheral blood stem cell processing before mismatched hemopoietic stem cell transplantation in patients without identical donor or before autologous transplantation for severe autoimmune diseases. However, magnetic separation using CliniMACS system results in higher levels of purity and recovery with efficient T cell depletion.

Conditioned medium from HeLa cells enhances motility of human monocyte-derived dendritic cells but abrogates their maturation and endocytic activity.

Progressive tumor proliferation may be associated with suppression of the immune response. Several different mechanisms can contribute to immune evasion. It is generally proposed that inhibition of dendritic cell functions would be a key mechanism by which tumors could escape immune surveillance. Therefore, the purpose of this study was to evaluate the capacity of HeLa cells conditioned medium (HeLa-CM) to modulate phenotypic and functional parameters of human peripheral blood monocyte-derived dendritic cells (DCs). Two types of reference DCs population were generated in vitro, the first cultured in the presence of IL-4 and GM-CSF which represented immature DCs (iDCs) and the second, representing mature DCs (mDCs), was raised from the iDCs by additional stimulation with a maturation cocktail - TNF-alpha, IL-1beta, IL-6, PGE2. In parallel, the iDCs were treated with HeLa-CM collected from the tumor cells. The analysis of DC populations demonstrated that the HeLa-CM prevented maturation of these cells and also impaired their capacity to uptake an antigen and stimulate proliferation of allogeneic T cells. In contrast, HeLa-CM modulated DCs exhibited a 3-fold increase mobility over iDCs. The latter functional capacity did not correlate with the levels of matrix metalloproteinase expression in the analysed cells. Altogether, our results provide evidence that HeLa cells produce soluble factors that might dramatically alter basic phenotypic and functional characteristics of DCs.

Leukemic transformation of polycythemia vera after treatment with hydroxyurea with abnormalities of chromosome 17.

The leukemogenic risk attributed to therapy of polycythemia vera with radiophosphorus and alkylating drugs has led, over the last 20 years, to the increased use of myelosupressive nonmutagenic drugs, especially hydroxyurea. But there exist reports, which showed the development of polycythemia vera into acute leukemia not only in patients treated with alkylating agents and radiophosphorus but also with single hydroxyurea. In this article we present two cases of polycythemia vera, in which the development to acute myeloblastic leukemia occurred after long-term treatment with hydroxyurea. Significant is the fact, that in both presented cases cytogenetic and FISH analysis showed abnormalities of chromosome 17, in the one of case fullfilled criteria for "17p-syndrome". Due to the possibility of leukemogenic potential in the time of hydroxyurea treatment, it is necessary to be careful especially in young patients. The dynamic follow up of cytogenetic analysis is necessary, especially, in those, where long-term hydroxyurea therapy is supposed.

P-glycoprotein expression in adult acute myeloid leukemia: correlation with induction treatment outcome.

Drug resistance has become a major cause of the treatment failure in patients with acute leukemia. P-glycoprotein (P-gp), which is associated with multidrug resistance (MDR) phenotype, has been reported to be an important predictor of the treatment outcome. The aim of this study was to analyze the value of P-gp expression in bone marrow cells as a predictor of the response to remission induction chemotherapy, as well as duration of remission in adult patients with newly diagnosed acute myeloid leukemia (AML). We examined the expression of P-gp in 31 patients using the monoclonal antibody UIC2. Direct immunofluorescent labeling was performed and samples were analyzed by flow cytomery. Kolmogorov-Smirnov test (D-value) was used to estimate UIC2 staining. A D > or = 0.3 for labeling of gated leukaemic blasts as compared to that of the isotypic control was defined positive (+) and compared to clinical data. P-gp expression was found in 14/31 (45.6%) patients, 17/31 (54.8%) of the samples were found P-gp negative(-). No correlation was found regarding age, sex and FAB subtype, altough 6/14 (43%) cases with more than 50% of cells having P-gp expression, were CD34+/CD7+. Complete remission rates were significantly lower in UIC2+ patients than in UIC2- cases (70% vs 35%, p < 0.01). Complete remission duration was also shorter in UIC2+ patients (6 vs 12.4 months). Our data indicate, that P-gp expression is a reliable marker of resistance to induction treatment in patients with de novo AML and can help to identify patients who may require alternative regimens designed to overcome therapy resistance.

