Leukemia-associated phenotypes: their characteristics and incidence in acute leukemia.

Leukemia-associated phenotypes have been suggested to be a valuable tool for the detection of minimal residual disease in acute leukemia patients, as they allow to distinguish leukemic blasts from normal hematopoietic progenitor cells. The aim of the present study was to analyze the proportion of acute leukemia patients (both with lymphoid and myeloid leukemias) in which the immunological detection of leukemia-associated phenotypes was convenient for the distinction of leukemic and normal cells. For this purpose we have studied the blast cells from 186 acute leukemia patients at diagnosis with a large panel of monoclonal antibodies by flow cytometry using double staining combinations. From aberrant phenotypes on blast cells we followed lineage infidelity (coexpression of myeloid markers in lymphoid leukemia cells and vice versa, as well as the simultaneous expression of both, T and B cell markers in one lymphoid blast cell) and asynchronous marker expression (simultaneous expression of early and late markers in one cell). One hundred and five of the 186 acute leukemia cases analyzed (56%) showed the presence of leukemia-associated phenotypes. In 41 of the 90 ALL cases followed (46%) and in 40 of the 96 AML cases studied (42%) lineage infidelity was observed. Asynchronous antigen expression was detected in 24 followed cases (13%). Evaluation of the cell marker density by means of calibration microbeads demonstrated abnormal mean channel immunofluorescence and molecules of equivalent soluble fluorescein for CD8 in two patients with T cell malignancies at diagnosis. Abnormal CD8 density might thus represent a characteristic feature of malignant CD8-positive T cell clone. Quantitative marker evaluation therefore seems to be another important mean for the detection of aberrant phenotypes on leukemia cells suitable for the detection of minimal residual disease.

Some early differentiation markers detected in cytoplasm of pre-B cells by flow cytometry.

Immunofluorescent staining of cytoplasmic IgM (heavy chains) and CD24 as well as their simultaneous staining with surface B cell markers was used to study immunophenotype changes in B cell differentiation. Human hematopoietic B cell lines P3HR1 and RAJI were used. We found that IgM and CD24 cell markers while absent on cell membrane could be detected in their cytoplasm (c). The presence of cIgM in cell lines RAJI, P3HRI indicates their early pre-B differentiation stage. The presence of cCD24 simultaneously with mCD22 and cIgM is the evidence that hematopoietic cell lines or leukemias may not accurately reflect normal differentiation pathway. Combinations of cIgM, cCD24 with surface B cell markers CD10, CD19 on these cell lines can be considered as leukemia associated phenotypes. Some of them were shown in bone marrow and peripheral blood of pre-B ALL and B-CLL patients and can be used for the detection of minimal residual disease. Different fixation/permeabilization methods were tested in order to choose the optimal one for simple detection of cytoplasmic markers or their simultaneous detection with surface markers by flow cytometry. They included "one-component-methods" (methanol-M, saponin-S), methods combining these components with paraformaldehyde (P+M, P+S) or buffered formaldehyde acetone (BFA). The choice depended on individual marker detected. General parameters like the proportion of debris, cell aggregation, cell loss and the changes of scatter parameters FSC and SSC were taken into consideration. The priorities of combined methods P+S, P+M1 and BFA over one-component methods are demonstrated.

Flow cytometric detection of some activation and proliferation markers in human hematopoietic cell lines.

Simultaneous surface marker/DNA, cytoplasmic/DNA or nuclear/DNA staining was used to study proliferation of hematopoietic cell lines (MOLT4, BJAB, P3HR1). Different fixation/permeabilization methods (paraformaldehyde with metanol or Tween 20 or saponin, buffered formaldehyde-acetone) were used providing optimal results of the double stainings. There was a significant increase of S phase and proliferation index (PI) of CD71+ and Ki67+ MOLT4 cells in comparison with their negative counterparts. This indicates their close connection with proliferation. Unlike that, the correlation between the expression of CD38 and S phase or PI was not significant either in MOLT4 or in P3HRI cells. For cytoplasmic markers CD3 (in MOLT4 cells) and CD22 (in BJAB cells) statistically significant (cCD3) and not significant (cCD22) correlation was demonstrated between their expression and S phase or PI. Molecular equivalents of soluble fluorescein values for CD71 were always higher than for CD38. The density of these cell surface markers in addition to the percentage of their expression is of considerable significance for their evaluation as activation or proliferation markers.

