Tissues Of Tumor-bearing Mice Research Articles

Exposure of tumor-bearing mice to extremely high-frequency electromagnetic radiation modifies the composition of fatty acids in thymocytes and tumor tissue

Purpose: To test the participation of fatty acids (FA) in antitumor effects of extremely high-frequency electromagnetic radiation (EHF EMR), the changes in the FA composition in the thymus, liver, blood plasma, muscle tissue, and tumor tissue in mice with Ehrlich solid carcinoma exposed to EHF EMR were studied.Materials and methods: Normal and tumor-bearing mice were exposed to EHF EMR with effective parameters (42.2 GHz, 0.1 mW/cm2, 20 min daily during five consecutive days beginning the first day after the inoculation of tumor cells). Fatty acid composition of various organs and tissues of mice were determined using a gas chromatography.Results: It was shown that the exposure of normal mice to EHF EMR or tumor growth significantly increased the content of monounsaturated FA (MUFA) and decreased the content of polyunsaturated FA (PUFA) in all tissues examined. Exposure of tumor-bearing mice to EHF EMR led to the recovery of FA composition in thymocytes to the state that is typical for normal animals. In other tissues of tumor-bearing mice, the exposure to EHF EMR did not induce considerable changes that would be significantly distinguished between disturbances caused by EHF EMR exposure or tumor growth separately. In tumor tissue which is characterized by elevated level of MUFA, the exposure to EHF EMR significantly decreased the summary content of MUFA and increased the summary content of PUFA.Conclusions: The recovery of the FA composition in thymocytes and the modification of the FA composition in the tumor under the influence of EHF EMR on tumor-bearing animals may have crucial importance for elucidating the mechanisms of antitumor effects of the electromagnetic radiation.

Abstract 1886: Metabolic alterations associated with pancreatic cancer-induced cachexia.

Abstract Cachexia, a metabolic syndrome, leads to loss of muscle weight and fat tissues. Cancer-induced cachexia accounts for nearly 20% of all cancer-related deaths and is most prevalent in patients with gastric, pancreatic, colon and lung cancer. Although association of cachexia with various types of cancers has been known for a long time, the molecular mechanism of cancer-induced cachexia is still not well understood. Better understanding of the cancer-related cachexia syndrome may provide novel therapeutic targets and improved health care for cancer patients. By culturing differentiated C2C12 and 3T3-L1 cells in the presence of pancreatic adenocarcinoma cell or immortalized epithelial cell supernatants, we established cell culture-based cachexia model systems to investigate the depletion of muscle mass and fatty acid storage. Progressive physiological and biochemical alterations during muscle fibre breakdown and adipocyte fat depletion were assayed by utilizing western blotting, real-time PCR and cell imaging. We then investigated metabolomic alterations in C2C12 and 3T3-L1 cell lines in response to the cachectic factors secreted by the tumor cells. We performed differential metabolomic analyses on tumor cell supernatant-treated or control treated differentiated C2C12 muscle fibers and 3T3-L1-derived adipocytes by utilizing 2D 1H-13C HSQC NMR technique. Alterations in metabolic pathways were also investigated by evaluating the expression of metabolic genes in the corresponding pathways by performing quantitative real-time PCR. To obtain further insights into the metabolic alterations that trigger cachexia, we extended our studies to in vivo mouse orthotopic xenograft models and investigated alterations in metabolic gene expression and metabolite flux in muscle and fat tissues of tumor-bearing mice. Our results identify crucial nodes in metabolite flux that can be targeted to regulate cell growth, proliferation, and turnover in muscle and fat tissues during cancer-induced cachexia. Citation Format: Surendra K. Shukla, Pankaj K. Singh. Metabolic alterations associated with pancreatic cancer-induced cachexia. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1886. doi:10.1158/1538-7445.AM2013-1886

Synthesis of anisotropic plasmonic nanoparticles with core-shell structure and prospects of their application in laser treatment of tumors