Human glioma cells expressing herpes simplex virus thymidine kinase gene treated with acyclovir, ganciclovir and bromovinyldeoxyuridine. Evaluation of their activity in vitro and in nude mice.

Human glioma cell lines 8-MG-BA and 42-MG-BA were infected with retrovirus vector containing the herpes simplex virus thymidine kinase (HSVtk) gene. The effect of acyclovir (ACV), ganciclovir (GCV), and bromovinyldeoxyuridine (BVDU) on both, parental and HSVtk expressing glioma cells was studied in vitro. BVDU displayed the most potent cytotoxic properties in HSVtk-containing cells, however bystander killing of nontransduced parental cells in a mixture with HSVtk-containing cells was less potent, than observed for ACV or GCV. Taking into account the cytotoxic effect of different prodrugs used, as well as their ability to kill nontransduced bystander cells, ganciclovir was shown to be the most effective. Therefore the effect of GCV treatment on 8-MG-BA xenografts inoculated with PA-317JH5cl13 virus producer cells was further studied on nude mice.

Polymorphism of the p53 gene within the codon 72 in lung cancer patients.

We tested the codon 72 single nucleotide polymorphism (SNP) of the tumor suppressor gene p53 for association with lung cancer. In our hospital-based case-control study, 168 lung cancer patients (134 males and 34 females) and 148 controls without malignant diseases were recruited. The genotype characteristics were determined by PCR-based RFLP method using DNA extracted from peripheral blood. Only in lung cancer patients but not in the controls we found both significant decrease of A1 allele of the p53 codon 72 (p=0.024, OR 0.56, 95% CI 0.43-0.72) and A1/A1 homozygous genotype (p=0.006, OR 0.27,95% CI 0.15-0.51). The results of this study suggest a protective effect of A1 allele against lung cancer.

Inhibition of RNA synthesis in vitro and cell growth by anthracycline antibiotics.

New derivatives of doxorubicin and daunorubicin with amidine group bonded to daunosamine at C-3' atom and bearing the morpholine ring attached to the amidine group have been recently synthesized. Their cytotoxic activities and effects on RNA synthesis in vitro were assayed. The drug concentrations inhibiting mouse leukaemia L1210 cell growth to 50% were about two- and three fold higher for the derivatives compared to doxorubicin and daunorubicin respectively. Inhibition of phage T7 RNA polymerase by the non-covalently interacting derivatives was also slightly lower than that by the parent compounds. As doxorubicin and daunorubicin, their amidine derivatives in the presence of dithiothreitol and Fe(III) ions are activated and covalently bind to DNA. The adducts formed affect RNA polymerase activity. Several bands corresponding to prematurely terminated RNA chains are observed by means of polyacrylamide gel electrophoresis. The patterns of bands are virtually identical for all the anthracyclines studied here and are similar to the terminations induced by actinomycin D. This observation is consistent with a notion that the adducts are formed at guanine in GpC sequences which are also binding sites of actinomycin D. A substantial difference between daunorubicin and its amidine derivative is shown by means of high performance liquid chromatography. The derivative undergoes rapid rearrangements in the presence of dithiothreitol and Fe(III) ions, while daunorubicin is stable for several hours under these conditions. The results presented here indicate that the amidine derivatives despite bulky morpholine substitution exhibit biological activity in the systems used here.

Androgen sensitivity related proteins in hormone-sensitive and hormone-insensitive prostate cancer cell lines treated by androgen antagonist bicalutamide.

