Capsaicin alleviates the imbalance in xenobiotic metabolizing enzymes and tumor markers during experimental lung tumorigenesis

Lung cancer is currently a leading cause of death all over the world. Environmental risk factors, particularly genotoxic chemicals such as polycyclic aromatic hydrocarbons (PAH), are likely to account for a much higher mortality. Xenobiotic metabolizing enzymes are potentially chief determinants in both the susceptibility to the mutagenic effects of chemical carcinogens and in the response of tumors to chemotherapy. The well-known carcinogen benzo(a)pyrene (B(a)P) of PAH family was given orally (50 mg/kg body weight) to induce lung cancer in Swiss albino mice. B(a)P induction altered the levels of cytochromes (P450, b5), activities of phase I biotransformation enzymes (NADPH-cytochrome P450 reductase, NADH-cytochrome b5 reductase and epoxide hydrolase), phase II enzymes (glutathione-S-transferase, UDP-glucuronyl transferase and DT-diaphorase), and the levels of serum tumor markers. Treatment with capsaicin (CAP) (10 mg/kg body weight) to the lung carcinoma mice restored back the activities of phase I and II biotransformation enzymes and the levels of tumor markers to near normalcy. The above findings were substantiated by immunoblotting and immunohistochemical analysis of cytochrome P450 1A1 (CYP1A1) in the lung tissues. Our present study unravels that CAP can effectively detoxify the carcinogens which discloses its anti-carcinogenic effect during experimental lung cancer.

[Peculiarities of fractional composition of serum glycoproteins in Guerin's carcinoma development under condition of different vitamin A provision]

The most substantial change in the ratio between glycoprotein fractions distributing in the blood serum of rat under conditions of different vitamin A provision (0.50-0.70 micromol/L) are observed; they are characteristic of gamma-globulin, haptoglobin and alpha 1-acid glycoprotein; the intensity of colouring of their bars decreases on serum electrophoregrammes. At the same time, the decline of intensity of bar coloration of ceruloplasmin fraction takes place under the conditions of middle vitamin A deficiency (0.35-0.50 micromol/L) while that of transferrin takes place at marginal A-deficient state (< 0.35 micromol/L). In latent and logarithmic periods of Guerin's carcinoma growth, regardless of conditions of different vitamin A provision, the intensity of bars colouring, on electrophoregrammes, which correspond to immunoglobulin, haptoglobin, ceruloplasmin alpha2-Macroglobulin, alpha 1-acid glycoprotein and alpha1-antytrypsyn, increases. In a stationary period of tumour growth a decrease of coloration intensity of gamma- and alpha2-globulin fractions is observed.

[Prognostic significance of lysosomal cysteine proteases in the estimation of the effectiveness of the antitumorigenic therapy]

The influence of the untitumor drugs, cyclophosphamide (CPA) and nitrosomethylurea (NMM) on the activity of lysosomal cysteine proteases cathepsin B and L in the tumor tissue was studied. Regression or reduction in the rate of growth of LS and RLS (drug sensitive and resistant sarcomas, respectively) during injection of CPA or NMM was accompanied by the increase in the activity of cysteine proteases cathepsin B and L in the tumor tissue. The increase of cathepsin B and L activity in the tumor tissue was correlated with the therapeutic effect of the used drugs. Data obtained suggest that cathepsin B and L activity in the tumor tissue have a prognostic significance for the effectiveness of antitumor therapy.

Redefining the target again: chemotherapeutics as vascular disrupting agents?

In this issue of Cancer Cell, Shaked et al. (2008) provide novel mechanistic evidence that some chemotherapeutics induce circulating endothelial progenitor (CEP) mobilization with subsequent homing to tumor vasculature. Addition of an anti-VEGFR2 antibody increased antitumor activity only in combination with CEP-mobilizing chemotherapeutics. Here we discuss the implications of this work.