Aggregative stable dispersions of particles with anisotropic cores of iron(III) oxyhydroxide and gold or silver nanoshells are synthesized. They feature maximum plasmonic absorption at about 1000 nm (i.e., in the “optical window” of biological tissues). Such composite particles are of considerable interest for their potential use in cancer therapy. The possibility of finely tuning the position of localized surface plasmon resonance to the required wavelength is demonstrated for the FeOOH core/Au(Ag) shell nanostructures through a controlled variation of the metal shell thickness with a very small step (up to 1 nm). The surface modification of such composite particles by polyethylene glycol (PEG) considerably enhances the aggregative stability of their aqueous dispersions. Quantitative information about the distribution dynamics of the PEG-conjugated composite FeOOH core/Au shell particles in various organs and tissues of tumor-bearing mice has been obtained after an intravenous injection of a colloid solution of these particles. It is shown that composite particles can remain for a rather long time in a bloodstream without aggregation; moreover, their accumulation in a tumor takes place. Preliminary in vivo experiments have shown that PEGylated FeOOH core/Au(Ag) shell particles are effective thermosensibilizers in the pulse laser therapy of tumors.

Coassembled Cytotoxic and Pegylated Peptide Amphiphiles Form Filamentous Nanostructures with Potent Antitumor Activity in Models of Breast Cancer

Self-assembled peptide amphiphiles (PAs) consisting of hydrophobic, hydvrogen-bonding, and charged hydrophilic domains form cylindrical nanofibers in physiological conditions and allow for the presentation of a high density of bioactive epitopes on the nanofiber surface. We report here on the use of PAs to form multifunctional nanostructures with tumoricidal activity. The combination of a cationic, membrane-lytic PA coassembled with a serum-protective, pegylated PA was shown to self-assemble into nanofibers. Addition of the pegylated PA to the nanostructure substantially limited degradation of the cytolytic PA by the protease trypsin, with an 8-fold increase in the amount of intact PA observed after digestion. At the same time, addition of up to 50% pegylated PA to the nanofibers did not decrease the in vitro cytotoxicity of the cytolytic PA. Using a fluorescent tag covalently attached to PA nanofibers we were able to track the biodistribution in plasma and tissues of tumor-bearing mice over time after intraperitoneal administration of the nanoscale filaments. Using an orthotopic mouse xenograft model of breast cancer, systemic administration of the cytotoxic pegylated nanostructures significantly reduced tumor cell proliferation and overall tumor growth, demonstrating the potential of multifunctional PA nanostructures as versatile cancer therapeutics.

Changes in fatty acid composition of thymus cells, liver, blood plasma, and muscle tissue in mice with solid Ehrlich carcinoma

The fatty acid composition of thymus cells, liver, blood plasma, muscle tissue, and tumor focus has been studied in mice with solid Ehrlich carcinoma. The tumor growth in the mice was associated with an increase in the total content of monounsaturated fatty acids in all organs and tissues studied and with a decrease in the total amount of polyunsaturated fatty acids in all tissues except blood plasma. The tumor tissue was characterized by increased levels of monounsaturated fatty acids in comparison with their levels in organs and tissues of intact animals. In the thymus of tumor-bearing mice, the contents of myristic and palmitic saturated fatty acids, which are associated with activation of the T-cell immunity, were increased. The most expressed and considerable changes in the fatty acid composition during tumor growth were observed in the muscle tissue of the animals. A possible role of changes in the fatty acid composition in the investigated organs and tissues of tumor-bearing mice in the organism's response to tumor growth is discussed.