Members of the bcl-2 gene family and endogenous inhibitors of cyclin-dependent kinases participate in the regulation of apoptosis and cell cycle in a diverse range of cell types and are implicated in the development of hormone refractory prostate cancer and resistance to anti-cancer therapy. The expression of several of these genes can be regulated by steroid hormones and related agents via their nuclear receptors. However, insufficient information considering the protein expression after the treatment by hormone antagonists is available. The aim of this study was to evaluate the expression of anti- and pro-apoptotic proteins, (Bcl-2, Bax), and to correlate this with the appearance of some nuclear receptors and cell cycle related proteins in androgen sensitive and androgen insensitive prostate cancer cell lines, LNCaP and DU-145, after the treatment by androgen antagonist bicalutamide. Our results revealed that androgen receptor (AR) expression in LNCaP cells decreased, however in DU-145 cells AR slightly increased following anti-androgen treatment. The same agent stimulated expression of p21Waf1/Cip5 and p27Kip1 in LNCaP, as well as in DU-145 cell lines. Bcl-2 level increased slightly in LNCaP cells and, in DU-145 cells was almost undetectable. Bax expression was not changed in LNCaP but significantly decreased in DU-145 cells. Similarly, retinoid X receptor beta (RXRbeta) level was significantly down regulated after 24 hours in DU-145 and also in LNCaP cells after 72 hours. These results confirm that androgen withdrawal therapy employing anti-androgens may elicit different signalling pathways in various types of prostate cancer that may be dependent on AR status and AR sensitivity.

Contemporary trends in in vivo and in vitro testing of chemical carcinogens.

In the sixties of the last century it was realized that many human cancers are caused by environmental carcinogens and that the best way how to reduce cancer is first to identify in environment chemical carcinogens and second to prevent people from being exposed to such carcinogens. Epidemiological studies are probably the only way to confirm human carcinogenesis, however, this approach is so retrospective that carcinogens can be identified only after many victims have appeared. Carcinogenicity testing in long-term, medium-term, and short-term studies is therefore the only way for the prospective identification of possible human carcinogens. End-points of interest in a carcinogenicity study are primarily preneoplastic and neoplastic changes, but also include degree of malignancy, time to tumor appearance, multiplicity of (pre)neoplasia, and occurence of metastases. Long-term bioassays are designed and conducted to detect all of these end-points. Medium-term bioassays are mainly based on the detection of putative preneoplastic lesions and short-term tests can provide very important information concerning genotoxic effects of studied compounds.

Flavonoids as chemoprotective agents in civilization diseases.

Flavonoids, a class of polyphenolic compounds widely distributed in the plant kingdom, are capable of protecting against several chronic and degenerative diseases, among them cancer, cardiovascular diseases, stroke, cataracts and brain and immune dysfunctional states. These substances are common dietary components. They exhibit many biological properties through various mechanism of activity. Early studies of flavonoids investigated their significant antioxidant, antitumor, anti-inflammatory, antiallergenic and hepatoprotective effect. Additionally, their ability to modulate the activity of various enzymes affects normal as well as malignant systems. This review summarizes data on the beneficial effects of flavonoids in humans.

Radiation-induced meningiomas.

High dose radiation-induced meningiomas are a rare, severe and late complication of craniospinal radiotherapy for brain tumors. Radiation-induced meningiomas are, according to the literature, several times more frequent than radiogenic gliomas and sarcomas. It is suggested that every new case of radiogenic meningioma has to be reported to elucidate this particular pathologic entity with its many grey areas. In addition to high dose radiation-induced meningiomas, intracranial meningiomas were observed in patients who underwent low-dose radiation for tinea capitis in childhood, applied en mass to immigrants coming to Israel from the North Africa and the Middle East during the 1950. Authors summarize the data on radiogenic meningiomas from the literature and, as the previous radiotherapy may confer a low, but life-long risk for meningioma occurrence, they suggest that surveillance MRI after high dose cerebrospinal radiotherapy should be extended to several (3-5) decades after radiotherapy.

Germline mutation of the RET proto-oncogene in members of Slovak families with multiple endocrine neoplasia 2.

