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The antitumor and antimetastatic activity of dopamine D2 receptor antagonists spiperone was studied in C57BL/6 mice in a model of combined pathology (emphysema and lung cancer). Emphysema was induced by administration of LPS and cigarette smoke extract. Lung cancer was induced by injection of Lewis lung carcinoma cells into the lung. It has been shown that under conditions of combined lung pathology, spiperone prevents inflammatory infiltration and emphysematous expansion of the lungs and reduces the size of the primary tumor node, the number of metastases, and the area of the lungs affected by metastases. Spiperone reduces the number of cancer stem cells (CSCs) in the lungs and blood of mice with combined pathology. CSCs isolated from the lungs and blood of mice with combined pathology treated with spiperone had a significantly lower potential to form a tumorosphere in vitro than CSCs from untreated mice with emphysema and lung carcinoma. Thus, blockade of dopamine D2 receptors is a promising approach for correcting combined lung pathology and can be used in the development of a method for treating lung cancer in patients with emphysema. [ABSTRACT FROM AUTHOR]

The responses of tumor stem cells and various populations of CD4 and CD8 T cells of young and aged C57BL/6 mice were studied in a lung cancer model. Using Lewis lung carcinoma cell line, an orthotopic model of lung cancer was modeled. Cancer stem cells, circulating tumor cells, and various populations of CD4 and CD8 T cells in the blood and lung tissue were studied by cytometry. We revealed age-related differences in the content of various populations of CD4 and CD8 T cells in the blood and lungs of intact young and aged mice. Age-related features of the reaction of various populations of cancer stem cells and CD4 and CD8 T cells in the blood and lungs of animals in the Lewis lung carcinoma were shown. [ABSTRACT FROM AUTHOR]

Extracts from the above-ground part of the elm-leaved meadowsweet Filipendula ulmaria (L.) Maxim. in 70% ethanol were prepared by extraction using heat (FUh) and countercurrent extraction (FU). Comparative analysis of the actions of these extracts in experiments on C57Bl/6 mice with Lewis lung carcinoma (LLC) indicated that FUh had greater efficacy when used in complex therapy with cyclophosphamide (CPX). FUh (25, 50 and 100 mg/kg) in combination with CPX increased the antitumor effect of CPX against primary tumors. No significant changes were found in the development of the metastatic process in mice given CPX and 50 and 100 mg/kg FUh; FUh at a lower dose (25 mg/kg) weakened the antimetastatic activity of CPX. FU at a dose of 25 mg/kg increased the efficacy of CPX against primary tumors, while use of FU at doses of 50 and 100 mg/kg did not influence the antitumor effect of CPX. In C57Bl/6 mice with lung cancer-67, all FUh doses studied (50, 100, and 200 mg/kg) increased the antimetastatic effect of CPX. [ABSTRACT FROM AUTHOR]

The effect of low-dose radiation was studied on the growth dynamics of transfused Lewis carcinoma cells in female C57Bl/6 mice. Fourfold total fractionated irradiation was conducted at a dose of 75 mGy (at a dose rate of 0.154 Gy/min and a voltage of 200 kV), starting from day 10 after the transplantation with a four-day interval. On days 14 and 22, a group of mice was euthanized to study the expression levels of genes and noncoding RNAs (microRNAs and long noncoding RNAs) in tumor cells, as well as in normal tissues (bone marrow, liver, spleen, thymus). The total RNA was obtained, and complementary DNA was synthesized according to the manufacturer's protocol. After that, a real-time PCR reaction was performed using the SYBR Green I dye (Thermo Scientific, United States) or a TaqMan probe and specific primers. Genes and noncoding RNAs were divided into groups of oncogenes and oncosuppressors according to scientific research. In the group of irradiated mice, a decrease in the tumor growth rate was observed, mainly from day 20, accompanied by a change in the activity of the studied genes. The ratio of the activity of oncosuppressors to oncogenes was calculated for the obtained tissues. These fractions were 0.5 for the tumor, 10.7 for the bone marrow, and 2.4 for the spleen and thymus. Thus, it can be stated that in the tumor there was a particularly pronounced activation of oncogenes compared to the activity of oncosuppressors, while the opposite effect was observed in normal tissues. [ABSTRACT FROM AUTHOR]

The results of studying the effect of the anthocyanin-containing complex from Sorbus aucuparia L. on the main indicators of erythropoiesis in the blood and bone marrow of mice with Lewis lung carcinoma against the background of doxorubicin administration were presented. It was shown that administration of the anthocyanin-containing complex from S. aucuparia L. to animals with the tumor prevented the development of anemic syndrome by promoting regeneration of the erythropoiesis after its depletion caused by single administration of a cytostatic agent. [ABSTRACT FROM AUTHOR]

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a repair enzyme for 3′-end DNA lesions, predominantly stalled DNA–topoisomerase 1 (Top1) cleavage complexes. Tdp1 is a promising target for anticancer therapy based on DNA damage caused by Top1 poisoning. Earlier, we have reported about usnic acid enamine derivatives that are Tdp1 inhibitors sensitizing tumor cells to the action of Top1 poison (Zakharenko in J Nat Prod 79:2961−2967, 2016). In the present work, we showed a sensitizing effect of an enamine derivative of usnic acid (when administered intragastrically) on Lewis lung carcinoma in mice in combination with topotecan (TPT, Top1 poison used in the clinic). In the presence of the usnic acid derivative, both the volume of the primary tumor and the number of metastases significantly diminished. The absence of acute toxicity of this compound was demonstrated, as was the importance of the method of its administration for the manifestation of the sensitizing properties. [ABSTRACT FROM AUTHOR]

Background: Berberine (Ber) is a herbal alkaloid with pharmacological activity in general and a high anticancer potency in particular. However, due to its low bioavailability, the difficulty in reaching a target and choosing the right dose, there is a need to improve approaches of Ber use in anticancer therapy. In this study, Ber, noncovalently bound to a carbon nanostructure C60 fullerene (C60) at various molar ratios of the components, was explored against Lewis lung carcinoma (LLC). Methods: C60–Ber noncovalent nanocomplexes were synthesized in 1:2, 1:1 and 2:1 molar ratios. Ber release from the nanocomplexes was studied after prolonged incubation at different pH with the liquid chromatography–mass spectrometry analysis of free Ber content. Biological effects of the free and C60-complaxated Ber were studied in vitro towards LLC cells with phase-contrast and fluorescence microscopy, flow cytometry, MTT reduction, caspase activity and wound closure assays. The treatment with C60–Ber nanocomplex was evaluated in vivo with the LLC-tumored C57Bl mice. The mice body weight, tumor size, tumor weight and tumor weight index were assessed for four groups, treated with saline, 15 mg C60/kg, 7.5 mg Ber/kg or 2:1 C60-Ber nanocomplex (15 mg C60/kg, 7.5 mg Ber/kg). Results: Ber release from C60–Ber nanocomplexes was promoted with medium acidification. LLC cells treatment with C60–Ber nanocomplexes was followed by enhanced Ber intracellular uptake as compared to free Ber. The cytotoxicity of the studied agents followed the order: free Ber < 1:2 < 1:1 < 2:1 C60–Ber nanocomplex. The potency of cytotoxic effect of 2:1 C60–Ber nanocomplex was confirmed by 21.3-fold decrease of IC50 value (0.8 ± 0.3 µM) compared to IC50 for free Ber (17 ± 2 µM). C60–Ber nanocomplexes induced caspase 3/7 activation and suppressed the migration activity of LLC cells. The therapeutic potency of 2:1 C60–Ber nanocomplex was confirmed in a mouse model of LLC. The tumor growth in the group treated with 2:1 C60–Ber nanocomplex is suppressed by approximately 50% at the end of experiment, while in the tumor-bearing group treated with free Ber no therapeutic effect was detected. Conclusions: This study indicates that complexation of natural alkaloid Ber with C60 may be a novel therapeutic strategy against lung carcinoma. [ABSTRACT FROM AUTHOR]