Rapid and Simple Analysis of <i>N</i>-Aspartylchlor in E6 (Talaporfin) Using Fluorescence Microtiterplate and Its Application for Determination in Cells, Tissues and Blood

N-aspartylchlorin e6 (talaporfin) concentrations in cancer cells, mouse liver tissues, and human plasma specimens were determined with fluorescence microtiter plate analysis. Talaporfin standard curves were obtained in each of the sample specimens of cells, mouse tissues, or human plasma including serial concentration of talaporfin. The correlation co-efficiencies (r2) of talaporfin standard curves were 0.99-1.00, and the CV less than 5%. Talaporfin incorporation into cells of human breast cancer cell line MCF-7 after incubating with 25 μg/mL talaporfin for up to 24 h revealed that the t-max of the drug incorporation was approximately 5 h, and the maximum drug concentration incorporated was 25 μg/107 cells. Talaporfin incorporation into MCF-7 cells was significantly decreased in the presence of 3 μg/mL cyc-losporine (p < 0.05). Balb/c nu/nu mice implanted human cholangiocarcinoma NOZ cells in liver were administered intravenously 5mg/mouse of talaporfin, and the tissues of normal liver and tumor, as well as plasma specimens, were analyzed for talaporfin concentrations. The mean (SD) of talaporfin concentration in plasma after 30 min of administration was 41.6 (2.3) μg/mL, while the level decreased to undetectable concentrations 2 h after administration. In contrast, the talaporfin concentrations in normal and tumor tissues after 30 min of administration were 1.1-7.8 μg/g tissue, and the level slightly increased or was almost maintained for up to 2-4 h after administration. The heparinized blood of the healthy subjects was incubated with 25 μg/mL talaporfin for up to 24 h. The plasma talaporfin concentration did not significantly change during the incubation, and thus talaporfin appears not to be incorporated into the blood cells. We established rapid and simple analysis procedures of talaporfin in biological specimens using a fluorescence microtiter plate assay. Using this assay procedure, the unique pattern of talaporfin disposition and pharmacokinetics were revealed in human cancer cells, liver tissues of tumor bearing mice, and human blood.

Folate mediated l-arginine modified oligo (alkylaminosiloxane) graft poly (ethyleneimine) for tumor targeted gene delivery

Folate receptor mediated gene targeting provides several advantages such as delivery of high concentration of gene at specific tumor sites including brain, lung, ovary, uterus and kidney where folate receptors are over expressed. In the present study for both systemic stability and tumor targeting ability, poly (ethylene glycol)–folic acid (PEG–FA) conjugate was coupled with an arginine modified oligo (alkylaminosiloxane) graft poly (ethyleneimine) having enhanced transfection efficiency compared to poly (ethyleneimine). The resultant polymer P(SiDAAr)5FP2 complexed pDNA effectively and showed protection against nuclease degradation. The PEG group provided improved blood compatibility and cell viability. Uniformly oriented arginine moiety helped to enhance cellular and nuclear localisation, which led to improved transfection. The polymer was capable of releasing pDNA at the nucleus and being cleared from the cell after its purpose. Transfection in presence of cellular uptake inhibitors showed multiple pathways for cellular uptake of the targeted polymer, out of which folate receptor mediated uptake was more prominent. The folate mediated cellular uptake of P(SiDAAr)5FP2 was then confirmed by flow cytometric evaluation. The high accumulation of targeted polymers in the tumor tissues of tumor bearing mice from 2nd hour onwards proved the active targeting effect of the polymer. Besides tumor accumulation, the material showed capability to diffuse through the vascular endothelium. This property is expected to be beneficial for brain targeting experiments.