Comparative studies of the effects of Tabebuia avellanedae bark extract and beta-lapachone on the hematopoietic response of tumour-bearing mice

The effects of Tabebuia avellanedae (TACE), traditionally prescribed in the treatment of cancer, and the naphtoquinone beta-lapachone (beta-lap) on the growth and differentiation of granulocyte and macrophage progenitor cells (CFU-GM) were studied in Ehrlich ascites tumour-bearing mice. Myelosuppression concomitant with increases in spleen CFU-GM and in serum colony-stimulating activity (CSA) were observed in these animals. Treatment with TACE (30-500 mg/kg) and beta-lap (1-5mg/kg) reversed these effects in a dose-dependent manner. The optimal biologically active doses of 120 mg/kg TACE and 1mg/kg beta-lap prolonged life span of tumour-bearing mice, both producing the same rate of extension in the duration of survival. Toxic manifestations were produced by the higher doses of beta-lap in normal and tumour-bearing mice. In spite of similarities between treatments, TACE concentrations used to treat the animals presented no traces of beta-lap, as measured by TLC and HPLC analyses. Our findings suggest that the antitumour effect of TACE and beta-lap, acting synergistically with other factors, such as specific cytokines, may result from enhanced macrophage activation against tumour cells. In addition, it is clear from our results that hematopoietic disorders produced by tumours are an important pathological condition that must be considered in drug development.

Dichlorotetra-mu-Isobutyratodirhenium(III): enhancement of cisplatin action and RBC-stabilizing properties

BACKGROUND

Previous investigations showed antitumor properties of dirhenium carboxylate introduced to tumor-bearing animals at high doses. The development of liposomal forms of rhenium substances and the activity of dichlorotetra-mu-isobutyratodirhenium (III) (Re1) in stabilizing red blood cells (RBC) shown in experiments in vitro and in vivo enabled the use of this substance in the present study. The aim of the work was to investigate the antitumor properties of Re1 in liposomal form alone and together with cisplatin, and to analyze whether Re1 can support RBC in the model of tumor growth.

MATERIALS AND METHODS

Introduction of a single dose of cisplatin and liposomal forms of Re1 according to a scheme of antioxidant therapy was tested in a rat model of specific Guerink (T-8) carcinoma. The dynamics of tumor growth, weights of isolated tumors, RBC morphology and hemoglobin levels were measured.

RESULTS

The cluster rhenium compound, Re1, with carboxylic ligands had its own anticancer properties and enhanced cisplatin action on tumor growth. Introduction of the rhenium substance led to an increase in quantities of normal RBC forms in blood of tumor-bearing animals. Possible mechanisms of enhancement of cisplatin efficiency by Re1 according to its structural peculiarities are discussed.

CONCLUSION

A novel antitumor system including the use of a cluster rhenium compound and cisplatin is presented. Enhancement of cisplatin action and antitumor properties of rhenium compound initially took place due to the properties of quadruple metal-to-metal bond between two atoms of rhenium.

Establishment of the enzyme-linked immunosorbent assay system to detect the amino terminal secretory form of rat Erc/Mesothelin

By representational difference analysis, we previously identified the rat Erc (Expressed in renal carcinoma) gene that was more abundantly expressed in the renal carcinoma tissues of Eker rats than in the rat normal kidney. In this study, we raised antibodies against the amino-terminal portion of the rat Erc, and demonstrated the existence of a approximately 30-kDa secretory form in the supernatant of cultured cells derived from rat renal carcinoma. The enzyme-linked immunosorbent assay (ELISA) system using these antibodies detected high concentrations of this form in the sera of Eker rats bearing renal carcinomas, and in the sera of rats transplanted with mesothelioma cells. Mesothelin, a human homolog of the rat Erc, was recently reported to be a serum marker of malignant mesothelioma. The prognosis of mesothelioma is poor and there is no effective treatment at present. There are several rat model systems of mesothelioma that may be promising tools in the development of an antimesothelioma treatment. We hope our ELISA to detect the soluble form of rat Erc/Mesothelin is useful in the rat model system to exploit the antimesothelioma therapy to be used in human cases.