Expression of tumor-associated protein beta-III tubulin (TUBB3) was evaluated quantitatively by immunofluorescence analysis using flow cytometry in lung tissue of intact animals and on day 11 after the Lewis lung carcinoma transplantation as well in lung metastasis tissue and in visually "normal" surrounding tissue. It was shown that the tumor is characterized by a high TUBB3 expression, while also the expression of the marker was detected in both variants of visually normal lung tissue: it was lower than in tumor tissue but significantly higher than in lung tissue of intact animals. The detection of TUBB3 outside the tumor indicates that the tissue appeared to be normal has already involved in malignancy and this supports the hypothesis that tumor-associated protein TUBB3 can be used as a molecular marker of local tumor spread. [ABSTRACT FROM AUTHOR]

Three extracts were produced from the above-ground part of the meadowsweet Filipendula ulmaria (L.) Maxim. using water, 40% ethanol, and 70% ethanol. Comparative assessment of their actions on the development of Lewis lung carcinoma (LLC) in C57Bl/6 mice showed that isolated administration led to inhibition of the development of the metastatic process by meadowsweet extracts prepared with water and 70% ethanol, with no effect on growth of the primary tumor. Comparative evaluation of the effects of meadowsweet extracts on the antitumor activity of cyclophosphamide (CP) in relation to primary tumors revealed no change in the efficacy of the cytostatic agent. Inclusion of meadowsweet extracts at doses of 25 and 50 mg/kg in the therapeutic regimen of mice with LLC produced significant increases in the antimetastatic action of CP using the aqueous extract (the indexes of inhibition of metastasis (IIM) were 75% and 98%). Meadowsweet extract prepared with 40% ethanol had no effect on the development of the tumor process in mice with LLC or the efficacy of CP treatment. [ABSTRACT FROM AUTHOR]

The antitumor activity of the binuclear form of dinitrosyl iron complexes with mercaptosuccinate administered intravenously was studied in murine models of solid tumors: Lewis lung carcinoma and Acatol adenocarcinoma. The maximum effect, suppression of tumor growth by 65% in comparison to the control for Lewis carcinoma, was observed for a course of six intravenous injections in a daily dose of 2.5 μM/kg administered every 2 or 3 days over the period of days 1–17 after tumor transplantation. [ABSTRACT FROM AUTHOR]

Meadowsweet extract was prepared by heating the aerial part of Filipendula ulmaria (L.) Maxim. in EtOH (70%). Experiments in C57BL/6 mice with Lewis lung carcinoma (LLC) showed that the extract at doses of 50 and 100 mg/kg exhibited dose-dependent antimetastatic action. Combined treatment of animals with LLC using cyclophosphamide and meadowsweet extract at doses of 50 and 100 mg/kg increased the antitumor effect of the cytostatic drug. [ABSTRACT FROM AUTHOR]

Lung cancer is currently the leading cause of cancer-related mortality with very limited effective therapy. Screening of a variety of traditional Chinese medicines (TCMs) for their capacity to inhibit the proliferation of human lung cancer A549 cells and to induce the in vitro maturation of human DCs led to the identification of cryptotanshinone (CT), a compound purified from the TCM Salvia miltiorrhiza Bunge. Here, CT was shown to inhibit the proliferation of mouse Lewis lung carcinoma (LLC) cells by upregulating p53, downregulating cyclin B1 and Cdc2, and, consequently, inducing G2/M cell-cycle arrest of LLC cells. In addition, CT promoted maturation of mouse and human DCs with upregulation of costimulatory and MHC molecules and stimulated DCs to produce TNFα, IL-1β, and IL-12p70, but not IL-10 in vitro. CT-induced maturation of DCs depended on MyD88 and also involved the activation of NF-κB, p38, and JNK. CT was effective in the treatment of LLC tumors and, when used in combination with low doses of anti-PD-L1, cured LLC-bearing mice with the induction of subsequent anti-LLC long-term specific immunity. CT treatment promoted T-cell infiltration and elevated the expression of genes typical of Th1 polarization in LLC tumor tissue. The therapeutic effect of CT and low doses of anti-PD-L1 was reduced by depletion of CD4 and CD8 T cells. This paper provides the first report that CT induces immunological antitumor activities and may provide a new promising antitumor immunotherapeutic. [ABSTRACT FROM AUTHOR]

Introduction: Over the last decade, atomic force microscopy (AFM) has played an important role in understanding nanomechanical properties of various cancer cell lines. This study is focused on Lewis lung carcinoma cell tumours as 3D multicellular spheroid (MS). Not much is know about the mechanical properties of the cells and the surrounding extracellular matrix (ECM) in rapidly growing tumours. Methods: Depth-dependent indentation measurements were conducted with the AFM. Force-vs.-indentation curves were used to create stiffness profiles as a function of depth. Here studies were focused on the outer most layer, i.e., proliferation zone of the spheroid. Results: Both surface and sub-surface stiffness profiles of MS were created. This study revealed three nanomechanical topographies, Type A-high modulus due to collagen fibers, Type B-high stiffness at cell membrane and ECM interface and Type C-increased modulus due to cell lying deep inside matrix at a depth of 1.35 μm. Both Type and Type-B topographies result from collagen-based structures in ECM. Conclusion: This study has first time revealed mechanical constitution of an MS. Depth-dependent indentation studies have the revealed role of various molecular and cellular components responsible for providing mechanical stability to MS. Nanomechanical heterogeneities revealed in this investigation can shed new light in developing correct dosage regime for collagenase treatment of tumours and designing better controlled artificial extracellular matrix systems for replicating tissue growth in-vitro. [ABSTRACT FROM AUTHOR]

The antimetastatic activity of combined or individual administration of topotecan and tyrosyl-DNA phosphodiesterase 1 (Tdp1) inhibitor was examined under various administration schedules in mice with Lewis lung carcinoma modeled by intravenous injection of 200,000 clone/mouse. The greatest antimetastatic effect was observed after combined use of topotecan and Tdp1 inhibitor as documented by macroscopic study of the lungs that revealed the decreased metastatic scores by 76, 91, or 74% at the respective inhibitor doses of 2, 4, or 6 mg/mouse, respectively, in parallel with inhibition of metastasis up to 98% (at inhibitor dose of 4 mg/mouse) and morphological and morphometric analyses of the lung sections, which revealed elevation of metastasis growth delay index to 86 and 63% at the respective inhibitor doses of 4 and 6 mg/mouse, respectively. The combined administration of topotecan and Tdp1 inhibitor is viewed as the most effective way to eliminate the metastatic formations with possible restitution of focal lesions. [ABSTRACT FROM AUTHOR]