Changes in 2′-deoxycytidine levels in various tissues of tumor-bearing mice

The nucleoside 2'-deoxycytidine (dCyd) increases in the plasma of cancer patients with poor prognoses. 5-fluorouracil (5FU) is one of the anti-cancer agents used in chemotherapy for patients whose plasma dCyd is elevated. We examined the free dCyd level in various tissues of mice, with and without tumors, and in mice with and without the administration of 5FU or of dCyd, and investigated the effects of dCyd in tumor-bearing animals. SP2/0-Ag14 mouse myeloma cells were transplanted subcutaneously into mice and 5FU or dCyd was administered intraperitoneally. Free dCyd was measured in blood and tissues by HPLC at two time points, once when mouse body weight was maximally decreased (1 day after the last administration of 5FU, day 16) and again when it returned to control level at 1 week after the last 5FU treatment (day 22). Results showed that in tumor-bearing mice, the level of dCyd (per g wet weight) increased in the spleen. The change in liver weight caused by the administration of 5FU correlated with the level of dCyd in the liver. Notably, the relative tumor volume and tumor weight was decreased in dCyd-treated animals in comparison with controls. In conclusion, the levels of dCyd were markedly altered in the tissues of the reticuloendothelial and lymphatic systems, such as liver and spleen, and dCyd apparently had the ability to inhibit tumor growth in the body.

Cancer-Specific Transgene Expression Mediated by Systemic Injection of Nanoparticles

The lack of safe and efficient systemic gene delivery vectors has largely reduced the potential of gene therapy in the clinic. Previously, we have reported that polypropylenimine dendrimer PPIG3/DNA nanoparticles are capable of tumor transfection upon systemic administration in tumor-bearing mice. To be safely applicable in the clinic, it is crucial to investigate the colloidal stability of nanoparticles and to monitor the exact biodistribution of gene transfer in the whole body of the live subject. Our biophysical characterization shows that dendrimers, when complexed with DNA, are capable of forming spontaneously in solution a supramolecular assembly that possesses all the features required to diffuse in experimental tumors through the enhanced permeability and retention effect. We show that these nanoparticles are of sizes ranging from 33 to 286 nm depending on the DNA concentration, with a colloidal stable and well-organized fingerprint-like structure in which DNA molecules are condensed with an even periodicity of 2.8 nm. Whole-body nuclear imaging using small-animal nano-single-photon emission computed tomography/computer tomography scanner and the human Na/I symporter (NIS) as reporter gene shows unique and highly specific tumor targeting with no detection of gene transfer in any of the other tissues of tumor-bearing mice. Tumor-selective transgene expression was confirmed by quantitative reverse transcription-PCR at autopsy of scanned animals, whereas genomic PCR showed that the tumor sites are the predominant sites of nanoparticle accumulation. Considering that NIS imaging of transgene expression has been recently validated in humans, our data highlight the potential of these nanoparticles as a new formulation for cancer gene therapy.

Antitumor efficacy of cisplatin-loaded glycol chitosan nanoparticles in tumor-bearing mice

To make a tumor targeting nano-sized drug delivery system, biocompatible and biodegradable glycol chitosan ( M w = 250 kDa) was modified with hydrophobic cholanic acid. The resulting hydrophobically modified glycol chitosans (HGCs) that formed nano-sized self-aggregates in an aqueous medium were investigated as an anticancer drug carrier in cancer treatment. Insoluble anticancer drug, cisplatin (CDDP), was easily encapsulated into the hydrophobic cores of HGC nanoparticles by a dialysis method, wherein the drug loading efficiency was about 80%. The CCDP-encapsulated HGC (CDDP-HGC) nanoparticles were well-dispersed in aqueous media and they formed a nanoparticles structure with a mean diameter about 300–500 nm. As a nano-sized drug carrier, the CDDP-HGC nanoparticles released the drug in a sustained manner for a week and they were also less cytotoxic than was free CDDP, probably because of sustained release of CDDP from the HGC nanoparticles. The tumor targeting ability of CDDP-HGC nanoparticles was confirmed by in vivo live animal imaging with near-infrared fluorescence Cy5.5-labeled CDDP-HGC nanoparticles. It was observed that CDDP-HGC nanoparticles were successfully accumulated by tumor tissues in tumor-bearing mice, because of the prolonged circulation and enhanced permeability and retention (EPR) effect of CDDP-HGC nanoparticles in tumor-bearing mice. As expected, the CDDP-HGC nanoparticles showed higher antitumor efficacy and lower toxicity compared to free CDDP, as shown by changes in tumor volumes, body weights, and survival rates, as well as by immunohistological TUNEL assay data. Collectively, the present results indicate that HGC nanoparticles are a promising carrier for the anticancer drug CDDP.