The platelet aggregation-inducing factor aggrus/podoplanin promotes pulmonary metastasis

Tumor cell-induced platelet aggregation has been reported to facilitate hematogenous metastasis. Aggrus/podoplanin is a platelet aggregation-inducing factor that is up-regulated in a number of human cancers and has been implicated in tumor progression. We studied herein the role of Aggrus in tumor growth, metastasis , and survival in vivo. Aggrus expression in Chinese hamster ovary cells promoted pulmonary metastasis in both an experimental and a spontaneous mouse model. No differences in the size of metastatic foci or in primary tumor growth were found in either set of mice. Aggrus expressing cells , which were covered with platelets, arrested in the lung microvasculature 30 minutes after injection. In addition, lung metastasis resulting from Aggrus expression decreased the survival of the mice. By generating several Aggrus point mutants, we revealed that point mutation at the platelet aggregation-stimulating domain of Aggrus(Thr34 and Thr52) obliterated both platelet aggregation and metastasis. Furthermore, administration of aspirin to mice reduced the number of metastatic foci. These results indicate that Aggrus contributes to the establishment of metastasis by promoting platelet aggregation without affecting subsequent growth. Thus, Aggrus could serve as an ideal therapeutic target for drug development to block metastasis.

[Monitoring changes of serum protein markers in metastatic colorectal carcinoma model]

OBJECTIVE

To investigate the changes of several protein markers in a metastatic colorectal carcinoma model by serum proteomic analysis.

METHODS

The pEGFP-N1 plasmid with enhanced expression of green fluorescence protein (EGFP) was transfected into human colon carcinoma cell line SW480 to obtain a stable SW480-EGFP cell line, the SW480-EGFP cells were then injected subcutaneously into nude mice. The harvested tumor cells were implanted orthotopically into the colon of the nude mice. Real-time tumor growth and metastasis formation were visualized by whole-body fluorescent imaging system. Serum samples at different metastatic stages were collected and differential proteomic profiles were investigated by two-dimensional gel electrophoresis (2DE) and matrix-assisted laser absorption/ionization time of flight mass spectrometry (MALDI-TOF MS).

RESULTS

The SW480- EGFP cells enabled to express EGFP stably. The rates of subcutaneous and orthotropic tumor formation were 100%. The metastasis rates to local lymph nodes, liver and lung were 100%, 40% and 30%, respectively. Furthermore, 5 differentially expressed proteins were analyzed by serum proteome technologies, including haptoglobin alpha chain, apolipoprotein E, apolipoprotein A-IV, Ig kappa chain V region chain L and transferrin.

CONCLUSIONS

Visualized metastatic model of colorectal carcinoma was successfully established. Several differentially expressed serum proteins collected at different stages after the occurrence of metastasis were identified. These differentially expressed proteins may be candidate serum biomarkers for diagnosis and therapeutic evaluation of colorectal carcinoma metastasis.

Antitumor activity ofHypericum hookerianum against DLA induced tumor in mice and its possible mechanism of action

A large number of plants belonging to the genus Hypericum and their phytoconstituents are known to possess potent anticancer nature. Earlier studies from our laboratories indicated a strong cytotoxic nature of the methanol extract of Hypericum hookerianum stem (MEHH). In the present study, the in vivo antitumor activity of MEHH against the Dalton's lymphoma ascitic (DLA) model was determined at 100 and 200 mg/kg body weight given orally for 10 days. The results indicate that administration of the extract not only increased the survival of animals with ascites tumor, decreased the body weight induced by the tumor burden and reduced the packed cell volume and viable tissue cell count, but also altered many hematological parameters changed during tumor progression indicating the potent antitumor nature of the extract. Hematological and biochemical analysis were carried out to prove the anticancer and antioxidant nature of the extract.

A novel immunotherapeutic modality with direct hemoperfusion targeting transforming growth factor-beta prolongs the survival of tumor-bearing rats

Immune responses are frequently depressed in patients with cancer. One of the reasons for a poor immune response is the presence of increased levels of immunosuppressive substances associated with tumor growth. Transforming growth factor-beta (TGF-beta), a representative immunosuppressive cytokine, plays various roles in the progression of cancer. To remove immunosuppressive substances from tumor-bearing hosts, we developed an immunosuppressive substance adsorption (ISA) column for direct hemoperfusion (DHP) treatment. It is filled with extra-fine fibers that can adsorb TGF-beta. In this study, we investigated the effects of this DHP treatment on serum levels and activities of TGF-beta, cellular immune responses, and anti-tumor effects in KDH-8 (TGF-beta-producing hepatocellular carcinoma cell line)-bearing rats. We further studied the ability of ISA fibers to adsorb tumor-associated immunosuppressive cytokines [TGF-beta, interleukin (IL)-6 and vascular endothelial growth factor (VEGF)] in samples of body fluids obtained from patients with metastatic cancer. DHP treatment decreased serum levels and activities of TGF-beta in tumor-bearing rats and restored T lymphocyte response to mitogen. Tumor growth in rats treated by DHP was significantly slower than that in untreated rats. The survival time of treated rats was significantly longer than that of untreated rats. The concentrations of TGF-beta, IL-6, and VEGF in the samples of human body fluids were decreased markedly by in vitro treatment with ISA fibers. These results suggest that DHP treatment with an ISA column, which removes TGF-beta and other immunosuppressive substances from the sera of tumor-bearing hosts, is potentially a new immunotherapeutic strategy for cancer.