The composition of phenolic compounds of rowanberry (Sorbus aucuparia L.) fruit extracts prepared with 40% ethanol and 95% acidified ethanol was studied. The differences in the content of flavonoids, including anthocyanins, and phenolic acids were shown. It was found that the antimetastatic activity of cyclophosphamide was most efficiently increased by the rowanberry fruit extract in 95% acidified ethanol enriched in anthocyanins. The aim of the present research was to investigate the effect of hydroalcoholic extracts of rowanberry fruit on the development of Lewis lung carcinoma and the antitumor activity of cyclophosphamide and to reveal the most effective extract containing a phenolic complex for its further study as a promising drug. [ABSTRACT FROM AUTHOR]

Purpose: Tumor cell resistance to platinum-based chemotherapeutic agents is one of the major hurdles to successful cancer treatment with these drugs, and is associated with alterations in tumor cell immune evasion and immunomodulatory properties. Immunocyte targeting is considered as a relevant approach to fight drug-resistant cancer. In this study, immunological hallmarks of cis-DDP-resistant Lewis lung carcinoma cells (LLC/R9) were investigated.Methods: Immunological features of LLC/R9 cells cultured in vitro in normoxic and hypoxic conditions as well as of those that were grown in vivo were examined. The expression of immunologically relevant genes was evaluated by RT-PCR. Tumor cell susceptibility to the macrophage contact tumoricidal activity and NK-mediated cytolysis was investigated in MTT test. TNF-α-mediated tumor cell apoptosis as well as macrophage phagocytosis, oxidative metabolism, and CD206 expression after the treatment with conditioned media from normoxic and hypoxic tumor cells were studied by flow cytometry. Flow cytometry was also used to characterize dendritic cell maturity.Results: When growing in vitro, LLC/R9 were characterized by slightly increased immunosuppressive cytokine gene expression. Transition to in vivo growth was associated with the enhancement of transcription of these genes in tumor cells. LLC/R9 cells had lowered sensitivity to contact-dependent macrophage-mediated cytotoxicity and to the TNFα-mediated apoptosis in vitro. Conditioned media from hypoxic LLC/R9 cells stimulated reactive oxygen species generation and CD206 expression in non-sensitized macrophages. Acquisition of drug resistance by LLC/R9 cells was associated with their increased sensitivity to NK-cell-mediated cytolysis. Meanwhile, the treatment of LLCR/9-bearing animals with generated ex vivo and loaded with LLC/R9 cell-lysate dendritic cells (DCs) resulted in profoundly enhanced tumor metastasizing.Conclusion: Decreased sensitivity to macrophage cytolysis, polarizing effect on DCs maturation along with increased susceptibility to NK-cell cytotoxic action promote extensive local growth of chemoresistant LLC/R9 tumors in vivo, but hamper their metastasizing. [ABSTRACT FROM AUTHOR]

The effects of Fructus Sorbi aucupariae extract, originally saturated with anthocyans, on the development of Lewis lung carcinoma and B-16 melanoma in C57Bl/6 mice and the efficiency of cyclophosphamide treatment were studied. Antitumor activity of the extract and potentiation of the antimetastatic activity of the cytostatic were demonstrated. Studies on melanoma B-16 model revealed an increase in the counts of stromal progenitor cells in the tumor node and their accelerated maturation after treatment with the extract. No effects towards the tumor stem and committed cells were detected. [ABSTRACT FROM AUTHOR]

Stem cell factor (SCF) plays an important role in tumor growth and metastasis. However, the function of SCF in regulating stemness and migration of cancer stem cells (CSCs) remains largely undefined. Here, we report that non-adhesive culture system can enrich and expand CSCs derived from Lewis lung carcinoma (LLC) cells and that the expression level of SCF in CSCs was higher than those in LLC cells. Silencing SCF via short hairpin (sh) RNA lentivirus transduction attenuated sphere formation and inhibited expressions of stemness genes, ALDH1, Sox2, and Oct4 of CSCs in vitro and in vivo. Moreover, SCF-silenced CSCs inhibited the migration and epithelial-mesenchymal transition, with decreased expression of N-cadherin, Vimentin, and increased expression of E-cadherin in vitro and in vivo. Finally, SCF-short hairpin RNA (shRNA) lentivirus transduction suppressed tumorigenicity of CSCs. Taken together, our findings unraveled an important role of SCF in CSCs derived from LLC cells. SCF might serve as a novel target for lung cancer therapy. [ABSTRACT FROM AUTHOR]

Experiments on male C57Bl/6 mice with transplantable Lewis lung epidermoid carcinoma were performed to evaluate the effect of early or delayed administration of compound SNK-411 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine) on tumor growth and animal survival. Intraperitoneal injection of SNK-411 in doses of 25 and 50 mg/kg on days 2-8 of tumor growth was followed by significant inhibition of tumor growth (by 1.8 and 2.2 times, respectively, in comparison with the untreated control). Administration of this compound on days 8-15 of tumor development had little effect on tumor growth. SNK-411 in doses of 25 and 50 mg/kg (both dosing regimens) significantly increased survival rate and lifespan of animals with tumors. The drugs for verification of this model (Fluorofur, 400 mg/kg; and doxorubicin hydrochloride, 4 mg/kg) were injected intraperitoneally on days 2-4 and 8-10 of tumor development. Administration of Fluorofur and doxorubicin hydrochloride at the late stage was accompanied by significant inhibition of tumor growth (by 1.6 and 1.4 times, respectively). The increase in the survival rate of animals receiving the cytostatic according to standard dosing regimens was less significant than in experiments with SNK-411. [ABSTRACT FROM AUTHOR]

The antitumor activity of the binuclear form of dinitrosyl iron complexes with glutathione against Lewis lung carcinoma was found earlier with intraperitoneal administration of the complexes. This activity was also observed when this preparation was injected subcutaneously. The complex inhibited the tumor growth by 43% upon subcutaneous injection at a daily dose of 100 µM/kg (as calculated per one iron atom in the binuclear dinitrosyl iron complex) for 10 or 15 days. The effect was observed during the first 2 weeks after tumor transplantation. After this, the tumors began to grow at a rate that was equal to or even higher than that for the control animals. The mean survival time for the treated mice exceeded the control values by 30%. Binuclear dinitrosyl iron complexes were also effective against Ca-755 adenocarcinoma with intraperitoneal administration. In this case, however, the mean survival time for the treated animals only increased by 7%. It was also shown that S-nitrosoglutathione inhibited the growth of Lewis lung carcinoma and Ca-755 adenocarcinoma by 70 and 90%, respectively. However, in contrast to binuclear dinitrosyl iron complexes, the antitumor effect of S-nitrosoglutathione decreased with an increase in the daily dose of the compound from 200 to 400 µM/kg. The initial antitumor effect of binuclear dinitrosyl iron complexes and S-nitrosoglutathione is suggested to be due to NO that is released from both compounds. The subsequent suppression of the effect is caused by the activation of antinitrosative and antioxidant defense systems in tumors. [ABSTRACT FROM AUTHOR]