Marqibo (Vincristine Sulfate Liposomes Injection, OPTISOME™) Concentrates Vincristine in Tumor Tissue and Lymphoid Malignancy Oriented Tissues in Tumor-Bearing Mice.

Background: Vincristine sulfate (VCR) is a cell-cycle specific, lipophilic, anti-cancer drug that inhibits cell division by binding to tubulin in mitotic spindles. Marqibo is a proprietary sphingomyelin/cholesterol liposome (OPTISOME) encapsulated formulation of VCR with an extended circulating half-life and the potential for preferential malignancy targeting, exposure, and anti-cancer activity. This report evaluates the concentration and accumulation of VCR in solid tumor tissue as well as tissues frequently involved with lymphoid malignancies in tumor-bearing mice following equivalent doses of Marqibo or conventional VCR.Methods: Mice were implanted subcutaneously with MX-1 human breast tumor tissue. When the tumor volume reached 162–485 mm3, mice received a single intravenous dose of Marqibo, containing 1.5 mg/kg of [14C]-VCR, or 1.5 mg/kg of non-liposomal [14C]-VCR. The total radioactivity from parent compound and metabolites in tissue, VCReq, was analyzed by Quantitative Whole Body Autoradioluminography (QWBA) and tissue digestion (TD). QWBA analysis of bone marrow (BM), tumor tissue, lymph nodes, liver, and spleen required 1 flash-frozen mouse per group at various time intervals. Sagittal sections were examined histologically for radioactivity. For TD, all tissues except bone marrow were obtained from 3 mice per group prior to infusion and at selected time points. The samples were chemically digested and analyzed for radioactivity by liquid scintillation counting.Results: QWBA analysis revealed at least two-fold higher VCReq tissue concentrations in the Marqibo-injected mice compared to the conventional VCR-injected mice.VCReq Tissue Concentration (mcg/g) at 48 hours Post-InjectionBMTumorLymphLiverSpleenMarqibo0.991.351.980.476.08VCR0.360.31--0.130.76Marqibo/VCR ratio2.754.35--3.618The TD results are consistent with the QWBA results shown in the table. Marqibo-injected mice demonstrated a minimum 5-fold increase in VCR exposure over a 96 hour period (VCReq AUC analysis) compared to VCR-injected mice over a 48 hour period, as defined in the parameters of the study, in the implanted tumor (123 vs. 21 hr*μg/g), lymph nodes (121 vs. 16.5 hr*μg/g), liver (68.8 vs. 12 hr*μg/g), and spleen (512 vs. 68.9 hr*μg/g). Though the parameters for the AUC values may favor Marqibo, the Tmax of all specified tissues are at least 16 times greater in Marqibo-injected mice than in VCR-injected mice (16 hrs vs. 1hr in tumor, spleen, and lymph; 4 hrs vs. 15 min. in liver; 16 hrs. vs. 15 min. in the kidney). The greatest increase in VCR exposure produced by Marqibo was observed in the spleen and lymph nodes (7.4- and 7.3-fold).Conclusions: Marqibo resulted in targeted delivery of VCR; concentration of VCR in tumor tissue, BM, lymph nodes, liver, and spleen; and maintenance of significant tissue drug concentrations for an extended period of time compared to conventional VCR. The ability of Marqibo to target drug to these tissues and organs makes it particularly attractive as a treatment for hematologic malignancies like myeloma, lymphoma, and acute lymphoblastic leukemia (ALL). Late-stage clinical development of Marqibo in adult ALL is underway.