Organ-specific metastatic tumor cell adhesion and extravasation of colon carcinoma cells with different metastatic potential

Adhesive and invasive characteristics appear to be crucial for organ-specific metastasis formation. Using intravital microscopy we investigated the relation between the metastatic potential of colon carcinoma cells and their adhesive and invasive behavior during early steps of metastasis within microvasculatures of rat liver, lung, intestine, skin, muscle, spleen, and kidney in vivo. Colon carcinoma cells with low (HT-29P), intermediate (KM-12C), and high (HT-29LMM, KM-12L4) metastatic potential were injected into nude or Sprague-Dawley rats. Initial interactions with host organ microvasculatures were semiquantitatively analyzed throughout 20 to 30 minutes. Circulating cells passed microvessels in all observed organs without size restriction. All cell lines showed high adhesion rates, independent from their metastatic potential, within liver and lung but very rarely in other organs. Diameters of involved microvessels were larger than diameters of adherent tumor cells. Cell extravasation of highly metastatic HT-29LMM and KM-12L4 cells into liver parenchyma was significantly higher compared to low metastatic cells (P<0.05). Our results indicate that colon carcinoma cells can arrest in target organs without size restriction. Cell adhesion of circulating tumor cells occurred in metastatic target organs only, likely attributable to specific interactions. Migration into target organs correlated with their metastatic potential.

Method for improved accuracy in endogenous urea recovery marker calibrations for microdialysis in tumors

INTRODUCTION

Urea has been proposed as an endogenous recovery marker for microdialysis for absolute concentration calculations of analytes in microdialysis samples. Previously we demonstrated a linear relationship between urea concentrations in a rat mammary carcinoma and that in plasma, validating its use as a recovery marker for that particular tumor. In this paper, we have extended the validation to two other tumor lines, thereby providing confidence that the calibration is constant across tumor types. To improve the accuracy in the determination of the plasma/tumor urea relationship from no net flux calibrations, we extended the range of the calibration by adding exogenous urea to tumor bearing animals. This method enabled more accurate calculations of absolute recovery from plasma and dialysate urea concentrations. We confirm that by using this method the calibration is valid across three different tumor lines. The existence of a common calibration between tumors provides rationale for using plasma urea as a recovery marker for clinical trials. The existence of a common calibration between tumor types bypasses the need to perform time consuming calibrations for each patient. This makes the procedure much more practical for clinical studies.

METHODS

The no net flux technique was used to determine the plasma vs. tumor urea relationship for the R3230Ac mammary carcinoma, 9 L glioma, and a fibrosarcoma (FSa), grown in Fischer 344 rats. Plasma urea was stably increased beyond the normally occurring concentration for some of the data points by subcutaneous bolus administration to extend the range of data for the no net flux calibration.

RESULTS

Urea recovery was unaffected by plasma urea concentration and was consistent with other reported values. The relationship between plasma and tumor urea was fit by a line, and linear regressions of the data with the extended plasma urea range had better R2 values than we reported previously. Statistical comparison of the regressions suggests that within reasonable uncertainty limits, they are the same for the different tumor types.

DISCUSSION

Increasing the plasma urea concentration range for no net flux calibrations of urea as an endogenous recovery marker in tumors resulted in more accurate determination of the plasma/tumor urea relationship. A single linear regression may describe the relationship between plasma and tumor urea concentration across tumor lines for a given set of microdialysis parameters.