Detection of mutations in RET proto-oncogene in Slovak families from different localities and of different ethnic origin with MEN 2 syndrome is reported. Despite the fact that the same mutation of RET oncogene was found in different family members, the latency period of tumor appearance and their pathogenicity differed substantially. In addition, also different phenotypes of the disease were expressed in various family members having the same RET gene mutation. The data indicate that the mechanism of MEN2 syndrome is not only due to the RET gene mutation, and strongly support the conclusion that additional genetic events are involved in the disease formation.

Mutation screening of the BRCA1 gene in Slovak patients.

Breast cancer is the most commonly observed malignancy in women of the western world. The family history is the strongest risk factor for the disease. Two major genes, BRCA1 and BRCA2 that are involved in the familial breast and ovarian cancer have been described. Germ-line mutations of the BRCA1 gene have been linked to 85% of all hereditary breast and ovarian cancers. We performed a mutation screening ofthe entire codingregion of the BRCA1 gene in 29 Slovak families suspected of having inherited predisposition to breast cancer. For the analysis we used a combination of a single strand conformation polymorphism (SSCP), denaturing high-performance liquid chromatography (DHPLC) and sequencing. Genetic alterations were consistently indicated by SSCP and DHPLC and consequently confirmed by DNA sequencing as previously described pathogenic mutations. The patients with inherited BRCA1 mutations will undergo genetic counseling and cancer prevention health care program.

Effect of retinoic acid on the actin cytoskeleton in HL-60 cells.

The cytoskeleton, in addition to its structural and kinetic functions, is also involved in modulating signal transfer in cell proliferation, differentiation and death. In some myeloid leukemic cell lines, the process of cell differentiation accompanied by apoptosis, can be induced by all-trans retinoic acid (ATRA). In this report, we describe the morphological changes in actin cytoskeleton, taking place during apoptosis in cells of the human leukemic HL-60 cell line. By using fluorescent microscopy, the morphology of microfilaments and the proportion of apoptotic cells in the cell populations untreated or treated with 10(-6) M ATRA were detected. Interphase HL-60 cells showed aggregations of short, thick microfilament bundles in the region between the plasma membrane and the nucleus. In comparison with both interphase and mitotic cells, the cells with apoptotic nuclear fragmentation showed a different organisation of the actin cytoskeleton. The following types of F-actin structures were observed: (i) Cells with a high number of large dots/patches of F-actin under the plasma membrane. These dots might be localised only in the part of the cell or occurred under the whole plasma membrane. This arrangement was often associated with a diffuse signal for F-actin. (ii) Cells with 3D-network of F-actin fibres through the cytoplasm between remnants of the cell nucleus. This 3D-structure probably played an important active role in the process of apoptotic bodies formation. (iii) Cells without any detectable signal for F-actin or cells with only a very low F-actin signal. Both of these showed typical apoptotic collapse of chromatin. It is concluded that the actin cytoskeleton is a dynamic structure actively involved in the executive phase of the process of apoptosis. It is suggested that the rearrangement of the microfilament network and its subsequent degradation are necessary for the main morphological changes of apoptotic cells, i.e., plasma membrane blebbing and apoptotic bodies formation.

Plasminogen activator inhibitor type 2: potential prognostic factor for endometrial carcinomas.

The clinical determination of proteases which are involved in carcinogenesis, invasion and metastasis may contribute to the detection of the early stage of disease, and to the prognostic assessment of patients with the cancer. The aim of the present study was to determine the level of urokinase plasminogen activator (uPA), plasminogen activator inhibitor type 1 (PAI-1) and plasminogen activator inhibitor type 2 (PAI-2) in normal and malignant tissues of corpus uteri and to evaluate the possible correlation with clinical and histopathological prognostic factors. UPA, PA-I and PAI-2 were determined by the ELISA assay in tissue cytosol of matched pair samples from 27 patients with endometrial carcinoma. Results show that significantly higher levels of these proteins were found in malignant than in normal tissue samples (uPA: 1.266 versus 0.633 ng/mg protein, PAI-1:4.468 versus 1.958 ng/mg protein, and PAI-2:3.428 versus 0.483 ng/ml protein). The levels of uPA and PAI-1 did not correlate with clinical staging or pathohistological grading. However, in tumor tissues with clinical stages II and III, myometrial invasion > 50%, and lymphovascular invasion, increased levels of PAI-2 were determined. Our results indicate that components of the plasminogen activation cascade are up-regulated in endometrial cancer and suggest the role of PAI-2 in determining invasive potential of endometrial carcinomas.