The influence of low-molecular-weight sodium alginate, which is administered as an isolated agent and in combination with cyclophosphamide, on the parameters of peripheral blood and bone marrow was studied in mice with Lewis lung carcinoma. It was shown that administration of sodium alginate with a molecular weight of 1-10 and 20-30 kDa to tumor-bearing animals prevents bone marrow failure by activating the process of regeneration of granulocytic hemopoietic stem cells that are damaged by a single injection or repetitive injections of a cytostatic agent, due to stimulation of the clonal activity of granulocytopoiesis precursors. As a result, this treatment prevents the progression of leukopenia. [ABSTRACT FROM AUTHOR]

The dynamics of the endogenous production of NO metabolites, nitrites, nitrates, and volatile nitrosamines, has been investigated in the body, a tumor tissue, and peritoneal macrophages of mice F1 (C57Bl × CBA), Balb/c and BDF with subcutaneously transplanted tumors: Ehrlich carcinoma (EC) and Lewis metastatic lung carcinoma (LC). It has been shown that during the first three weeks, growth of EC is accompanied by a statistically significant increase in the total concentration of NO metabolites (NOx; nitrites + nitrates) up to levels (7.3 ± 3.49) × 10−(7.8 ± 2.57) × 10 mol/kg in the tumor tissue and a sharp increase in NOx excretion with urine. At the same time, in the LC tumor tissue the maximal level of NOx (3.6 ± 0.46) × 10 mol/kg was registered on day 7, and later it decreased demonstrating negative correlation with the tumor mass. At the stage of intensive LC growth (14, 21 days) there was significant inhibition of nitrite secretion by peritoneal macrophages. In all the controlled time-intervals the EC tumor tissue contained carcinogenic N-nitrosodimethylamine and N-nitrosodiethylamine; however, their concentrations significantly varied. Thus, the ability of the tumor tissue to produce NO metabolites was more pronounced in EC than in LC and depended on the time parameters of tumor growth. [ABSTRACT FROM AUTHOR]

Inhibition of growth of a transplanted solid tumor in BDF mice bearing Lewis lung carcinoma cells on days 1-5 and 7-11 after tumor transplantation was observed at daily intraperitoneal administration of an aqueous solution of binuclear form of dinitrosyl iron complexes with glutathione at a dose of 200 μmol/kg (relative to one Fe(NO) group in the complexes). Inhibition of tumor growth during the administration of complexes (for 11 days) was 70 and 85% when an iron complex: free glutathione ratio in solution was equal to 1: 1 and 1: 10, respectively. Accelerated tumor growth that was faster than in the control began after cessation of dinitrosyl iron complex administration. The selective accumulation of dinitrosyl iron complexes in the tumor, as well as the accumulation of nitrosyl complexes of heme proteins was detected by the EPR method. The latter were observed in the tumor and control animals. It is hypothesized that delayed tumor development during administration of the binuclear form of dinitrosyl iron complexes to mice is caused by inactivation of heme-containing proteins under the action of NO released from these complexes, which provides antinitrosative defenses produced in malignant tumors. [ABSTRACT FROM AUTHOR]

We investigated the effects of teichoic acid (TA) from Staphylococcus aureus Wood 46 on tumor growth and metastasis of the experimental Lewis lung carcinoma (LLC) in mice. Intranasal administration of TA alone aggravated both tumor growth and metastasis, whereas combined administration of TA with a synthetic bimetallic (copper: cadmium) ethylene diamine complex PO244 resulted in pronounced antitumor and antimetastatic effects. The group of animals subjected to the combined treatment with TA and PO244 manifested the highest degree of lymphocyte infiltration into the tumor tissue, compared to the control group and those exposed to TA or PO244 alone. Moreover, the combined treatment negatively affected the adhesive properties of peritoneal macrophages in the LLC bearing mice. Co-cultivation of the isolated macrophages with primary LLC cultures revealed significant ( p < 0.05) cytotoxic and cytostatic effects, detected as an increased level of apoptosis and a reduced fraction of replicating cells. [ABSTRACT FROM AUTHOR]

The antitumor dose-dependent effect of binuclear dinitrosyl iron complexes with glutathione as NO donors on a solid tumor in the mouse, Lewis lung carcinoma, was detected. The complexes being injected at doses of 21, 42, 105 mg/kg daily for 10 days blocked completely the development of the tumor for the first week after tumor cell implantation into animals. After that, the part of tumor cells which remained in intact alive state began to grow at a rate equal to that for control animals. The effect was proposed to be caused via formation of an antinitrosative defense system in the cells as a response to NO attack on cells. It was also hypothesized that this system can be inactivated by higher doses of dinitrosyl iron complexes. Data were obtained which were in line with the hypothesis. [ABSTRACT FROM AUTHOR]

Electron microscopic study of Lewis lung carcinoma cell mitochondria after intravenous injection of a magnetosensitive nanocomplex based on ferric oxide (FeO) nanoparticles and doxorubicin followed by radiofrequency hyperthermia showed that a common increase of the electron density of the cytoplasm was paralleled by mitochondrial edema in comparison with organelles of animals receiving doxorubicin alone. These changes were accompanied by virtually total lysis of the cristae and sharp clarification of mitochondrial matrix, which was seen from appreciable increase in mitochondria image brightness. Morphometric analysis showed lesser perimeter, area, and mean radius of the tumor cell mitochondria in animals receiving the injection of magnetosensitive nanocomplex and exposed to radiofrequency hyperthermia in comparison with those injected with doxorubicin alone. Histograms of distribution of the perimeter, area, and mean radius of the mitochondria after combined exposure to the nanocomplex and hyperthermia showed bimodal asymmetrical distribution. Injection of the magnetosensitive nanocomplex followed by radiosensitive hyperthermia led to more significant impairment of the tumor cell mitochondrial ultrastructure than doxorubicin alone. [ABSTRACT FROM AUTHOR]

We studied the content of tissue inhibitors of matrix metalloproteinases 1 and 2 (TIMP-1 and TIMP-2) and activities of matrix metalloproteinases (MMP) in the serum and lungs of mice with Lewis lung carcinoma metastasizing into the lung. Metastasizing was associated with increased serum content of TIMP-1 and TIMP-2 (only on day 20 at the terminal stage of the tumor process). These data confi rm the hypothesis on pro-tumorigenic role of TIMP-1 in the serum. Locally, the development of metastases was associated with a decrease in TIPM-1 concentration (day 7), an increase in TIMP-2 concentration (days 7 and 20), and elevated activity of MMP at all terms of the study (days 7, 15, and 20). Increased concentration of TIMP-2 in the lungs (but not in the serum) can be regarded as an indicator of Lewis lung carcinoma metastasizing. [ABSTRACT FROM AUTHOR]

Growth experiments of transplanted malignant tumors in the presence of water-soluble C fullerenes were performed on groups of mice. It was found that C fullerenes efficiently inhibit the growth of transplanted malignant tumors. This behavior can be explained through their high antioxidant activity and the blocking of the specific cell receptors (for example, endothelial growth factor). The findings demonstrate the possibility of using C fullerenes in anticancer therapy. [ABSTRACT FROM AUTHOR]