Role of STAT3 and NFκB signaling in the serum factor-induced apoptosis in AK-5 cells

AK-5, a rat histiocytoma, is rejected in about 70% of the syngeneic animals when injected subcutaneously. The sera from the tumor rejecting animals possess a potent factor, referred to as serum factor (SF) that induces apoptosis in AK-5 tumor cells. In the present study, we show that treatment with SF or JAK/STAT inhibitors AG490 and Piceatannol induces apoptosis to a similar extent in BC-8 (a single cell clone of AK-5) cells. Our results demonstrate downregulation of a transcription factor, STAT3, as a critical regulator of SF-induced apoptosis in BC-8 cells. SF treatment enhanced the activity of NFkappaB, another transcription factor that regulates both pro- and antiapoptotic genes. The enhanced NFkappaB activity resulted in the elevation of TRAIL and its receptor DR4, both known to induce apoptosis. Activation of death receptors in turn enhances caspase-8 activity and stimulates the downstream pathways regulating BC-8 cell apoptosis. SF induced apoptosis in BC-8 cells mediated through downregulation of STAT3 and elevated NFkappaB activity is abrogated by treatment with MAPK inhibitors-PD98059 and SB203580. Our studies therefore indicate that modulation of MAPK activity plays a central role in SF-induced death signaling pathways in BC-8 cells.

A liquid chromatographic–tandem mass spectrometric method for the determination of two selective thymidylate synthase inhibitors, BGC945 and BGC638, in mouse plasma

A LC-tandem mass spectrometry method to quantify the quinazoline-based thymidylate synthase inhibitors BGC945 and BGC638 in mouse plasma was developed. BGC945 and BGC638 were extracted from mouse plasma using protein precipitation with acetonitrile. Chromatography was performed on a Fluophase RP 5 microm, 100 mmx2.0mm i.d. column using a gradient of ammonium acetate and acetonitrile as a mobile phase with a flow rate of 0.2 mLmin(-1). The injection volume for each sample was 20 microL with a total run time of 7.5 min. This method was validated in the range 25-4000 nM (r2=0.99). The analytical assay performance showed that the method was accurate (mean intra- and inter-day assay R.E. were below 12% and 11%, respectively), reproducible (mean intra- and inter-day R.S.D. were less than 13% and 5% for all quality control levels, respectively) and sensitive (lower limit of quantification was 25 nM) in the range studied. This validated method has been used to define the first pharmacokinetic report of BGC945 and BGC638 in mice.

A high-performance liquid chromatographic assay for determination of cisplatin in plasma, cancer cell, and tumor samples

A method for determination of cis-diaminedichloroplatinum (II) (cisplatin) in ultrafiltered plasma, cell, and tumour samples is described. Cisplatin separation was carried out on a reversed-phase column using methanol-acetonitrile-water as the mobile phase. The flow rate was maintained constant at 1.6 mL/min and analysis was performed at 23 degrees C. Detection was carried out by absorbance at 254 nm. The method was linear in the range of 0.2-10 microg/mL, and the coefficients of variation were <10%. Using this technique, we measured the intracellular accumulation of cisplatin in cancer cells and in tumours of mice receiving treatment with cisplatin and evaluated the pharmacokinetics of cisplatin in nu/nu mice after intraperitoneal (i.p.) administration. The method proved to be adequate for measuring cisplatin both in vitro and in vivo and could be suitable for studies of cisplatin pharmacokinetics in animal models.

Elevated blood lactate is not a primary cause of anorexia in tumor-bearing rats

Tumor-bearing (TB) rats exhibit elevated concentrations of lactate in blood contiguous with the development of anorexia. Continuous intravenous infusion of lactate into non-TB rats reduced food intake at plasma concentrations lower than those observed in anorectic TB rats. Levels of neuropeptide Y (NPY) were elevated in the ventromedial (VMH) and dorsomedial hypothalamic regions of lactate-infused rats. The addition of the enhancer of pyruvate dehydrogenase activity, dichloroacetate (DCA), to the drinking water of TB rats (0.1-0.4%) normalized blood lactate concentration but had no significant effect on anorexia. However, the elevated concentration of NPY in the VMH of anorectic TB rats was also normalized by the DCA treatment. No alterations in regional hypothalamic levels of corticotropin-releasing factor were observed within any treatment conditions. These results suggest that, although hyperlactatemia may be involved in maintaining elevated NPY concentrations in anorectic TB rats, it does not appear to be a significant factor in the etiology of experimental cancer anorexia.