Cell surface phenotype and increased penetration of human multidrug-resistant ovarian carcinoma cells into in vitro collagen-fibroblasts matrix.

Human multidrug resistant ovarian carcinoma cells (A2780/ADR) exhibited increased in vitro penetration into the collagen-normal human fibroblasts matrix, increased cell surface expression of alpha 6 integrin (CD49f antigen) and slightly increased expression of alpha 2 (CD49b) integrin compared with that of parental drug-sensitive A2780 cells. Both, multidrug-resistant and parental, drug-sensitive, cell lines did not express the 67 kDa non-integrin high affinity laminin receptor on their cell surfaces. As there were no marked differences between metalloproteinase activity of both A2780 cell sublines (with similar intensity of 72 kDa and 92 kDa lysis bands in zymograms), the increased penetration of the drug-resistant subline into the collagen-fibroblast gel matrix might be associated with the increased expression of adhesion proteins (including collagen-binding alpha 2 integrin), or cell surface-associated collagenase-stimulating protein(s). This multidrug resistant ovarian carcinoma cell line might serve as an in vitro model of neoplastic cells with increased biological aggressiveness, molecular mechanisms of which require further analysis.

The study of AgNOR proteins in leukemias: diagnostic value and correlation to S-phase cell fraction.

The study assessed the diagnostic value of silver staining method and its possible relevance as an alternative to DNA analysis for the study of cellular proliferation in various leukemias (ALL, AML, CML). Silver staining of nucleolar organizer region-related proteins (AgNORs) was applied to peripheral blood and bone marrow cells. The analysis of S-phase cells was carried out using a FACStar flow cytometer. The mean number of AgNOR dots per nucleus and the percentage of S-phase cells varied according to immunophenotype of leukemic cells, depending on the time of initial diagnosis, remission or relapse. Peripheral blood and bone marrow cells of healthy subjects exhibited less AgNOR dots than leukemic cells. The number of AgNORs in bone marrow cells was higher than that of AgNORs in peripheral blood. Significant differences between ALL and AML, as well as AML and CML in AgNOR quantity were observed. Important increase in AgNOR values was evident in relapsed leukemias and in the CML blast crisis. DNA flow cytometry analyses provided results comparable to those of AgNOR enumeration. The correlation between AgNOR dots and proportion of S-phase cells prompted us to consider that AgNOR count reflects cell proliferation capacity of leukemic cells.

Potential carcinogenicity of the synthetic 1,3,6-triazine (6-aza) nucleic acid analogues determined by DC polarography. I. Nucleobases.

The polarographic reduction of several synthetic 1,3,6-triazine (6-aza) nucleobases in the strictly anhydrous solution was studied in the absence and presence of alpha-lipoic acid. The values of the half-wave potentials E1/2 and the parameter of potential carcinogenicity tg alpha were determined for one natural and 5 synthetic nucleobases. The current value of the first diffuse polarographic wave or a new diffuse polarographic wave belonging to the nucleobase-alpha-lipoic acid complex increased with the increased alpha-lipoic acid concentration for the all compounds only marginally. Although this diffuse current increase was linearly depended on the alpha-lipoic acid concentration in anhydrous solutions, the determined index tg alpha values ranging between 0.029 and 0.108 indicated a very low potential carcinogenicity of the all nucleobases investigated.

Comparison of the in vitro effect of adriblastina on induction of SCEs in V79 cells and human peripheral blood lymphocytes.

Induction of sister chromatid exchanges (SCEs) by the cytotoxic antibiotic adriblastina (doxorubicin, 14-hydroxyrubidomycin) of the anthracycline group isolated from Streptomyces peucetius var. caesius by Farmitalia Research Laboratories was tested in vitro at concentrations of 0.01 microgram/ml, 0.1 microgram/ml and 0.2 microgram/ml using V79 cells and human peripheral blood lymphocytes from healthy donors. In comparison with negative control, adriblastina significantly elevated the SCE frequency both in V79 cells and in human peripheral blood lymphocytes. The results obtained by comparing the effect of equivalent adriblastina concentrations on V79 cells and human peripheral blood lymphocytes showed no significant difference in the mutagenicity effect of both of these cell lines to adriblastina.

Approaches to prove the melanoma origin in amelanotic human melanoma cell lines.