Chemomodulatory effects of Azadirachta indica on the hepatic status of skin tumor bearing mice

The liver plays an important role in the modulation of the process of carcinogenesis, as it is the primary site for the biotransformation of xenobiotics including carcinogens as well as anticancer drugs. The present study was designed to evaluate the biochemical alterations occurring in the liver of 7,12-dimethylbenz(a)anthracene (DMBA) induced skin tumor bearing male Balb/c mice and their modulation by aqueous Azadirachta indica leaf extract (AAILE). It was observed that skin tumor induction caused hepatic damage characterized by a decreased hepatosomatic index and significantly increased (p < 0.001) activities of the hepatic tissue injury marker enzymes, namely alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase. However, upon treatment with AAILE, the above-mentioned alterations, including the increased activities of hepatic tissue injury marker enzymes, were significantly reversed, which signified the hepato-protective efficacy of Azadirachta indica. Increased oxidative stress was also observed in the hepatic tissue of skin tumor bearing mice as revealed by a significant increase (p < 0.001) in lipid peroxidation levels and a decrease in reduced glutathione contents and activities of various antioxidant enzymes studied, namely glutathione-S-transferase, glutathione peroxidase and glutathione reductase. The AAILE treatment reduced oxidative stress by decreasing lipid peroxidation levels and enhancing the reduced glutathione contents and activities of various antioxidant enzymes. The activities of the xenobiotic biotransformation enzymes, namely cytochrome P450, cytochrome b5 and glutathione-S-transferase, were found to be decreased in the hepatic tissue of tumor bearing mice. Treatment with AAILE further caused a decrease in the activity of cytochrome P450 and cytochrome b5, whereas it up-regulated the activity of glutathione-S-transferase. The significance of these observations with respect to the progress of the process of carcinogenesis is explained in the present research article.

Tumor penetration of gefitinib (Iressa), an epidermal growth factor receptor tyrosine kinase inhibitor

The relative distribution of gefitinib-related material in nude mice bearing s.c. human tumor xenografts and in an orthotopic rat lung tumor model was investigated following oral administration (50 mg/kg) of [14C]-gefitinib. Selected tissue samples were monitored for radioactivity by liquid scintillation counting, whereas plasma and tumor extracts were assayed for gefitinib and its major metabolites (M523595 and M537194) by high-performance liquid chromatography with tandem mass spectrometric detection. Tissue distribution was also determined by whole body autoradiography. Gefitinib was extensively distributed into the tissues of tumor-bearing mice and unchanged gefitinib was shown to account for most of the tumor radioactivity. Concentrations of gefitinib in mouse s.c. tumor xenografts were similar to skin concentrations and substantially greater (up to 12-fold based on area under the concentration-time curve) than plasma. Concentrations of gefitinib-related material in an orthotopic rat lung tumor were similar to those in healthy lung tissue and were much higher than corresponding blood levels. Following treatment of breast cancer patients with oral gefitinib (Iressa) 250 mg/d for > or = 14 days, gefitinib concentrations (mean, 7.5 microg/g, 16.7 micromol/L) in breast tumor tissue were 42 times higher than plasma, confirming the preferential distribution of gefitinib from blood into tumor tissue in the clinical situation. These gefitinib tumor concentrations are considerably higher than those reportedly required in vitro to achieve complete inhibition of epidermal growth factor receptor autophosphorylation in both epidermal growth factor receptor mutant (0.2 micromol/L) and wild-type cells (2 micromol/L).

Effect of tumor weight and tube feeding on TNF-alpha and IL-1beta mRNA expression in the brain of mice.