In vivo protein biotinylation for identification of organ-specific antigens accessible from the vasculature

We describe a new methodology, based on terminal perfusion of rodents with a reactive ester derivative of biotin that enables the covalent modification of proteins readily accessible from the bloodstream. Biotinylated proteins from total organ extracts can be purified on streptavidin resin in the presence of strong detergents, digested on the resin and subjected to liquid chromatography-tandem mass spectrometry for identification. In the present study, in vivo biotinylation procedure led to the identification of hundreds of proteins in different mouse organs, including some showing a restricted pattern of expression in certain body tissues. Furthermore, biotinylation of mice with F9 subcutaneous tumors or orthotopic kidney tumors revealed both quantitative and qualitative differences in the recovery of biotinylated proteins, as compared to normal tissues. This technology is applicable to proteomic investigations of the differential expression of accessible proteins in physiological and pathological processes in animal models, and to human surgical specimens using ex vivo perfusion procedures.

Alterations in hemorheological properties of erythrocytes in nude mice with erythroleukemia and the treatment effects of etoposide

The purpose of this study was to examine the changes of hemorheological properties of erythrocytes in the nude mice with erythroleukemia and the treatment effects of etoposide (VP16). Thirty mice were randomly divided into three groups: the control group (C group), injected with 1 ml saline solution, the MEL group (M group) injected with 1 ml MEL (murine erythroleukemia cell line) and the MEL + VP16 group (V group) injected with 1 ml MEL and from the 8th day after injection, 20 microl VP16 (1 microg/microl) was injected intraperitoneally every five days. One week after MEL injection, erythroblastic cells increased in the bone marrow and proerythroblasts were found in the peripheral blood, suggesting that erythroleukemia was induced. Abnormalities were also found in spleens and livers later. At around twenty days after injection, the mice in M group died and about four weeks after injection, the mice in V group also died. Compared with C group, the hemorheological indexes [the deformation index DI, orientation index (DI(or)), and the small deformation index (DI(d))], electrophoretic mobility, membrane fluidity as well as osmotic fragility of red blood cells (RBC) in M and V groups changed significantly. But after VP16 administration, the changes of above parameters in V group were less significant than those of M group. The results above suggested that intraperitoneal injection of MEL cells could cause erythroleukemia in nude mice, VP16 could alleviate the erythroleukemia symptom and improve the hemorheological properties, and could prolong V group nude mice survival.

High throughput quantitative analysis of serum proteins using glycopeptide capture and liquid chromatography mass spectrometry

It is expected that the composition of the serum proteome can provide valuable information about the state of the human body in health and disease and that this information can be extracted via quantitative proteomic measurements. Suitable proteomic techniques need to be sensitive, reproducible, and robust to detect potential biomarkers below the level of highly expressed proteins, generate data sets that are comparable between experiments and laboratories, and have high throughput to support statistical studies. Here we report a method for high throughput quantitative analysis of serum proteins. It consists of the selective isolation of peptides that are N-linked glycosylated in the intact protein, the analysis of these now deglycosylated peptides by liquid chromatography electrospray ionization mass spectrometry, and the comparative analysis of the resulting patterns. By focusing selectively on a few formerly N-linked glycopeptides per serum protein, the complexity of the analyte sample is significantly reduced and the sensitivity and throughput of serum proteome analysis are increased compared with the analysis of total tryptic peptides from unfractionated samples. We provide data that document the performance of the method and show that sera from untreated normal mice and genetically identical mice with carcinogen-induced skin cancer can be unambiguously discriminated using unsupervised clustering of the resulting peptide patterns. We further identify, by tandem mass spectrometry, some of the peptides that were consistently elevated in cancer mice compared with their control littermates.

