Metabolic clogging of mannose triggers dNTP loss and genomic instability in human cancer cells.

Mannose has anticancer activity that inhibits cell proliferation and enhances the efficacy of chemotherapy. How mannose exerts its anticancer activity, however, remains poorly understood. Here, using genetically engineered human cancer cells that permit the precise control of mannose metabolic flux, we demonstrate that the large influx of mannose exceeding its metabolic capacity induced metabolic remodeling, leading to the generation of slow-cycling cells with limited deoxyribonucleoside triphosphates (dNTPs). This metabolic remodeling impaired dormant origin firing required to rescue stalled forks by cisplatin, thus exacerbating replication stress. Importantly, pharmacological inhibition of de novo dNTP biosynthesis was sufficient to retard cell cycle progression, sensitize cells to cisplatin, and inhibit dormant origin firing, suggesting dNTP loss-induced genomic instability as a central mechanism for the anticancer activity of mannose.

In order to grow and divide, cells require a variety of sugars. Breaking down sugars provides energy for cells to proliferate and allows them to make more complex molecules, such as DNA. Although this principle also applies to cancer cells, a specific sugar called mannose not only inhibits cancer cell division but also makes them more sensitive to chemotherapy. These anticancer effects of mannose are particularly strong in cells lacking a protein known as MPI, which breaks down mannose. Evidence from honeybees suggests that a combination of mannose and low levels of MPI leads to a build-up of a modified form of mannose, called mannose-6-phosphate, within cells. As a result, pathways required to release energy from glucose become disrupted, proving lethal to these insects. However, it was not clear whether the same processes were responsible for the anticancer effects of mannose. To investigate, Harada et al. removed the gene that encodes the MPI protein in two types of human cancer cells. The experiments showed that mannose treatment was not lethal to these cells but overall slowed the cell cycle ­ a fundamental process for cell growth and division. More detailed biochemical experiments showed that cancer cells with excess mannose-6-phosphate could not produce the molecules required to make DNA. This prevented them from doubling their DNA ­ a necessary step for cell division ­ and responding to stress caused by chemotherapy. Harada et al. also noticed that cancer cells lacking MPI did not all react to mannose treatment in exactly the same way. Therefore, future work will address these diverse reactions, potentially providing an opportunity to use the mannose pathway to search for new cancer treatments.

Discovery of 2,6-Dihalopurines as Stomata Opening Inhibitors: Implication of an LRX-Mediated H+-ATPase Phosphorylation Pathway.

Stomata are pores in the leaf epidermis of plants and their opening and closing regulate gas exchange and water transpiration. Stomatal movements play key roles in both plant growth and stress responses. In recent years, small molecules regulating stomatal movements have been used as a powerful tool in mechanistic studies, as well as key players for agricultural applications. Therefore, the development of new molecules regulating stomatal movement and the elucidation of their mechanisms have attracted much attention. We herein describe the discovery of 2,6-dihalopurines, AUs, as a new stomatal opening inhibitor, and their mechanistic study. Based on biological assays, AUs may involve in the pathway related with plasma membrane H+-ATPase phosphorylation. In addition, we identified leucine-rich repeat extensin proteins (LRXs), LRX3, LRX4 and LRX5 as well as RALF, as target protein candidates of AUs by affinity based pull down assay and molecular dynamics simulation. The mechanism of stomatal movement related with the LRXs-RALF is an unexplored pathway, and therefore further studies may lead to the discovery of new signaling pathways and regulatory factors in the stomatal movement.

In vivo evaluation of pharmacokinetic drug-drug interactions between fluorinated pyrimidine anticancer drugs, 5-fluorouracil and capecitabin, and an anticoagulant, warfarin.