Damage-associated molecular patterns (DAMPs), danger signal molecules expressed after injury or infection, have become recognized as prerequisite for orchestrating effective anti-tumor host response. The expression of two prototypical DAMPs, calreticulin and high-mobility group box-1 (HMGB1) protein, was examined following Photofrin™-photodynamic therapy (PDT) of Lewis lung carcinoma (LLC) cells in vitro and LLC tumors growing in syngeneic mice. Cell surface expression of calreticulin was found to be highly increased at 1 h after PDT treatment both in vitro and in vivo. Increased exposure of calreticulin was also detected on the surface of macrophages from PDT-treated LLC tumors. At the same time interval, a rise in serum HMGB1 was detected in host mice. Intracellular staining of macrophages co-incubated for 16 h with PDT-treated LLC cells revealed elevated levels of HMGB1 in these cells. The knowledge of the involvement of these DAMPs uncovers important mechanistic insights into the development of host response induced by PDT. [ABSTRACT FROM AUTHOR]

Many lung cancer treatment regimens include radiotherapy. We sought to improve the efficacy of such treatment by invoking the targeted delivery of a model radiosensitizer (nicotinamide) to malignant tissues. Ephrin receptors (Eph), which are often overexpressed in lung cancers, were selected as the target of our delivery system. Molecular targeting was achieved utilizing a small peptide derived from the C-terminal portion of azurin, a copper-containing redox protein ('cupredoxin') that is capable of binding to ephrin receptors. We prepared and screened a sub-library of peptides derived from the C-terminal region of azurin and found several small analogues that bound ephrin receptors EphA2, EphB2, and EphB4. One such peptide, termed AzV36, was selected for conjugation with nicotinic acid via an amide bond to form AzV36-NicL. The resulting linear peptide contains 15 residues (including unusual and d-amino acids), is very stable in human serum, and can be easily manufactured. AzV36-NicL conjugate was tested in vivo for its ability to radiosensitize Lewis lung carcinoma (LCC) in artificial metastasis and solid tumor engraftment models. The compound increased the efficacy of radiotherapy with tumor colonies being ~2-13 fold lower than with radiation alone depending on experimental schedule. In contrast, equimolar amounts of unconjugated peptide (AzV36-L) or nicotinamide alone only marginally improved radiation efficacy. The targeted delivery of radiosensitizer(s) to ephrin receptors may enhance the efficacy of radiation treatment of lung cancer and of other cancers that overexpress ephrin receptor(s). [ABSTRACT FROM AUTHOR]

Purpose: The natural flavonoid fisetin was recently identified as a lead compound that stabilizes endothelial cell microtubules. In this study, we investigated the antiproliferative and antiangiogenic properties of fisetin in vitro and in vivo. Methods: Fisetin cytotoxicity was evaluated using Lewis lung carcinoma cells (LLC), endothelial cells and NIH 3T3 cells. Endothelial cell (EC) migration and capillary-like structure formation were evaluated using EAhy 926 cells. In vivo tumour growth inhibition studies were performed using LLC-bearing mice treated with fisetin and/or cyclophosphamide (CPA). Results: The fisetin IC was 59 μM for LLC and 77 μM for EC cells, compared to 210 μM for normal NIH 3T3 cells (24 h). Fisetin inhibited EC migration and capillary-like structure formation at non-cytotoxic concentrations (22-44 μM). In mice, fisetin inhibited angiogenesis assessed using the Matrigel plug assay. In LLC-bearing mice, fisetin produced a 67% tumour growth inhibition (223 mg/kg, intraperitoneal), similar to the 66% produced by low-dose CPA (30 mg/kg, subcutaneous). When fisetin and CPA were combined, however, a marked improvement in antitumour activity was observed (92% tumour growth inhibition), with low systemic toxicity. Tumour histology showed decreased microvessel density with either fisetin or CPA alone, and a dramatic decrease after the fisetin/CPA combination. Conclusions: We have shown that fisetin not only displays in vitro and in vivo antiangiogenic properties, but also can markedly improve the in vivo antitumour effect of CPA. We propose that this drug combination associating a non-toxic dietary flavonoid with a cytotoxic agent could advantageously be used in the treatment of solid tumours. [ABSTRACT FROM AUTHOR]

The present study assessed the effects of dietary fat on spontaneous metastasis of Lewis lung carcinoma in mice. Three-week old male C57BL/6 mice were fed the AIN-93G diet or a 45% fat diet (% kcal.) for 7 weeks before they were subcutaneously injected with 2.5 × 10 viable carcinoma cells. The primary tumor was resected 2 weeks later, and mice were maintained on their respective diets for an additional 2 weeks. The high-fat diet significantly increased body weight and abdominal adipose weight compared to the AIN-93G diet. Feeding mice the 45% fat diet resulted in a two-fold increase in the number of lung metastases ( P < 0.05), a 35% increase in tumor cross-sectional area, and a 50% increase in tumor volume compared to mice fed the AIN-93G diet. There were no differences in plasma concentrations of TIMP-1, IL-1β, VEGF and MCP-1 in non-tumor-bearing mice fed the AIN-93G diet or the high-fat diet, but significant increases in these cytokines in tumor-bearing mice fed the AIN-93G diet compared to the non-tumor-bearing mice fed the same diet ( P < 0.05 for each comparison). Further significant increases in these cytokines in tumor-bearing mice fed the 45% fat diet compared to the same tumor-bearing mice fed the AIN-93G diet ( P < 0.05 for each comparison). The high-fat diet significantly increased plasma leptin and significantly decreased plasma adiponectin compared to the AIN-93G diet in both non-tumor-bearing and tumor-bearing mice. Results of the present study demonstrated that the high-fat diet enhanced spontaneous metastasis of Lewis lung carcinoma in mice and that this aggressiveness was accompanied with significant increases in plasma concentrations of angiogenic cytokines, suggesting that dietary fat affects metastasis by promoting angiogenic processes. [ABSTRACT FROM AUTHOR]

Tubulin polymerization promoting protein 3 (TPPP3), a member of the TPPP family, can induce tubulin polymerization and microtubule bundling. Previously, it has been shown that TPPP3 plays an important role in cell proliferation. Depletion of TPPP3 by microRNA-based RNA interference (RNAi) inhibits cell growth, arrests cell cycles, and causes mitotic abnormalities in HeLa cells. In the present study, we knocked down TPPP3 in Lewis lung carcinoma (LLC) cells with the same RNAi construct, and observed a retarded tumor cell growth in vitro. Furthermore, C57BL/6 mice that received subcutaneously injected LLC cells in which TPPP3 was knocked down showed a pronounced reduction in tumor progression. The migration/invasion activity of TPPP3-knockdown LLC cells was significantly suppressed in a transwell chamber migration assay. When these cells were injected into the tail veins of C57BL/6 mice, they exhibited milder lung metastasis compared with control tumor cells. Taken together, these findings suggested that the TPPP3 gene played an important role in tumorigenesis and metastasis, and it could potentially become a novel target for cancer therapy. [ABSTRACT FROM AUTHOR]