Previous studies have shown that cytokine mRNA expression is elevated in the brains of anorectic, tumor-bearing rats. The objectives of the current study were as follows: (1) to determine whether a small tumor would result in up-regulation of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta mRNA expression in the brain and other tissues of tumor-bearing mice; and (2) to determine whether hyperalimentation by tube feeding would prevent up-regulation of cytokine mRNA expression in the brain and other tissues of tumor-bearing mice. Male C57BL/6 mice were divided into 4 groups: (1) control mice fed ad libitum (Control); (2) tumor-bearing mice fed ad libitum (TB); (3) control mice receiving tube feeding (CTF); and (4) tumor-bearing mice receiving tube feeding (TBTF). TNF-alpha and IL-1beta mRNA expression was elevated in the brains of mice with a 1% body weight tumor, relative to the control and CTF groups, without any detectable changes in the other organs. On the other hand, TNF-alpha and IL-1beta mRNA expression was elevated in all organs of mice with an 8% body weight tumor, relative to the control and CTF groups. Tube feeding did not change TNF-alpha and IL-1beta mRNA expression in mice burdened with either a 1% or 8% body weight tumor. Up-regulation of cytokine mRNA synthesis occurs earlier in the brain than in other organs, and hyperalimentation does not change cytokine mRNA expression in tumor-bearing mice.

Increase in histidine decarboxylase activity in tissues of mice bearing Colon-26 tumor cells.

The changes in histidine decarboxylase (HDC) activity, histamine and tele-methylhistamine contents were examined in tissues of mice after the inoculation of Colon-26 tumor cells subcutaneously into the lower back. The HDC activity in the spleen of mice increased significantly 14 days after the inoculation of Colon-26 and the increase in HDC activity continued for up to 28 days. However, the histamine content in the spleen of tumor-bearing mice was not changed significantly during the observation period. In the following experiments, two subclones of the Colon-26 cell line, cachexia-inducing clone-20 and non cachexia-inducing clone-5, were used and the induction of HDC activity in mice was examined in four tissues, spleen, lung, liver and kidney. Both clone-20 and clone-5 induced the increase in HDC activity to the same extent in the spleen and lung, but not in the liver and kidney. As observed using the Colon-26 original cell line, the histamine contents in the four tissues of tumor-bearing mice were not different from those in the control mice. In contrast, the levels of tele-methylhistamine, one of the major catabolites of histamine, in the tumor-bearing mice increased significantly compared with the control mice in all four tissues examined. There was a correlation between the increase in tele-methylhistamine level and the increase in HDC activity in the tissues. A histological study indicated that the tissue mast cells were not increased in spleen and lung of tumor-bearing mice. These findings indicated that the increase in HDC activity in the spleen and lung occurred in parallel with the growth of inoculated tumor cells in mice and suggested that the cells other than mast cells may be involved in the increase in HDC activity. The tumor-bearing state produced histamine with a high turnover rate in the mouse tissues, especially in the spleen and lung.

Relationship between the Tissue Distribution and Antitumor Activity of Highly Branched (1.RAR.3)-.BETA.-D-Glucan, SSG.

Distribution of 3H-labeled (1-->3)-beta-D-glucan([3H]SSG) obtained from the culture filtrate of Sclerotinia sclerotiorum IFO 9395, in various tissues in tumor-bearing mice was examined. [3H]SSG administered intra-peritoneally was mainly detected in liver, spleen, kidney and tumor masses. In contrast to i.p. administration, intra-lesionally administered [3H]SSG was not released from the tumor. Similarly, in a double grafted tumor system, [3H]SSG was located in the administered tumor and not distributed in the distant site tumor, in spite of the fact that significant antitumor effect was shown in both tumor sites in this system. Winn assay confirmed the activation of the systemic antitumor immunity. These results suggested that the distribution of glucans would be one important factor in determining their antitumor effects. However, this would not always be necessary if systemic immunity could be induced.