The human melanoma B-HM8 cell line was derived from highly pigmented malignant skin melanoma. After 5 weeks of cultivation it entirely lost the pigmentation and has remained amelanotic since. Electron microscopy revealed neither premelanosomes nor melanosomes and the cells did not release detectable amount of dopa-oxidase activity into culture medium. Immunocytochemical studies using the polyclonal anti-S-100 antibody and detection of alpha-mannosidase activity in culture medium proved the melanoma origin of B-HM8 cells. Chromosomal changes in the karyotype of these cells were typical for human melanoma with chromosomes No. 1, 5, 7, 9, and 11 involved most frequently.

Protective effects of cardioxane against anthracycline-induced cardiotoxicity in relapsed acute myeloid leukemias.

The clinical use of anthracyclines and related antitumor agents is limited by their cumulative dose-related cardiac toxicity. Cardioxane (ICRF-187) is an agent that has been recommended to block selectively this toxicity which e.g. limits the use of daunorubicin (DNR) in doses higher than 550-700 mg/m2. We decided to use cardioxane in patients with relapsed acute myeloid leukemias (AML) who have previously been treated with DNR doses above 500 mg/m2. Seven patients with relapsed AML received cardioxane 30 min before DNR or mitozantrone (MTZ) in doses 8-13x higher than DNR or 40-60x higher than MTZ. Two patients received anthracyclines cumulative doses corresponding to more than 1300 mg/m2 and 1000 mg/m2 of DNR, respectively, without any signs of cardiac toxicity. The other 5AML patients in relapse received 1-3 chemotherapy cycles with cardioxane. Their total cumulative doses of DNR were 550-750 mg/m2 and their left ventricular ejection fraction remained above 50% as were their pretreatment values. Cardioxane seems to be a useful cardioprotective agent in relapsed AML which enables further treatment with anthracyclines.

Incidence and kinetics of distant metastases in patients with operable breast cancer.

The purpose of this paper is to evaluate the incidence and kinetics of distant metastases in operable breast cancer and to relate these estimates to various tumor and patient characteristics. The records of 309 consecutive patients with operable breast cancer in stage T1-4N0-1M0 were reviewed, and the incidence of distant metastases (DM) and death due to DM were evaluated. 195 patients had positive axillary nodes with the following distribution of the number of nodes: 45% had 1-2 node, 16% had 3-4 nodes, 14% and 25% had 5-7 and more nodes, respectively. All patients were treated with radical mastectomy with axillary nodes dissection (the only treatment in 39% of cases). In 198 cases radical mastectomy was combined with radiotherapy and/or chemotherapy given pre- or postoperatively. Hormonal treatment was given in 27% of cases. Minimum follow-up was 10 years. Distant metastases were found in 150 cases (49%) and in 78 cases (25%) they developed early, during the first 18 months follow-up. Average rate of DM in N0 cases was 25%. Number of involved nodes and extracapsular invasion were found significant and independent prognostic factors. High risk (50%) of DM and death due to DM correlate with age < 40 y, premenopausal status, tumor stage > or = T3, more than 2 axillary nodes and/or extracapsular invasion. The linearity of the curves for freedom from DM and for freedom from death due to the DM suggest uniform distribution of progression rates with a median value for halving time for freedom from early DM of about 8 months, and of about 40 months for freedom from the DM occurring later than 18 months, being for whole group an average of 20 months. High incidence of DM is a significant cause of poor long-term survival. Early appearance (< 18 month follow-up) of about half of the DM suggests that they are already present as subclinical micrometastases at the time of initial loco-regional treatment. The time of appearance of distant metastases is consistent with a wide range of metastatic cell burdens among patients. Systemic therapy, at least for selected group of patients, might decrease the incidence of DM and improve long-term results.

Prognostic parameters in low-grade non-Hodgkin's lymphomas.

In a group of 73 patients with low-grade non-Hodgkin's lymphomas (LG NHL) a multivariate analysis of the following variables was performed: pathological types following the International Working Formulation, clinical stage, B-symptoms, erythrocyte sedimentation rate, hemoglobin level, white blood cell and lymphocyte count, serum gamma globulin level, serum total lactic dehydrogenase (LDH) level, mitotic and complete remission. The patients with lymphocytic lymphoma manifested the best survival in this group. Low-proliferative lymphomas showed better survival than high-proliferative lymphomas at 3 and 10 years. B-symptoms, serum total LDH level and complete remission were significant independent prognostic factors.