This study examined the anti-metastatic effects of oxythiamine (OT) both in cell culture and in vivo. Cell culture results revealed that OT (0–20 μM) significantly inhibited the invasion and migration (IC50 = 8.75 μM) of Lewis lung carcinoma (LLC) cells. These effects of OT were accompanied by the inhibition of metalloproteinases-2 and -9 (MMP-2, MMP-9), urokinase-type plasminogen activator (uPA) activities and by the increases in protein expression of tissue inhibitors of metalloproteinases-1 and -2 (TIMP-1, TIMP-2). We then implanted (s.c.) C57BL/6 mice with LLC cells and supplemented the mice with a low- or a high-dose of OT (250 or 500 mg/kg BW) daily for 5 wk. During the 5-wk period, OT supplementation decreased plasma MMP-2 activity in a dose-dependent manner, and this effect was significant after 4 wk of tumor cell implantation. Tumor metastasis was found to confine to the lungs of mice injected with the tumor cells. High-OT supplementation strongly lowered the number and area of tumors and inhibited protein expression of MMP-2 and MMP-9 in the lungs. In addition, high-OT supplementation markedly decreased the extent of proliferating cell nuclear antigen (PCNA) staining in the lungs. By contrast, OT supplementation increased TIMP-1 and -2 protein expression in the lungs. These results demonstrate that OT supplementation attenuates tumor cell metastasis, possibly via inhibition of protein expression of MMPs, extent of PCNA staining and via increase of proteins expression of TIMPs. [ABSTRACT FROM AUTHOR]

Patients with solid tumors have defects in immune effector cells, which have been associated with a poorer prognosis. Previous studies by our laboratory have shown that exposure to Lewis lung carcinoma (LLC)-secreted products induces the formation of suppressor endothelial cells in vitro. The current studies examined if tumors could induce the formation of suppressor endothelial cells in vivo. Endothelial cells were immunomagnetically isolated from the lungs of tumor-bearing mice or normal controls and examined for their ability to modulate NK cell, T-cell and macrophage functions. Compared to normal controls, supernatants from endothelial cells isolated from tumor-bearing lungs had elevated secretion of PGE2, IL-6, IL-10 and VEGF. Conditioned media from endothelial cells isolated from normal lungs increased CD8+ T-cell IFN-γ and CD4+ T-cell IL-2 production in response to anti-CD3 stimulation, while media conditioned by endothelial cells from tumor-bearing lungs had a diminished stimulatory capacity. Examination of NK cell functions showed that supernatants from endothelial cells isolated from normal lungs were potent activators of NK cells, as indicated by their secretion of TNF-α and IFN-γ. Endothelial cells isolated from tumor-bearing lungs had a significantly diminished capacity to activate NK cells. Finally, supernatants from endothelial cells of tumor-bearing lungs diminished macrophage phagocytosis compared to either treatment with supernatants of normal endothelial cells or treatment with media alone. The results of these studies demonstrate that tumors induce the formation of suppressor endothelial cells in vivo and provide support for the role of endothelial cells in tumor-induced immune suppression. [ABSTRACT FROM AUTHOR]

We studied the effects of SNK-411, a new 5-pyrimidinol derivative, on serum cytokine profile of C57Bl/6 mice with Lewis lung carcinoma. The compound was injected intraperitoneally in doses of 25 and 50 mg/kg. A significant (by 3.5 times) increase in serum IL-4 content was detected in mice with tumors on day 9 of tumor development. In mice receiving SNK-411 in doses of 25 and 50 mg/kg, IL-4 content significantly decreased (by 4.0 and 3.6 times) on days 2-8 of carcinoma development; IL-2 content decreased by 1.4 and 1.2 times and IL-6 content decreased by 2.7 and 1.6 times, respectively, in comparison with control mice with tumors. Injections of SNK-411 in the same doses on days 8-15 of carcinoma development led to a significant decrease in IL-4 levels (by 2.2 and 4.5 times, respectively, in comparison with control mice with tumors) and did not affect serum levels of other cytokines. [ABSTRACT FROM AUTHOR]

The efficiency of aranose combinations with gemcitabine and cisplatin was studied in experimental Lewis lung epidermoid carcinoma. Significant synergism of all the studied combinations and their satisfactory tolerance was demonstrated. The gemcitabine+cisplatin+aranose combination was significantly more effective than gemcitabine+cisplatin. [ABSTRACT FROM AUTHOR]

Mechanical loading is known to trigger proliferation of tumor cells. Periostin is a new molecule found to increase in many cancers. To determine how mechanical strain modulates tumor growth and its possible mediation by periostin through TGF-β1, Lewis lung cancer cells were cultured on flexible-bottomed culture plates and cyclically strained using Flexercell Strain Unit. Real-time RT-PCR was used to quantify periostin and TGF-β1 mRNA levels at 6, 12, 18, and 24 h of loading. In addition, periostin and TGF-β1 neutralizing antibodies were added to the medium. We showed that the proliferative ability of Lewis cancer cells was significantly increased by cyclical strain. This change can be blocked by 5 µg/ml of periostin neutralizing antibody. Periostin mRNA increased by 1.1-, 3.2-, 4.7-, and 9.2-fold while TGF-β1 mRNA increased by 5.3-, 10.3-, 7.1-, and 6.5-fold at 6, 12, 18, and 24 h, respectively. Periostin protein in medium increased after cyclical strain. Expression of periostin mRNA in response to mechanical loading was completely blocked by 2.5 µg/ml of TGF-β1 neutralizing antibody. In addition, overexpression of periostin in Lewis cells can promote cell proliferation. Our results suggest that periostin is a potent positive regulator of tumor growth in response to mechanical loading and is possibly a downstream factor of TGF-β1. [ABSTRACT FROM AUTHOR]

Patients and mice with solid tumors, such as Lewis lung carcinoma (LLC), have defects in functions of immune effector cells. Endothelial cells, a component of the tumor vasculature, are potential regulators of immune cell functions. Therefore, these studies examined the impact of exposure to LLC tumor on the ability of endothelial cells to modulate immune cell functions. Endothelial cells were pre-treated with LLC tumor-conditioned medium (EndoT-sup) for 24 h. Control endothelial cells that were exposed to medium (EndoMedia) or epithelial cell-conditioned medium (EndoEpi-sup). After the initial 24 h incubation, endothelial cells were washed and fresh media was added. Cells were allowed to incubate for an additional 24 h. Supernatants from EndoMedia, EndoEpi-sup or EndoT-sup were collected and assayed for immune modulatory products and for immune modulatory activity. Supernatant from EndoT-sup contained increased levels of PGE2, IL-6 and VEGF as compared to EndoMedia and EndoEpi-sup controls. NK cell activity, as measured by TNF-α and IFN-γ secretion, was increased following exposure to media conditioned by EndoMedia and EndoEpi-sup. Exposure of NK cells to supernatants of EndoT-sup, also increases TNF-α and IFN-γ secretion, but to a lesser extent than by EndoMedia and EndoEpi-sup. Examination of macrophage functions demonstrated that supernatant from EndoT-sup decreased microbead phagocytosis and increased production of the immune suppressive mediators, IL-10 and PGE2. Lastly, T-cell responses to stimulation with anti-CD3 in the presence of supernatants from EndoT-sup were examined. IFN-γ production by CD8+ T-cells was reduced after exposure to EndoT-sup-conditioned medium, as compared to cells treatments with medium or control conditioned medium. Production of IFN-γ by CD4+ T-cells exposed to EndoT-sup was not altered. Taken together, these studies demonstrate that tumors skew endothelial cells to disrupt NK cell, T-cell and macrophages functions, and represents a novel mechanism of tumor-induced immune suppression. [ABSTRACT FROM AUTHOR]