Warfarin is a common anticoagulant and has demonstrated interactions with several drugs. Among them, as a serious adverse event, a case of death due to the enhanced warfarin action owing to its combined use with a fluoropyrimidine anticancer drug has been reported, but the detailed mechanism has not been elucidated.Some reports have advocated that fluorinated pyrimidine anticancer drugs reduce cytochrome P450 2C9 expression, leading to the enhanced pharmacological effects of warfarin.The purpose of this study was to clarify the mechanisms of drug-drug interactions between warfarin and 5-fluorouracil (5-FU) and capecitabine in vivo using rats. Rats were administered warfarin in combination with 5-FU (15 mg/kg/d) or capecitabine (15 mg/kg/d) for 7 d. Prothrombin time (PT) and activated partial thromboplastin time were significantly prolonged in the warfarin plus 5-FU or capecitabine groups compared with those in the warfarin alone group. No significant difference was observed in the area under the plasma concentration-time curve of the warfarin alone group compared with the warfarin with 5-FU or capecitabine groups.These data suggest that the enhancement of warfarin efficacy caused by the combination of 5-FU or capecitabine was due to a pharmacological interaction rather than a pharmacokinetic interaction.

Novel nitric oxide donor, nitrated phenylbutyrate, induces cell death of human pancreatic cancer cells and suppresses tumor growth of cancer xenografts.

Pancreatic cancer has a low response rate to chemotherapy due to the low drug transferability caused by the low blood flow around the tumor. In the present study, focusing on nitric oxide (NO) for its vasodilatory and antitumor effects, a novel NO donor, a nitrated form of phenylbutyrate (NPB) was synthesized and the antitumor effect on human pancreatic cancer cells (AsPC1 and BxPC3) and xenografts was examined. Using Annexin V, NPB was confirmed to induce cell death against AsPC1 and BxPC3 in a time­ and concentration­dependent manner. In NPB­exposed cells, DAF­FM DA (a probe to detect intracellular NO) derived fluorescence was observed. Release of nitrite and nitrate from NPB in aqueous solution was very gradual until even 72 h after dissolution. Phenylbutyrate (PB) and hydroxy PB in which the nitro group of NPB was replaced with a hydroxyl group did not have the cell death­inducing effect as observed in NPB. These results suggest that the effect of NPB was dependent on NO release form NPB. Apoptosis inhibitor, Z­VAD FMK, had no effect on the cell death­inducing effect of NPB, and NPB did not show significant activation of caspase­3/7. In addition, NPB significantly decreased cellular ATP levels, suggesting that necrosis is involved in the effect of NPB. NPB also accumulated cells specifically at the S phase of the cell cycle. A single dose of NPB (10 mg/kg) into mice with established BxPC3 xenografts significantly suppressed tumor growth for at least 7 weeks without apparent toxicity. The findings of the present study indicate that NPB has potential as a novel therapeutic agent for NO­based therapy of pancreatic cancer.

Effect of robot's vertical body movement on its perceived emotion: A preliminary study on vertical oscillation and transition.

The emotion expressions of social robots are some of the most important developments in recent studies on human-robot interactions (HRIs). Several research studies have been conducted to assess effective factors to improve the quality of emotion expression of the robots. In this study, we examined the effects of a robot's vertical oscillation and transition on the quality of its emotion expression, where the former indicates the periodic up/down movement of the body of the robot, while the latter indicates a one-time up or down movement. Short-term and long-term emotion expressions of the robot were studied independently for the four basic emotions described in the circumplex model of emotions: joy, anger, sadness, and relief. We designed an experiment with an adequate statistical power and minimum sample size of human subjects based on a priori power analysis. Human subjects were asked to evaluate the robot's emotion expressions by watching its video with/without vertical movement. The results of the experiment showed that for the long-term emotions, the speed of vertical oscillation corresponded to the degree of arousal of the emotion expression as noted in the circumplex model; this indicated that fast oscillations improved the emotion expression with a higher degree of arousal, such as joy and anger, while slow or no oscillations were more suited to emotions with a lower degree of arousal, such as sadness and relief. For the short-term emotions, the direction of the vertical transition corresponded to the degree of valence for most of the expressed emotions, while the speed of vertical oscillation reflected the degree of arousal. The findings of this study can be adopted in the development of conversational robots to enhance their emotion expression.

An ectopic thymoma arising in the middle mediastinum that was difficult to distinguish from a lymph node metastasis.