Clinical thermoradiotherapy: the influence of some prognostic parameters on recurrence-free survival.

Thirty-one patients with loco-regional advanced tumors accessible for local thermoradiotherapy were treated at the Institute of Oncology in Ljubljana, between 1989-1993. There were six primary inoperable and 25 recurrent or residual tumors after previous radiotherapy. In 13 patients treatment consisted of combined interstitial water hyperthermia and brachyradiotherapy, in 5 patients combination of interstitial hyperthermia and percutaneous radiotherapy was used, and percutaneous microwave hyperthermia with percutaneous irradiation was employed in remaining 13 patients. Complete response (CR) was achieved in 17/31 (55%) of all treated patients. Among various tumoral and therapeutic parameters tested significant influence on complete response rate was found for tumor volume (p = 0.047), minimum intratumoral temperature (p = 0.004), time interval between hyperthermia and radiotherapy (p = 0.02), and fraction-size of immediate radiotherapy (p = 0.002). More than one hyperthermia treatment and total tumor dose of irradiation > 45 Gy did not significantly improve local control rate in our patients. For all 31 patients treated with thermoradiotherapy 3-year recurrence-free survival (RFS) of 41% was achieved. For the group of 9 patients in whom the interval between hyperthermia and irradiation exceeded 1 hour, RFS of 18% compared to 53% for 22 patients treated with "synchronous" thermoradiotherapy was achieved, however the difference between the groups was not significant (log rank p = 0.17). In 25 patients in whom minimum intratumoral temperature (Tmin50) exceeded 42.5 degrees C significant difference in RFS between the subgroups of 19 patients treated synchronously and 6 patients in whom time interval between the two modalities was longer than 1 hour, i.e. 65% vs. 25% respectively, was found (log rank p = 0.048). However, most favorable RFS of 81% was achieved in the subgroup of 15 patients in whom good hyperthermia treatment (Tmin50 > or = 42.5 degrees C) was followed by an immediate irradiation using fraction size > or = 3 Gy (p = 0.015). Treatment related toxicity was acceptable and did not correlate with response rate. Our conclusion is that thermoradiotherapy is more effective when somewhat larger fraction-size of radiotherapy than conventional, i.e. 3-5 Gy, are employed in synchronous combination of both treatment modalities.

In vitro and in vivo studies of murine sarcoma cells after prolonged treatment with promoting phorbol ester TPA.

Murine sarcoma cell line (L-1) treated with promoting phorbol ester (TPA) showed decreased content and activity of protein kinase C (PKC) as measured by Western blotting and histone phosphorylation methods. The PKC depleted line (L-1R) produced bigger, tumors after s.c. transplantation into syngeneic mice and more spontaneous and artificial metastases developing after i.v. injection of tumor cells. The in vitro studies revealed decreased: adhesiveness, migratory and invasiveness properties of PKC depleted cells. Negative correlation between in vitro and in vivo studies were found.

Growth-regulating influence of nonactivated resident macrophages on transformed and tumor cells in the in vitro contact interactions.

Susceptibility to cytostatic activity of nonactivated macrophages (Mph) of Syrian hamster embryo fibroblasts (HEF) transformed in vitro by BAV-3, SV40, RSV-SR, or spontaneously and of their in vivo selected variants was studied in dynamics (5 days of co-incubation). With the use of 3H-TdR incorporation test it was demonstrated that HEF transformed by BAV-3 appeared to be able to overcome the cytostasis at 4-5 day of the co-incubation with Mph, in contrast to deeply suppressed spontaneously transformed cells of STHE strain. HEF transformed by SV40, or RSV-SR appeared to be resistant to growth-inhibiting activity of Mph during almost all the 5-day period. The in vivo selected malignant variants of STHE cells were able to recover from cytostasis after 4-5 days of the co-incubation with nonactivated Mph, in contrast to low-malignant variant and to parental cell strain.

Retinoic acid-induced alteration of cell surface topography and other changes in an oral carcinoma cell line in culture.

