Distribution and toxicity evaluation of ZnO dispersion nanoparticles in single intravenously exposed mice.

ZnO nanoparticles (NPs) have been widely used in various commercial products. Application of ZnO NPs is expected to apply to cancer diagnosis and therapy, used as drug delivery carriers. In the present study, the lethal dose 50 (LD50) of intravenously administered ZnO NPs (0.3 mg/kg) was calculated in mice. Blood kinetics and tissue distribution of a toxic dose of ZnO NPs (0.2 mg/kg, 0.05 mg/kg) were investigated after intravenous exposure. In addition, 8-hydroxy-2'-deoxyguanosine (8-OHdG) was evaluated. Following the injection, ZnO NPs were rapidly removed from the blood and distributed to organs. Pulmonary emphysema was observed pathologically study in mice at 3 days after the 0.2 mg/kg dose and at 6 days after the 0.05 mg/kg dose. ZnO NPs were mainly accumulated in the lung and spleen within 60 min. From the long-term tissue distribution study, the liver showed peak concentration at 6 days, and spleen peaked at 1 day. The lungs kept high levels until 6 days. Tissue distribution and pathological study showed that the spleen, liver, and lungs are target organs for ZnO NPs. Accumulation in the liver and spleen may be due to the phagocytosis by macrophages. A dose-dependent increase in 8-OHdG was observed in mice treated with ZnO NPs. This study is the first to show information on kinetics and target organs following intravenous ZnO injection.

Intermittent chemotherapy can retain the therapeutic potential of anti-CD137 antibody during the late tumor-bearing state.

Immunomodulating monoclonal antibodies (mAb) can evoke antitumor T-cell responses, which are attenuated by regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC). Treatment with cyclophosphamide (CP) and gemcitabine (GEM) can mitigate the immunosuppression by Treg and MDSC, respectively. In the current study, we examined the antitumor effects of a combination of local injection with anti-CD137 mAb and intermittent low-dose chemotherapy using CP and GEM in subcutaneously established CT26 colon carcinoma. Although a significant antitumor effect was observed when local anti-CD137 mAb therapy (5 µg) was started early in the tumor-bearing stage (day 10), no therapeutic efficacy was observed when the mAb therapy was started at a later tumor-bearing stage (day 17). Analyses of the tumor-infiltrating immune cells revealed that the number of Gr-1(high/low) CD11b(+) MDSC started to increase 13 days after tumor inoculation, whereas injection with low-dose (50 mg/kg) CP and GEM mitigated this increase. In addition, although intermittent injections with low-dose CP and GEM on days 10 and 18 suppressed tumor growth significantly, additional local injections of anti-CD137 mAb on days 19, 21, and 23 further augmented the therapeutic efficacy. Cytotoxic T lymphocytes reactive to CT26 and a tumor antigen peptide were induced successfully from the spleen cells of tumor-cured or tumor-stable mice. In a bilateral tumor inoculation model, this combination therapy achieved systemic therapeutic effects and suppressed the growth of mAb-untreated tumors. These results suggest that intermittent immunochemotherapy using CP and GEM could retain the therapeutic potential of anti-CD137 mAb that is normally impaired during the late tumor-bearing stage.

Field trial of GABA-fortified rice plants and oral administration of milled rice in spontaneously hypertensive rats.

Hypertension is one of the most critical risk factors accompanying cardiovascular diseases. γ-Aminobutyric acid (GABA) is a non-protein amino acid that functions as a major neurotransmitter in mammals and also as a blood-pressure lowering agent. We previously produced GABA-fortified rice lines of a popular Japonica rice cultivar 'Koshihikari' by genetic manipulation of GABA shunt-related genes. In the study reported here, we grew these same novel rice lines in a field trial and administered the milled rice orally to rats. The yield parameters of the transgenic rice plants were almost unchanged compared to those of untransformed cv. 'Koshihikari' plants, while the rice grains of the transgenic plants contained a high GABA content (3.5 g GABA/kg brown rice; 0.75-0.85 GABA g/kg milled rice) in a greenhouse trial. Oral administration of a diet containing 2.5% GABA-fortified rice, with a daily intake for 8 weeks, had an approximately 20 mmHg anti-hypertensive effect in spontaneous hypertensive rats but not in normotensive Wistar-Kyoto rats. These results suggest that GABA-fortified rice may be applicable as a staple food to control or prevent hypertension.