Doxorubicin Encapsulated in Long-Circulating Thermosensitive Liposomes

AbstractDoxorubicin (DXR) was encapsulated in long-circulating, thermosensitive liposomes (TSL, 180-200 nm in mean diameter), prepared from dipalmitoyl phosphatidyl choline (DPPC)/distearoyl phosphatidyl choline (DSPC) (9:1, m/m) and either 3 mol% of amphipathic polyethylene glycol (PEG) with 1000 in average molecular weight or 6 mol% of ganglioside GMI (GMI), with 95-98% entrapping efficiency by the pH gradient method. 57% or 45% of the entrapped DXR was released from PEG/DPPC/DSPC or GM1/DPPC/DSPC liposomes, respectively, by incubation with 20% serum at 42°C for 5 min. Inclusion of PEG or GM1 endowed TSL with prolonged circulation ability, resulting in increased blood levels of liposomes and decreased reticuloendothelial system (RES) uptake over 6 hours after injection. Concomitantly, high DXR level in blood was kept for long time.Accumulation of DXR into tumor tissue of tumor-bearing mice (mouse colon carcinoma 26) by local hyperthermia after injection of DXR-long-circulating TSL was 2 times or 7 times...

Monoclonal secretory immunoglobulin A protects mice against oral challenge with the invasive pathogen Salmonella typhimurium.

Hybridomas producing monoclonal immunoglobulin A (IgA) antibodies against Salmonella typhimurium were generated by mucosal immunization of BALB/c mice with attenuated strains of S. typhimurium and subsequent fusion of Peyer's patch lymphoblasts with myeloma cells. To test the role of secretory IgA (sIgA) in protection against Salmonella sp., we analyzed in detail the protective capacity of a monoclonal IgA, Sal4, produced in polymeric as well as monomeric forms, that is directed against a carbohydrate epitope exposed on the surface of S. typhimurium. BALB/c mice bearing subcutaneous Sal4 hybridoma tumors and secreting monoclonal sIgA into their gastrointestinal tracts were protected against oral challenge with S. typhimurium. This protection was directly dependent on specific recognition by the monoclonal IgA, since mice secreting Sal4 IgA from hybridoma tumors were not protected against a fully virulent mutant that lacks the Sal4 epitope. Although monoclonal Sal4 IgA was present in the bloodstreams and tissues of tumor-bearing mice, it did not protect against intraperitoneal challenge and did not possess complement-fixing or bacteriocidal activity in vitro. Taken together, these results indicate that secretion of sIgA alone can prevent infection by an invasive enteric pathogen, presumably by immune exclusion at the mucosal surface.

Zinc, calcium, and magnesium metabolism: effects on plasmacytomas in Balb/c mice

The effects of different amounts of dietary zinc on the Zn absorption rate and on Zn, calcium and magnesium concentrations in tissues of MOPC 104E tumor-bearing Balb/c mice were determined. The Zn absorption rate was inversely related to the amounts of Zn in their diets and was lower than that of nontumor-bearing control mice fed a laboratory mice chow. Zn concentrations of tumor-bearing mice were also low compared with control mice but tumor Zn concentrations, regardless of the concentrations of Zn in the diets, were higher than those of normal tissues of the host other than the pancreas. Ca concentrations in tumor and tissues of tumor-bearing mice were higher than in control animals but Mg concentrations in tissues of tumor-bearing mice appeared to be similar to those of control mice. Results suggest that tumor-bearing mice have a lower intestinal Zn absorption capacity and a higher Zn uptake rate causing other tissues to become hypozincemic and hypercalcemic.

The effect of TEPC-183 plasmacytoma growth on β-glucuronidase activity in serum and tissues of tumor-bearing mice

β-Glucuronidase activity increased in the serum of BALB c mice during the growth of the IgM-secreting plasmacytoma, TEPC-183. The increase appeared to correlate with tumor burden. The β-glucuronidase activity in tissue homogenates of spleen, liver, and kidney from tumor-bearing mice also increased significantly compared to the levels found in corresponding tissues from normal control mice. Assays of lysosomal and microsomal fractions from livers of TEPC-bearing mice indicated that approximately 70% of the enzyme activity was associated with the lysosomal fraction and the remainder with the microsomal fraction. A similar distribution was found in homogenates prepared from the plasmacytoma itself. In contrast to this the β-glucuronidase activity in livers from normal BALB c mice is nearly equally distributed between lysosomal and microsomal fractions.