Nature of antiproliferative action of retinoic acid (RA) on KB cells was studied by using monolayer and agar culture techniques. RA-treated cultures showed increased requirement of serum for their growth. Growth of colonies in agar culture was significantly retarded when cells were treated with 40 mumol RA. RA-induced growth inhibitions in both monolayer and agar cultures were independent of cell seeding densities. Cortisone and hydrocortisone showed no reversal of the inhibitory effects induced by RA on KB cells. Scanning electron microscopy study revealed a significant alteration in cell surface topography of RA-treated cells in monolayer culture. The results demonstrate that RA has a potential of reversing some of the properties which are associated with transformed state of oral carcinoma cells.

Glutathione and glutathione metabolizing enzymes in tissues and blood of breast cancer patients.

Many reports indicate that glutathione and enzymes cooperating with it are important in neoplastic processes. Glutathione (GSH) concentrations and glutathione S-transferase (GSH STr) and glutathione peroxidase (GSH-Px) activities were determined in breast cancer tissue and adjacent healthy tissues, as well as in blood of 28 patients. There were considerable differences in the investigated parameters among individual patients. Therefore we analyzed the paired samples of normal and cancerous tissues from the same individual. In 68% of the patients the activities of GSH-Px and in 85% patients those of GSH STr were found to be higher in the tumor than in the normal tissue. GSH concentration in 48% tumor samples were higher and in 44% lower than in corresponding normal tissues. Statistically significant correlation was found between GSH-Px and GSH STr in normal (r = 0.51, p < 0.005) and in cancer tissues (r = 0.64, p = 0.001). Correlation coefficient between GSH Px activity in normal and corresponding cancer tissues was r = 0.71 (p < 0.001), however this correlation in the case of GSH STr was much lower but still significant (r = 0.38, p < 0.05). No significant correlation in the determined parameters was found between erythrocytes or plasma and normal or cancer tissues.

Phylloid breast tumors and three steroid hormone receptors.

The concentrations of three steroid hormones (estrogen, progesteron and 1,25-dihydroxycholecalciferol) receptors (ER, PgR, DR) in tissue cytosol were analyzed in a group of 17 breast phylloid tumors. Comparison with breast carcinoma tissue samples (n = 37) did not reveal significant differences in average values of ER, PgR, and DR. Comparison with another control set of 30 samples of dysplastic tissue of the mammary gland showed significant differences only in PgR values. Only 18% of phylloid tumor samples contained levels above cut-of-line of all three receptors (ER, PgR, DR-5,10,10 resp. fmol/ mg protein). The most frequent combination was ER+PgR+DR-(41%). As far as we know, DR in phylloid breast tumors have never been examined before. In approximately 60% of our samples we found the expression of DR, in 36% the estimated values were above 10 fmol/mg protein. Cells of the tissue not expressing DR seem to belong to a special phenotype. We found no ER+PgR- or ER-PgR-combinations in them. The group which expresses DR is characterized by a higher dispersion of PgR values.

Familial testicular cancer and developmental anomalies.

Familial occurrence belongs to factors followed in etiology and pathogenesis of testicular germ-cell tumors. Association with abnormal testicular development, or with other risk factors is relatively frequent. In our material 650 patients had been treated for testicular cancer in the period of 1981-1995. Familial occurrence was observed 7-times (1.08%), most frequently in combination with cryptorchidism. Individual families were analyzed in details, including HLA typing. On basis of the observations the supplementation of initial examination of each patient with suspicious testicular cancer with detailed familial history aimed also at the occurrence of urogenital developmental anomalies and tumors has been recommended. The knowledge about familial tumor occurrence in the first-degree relatives in combination with thorough testicular self-examination is being considered of great importance in the secondary prevention.

Richter syndrome with emphasis on large-cell non-Hodgkin lymphoma in previously unrecognized subclinical chronic lymphocytic leukemia.

The authors report seven cases of Richter's syndrome, i.e. of large-cell non-Hodgkin's lymphoma (NHL) arising in association with chronic lymphocytic leukemia (CLL). Six patients had the recently recognized variant of this syndrome, occurring in patients with previously undiagnosed subclinical CLL. All patients were treated with aggressive chemotherapy and a complete response of large cell NHL was achieved in 4/7. A complete response of NHL was observed in 3 out of 6, and a partial response in 2/6 patients with simultaneous occurrence of subclinical CLL and large cell NHL (response rate 5/6). Our findings might suggest that patients with Richter syndrome occurring in previously undiagnosed subclinical CLL could represent a better prognostic group in the overall population of patients with large cell NHL transformation of CLL.