Pifithrin-µ, an inhibitor of heat-shock protein 70, can increase the antitumor effects of hyperthermia against human prostate cancer cells.

Hyperthermia (HT) improves the efficacy of anti-cancer radiotherapy and chemotherapy. However, HT also inevitably evokes stress responses and increases the expression of heat-shock proteins (HSPs) in cancer cells. Among the HSPs, HSP70 is known as a pro-survival protein. In this study, we investigated the sensitizing effect of pifithrin (PFT)-µ, a small molecule inhibitor of HSP70, when three human prostate cancer cell lines (LNCaP, PC-3, and DU-145) were treated with HT (43°C for 2 h). All cell lines constitutively expressed HSP70, and HT further increased its expression in LNCaP and DU-145. Knockdown of HSP70 with RNA interference decreased the viability and colony-forming ability of cancer cells. PFT-µ decreased the viabilities of all cell lines at one-tenth the dose of Quercetin, a well-known HSP inhibitor. The combination therapy with suboptimal doses of PFT-µ and HT decreased the viability of cancer cells most effectively when PFT-µ was added immediately before HT, and this combination effect was abolished by pre-knockdown of HSP70, suggesting that the effect was mediated via HSP70 inhibition. The combination therapy induced cell death, partially caspase-dependent, and decreased proliferating cancer cells, with decreased expression of c-Myc and cyclin D1 and increased expression of p21(WAF1/Cip), indicating arrest of cell growth. Additionally, the combination therapy significantly decreased the colony-forming ability of cancer cells compared to therapy with either alone. Furthermore, in a xenograft mouse model, the combination therapy significantly inhibited PC-3 tumor growth. These findings suggest that PFT-µ can effectively enhance HT-induced antitumor effects via HSP70 inhibition by inducing cell death and arrest of cell growth, and that PFT-µ is a promising agent for use in combination with HT to treat prostate cancer.

Butyric acid attenuates intestinal inflammation in murine DSS-induced colitis model via milk fat globule-EGF factor 8.

Butyric acid, a short-chain fatty acid and one of the main metabolites of intestinal microbial fermentation of dietary fiber, has been shown to have an important role in maintaining the integrity of the intestinal mucosa, while it also has been shown to exert potent anti-inflammatory effects both in vitro and in vivo. However, the precise mechanisms underlying those effects have not been fully identified. We exposed colonic epithelial cells to butyric acid, then extracted total RNA samples, and subsequently hybridized them to microarray chips. Among the upregulated genes, milk fat globule-epidermal growth factor 8 (MFG-E8) was elevated by approximately fivefold. We previously reported that the potential therapeutic benefits of MFG-E8 in intestinal tissue injury were dependent not only on enhanced clearance of apoptotic cells but also required diverse cellular events for maintaining epithelial integrity. The influence of butyric acid on cell function is often attributed to its inhibition of histone deacetylases (HDACs). We found that acetylation on histone 3 lysine 9 (acetyl-H3K9) around the MFG-E8 promoter was significantly increased with butyric acid exposure. Experimental colitis was induced by administration of dextran sodium sulfate (DSS) in C57BL/6N (MFG-E8+/+) and MFG-E8-/- mice. Although the colonic bacterial compositions in wild-type (WT) and MFG-E8-/- mice were not significantly different, intrarectal administration of butyric acid during an acute phase of colitis attenuated intestinal inflammatory parameters and inhibited body weight loss in the WT mice. Our novel findings suggest that butyric acid has significant anti-inflammatory effects partly via MFG-E8 on DSS-induced murine experimental colitis.

Metronomic chemotherapy with low-dose cyclophosphamide plus gemcitabine can induce anti-tumor T cell immunity in vivo.