Two triterpene fractions and a single ganoderma alcohol obtained from an antlered form of the fruiting bodies of Ganoderma lucidum were examined for their antitumor effects on the growth of inoculated mouse Lewis lung carcinoma in mice by intraperitoneal administration. The ganoderma alcohol fraction significantly suppressed the tumor growth at doses of 50 and 100 mg/kg in the treatment period, and even after the administration, showing antitumor activity with a T/ C value of 70.6% at a dose of 100 mg/kg. On the other hand, no obvious activity was shown at each dose in the ganoderma-acid-fraction-treated groups. Furthermore, ganoderiol F, which exhibited the strongest cytotoxicity against four tumor cell lines among five ganoderma alcohols examined, remarkably inhibited the tumor growth, accounting for 63.7% and 78.7% of control group at a dose of 5 mg/kg, 54.1% and 63.0% at a dose of 10 mg/kg, and 47.7% and 53.9% at a dose of 20 mg/kg in and after the administration period, respectively, in a dose-dependent manner. These results suggest that the antitumor effects of bitter principles in G. lucidum are mainly due to ganoderma alcohols. [ABSTRACT FROM AUTHOR]

The chick-embryo model has been an important tool to study tumor growth, metastasis, and angiogenesis. However, an imageable model with a genetic fluorescent tag in the growing and spreading cancer cells that is stable over time has not been developed. We report here the development of such an imageable fluorescent chick-embryo metastatic cancer model with the use of green fluorescent protein (GFP). Lewis lung carcinoma cells, stably expressing GFP, were injected on the 12th day of incubation in the chick embryo. GFP-Lewis lung carcinoma metastases were visualized by fluorescence, after seven days additional incubation, in the brain, heart, and sternum of the developing chick embryo, with the most frequent site being the brain. The combination of streptokinase and gemcitabine was evaluated in this GFP metastatic model. Twelve-day-old chick embryos were injected intravenously with GFP-Lewis lung cancer cells, along with these two agents either alone or in combination. The streptokinase-gemcitabine combination inhibited metastases at all sites. The effective dose of gemcitabine was found to be 10 mg/kg and streptokinase 2000 IU per embryo. The data in this report suggest that this new stably fluorescent imageable metastatic-cancer chick-embryo model will enable rapid screening of new antimetastatic agents. Abbreviation: GFP — green fluorescent protein [ABSTRACT FROM AUTHOR]

Purpose. We examined the interaction between cyclophosphamide (CPA) and angiostatin (AS) on the growth of primary Lewis lung carcinoma (LLC) tumors and on the development of LLC pulmonary metastases. We studied the effects of AS and CPA on the stages of angiogenesis employing in vitro assays. Methods. Primary tumor growth and pulmonary metastases were measured to evaluate the effects of treatment with AS alone, CPA alone or the combination of CPA and AS. We examined the effects of CPA plus AS on endothelial cell (HUVEC) survival, migration and tube formation. Results. Combined treatment with CPA and AS did not significantly affect primary tumor growth when compared with CPA treatment alone. However, a significant decrease in the number of pulmonary metastases was observed following CPA plus AS treatment when compared with CPA treatment alone (P<0.001). AS did not enhance CPA-mediated HUVEC cytotoxicity, and CPA failed to enhance AS-mediated inhibition of migration. However, tube formation was inhibited following combined treatment with CPA and AS when compared with either treatment alone. Conclusions. AS enhanced the antimetastatic effects of CPA without significantly influencing the effects of CPA on primary tumor growth. CPA plus AS inhibited tube formation, suggesting that interrupting specific steps in the angiogenesis process might be an effective approach to the treatment of subclinical distant metastases. [ABSTRACT FROM AUTHOR]

Purpose: Interleukin-11 (IL-11) is a stromal cell derived multifunctional cytokine, which plays important roles in the hematopoietic and nonhematopoietic systems. Recombinant human IL-11 (rhIL-11) is used in the treatment of chemotherapy-induced thrombocytopenia. We have investigated the effects of rhIL-11 on the antitumor activity of chemotherapeutic agents and on thrombocytopenia in myelosuppressed mice bearing tumor cells. Methods: We tested the effect of rhIL-11 on Lewis lung carcinoma (LLC) cell proliferation when used alone or in combination with three antitumor agents in vitro. Also, a newly developed chemotherapy-induced myelosuppressed mice model bearing LLC cells was used to study the effects of rhIL-11 on the antitumor activity and on thrombocytopenia. Results: On its own, rhIL-11 (1–100 ng/ml) did not stimulate cell proliferation, and did not alter the antitumor activities of carboplatin, mitomycin C, or etoposide in vitro. In mice implanted with LLC cells (1×104), carboplatin (50 mg/kg/day for 2 consecutive days, i.p.) inhibited tumor growth and caused thrombocytopenia. Treatment with rhIL-11 (500 µg/kg/day, from the day following the last dosing with carboplatin for 14 days, s.c.) successfully prevented thrombocytopenia without affecting the antitumor activity of carboplatin. With rhIL-11 there was no obvious effect on the red blood cell count, white blood cell count, or body weight. Conclusion: These results support the assertion that rhIL-11 may be a significant therapeutic agent for thrombocytopenia following cancer chemotherapy, and that it need be associated with little fear of tumor proliferation. [ABSTRACT FROM AUTHOR]

In cell culture, the compound 317615.2HCl, a potent inhibitor of VEGF-stimulated HUVEC proliferation, was not very effective against Calu-6 non-small-cell lung carcinoma cells (IC50 26 microM). Exposure to combinations of paclitaxel or carboplatin and 317615.2HCl with Calu-6 cells in culture resulted in cell survival that reflected less-than-additivity to additivity of the two agents. Administration of 317615.2HCl orally twice daily to nude mice bearing subcutaneous Calu-6 tumors resulted in a decreased number of intratumoral vessels as determined by CD31 and CD105 staining to 50% of the number in control tumors. 317615.2HCl showed antitumor activity against the Lewis lung carcinoma and increased the tumor growth delay produced by paclitaxel by 5-fold, that produced by gemcitabine by 2-fold and that produced by carboplatin by 1.7-fold. There was a decrease in the number of lung metastases in the Lewis lung carcinoma that paralleled the increased response of the primary tumor with each treatment combination. Administration of 317615.2HCl also increased the tumor growth delay produced by fractionated radiation therapy in the Lewis lung tumor. Treatment with 317615.2HCl was an effective therapy in the Calu-6 non-small-cell lung carcinoma xenograft when the compound was administered early (days 4-18) or later (days 14-30). Combination treatment regimens in which 317615.2HCl was administered along with or sequentially with paclitaxel or carboplatin were much more effective than the chemotherapeutic agents administered alone. 317615.2HCl is in early clinical testing. [ABSTRACT FROM AUTHOR]