Possible role of indoor environment and coal combustion emission in lung carcinogenesis in Fuyuan County, China.

Fuyuan Country, in Yunnan Province, China has an extremely high lung cancer mortality both in males and non-smoking females. Out of 5768 deaths, 588 patients died of malignant diseases. Lung cancer was the number one cause of death among malignant diseases both in males and females. The rate of lung cancer death to the whole of malignant diseases was 56.2% for males and 55.0% for females. Indoor soot and combustion emission derived from smoky coal produced in northern Fuyuan exhibited high mutagenic activities against Salmonella typhimurium TA98 strain in Ames test. Resected lung tissues derived from the patients with lung cancer in Fuyuan contained significantly higher concentrations of benzo(a)pyrene than those in Japan, both in males and females (i.e., 608.7 +/- 477.1 pg/dry weight for samples of the patients in Fuyuan, 180.1 +/- 104.5 for Japanese non-smokers, and 207.5 +/- 98.8 for Japanese heavy smokers, respectively). These results suggest that mutagenic chemicals contained in coal as well as indoor environment may have a great influence on lung carcinogenesis in Fuyuan, Yunnan Province, China.

Increasing occurrence of oropharyngeal cancers among males in Slovakia.

The gradual decline of oropharyngeal cancers in postwar period was followed by their rapid increase during recent two decades among males in Slovakia. Overall age-adjusted incidence rates of cancers of oral cavity and pharynx increased from 4.5 in 1968-1970 to 20.7 in 1990-1992 and corresponding mortality rates from 2.8 to 14.0 per 100,000 males. Oropharyngeal cancers have recently accounted for 6.5% of all newly diagnosed cancers yearly and present the fourth most frequent cancer site among males in this country. The cancers of tongue, floor of mouth, oropharynx and hypopharynx are responsible for the dramatic increase of this combined site in males. The culmination of the age-specific incidence and mortality rates of these cancers in the age groups 40-59 confirms the leading role of middle-aged men in their increase and dominant position. The occurrence of cancers of major salivary glands and nasopharynx in males, as well as the incidence and mortality rates of all oropharyngeal cancers in females remained very low and an unchanged (less than 1% of total). Increasing and extremely high incidence and mortality rates from oropharyngeal cancers among males in Slovakia require more effective primary prevention, above all substantial reduction of smoking.

Expression of 65-kDa oncofetal protein in experimental hepatoma after anticancer therapy.

We have tested the expression of a 65-kDa oncofetal protein (p65) after combined treatment with menadione and methotrexate in hamsters transplanted with Kirkman-Robins hepatoma. The treatment of tumor-bearing animals with these compounds significantly inhibited both the tumor development and the expression of p65. This inhibition in tumor tissue was calculated from densitograms of Western blots. The inhibition of p65 expression was also confirmed in the serum of hepatoma bearing animals by using solid-phase radioimmunoassay (RIA) to quantify the specificity of polyclonal antibodies to fetal p65 molecules. Additionally, p65 was shown to localize both in cytoplasm and in the nuclear extracts prepared from hepatoma tissue.

Increased efficacy of aphidicolin killing of human neuroblastoma cells in vitro by encapsulation in liposomes.

Aphidicolin is a tetracyclic diterpene antibiotic which kills human neuroblastoma cells (NB) in vitro while it has no significant effect on the viability of different human cell types including normal embryonal cells. In the present study, we tested whether aphidicolin encapsulated in liposomes kills NB cells with the efficacy superior to that of unencapsulated aphidicolin. The drug was entrapped in vesicles composed of phosphatidylcholine, phosphatidylserine and cholesterol in a molar ratio of 83:5:12. The treatment with encapsulated aphidicolin at a concentration of 200 nmol for 5 days killed all cells of three human NB cell lines. In contrast, at least 30% of the cells survived 5 days of treatment with 200 nmol unencapsulated aphidicolin. The results showed that aphidicolin killing of human NB cells may be increased by encapsulation in liposomes.

Preclinical comparison of bis-diketopiperazine-propane (dexrazoxane) and bis-diketopiperazine-ethane (antimet) on the adriamycin-cardiotoxic effect.