Several chemotherapeutic drugs have immune-modulating effects. For example, cyclophosphamide (CP) and gemcitabine (GEM) diminish immunosuppression by regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), respectively. Here, we show that intermittent (metronomic) chemotherapy with low-dose CP plus GEM can induce anti-tumor T cell immunity in CT26 colon carcinoma-bearing mice. Although no significant growth suppression was observed by injections of CP (100 mg/kg) at 8-day intervals or those of CP (50 mg/kg) at 4-day intervals, CP injection (100 mg/kg) increased the frequency of tumor peptide-specific T lymphocytes in draining lymph nodes, which was abolished by two injections of CP (50 mg/kg) at a 4-day interval. Alternatively, injection of GEM (50 mg/kg) was superior to that of GEM (100 mg/kg) in suppressing tumor growth in vivo, despite the smaller dose. When CT26-bearing mice were treated with low-dose (50 mg/kg) CP plus (50 mg/kg) GEM at 8-day intervals, tumor growth was suppressed without impairing T cell function; the effect was mainly T cell dependent. The metronomic combination chemotherapy cured one-third of CT26-bearing mice that acquired tumor-specific T cell immunity. The combination therapy decreased Foxp3 and arginase-1 mRNA levels but increased IFN-γ mRNA expression in tumor tissues. The percentages of tumor-infiltrating CD45(+) cells, especially Gr-1(high) CD11b(+) MDSCs, were decreased. These results indicate that metronomic chemotherapy with low-dose CP plus GEM is a promising protocol to mitigate totally Treg- and MDSC-mediated immunosuppression and elicit anti-tumor T cell immunity in vivo.

Sublingual Immunotherapy Induces Regulatory Function of IL-10-Expressing CD4(+)CD25(+)Foxp3(+) T Cells of Cervical Lymph Nodes in Murine Allergic Rhinitis Model.

Sublingual immunotherapy (SLIT) has been considered to be a painless and efficacious therapeutic treatment of allergic rhinitis which is known as type I allergy of nasal mucosa. Nevertheless, its mechanisms need to be further investigated. In this study, we constructed an effective murine model of sublingual immunotherapy in allergic rhinitis, in which mice were sublingually administered with ovalbumin (OVA) followed by intraperitoneal sensitization and nasal challenge of OVA. Sublingually treated mice showed significantly decreased specific IgE responses as well as suppressed Th2 immune responses. Sublingual administration of OVA did not alter the frequency of CD4(+)CD25(+) regulatory T cells (Tregs), but led to upregulation of Foxp3- and IL-10-specific mRNAs in the Tregs of cervical lymph nodes (CLN), which strongly suppressed Th2 cytokine production from CD4(+)CD25(-) effector T cells in vitro. Furthermore, sublingual administration of plasmids encoding the lymphoid chemokines CCL19 and CCL21-Ser DNA together with OVA suppressed allergic responses. These results suggest that IL-10-expressing CD4(+)CD25(+)Foxp3(+) Tregs in CLN are involved in the suppression of allergic responses and that CCL19/CCL21 may contribute to it in mice that received SLIT.

Color preferences of laboratory mice for bedding materials: evaluation using radiotelemetry.

Preferences for different housing conditions in mice were evaluated by radiotelemetry. Male C57BL/6J and ICR mice were used. Preference for bedding materials in mice was compared among three materials, wood shavings (WS), paper (CF) and cloth (AG), using the length of stay in cages as a parameter. The results indicated that mice stayed longer in a cage with AG than in cages with other bedding materials. The present study confirmed our previous results and thereby indicated that radiotelemetry is a useful method to evaluate impacts of housing conditions on animal welfare. In the second part of this study, we used radiotelemetry to evaluate color preference of the mice for cloth bedding material. In C57BL/6J mice, staying time in black cloth was significantly longer than that in white cloth. In ICR mice, staying time in white cloth was significantly longer than that in black cloth. The mice preferred the environment with the same color as their fur, which may be important for animal welfare.

A novel fusicoccin derivative preferentially targets hypoxic tumor cells and inhibits tumor growth in xenografts.