BACKGROUND: Ectopic thymomas often occur in the upper mediastinum; however, they rarely arise in the middle mediastinum, especially on the dorsal side of the innominate vein and superior vena cava in the peribronchial region. CASE PRESENTATION: Six years prior, a 27-year-old female presented to our department and was diagnosed with locally advanced left breast cancer. First, we administered chemotherapy including an anti-human epidermal growth factor receptor 2 antibody. The size of the tumor was markedly reduced, and a radical operation involving mastectomy and axillary lymph node dissection was then performed. The patient underwent radiotherapy after the mastectomy, followed by trastuzumab therapy; she continued to receive endocrine therapy thereafter. She underwent computed tomography once a year after the surgery, and a nodule in the middle mediastinum on the dorsal side of the innominate vein and superior vena cava in the parabronchial region was detected at 4 years. We speculated that the nodule was a solitary mediastinal lymph node metastasis from her breast cancer; therefore, we performed thoracoscopic resection of the tumor. We diagnosed the tumor as a thymoma. Currently, the patient visits our hospital to receive continuous hormone therapy for her breast cancer, and the latest computed tomography scan demonstrated no metastases from or recurrence of her breast cancer or thymoma. CONCLUSIONS: We report a case of ectopic thymoma in the middle mediastinum. The tumor, which was detected during systemic therapy for locally advanced breast cancer, was located on the dorsal side of the innominate vein and superior vena cava in the parabronchial region and was indistinguishable from a lymph node metastasis from breast cancer.

Discovery of Plant Growth Stimulants by C-H Arylation of 2-Azahypoxanthine.

A series of new AHX derivatives were synthesized by Pd-catalyzed C-H arylation. Their rice-growth-promoting activity was evaluated in vivo. Among the synthesized compounds, C8 phenyl-substituted AHX showed remarkable growth-promoting activity on rice. The present study shows the power and significant opportunity of C-H functionalization chemistry to rapidly transform biologically active natural products into more active compounds.

Adsorption of orthophosphoric, pyrophosphoric, and tripolyphosphoric acids from aqueous solutions by calcined gibbsite.

In this research, gibbsite (GB) samples calcined at 200-1000°C (GB200-GB1000) were produced. These GBs were used to adsorb orthophosphoric, pyrophosphoric, and tripolyphosphoric acids from aqueous solutions. The properties (amounts of hydroxyl groups, specific surface areas, mean pore diameters, and solution pHs) of the GBs were investigated, and their adsorption capacities for phosphoric acids evaluated. The amount of hydroxyl groups (0.46 mmol/g) and specific surface area (295.3 m(2)/g) of GB400 were greater than those of the other GBs. The mechanism of phosphoric acid adsorption on the GBs was related to the amount of hydroxyl groups and specific surface area. The optimal pH for phosphoric acid adsorption by GBs was 2.0-3.0. Equilibrium adsorption was reached within 24 h. The adsorption processes followed a pseudo-second-order kinetic model (correlation coefficient, 0.998-0.999). The adsorption capacity increased with increasing temperature. The adsorption isotherm data fitted the Langmuir (correlation coefficient: 0.921-0.992) and Freundlich (correlation coefficient: 0.948-0.997) equations well. Our results will be useful when developing methods for the adsorption of phosphoric acids from aqueous solutions.

A study on the adsorption of heavy metals by using raw wheat bran bioadsorbent in aqueous solution phase.

Raw wheat bran (R-WB) was used as a biomass adsorbent. The properties of R-WB were investigated. Moreover, the adsorption of cadmium and lead ions onto R-WB was evaluated. Adsorption equilibrium of cadmium and lead ions onto R-WB was achieved within 10 h, indicating that the adsorption followed a pseudo-second-order model rather than a pseudo-first-order kinetic model. The adsorption amount increased with increasing temperature. Correlation coefficient of the Langmuir equation is 0.999 for cadmium and 0.996 for lead ions, and that of the Freundlich equation is 0.994 for cadmium and 0.993 for lead ions. The negative ΔG value implied that the adsorption of cadmium and lead ions onto R-WB is a spontaneous process. The positive ΔS value indicated an increase in randomness at the solid-liquid interface. The optimal conditions for the adsorption column experiment were investigated (space velocity (SV) 2.2 1/h, linear velocity (LV) 0.1 m/h for cadmium; SV 6.51 1/h, LV 0.23 m/h for lead ions). Further, repeated adsorption-desorption of the cadmium and lead ions could be effected by using 0.01 mol/L HCl or 0.01 mol/L HNO3 solution. Consequently, polluted water could be successfully purified by using a column filled with this bioadsorbent.