A cardiotoxic effect induced by adriamycin (by repeated i.v. administration to experimental rats in 7-day intervals of administration) begins to be manifested in the ECG record by prolongation of the S alpha T segment between days 14 and 20, on day 30 it is statistically significant. By means of this index, the known protective effect of dexrazoxane (the preparation Cardioxan) against adriamycin cardiotoxicity has been successfully confirmed in a four-week experiment. A comparative study (using the identical frequency of the dosing scheme and S alpha T segment as the decisive parameter) has revealed that antimet-as another original substance of the diketopiperazines group-also involves (though less significantly) protective effects against the toxic action of adriamycin.

Ascorbic acid and 6-deoxy-6-chloro-ascorbic acid: potential anticancer drugs.

The role of ascorbic acid (AA) in prevention and suppression of carcinogenesis has been known for a long time. It was also found that AA may inhibit the growth of some tumor cells in vitro and in vivo. We examined the influence of ascorbic acid and 6-chloro-6-deoxy ascorbic acid (6-Cl-AA) on the growth of various human cell lines: lung fibroblasts (Hef), ovarian adenocarcinoma (OVCAR), colon adenocarcinoma (HT-29), laryngeal carcinoma (HEp2) cells, HEp2 cells resistant to vincristine (HEp2VA3), cervical carcinoma (HeLa) cells, HeLa cells resistant to cisplatin (Helacis), breast adenocarcinoma (SK-BR-3) cells, and SK-BR-3 resistant to doxorubicin (SK-BR-3-Dox), as well as mouse fibroblasts L929, mouse melanoma B16 (Mel B16) cells and Chinese hamster fibroblasts (V79). Both drugs arrested the growth of: HeLa, SK-BR-3, SK-BR-3-Dox, L929, and Mel B16 cells, but did not influence the growth of others: Hef, OVCAR, HEp2, HEp2VA3 and V79. 6-Cl-AA suppressed more the proliferation of HeLacis, SK-BR-3-Dox and Mel B16 cells than AA, while AA was active only against HT-29 cells. Inhibitory effect of 6-Cl-AA was confirmed by the in vivo experiments on solid melanoma B16 tumors. Our results indicate that AA and 6-Cl-AA could serve as potential antitumor agents, especially against some tumor cells resistant to chemotherapy.

The radiosensitivity of human malignant melanomas evaluated by cytokinesis-block micronucleus assay.

Cytokinesis-block micronucleus assay (CB-MNA) was applied for comparison of radiation sensitivity of 25 human malignant melanomas in primary culture. Cells obtained from tumor specimens were irradiated (0-4.Gy) on dishes, incubated with cytochalasin B (2 micrograms/ml) to block cytokinesis, stained in situ and micronuclei (MN) scored in binucleate cells (BNC). Proportions of BNC in nonirradiated controls after fixed time of incubation (96 h) ranged from 2.3 to 38% indicating great differences (C.V. = 74%) in proliferative activity among tumors evaluated. No correlation was observed between proliferative activity and susceptibility of cells to induction of MN by radiation. The great inter-tumor heterogeneity was observed in respect of radiation sensitivity expressed either as normalized (Net) frequency (Fq) of BNC with MN or as number of MN per BNC. Both endpoints differed widely at 2 Gy and 4 Gy as well (Net FqBNC with MN = 0.28-25.4% or 1.5-45% and MN/BNC = 0.004-0.309 or 0.013-0.593 respectively at 2 Gy and 4 Gy) with coefficients of variation ranging from 44 to 57%. Extreme difference in MN frequency was also observed between one primary tumor and its metastasis indicating intra-tumor heterogeneity. Our results suggest that CB-MNA may contribute some clinically useful information for discriminating tumors that will eventually respond to radiotherapy and those that will probably not. However, studies aimed at comparison of MN induction in vitro with clinical radioresponsiveness of malignant melanomas are urgently required.

Radiosensitivity of different aged human lymphocytes following electron irradiation in vitro.