Dose-Dependent Effects of Dietary - and -Tocopherols on Genetic Instability in Mouse Mutatect Tumors

Vitamin E in foodstuffs is a mixture of tocopherols. In mouse Mutatect tumors, a model designed to detect DNA mutations, the hypoxanthine phosphoribosyltransferase (Hprt) gene mutation frequency is associated with the number of tumor-infiltrating neutrophils and both are markedly decreased in mice fed high levels of alpha-tocopherol. Dietary alpha-tocopherol is also associated with a decrease in neutrophil-associated loss of an interleukin 8 (IL-8)-expressing transgene in this tumor model. We examined Hprt gene mutation frequency (expressed as the number of 6-thioguanine-resistant colonies per 10(5) clonable tumor cells), IL-8 transgene loss, and myeloperoxidase activity (an indirect measure of neutrophil number) in tumors from Mutatect mice fed diets supplemented with various concentrations of D-alpha-tocopherol acetate and/or D-gamma-tocopherol acetate or neither tocopherol for 4 weeks. Hprt gene mutation frequency and myeloperoxidase activity were statistically significantly lower in tumor cells from mice fed alpha-tocopherol at 50 or 100 mg/kg body weight per day than in tumor cells from mice fed 0 mg/kg body weight per day alpha-tocopherol (P<.001 for each comparison). IL-8 transgene loss occurred in 28 of 28 tumors (100%; 95% confidence interval [CI] = 86% to 100%) from mice fed alpha-tocopherol at 50 mg or less/kg body weight per day and seven of 18 tumors (39%; 95% CI = 24% to 54%) from mice fed 100 mg/kg body weight per day (P<.001, Fisher's exact test, referent groups [pooled] 0, 25, and 50 mg/kg). gamma-Tocopherol had no detectable effect on any of the three endpoints. Thus, dietary alpha-tocopherol decreases two forms of genetic instability in a dose-dependent manner in this experimental tumor model.

[Extracellular DNA fragments and DNAse activity in blood serum of rats with transplantated Guerin's carcinoma after multiple exposures to low doses of X-irradiation]

The fraction composition of extracellular free DNA (cfDNA) and activity of serum DNAses in blood of rats with the tumor transplantated against a background of the low-dose X-irradiation were investigated. Heterogeneous fragments of cfDNA and high level of DNAse activity were revealed in the serum of irradiated rats. The definite sizes of high-molecular homogenous fraction of cfDNA, which is observed in the serum of irradiated and unirradiated rats with tumor, and its presence from the first stages of tumor growth independent of serum DNAses activity show, that the emergence of this fraction is not accidental. Previous fractionated irradiation makes influence on the investigation data only on the primary stages of tumor growth.

[Effect of low-intensity laser radiation on the functional potential of neutrophilic granulocytes in blood of tumor-bearing animals]

Peripheral blood was sampled for cytochemical assay of cationic proteins from three groups of animals--intact ones, those with tumor C45 and bearers of the same tumor treated with helium-laser radiation and chemotherapy. Radiotherapy involved such manifestations of enhanced nonspecific antitumor resistance and, in particular, mobilization of the cellular component, as increased number of neutrophils containing cationic protein granules and relatively high levels of such proteins in them. Cytochemical assay of cationic proteins in neutrophil granules may serve as a criterion of nonspecific antitumor resistance assessment.

[Comparative characteristic of serpin--alpha-1 proteinase inhibitor in human and mice serum]

Serpin alpha-1-proteinase inhibitor have been studied in human subjects and in mice of different lines as acute phase reactant and during tumor development. In humans, there was no difference of serpin activity between men and women. Increased activity was noted in men with acute trauma (acute phase reaction). Comparatively to male, in female mice of different lines decreased activity of serum alpha-1-proteinase inhibitor, was shown. There was no increase of alpha-1-proteinase inhibitor activity during inflammation induced by zymosan administration in mice. alpha-1-proteinase inhibitor belongs to acute phase reactants in humans but not in mice; for mice alpha-2-macroglobulin is a more typical acute phase reactant as compared to alpha-1-proteinase inhibitor. Murine tumor development (hepatoma HA-1, lymphosarcoma LS, Lewis lung adenocarcinoma) was followed by a decreased activity of serum alpha-1-proteinase inhibitor both in successfully treated and untreated groups. According to data of literature, similar dated were obtained in humans with tumors. It was suggested that changes of expressiln of alpha-1-proteinase inhibitor by tumors and its secretion were involved in decreased activity of alpha-1-proteinase inhibitor.