Identification of a pepsin-sensitive type III-like collagen in breast cancer MCF-7 cells.

Electrophoretic analysis of [3H]proline-labeled culture medium proteins of MCF-7 cells revealed the presence of disulfide-bonded, bacterial collagenase-sensitive component which comigrated with pro(alpha)1 chains of type III and type I collagens. However, it was pepsin- and trypsin-sensitive. Within 1 min of pepsin-digestion, a component with a size of alpha1 chain of type I or III collagen was produced which degraded after 5 min of digestion. Similarly, the pepsin-sensitive band was completely degraded by trypsin at 30 degrees C within 5 min. We examined CNBr peptides of the collagenous band and demonstrated that it was alpha1 chain of type III collagen. When MCF-7 cells were cultured in the presence of 2 nM estradiol, a marked increase in the level of collagen secreted into medium was found. The identified proteinase-sensitive type III-like collagen as major protein of extracellular matrix, would be expected to be more susceptible to degradation which might contribute to tumor progression.

Significance of P-glycoprotein expression in childhood malignant tumors.

Resistance to chemotherapy significantly affects the treatment results in various cancers. Multidrug resistance caused by P-glycoprotein expression is now widely studied in human malignancies. We present the results of P-glycoprotein expression examination in 91 tumor tissue samples obtained from children treated for different malignant tumors in the Dept. of Pediatric Oncology, Prague. The correlation between the level of P-glycoprotein expression and tumor histology, clinical outcome, use of therapy, relapse rate and metastatic disease was made. P-glycoprotein expression was found significantly more frequent in soft tissue sarcomas, neuroblastomas, and hepatoblastomas, and generally in disseminated disease. On the contrary, a high expression of P-glycoprotein was not found in malignant brain tumors and nephroblastomas. The data strongly support the possibility that the percentage of P-glycoprotein expressing cells in selected tumors (soft tissue sarcomas, neuroblastomas), may have a clinical importance.

Establishment, morphological, growth and cytoskeletal properties of 135-BCA carcinoma cell line derived from lung brain metastasis.

Many cell lines have been established from lung cancer but carcinoma cell lines derived from brain metastases occur rarely. The carcinoma cells growth relatively slowly in comparison with brain cells which often overgrow the tumor cells in early passages. The origin of these rapidly dividing brain cells in carcinoma cultures is discussed with respect to the previous studies on adult human brain tissue cultures. It was found that the majority of cells in adult human brain cultures derived from brain biopsies of patients with non-cancer diseases do not express glial markers. Based on the previous studies we suggest that they are glial precursor cells. The high proliferative capacity and non-glial phenotype of these brain cells may lead to the suggestion that they are of cancer origin. In this study the establishment and characterization of a new carcinoma cell line 135-BCA is described. The tissue cultures were derived from brain metastasis of lung large cell carcinoma. The cell line is specific by the epithelial cell morphology and evident cytokeratins expression during the whole subcultivation. All tumor cells were strongly immunoreactive for vimentin and negative stained for glial fibrillary acidic protein (GFAP). The new cell line may prove of value in biological and therapeutic studies of lung cancer. In addition, the further comparative analysis may reveal the environmental influence of brain tissue on carcinoma cells.

Expression of apoptosis-regulating proteins p53, Bcl-2, and Bax in primary resected esophageal squamous cell carcinoma.