Cytochalasin B-blocking micronucleus test and chromosomal aberration analysis were used in this study to estimate the yield of individual variability in radiation response of different aged human lymphocytes. Both analyses were performed in three groups of adults, aged 18-65 years, on two sampling times, following irradiation by therapeutical dose of 2 Gy e- in vitro. No statistically significant difference in the induced yield of exchange aberrations between individuals under consideration was found. The yield of total aberration data showed greater variability and was statistically significant in the oldest group against two other adult groups. Regarding to fixation times no statistically significant differences in the induced yield of chromosomal aberrations (exchanges as well as total aberrations) were observed. The study has shown a slight increase in spontaneously occurring micronuclei with age. Almost equal mean number of radiation induced micronuclei was observed in the groups of adults aged 18-20 and 45-55 years. The highest mean number was observed in the oldest group. Evident variation in number of radiation induced micronuclei among individuals from the same age group was observed. The results of micronuclei assay for all individuals under consideration show statistically significant difference in the yield of radiation-induced micronuclei regarding the second fixation time. This study has shown that cytochalasin-B blocking micronucleus test is more sensitive assay than chromosomal aberration analysis for the estimation of individual radiosensitivity.

Comparative study of blood insulin levels in breast and endometrial cancer patients.

Blood insulin level was measured in 113 breast cancer (BC) patients, 18 endometrial cancer (EC) patients, and 35 women with benign breast disease (BBD), after fasting and after 120 min of oral glucose tolerance test (OGTT). A significant increase in reactive insulin level was shown in postmenopausal BC patients with abdominal obesity (waist/hip ratio > 0.85) and no differences in insulin level were found between BC and BBD patients. Menstrual status and overweight (Quetelet index) did not influence significantly blood insulin concentration in BC patients, but the basal insulin level was lower in those patients who had been moderate smokers. In EC patients, the level of insulin after fasting and following 120 min OGTT was much higher than in BC and BBD patients although they had a similar body mass to these groups of patients. The effect of age on insulin secretion in BC patients is discussed as well as the possible causes and consequences of hyperinsulinemia developing in EC and BC patients.

Prognostic value of DNA ploidy in breast cancer stage I-II.

The DNA content of paraffin-embedded tumor tissue has been measured by flow cytometry in 169 patients with operable breast cancer Stage I-II. The medium follow-up period was 123 months. Aneuploid primary tumors were found in 49% of patients. Tumor ploidy significantly correlated with histological type of tumor (p < 0.05), whereas no clear correlation between DNA ploidy and tumor size, histological grade and lymph node involvement was found. After 10-year follow-up, recurrence-free survival (RFS) of patients with diploid tumors was slightly better than the survival of those with aneuploid tumors, but the difference was not statistically significant (p = 0.39). In a Cox multivariate analysis only the axillary lymph node involvement and tumor size proved to be independent prognostic factors for recurrence, whereas DNA ploidy lost its prognostic value already in the univariate analysis. Therefore, we can conclude that the information on DNA ploidy, obtained from archival material, does not contribute significantly to better discrimination between good-risk and poor-risk operable breast cancer patients.

Differential chemosensitivity of leukemic cells in the myeloid and lymphoid phases of stem cell leukemia (a case report).

A five-year-old girl, initially diagnosed as having acute lymphoblastic leukemia (ALL; FAB-L1) relapsed with ALL 4 months after completion of chemotherapy (BFM 83). The initial ALL presentation and subsequent ALL relapse were analyzed using conventional morphology, cytochemistry, cytogenetics and immunophenotyping. The results were consistent with a diagnosis of B-lymphocyte precursor ALL. Bone marrow leukemic cells revealed a 46, XX karyotype at diagnosis and a 46, XX, del(7) (q22; qter) when the girl first relapsed. The case was managed with a BFM REZ-ALL 90 protocol. Upon completion of the first cycle of the protocol, severe myelosuppression developed. This was treated with GM-CSF. Three days later, however, GM-CSF was stopped because the WBC reached 1.1 x 10(9) per liter with 60% of blasts in peripheral blood. Laboratory characteristics were typical of AML. Cytogenetic analysis revealed 46, XX, del(7) (q22; qter) karyotype as before. The bcr-abl fusion gene was not detected. Myeloid blasts were placed in a culture and maintained at 37 degrees C and 7.5% CO2 for two weeks. During this period, formation of hemopoietic colonies was observed and subsequently analyzed using histology and electron microscopy. This showed that the colonies consisted of differentiating erythroid, megakaryocytic and myeloid cells. Further, the chemosensitivity of leukemic cells was examined in both "lymphoid" and "myeloid" relapse instances. While the "lymphoid" phenotype was characterized by good sensitivity to corticosteroids, a typical feature of the "myeloid" phenotype was a high resistance to corticosteroids with marginally increased sensitivity to ARA-C.