Malignant cells in solid tumors survive under prolonged hypoxia and can be a source of resistance to current cancer therapies. Tumor hypoxia is also associated with a more malignant phenotype and poor survival in cancer patients. Recent progress in our understanding of the biology of tumor cells under hypoxia has led to increased attention on targeting hypoxia for cancer therapy. We report here that a novel fusicoccin derivative (ISIR-042), but not its parent or related compounds such as fusicoccin A and cotylenin A, is more cytotoxic to hypoxic cells than to normoxic cells. The hypoxia-induced accumulation of hypoxia-inducible factor (HIF)-1α and the phosphorylation of Akt were effectively inhibited by treatment with ISIR-042, suggesting that the preferential cytotoxicity toward hypoxic cells is associated with a reduction of HIF-1α and Akt activation. ISIR-042 inhibited the growth of human pancreatic cancer MIAPaCa-2 cells while sparing normal endothelial cells, and significantly inhibited the growth of MIAPaCa-2 cells as xenografts without apparent adverse effects. Pancreatic cancer cells expressing CD24 and CD44 exhibited characteristics of stem cells. Treatment with gemcitabine increased this stem cell-enriched population, and this effect was significantly inhibited by ISIR-042, suggesting that ISIR- 042 preferentially inhibits stem/progenitors in pancreatic cancer cell lines compared with chemotherapeutic agents. These results suggest that ISIR-042 may be a potential therapeutic agent for hypoxic tumors such as pancreatic cancer.

Short review on sublingual immunotherapy for patients with allergic rhinitis: from bench to bedside.

Sublingual immunotherapy has been considered to be a painless and effective therapeutic treatment for allergic rhinitis, and is known as type 1 allergy of the nasal mucosa. So far, its mechanism of action has been elucidated employing peripheral blood serum and lymphocytes in an antigen-specific fashion. Because of the limitations in sampling human materials, there is still controversy among many reports between clinical efficacy and laboratory data. Therefore, its mechanism of action needs to be investigated further by using promising animal models such as rodents and monkeys. Bearing this in mind, in our present study, we successfully constructed an effective murine model for sublingual immunotherapy in allergic rhinitis in which mice were administered ovalbumin (OVA) sublingually followed by intraperitoneal sensitization and nasal challenge.

Functional and genetic survey of all known single-nucleotide polymorphisms within the human deoxyribonuclease I gene in wide-ranging ethnic groups.

The single-nucleotide polymorphisms (SNPs) in the human DNase I gene (DNASE1) might be involved in susceptibility to some common diseases; however, only limited population data are available. Further, the effects of these SNPs on in vivo DNase I activity remain unknown. The genotype and haplotype of all the SNPs in DNASE1 were determined in 3 ethnic groups including 14 populations using newly developed methods. Together with our previous data on the nonsynonymous SNPs, two major haplotypes based on the five exonic SNPs were identified; genetic diversity in the Asian population was low. Among 10 SNPs, other than exonic SNPs in the gene, only 3 were polymorphic among all the populations. Haplotype distribution, based on all the polymorphic SNPs, was clarified to be generally varied in an ethnic-dependent manner. Thus, the genetic aspects of DNASE1 with regard to all the SNPs in wide-ranging ethnic groups could be first demonstrated. Further, there was no correlation of all the polymorphic SNPs other than nonsynonymous ones with serum DNase I activity levels. Polymorphic SNPs other than the exonic SNPs might not be directly related to common diseases through alterations in in vivo levels of the activity.

Global analysis of genetic variation in human arsenic (+3 oxidation state) methyltransferase (AS3MT).

Human arsenic (+3 oxidation state) methyltransferase (AS3MT) is known to catalyze the methylation of arsenite. The objective of this study was to investigate the diversity of the AS3MT gene at the global level. The distribution of 18 single nucleotide polymorphisms (SNPs) in AS3MT was performed in 827 individuals from 10 populations (Japanese, Korean, Chinese, Mongolian, Tibetans, Sri Lankan Tamils, Sri Lankan Sinhalese, Nepal Tamangs, Ovambo, and Ghanaian). In the African populations, the A allele in A6144T was not observed; the allele frequencies of C35587 were much lower than those in other populations; the allele frequencies of A37616 and C37950 were relatively higher than those in other populations. Among Asian populations, Mongolians showed a different genotype distribution pattern. A lower C3963 and T6144 frequencies were observed, and, in the C37616A and T37950C polymorphism, the Mongolian population showed higher A37616 and C37950 allele frequencies than other Asian populations, similarly to the African populations. A total of 66 haplotypes were observed in the Ovambo, 48, in the Ghanaian, 99, in the Japanese, 103, in the Korean, 103, in the South Chinese, 20, in the Sri Lankan Tamil, 12, in the Sri Lankan Sinhalese, 21, in the Nepal Tamang, 50, in the Tibetan, and 45, in the Mongolian populations. The D' values between the SNP pairs were extremely high in the Sri Lankan Sinhalese population. Relatively higher D' values were observed in Mongolian and Sri Lankan Tamil populations. Network analysis showed two clusters that may have different origins, African and Asians (Chinese and/or Japanese). The present study is the first to demonstrate the existence of genetic heterogeneity in a world wide distribution of 18 SNPs in AS3MT.