Study of adsorption mechanism of heavy metals onto waste biomass (wheat bran).

In this study, raw wheat bran (R-WB), a type of waste biomass (WB) was treated with Pectinase PL (P-WB), and the properties (yield percentage, carboxy group surface concentration, the solution pH, and specific surface area) of R-WB and P-WB were investigated. The surface concentration of carboxy groups on R-WB (3.56 mmol/g) was greater than that of P-WB (2.11 mmol/g). In contrast, the specific surface area of P-WB (24.98 m²/g) was greater than that of R-WB (3.25 m²/g). In addition, the adsorption of cadmium and lead ions to WB was evaluated. Adsorption of the heavy-metal ions reached equilibrium within 9 h, and the experimental data was fitted to a pseudo-second-order model. More heavy-metal ions were adsorbed onto R-WB than onto P-WB. The correlation coefficient between the amount of ions adsorbed and the number of carboxy groups or pectin exceeded 0.884 and 0.975, respectively. This study indicated that wheat bran was useful for the removal of cadmium or lead ions from aqueous solutions. The adsorption mechanism of cadmium and lead ions to WB was associated with presence of carboxy group in pectin.

Phosphate-ion-adsorption capability of granulated boehmite fabricated using organic binder (polyethylene terephthalate).

We investigated a method for producing granulated boehmite (BE) by using an organic binder and measured its phosphate-ion-adsorption capacity. BE was granulated using polyethylene terephthalate (PET), and its structure was characterized by scanning electron microscopy and X-ray diffraction analyses. The properties of granulated BE such as specific surface area, mean pore diameter, pore volume, amount of hydroxyl groups, and solution pH were also investigated. Furthermore, adsorption isotherm; effects of contact time, temperature, and solution pH on phosphate-ion adsorption; and recovery of phosphate ions (using sodium hydroxide solution) were evaluated. BE granulated by PET (BE-PET30S) could be successfully used for phosphate-ion removal by adsorption. The specific surface area and amount of hydroxyl groups of BE-PET30S were found to be 119.8 m²/g and 1.4 mmol/g, respectively. Granulated BEs reached equilibrium adsorption capacities within 24 h. The phosphate-ion-adsorption rate data were fitted to the pseudo-second-order kinetic model (r=0.981-0.998). The adsorption isotherm data were fitted to both the Freundlich (0.987-0.989) and Langmuir (0.905-0.944) equations. Based on the thermodynamic study, it was found that the phosphate-ion adsorption by granulated BEs is a spontaneous and exothermic process. The phosphate ions adsorbed onto BE-PET30S could be easily recovered by using a sodium hydroxide solution (1-1000 mmol/L) and their recovery percentage was found to be between 63.3% and 94.0%. The results obtained from this study could be useful for recovering phosphate ions and preventing problems related to water pollution.

Application of activated carbons from coal and coconut shell for removing free residual chlorine.

This study investigated the removal of free residual chlorine by activated carbon (AC). ACs were prepared from coal (AC1) and coconut shell (AC2). The specific surface area of AC1 was larger than that of AC2. The removal of free residual chlorine increased with elapsed time and amount of adsorbent. The removal mechanism of free residual chlorine was the dechlorination reaction between hypochlorous acid or hypochlorite ion and AC. Moreover, AC1 was useful in the removal of free residual chlorine in tap water. The optimum condition for the removal of free residual chlorine using a column is space velocity 306 1/h; liner velocity 6.1 m/h.

Study on analysis of waste edible oil with deterioration and removal of acid value, carbonyl value, and free fatty acid by a food additive (calcium silicate).