Apoptosis plays a key role in the pathogenesis, aggressiveness, and therapy responsiveness of cancer. Proteins of the Bcl-2 family as well as p53 are important regulators of apoptosis. The present study retrospectively examines the expression of apoptosis-regulating proteins in primary resected esophageal squamous cell carcinoma (ESCC) and the correlation between the outcome of patients' treatment and the expression of the proteins. We used antibodies specific for the human p53, Bcl-2 and Bax proteins to examine the expression of these apoptosis-regulating proteins in 40 archival specimens of patients with primary resected esophageal squamous cell carcinoma. The overall expression of p53, Bcl-2, and Bax was 73%, 18%, and 100%, respectively. No significant correlations were found between the expression of p53, Bcl-2, and Bax. The expression of Bcl-2 had a negative influence on survival in this population of primary resected ESCC patients (p=0.03). But no differences in survival were observed in relation to the expression of p53 or Bax. In conclusion, Bcl-2 expression may provide additional and prognostic information for the clinical course of the disease and therefore to be developed as a prognostic indicator for primary resected esophageal squamous cell carcinoma.

Expression of p53 and bcl-2 proteins in acute leukemias: an immunocytochemical study.

We have analyzed by immunocytochemistry the p53 and Bcl-2 proteins expression in 49 patients with B-ALL, T-ALL and AML at the time of initial diagnosis. The diagnosis was based on morphologic and cytochemical criteria and on immunophenotyping. To demonstrate the p53 protein expression, p53 specific mouse antihuman immunoreagent clone DO-1 that recognizes both wild and mutated p53 protein was used. To detect Bcl-2 a monoclonal antibody that recognizes the 26-kD Bcl-2 protein was applied. For evaluation of both proteins a sensitive Immunotech detection kit based on peroxidase labeled streptavidin biotin reagent was utilized. The patients were divided according to the presence or absence of both, nuclear p53 and cytoplasmic Bcl-2 proteins. A relative low frequency of p53 protein expression in B- and T-lineage acute lymphoblastic leukemia has been shown at diagnosis. In AML cases, the frequency of p53 expression was higher than that in ALL. Bcl-2 protein immunoreactivity has been found in the majority of acute leukemia patients. The marked heterogeneity in the percentage of p53 and Bcl-2 positive cells in individual patients was observed. Comparative analysis of the distinct acute leukemia subtypes according to the percentage of p53 and Bcl-2 positive cells showed no significant differences except for p53 protein positivity in relation between T-ALL and AML cases. The samples from healthy subjects used as a control exhibited very low proportion of positively stained cells and significantly differed from p53 as well as Bcl-2 positive cases. p53 and Bcl-2 positivity have not been significantly affected neither by age, sex nor WB C counts. Association between myeloid cells maturation and proportion of p53 and Bcl-2 positive cells was observed. Noteworthy was the inverse relation between the higher proportion of p53 positive cells and low Bcl-2 positivity in some cases of acute leukemia. Although our preliminary results need to be confirmed in a larger group of patients, immunocytochemical analysis of p53 and Bcl-2 proteins, indicators of cell alterations, may help to identify risk patients requiring intensive therapy.

A study on nitric oxide secretion by transplantable melanoma cell lines with regard to their spontaneous apoptosis.

In the study we investigated if there exists any correlation in the nitric oxide (NO) secretion by two types of melanoma cells of the same origin but differing in their biological properties and ability to undergo spontaneous apoptosis. Our results suggest that there exists an inverse correlation between the dynamics of NO secretion by cells of two melanoma lines and their ability to undergo spontaneous apoptosis.

Polymerase chain reaction detection of cells carrying t(14;18) in bone marrow of patients with follicular and diffuse large B-cell lymphoma: the importance of analysis at diagnosis and significance of long-term follow-up.