Although altered levels of circulating essential trace elements are known to accompany malignant disease, the lack of sensitivity of conventional detection methods has generally limited their study to clinical conditions involving extensive disease (i.e., significant tumor burden). As such, the application of altered trace element levels as potential prognostic guides or as response indicators subsequent to treatment has been of limited use. During this study, proton-induced X-ray emission spectroscopy was evaluated as a tool to determine trace element imbalances in a murine tumor model. Using plasma from C57B1/6 mice bearing the syngeneic Lewis lung carcinoma (LLCa), levels of Fe, Cu, and Zn, as well as changes in the Cu/Zn ratio, were measured in animals carrying an increasing primary tumor burden. The plasma levels of Fe, Cu, and Zn were found to decrease significantly 7 d following implants of LLCa cells with no significant change observed in the Cu/Zn ratio. By d 21, however, an increase in the Cu/Zn ratio was found to accompany increased growth of the LLCa tumor; the plasma levels of Cu had returned to normal levels, whereas both the Fe and Zn plasma levels remained lowered. Collectively, the results suggest that although a net change in individual plasma trace element concentrations might not be accurately associated with tumor growth, a clear relationship was established between the Cu/Zn ratio and tumor size. [ABSTRACT FROM AUTHOR]

We studied the effect of macrophage stimulator water-soluble β-(1→3)-D-carboxymethylglucan on the efficiency of cyclophosphamide chemotherapy in Lewis lung carcinoma. Cyclophosphamide inhibited the growth of primary tumor nodes by 57%. The preparation possessed pronounced antimetastatic activity: metastases were found in 40.9% animals. Combination therapy with cyclophosphamide and (1→3)-beta;-D-glucan inhibited the growth of intramuscular tumors by 75-89% and reduced the incidence of metastases into the lungs by 92-94%. The therapeutic effect was most pronounced after simultaneous administration of these preparations: tumor growth was suppressed by 89.3% and metastases were found in only 7.5% animals (vs. 100% in the control). The potentiating effect of β-(1→3)-D-carboxymethylglucan is related to accumulation of cysteine proteinase inhibitors in the tumor tissue and plasma, but not to changes in blood cell composition. [ABSTRACT FROM AUTHOR]

Tumor development and aging can each alter immune competence. The present study aimed to determine the impact of Lewis lung carcinoma (LLC) presence on immune parameters of middle-aged (averaging 6.5 months) versus aged (averaging 21.3 months) mice. An age-associated decline in the CD4+ cell frequency was seen in freshly isolated spleen and lymph node cells, as well as in cultures stimulated with immobilized anti-CD3. This decline was not further exacerbated by tumor presence. What was prominently inhibited by tumor was the capacity of either splenic or lymph node CD4+ cells to become stimulated to express IFN-γ. Spleen and lymph node cultures from aged tumor-bearing mice had the lowest frequency of CD4+IFN-γ+ cells and the least amount of secreted IFN-γ. CD8+ cells were not affected by aging, but tumor presence reduced the induction of CD8+IFN-γ+ cells in lymph node cultures. We previously showed that LLC growth stimulates myelopoiesis, as seen by splenomegaly and the mobilization of immune inhibitory CD34+ progenitor cells. Tumor presence in middle-aged mice reduced spleen cell blastogenesis, which was mediated by CD34+ cells. Aged mice had reduced blastogenesis, and this was further reduced by presence of tumor. However, neither the age-associated immune dysfunction nor the tumor-induced immune suppression in aged mice was due to CD34+ progenitor cells. These studies show how tumor presence can further compromise the immune dysfunction that accompanies aging. In addition, they show that aging impacts on the mechanisms by which tumors inhibit T-cell capabilities, with myelopoiesis-associated CD34+ cells mediating the immune depression of middle-aged tumor-bearers and an independent mechanism being responsible for the immune depression in aged tumor-bearing mice. [ABSTRACT FROM AUTHOR]

The process of extravasation of the high metastatic Lewis lung carcinoma line was examined in different organs. Four of the five organs (liver, lungs, brain and adrenals) represent the most frequent metastatic sites in humans. In the case of each organ 150–350 tumor cells were analysed. The interaction of tumor cells with endothelial cells and the basement membrane showed significant differences between the organs. In the liver and lungs, endothelial cells were found to migrate onto the surface of the tumor cells, resulting in the removal of tumor cells from the circulation. The process was initiated by development of cytoplasmic projections on the luminal surface of the endothelial cells. In the liver only half of the tumor cells showed basement membrane degradation even after 24 h, although 6 h after injection 40% of the tumor cells were sequestered from the circulation. In the adrenals and brain, tumor cells were not covered by endothelial cells instead, limited retraction of endothelial cells was followed by penetration of the basement membrane. In the kidney both types of tumor cell-endothelial cell interactions were observed, but the process of extravasation was not completed, stopping as the tumor cells reached the basement membrane or the mesangial matrix. The time course of tumor cell extravasation also showed significant differences between the organs. The process was most rapid in case of the liver and adrenals. By 6 h 40–50% of the tumor cells were in the process of extravasation or were in an extracapillary position. These organs are preferential metastatic sites of this tumor line. The time of extravasation was much longer in the other organs (lungs 16 h, brain 48 h), for which this tumor line shows no preference. Conclusions: (1) Type and duration of tumor cell extravasation differ between the organs. (2) The time needed to reach extraluminal position, but not the type of extravasation correlates with the organ preference. (3) Endothelial cells of the lungs and liver can play a much more active role in the process of extravasation than previously suggested. (4) Tumor cells can complete the metastatic process without reaching a complete extracapillary position; contact with the basement membrane or extracellular matrix seems to be sufficient. [ABSTRACT FROM AUTHOR]

Antimetastatic and immunomodulating activity of Phytomix-40, a new plant preparation containing various adaptogens has been evaluated on the model of Lewis lung carcinoma. Intragastric administration of the drug decreased the intensity of metastatic process by 57% in comparison with the control and improved survival by 43%. This correlated with immunomodulating effect of the drug, which manifested by increased functional activity of T lymphocytes. [ABSTRACT FROM AUTHOR]

The apoptosis-resistant phenotype of cloned high-metastatic A11 and low-metastatic P29 cells isolated from Lewis lung carcinoma was compared. The results showed that A11 cells were more resistant to apoptosis induced by microenvironmental stresses such as serum starvation, glucose deprivation and hypoxia than P29 cells as judged by viability, DNA laddering, and chromatin condensation and fragmentation. Both cell lines were insensitive to tumor necrosis factor-α-mediated apoptosis. P29 cells expressed a much higher level of Fas antigen on the cell surface than A11 cells. However, both cell lines were also insensitive to Fas-mediated apoptosis. The apoptosis resistant phenotype of A11 cells was associated with the expression level of caspase-3, but not with those of Bcl-2, Bcl-XL Bax, p27Kip1 and DAP kinase. There was no difference between A11 and P29 cells in the expression of E-cadherin, the adhesiveness to the extracellular matrix components or the expression levels of metastasis-associated genes such as c-Ha-ras, c-jun, p53 and nm23. Furthermore, A11 cells exhibited lower motile and invasive abilities than P29 cells. These results suggest that the apoptosis-resistant phenotype is an important factor for determining the metastatic ability of A11 cells. Supporting this, P29 cells became more apoptosis-resistant after treatment of the cells with dimethylsulfoxide which is reported to enhance the experimental metastatic potential of the cells. [ABSTRACT FROM AUTHOR]