Immunogenic chemotherapy with cyclophosphamide and doxorubicin against established murine carcinoma.

Mitigation of regulatory T cell-mediated immunosuppression and elicitation of immunogenic tumor cell death are crucial events for optimal anti-tumor immune activity in vivo. This study was designed to investigate the potential synergistic activity of the combined use of cyclophosphamide (CP) and doxorubicin (DR), both of which are known to resolve these two issues. BALB/c mice were inoculated subcutaneously with CT-26 carcinoma cells in the bilateral flank and treated with an intraperitoneal injection of a low dose of CP followed by an intratumoral injection of DR into one side of the tumor. We found that, in addition to a significant suppression of growth on the DR-treated side of the tumor, combination therapy suppressed the growth of DR-untreated remote tumors in both tumor-specific and T cell-dependent manners. Mitomycin C showed no such synergistic anti-tumor activity with CP treatment. Combination therapy increased the frequency of interferon (IFN)-gamma-producing T lymphocytes specific to a CT-26-associated class I-binding tumor peptide in the tumor-draining lymph nodes. Real-time PCR analysis revealed that combination therapy led to an increase in IFN-gamma and tumor necrosis factor-alpha mRNA expression; however, levels of Foxp3 and transforming growth factor-beta within the remote tumor tissues were decreased. In addition, knock down of calreticulin expression in CT-26 cells using small interfering RNA attenuated anti-tumor vaccine effects induced by DR-treated CT-26 cells. These results provide an immunological rationale for the combined use of chemotherapeutic drugs, i.e., CP and DR, and further recommend their use with current cancer vaccines.

Evaluation of bedding and nesting materials for laboratory mice by preference tests.

Bedding and nesting materials can improve the health and environmental welfare of laboratory mice. This study was carried out to examine which items are actually preferred by mice. Two series of studies were performed on four types of floor-covering materials (Wood-shavings (Clean-chip), Cloth (Agrebe), Recycled-paper (Paper-clean), Paper (Care-feeaz), and on four types of nesting materials (Recycled-paper (Shepherd-shack), Cloth (Agrebe), Wood (Wood-cylinder), and Polycarbonate (Mouse-igloo). Preference of bedding materials was judged by the time length of staying in a cage. The results indicate that mice stayed in the cloth material (Agrebe) longer than in other bedding materials (light 51.1 +/- 5.3%, dark 51.5 +/- 2.6%). In the second experiment, the duration of stay in Agrebe was significantly longer than that in the other nesting materials in the light phase (70.9 +/- 2.4%). In the dark phase, staying time both in Agrebe and Shepherd-shack were significantly longer. These data suggest that cloth bedding and nesting is recommended for the environmental enrichment of laboratory mice.

[Experimental chemotherapy against human esophageal carcinoma xenografts with TS-1, cisplatin and docetaxel].

Three strains of human esophageal carcinoma xenografts established in our institution were tested against combination chemotherapy in vivo and in vitro. TS-1 plus cisplatin (CDDP) was shown to be an effective combination against two carcinoma strains of moderately-differentiated type. Determination of the thymidylate synthase (TS) demonstrated a higher inhibition of the enzyme by adding CDDP to 5-FU, suggesting biochemical modulation. The remaining strain of poorly-differentiated type was resistant to the combination and an attempt was made to add docetaxel (DTX) to show that the three-drug combination was effective against the strain. Combination chemotherapy including TS-1 and CDDP thus appears to be useful treatment choice for esophageal carcinoma.