The t(14;18) is the most frequent chromosomal aberration observed in follicular lymphoma (FL), and is less frequent in diffuse large cell lymphoma (DLCL). The bcl-2/IgH rearrangement constitutes good target for polymerase chain reaction (PCR) detection that allows to find out one tumor cell in 100,000 normal cells. The PCR assay was used to detect bcl-2-rearranged cells in blood and bone marrow (BM) in 63 previously untreated patients with DLCL and in 53 patients with FL. Twenty five FL patients (47%) and 9 DLCL patients (14%) had PCR-detectable lymphoma cells in BM and peripheral blood. Minimal residual disease (MRD) was evaluated in 17 FL and 5 DLCL patients undergoing first-line chemotherapy. Three DLCL patients (60%) but only 1 FL (6%) patient achieved molecular response (PCR-negative status in BM). Two PCR bcl-2/IgH positive patients with FL were treated with rituximab (anti-CD20 antibody) and had no PCR-detectable lymphoma cells in BM after the therapy. Peripheral blood stem cells (PBSC) were harvested in 5 FL (1 PCR-negative) and in 2 DLCL (1 PCR-negative) patients. PCR-positive lymphoma cells contamined PBSC in all patients with BM PCR-positivity before harvesting. Five FL patients underwent autologous transplantation (AT). No bcl-2/IgH positive cells were detected in 4 patients (80%) at any point after AT. One patient achieved molecular response after rituximab treatment. All the patients are in CR 6, 22, 30, 31 and 42 months respectively, after AT. On the other hand, 4 FL patients in clinical complete remission, but with persistent PCR positivity in BM relapsed with median of 21 months (interval, 14-28 months) from the end of a first-line chemotherapy. Thus, the results show that PCR detection of the bcl-2/IgH rearrangement is a very useful method in evaluating the BM infiltration by lymphoma cells especially in the situation of MRD. Conventional chemotherapy did not eradicate bcl-2 positive cells in BM in most of lymphoma patients, but autologous transplantation or rituximab immunotherapy can induce molecular response in a significant proportion of them. Our results support the previous observations of the molecular response importance in view of better disease free and probably also overall survival.

The role of palliative radiotherapy in locally advanced non-small cell lung cancer.

The aim of this study was to evaluate retrospectively the treatment results of non-small cell lung cancer (NSCLC) patients treated with palliative intent in Dokuz Eylul University Hospital, Radiation Oncology Department. One hundred and fifteen inoperable, non-metastatic and symptomatic NSCLC patients were treated with palliative radiotherapy (PRT) between July 1991 and May 2000. PRT was used in patients with low performance status, weight loss more than 10% within last 6 months, secondary malignancies, co-morbid diseases and socio-economic problems. Parallelly opposed isocentric antero-posterior fields including both the parenchymal and mediastinal masses were used. 10-55 Gy total doses were delivered in 1-23 fractions with a median of 30 Gy. Nineteen patients received systemic chemotherapy before PRT. Survival analysis was made from the treatment beginning date, and subjective palliation rates were assessed according to clinical improvements in symptomatology evaluated 1-6 weeks after PRT. The median follow-up time was 28 weeks (1-234 weeks). Totally, 245 disease-related symptoms were detected in 115 patients. Overall "improvement" in symptomatology was found to be 90% (221/245) with a "near-total response" rate of 46% (113/245). Hemoptysis was the best palliated symptom. Median survival time was 30 weeks. Karnofsky performance status (KPS) (p=0.015), weight loss (p=0.0015), histologic tumor type (p=0.0024) and tumor size (p=0.02) were found to effect overall survival rates significantly in uni-variant analysis. Multi-variant analysis revealed statistically significant effect with histological tumor type and weight loss status. Only 16% of patients (3/19) showed partial and 5% (1/19) complete response to systemic treatment. Median survival time was 46 weeks in this group. In conclusion, this retrospective study of patients with poor prognostic factors confirms that PRT is an effective treatment modality in symptomatic locally advanced NSCLC patients resulting in 90% symptomatic improvement rate and a median survival of 30 weeks.