This study investigated the regeneration of waste edible oil using a food additive (calcium silicate, CAS). Waste edible oil was prepared by combined heat and aeration treatment. Moreover, the deterioration of edible oil by combined heat and aeration treatment was greater than that by heat treatment alone. The acid value (AV) and carbonyl value (CV) increased with increasing deterioration; conversely, the tocopherol concentration decreased with increasing deterioration. The specific surface area, pore volume, and mean pore diameter of the 3 CAS formulations used (CAS30, CAS60, and CAS90) were evaluated, and scanning electron microscopic images were taken. The specific surface area increased in the order of CAS30 (115.54 m(2)/g) < CAS60 (163.93 m(2)/g) < CAS90 (187.47 m(2)/g). The mean pore diameter increased in the order of CAS90 (170.59 Å) < CAS60 (211.60 Å) < CAS30 (249.70 Å). The regeneration of waste edible oil was possible with CAS treatment. The AV reduced by 15.2%, 10.8%, and 23.1% by CAS30, CAS60, and CAS90 treatment, respectively, and the CV was reduced by 35.6%, 29.8%, and 31.3% by these 3 treatments, respectively. Moreover, the concentrations of tocopherol and free fatty acids did not change with CAS treatment. The characteristics of CAS were not related to the degree of change of AV and CV. However, the adsorption mechanism of polar and non-polar compounds generated in waste edible oil by CAS was related with the presence of silica gel molecules in CAS. The findings indicated that CAS was useful for the regeneration of waste edible oil.

Human adipose tissue-derived multilineage progenitor cells exposed to oxidative stress induce neurite outgrowth in PC12 cells through p38 MAPK signaling.

BACKGROUND: Adipose tissues contain populations of pluripotent mesenchymal stem cells that also secrete various cytokines and growth factors to support repair of damaged tissues. In this study, we examined the role of oxidative stress on human adipose-derived multilineage progenitor cells (hADMPCs) in neurite outgrowth in cells of the rat pheochromocytoma cell line (PC12). RESULTS: We found that glutathione depletion in hADMPCs, caused by treatment with buthionine sulfoximine (BSO), resulted in the promotion of neurite outgrowth in PC12 cells through upregulation of bone morphogenetic protein 2 (BMP2) and fibroblast growth factor 2 (FGF2) transcription in, and secretion from, hADMPCs. Addition of N-acetylcysteine, a precursor of the intracellular antioxidant glutathione, suppressed the BSO-mediated upregulation of BMP2 and FGF2. Moreover, BSO treatment caused phosphorylation of p38 MAPK in hADMPCs. Inhibition of p38 MAPK was sufficient to suppress BMP2 and FGF2 expression, while this expression was significantly upregulated by overexpression of a constitutively active form of MKK6, which is an upstream molecule from p38 MAPK. CONCLUSIONS: Our results clearly suggest that glutathione depletion, followed by accumulation of reactive oxygen species, stimulates the activation of p38 MAPK and subsequent expression of BMP2 and FGF2 in hADMPCs. Thus, transplantation of hADMPCs into neurodegenerative lesions such as stroke and Parkinson's disease, in which the transplanted hADMPCs are exposed to oxidative stress, can be the basis for simple and safe therapies.

[Detection of implicit memory for hard-to-encode tone sequences using an indirect recognition procedure].

Two experiments, using an indirect recognition procedure (Terasawa & Ohta, 1993) as an implicit memory task, were conducted to examine implicit memory for random tone sequences. The indirect recognition procedure involved two sessions. The second session was a general recognition experiment consisting of learning and a recognition test phase. The effects of the learning during the first session were examined based on the recognition performance in the second session. The interval between the sessions was 10 weeks for experiment 1 and 8 weeks for experiment 2. In each session, participants were required to rate their liking for each of the sequences presented. In the second session, participants were required to respond to an old-new recognition test about the items just presented. The targets and distractors in the test consisted of stimuli presented or not presented in the first session. Analyses of the hits and false alarms showed an effect of the number of presentations in the first session. This result indicates an effect of long lasting implicit memory for tone sequences.