Phosphorylation of DNA-binding domains of CLOCK-BMAL1 complex for PER-dependent inhibition in circadian clock of mammalian cells.

In mammals, CLOCK and BMAL1 proteins form a heterodimer that binds to E-box sequences and activates transcription of target genes, including Period (Per). Translated PER proteins then bind to the CLOCK-BMAL1 complex to inhibit its transcriptional activity. However, the molecular mechanism and the impact of this PER-dependent inhibition on the circadian clock oscillation remain elusive. We previously identified Ser38 and Ser42 in a DNA-binding domain of CLOCK as phosphorylation sites at the PER-dependent inhibition phase. In this study, knockout rescue experiments showed that nonphosphorylatable (Ala) mutations at these sites shortened circadian period, whereas their constitutive-phospho-mimetic (Asp) mutations completely abolished the circadian rhythms. Similarly, we found that nonphosphorylatable (Ala) and constitutive-phospho-mimetic (Glu) mutations at Ser78 in a DNA-binding domain of BMAL1 also shortened the circadian period and abolished the rhythms, respectively. The mathematical modeling predicted that these constitutive-phospho-mimetic mutations weaken the DNA binding of the CLOCK-BMAL1 complex and that the nonphosphorylatable mutations inhibit the PER-dependent displacement (reduction of DNA-binding ability) of the CLOCK-BMAL1 complex from DNA. Biochemical experiments supported the importance of these phosphorylation sites for displacement of the complex in the PER2-dependent inhibition. Our results provide direct evidence that phosphorylation of CLOCK-Ser38/Ser42 and BMAL1-Ser78 plays a crucial role in the PER-dependent inhibition and the determination of the circadian period.

GGT1 is a SNP eQTL gene involved in STAT3 activation and associated with the development of Post-ERCP pancreatitis.

Post-ERCP pancreatitis (PEP) is an acute pancreatitis caused by endoscopic-retrograde-cholangiopancreatography (ERCP). About 10% of patients develop PEP after ERCP. Here we show that gamma-glutamyltransferase 1 (GGT1)-SNP rs5751901 is an eQTL in pancreatic cells associated with PEP and a positive regulator of the IL-6 amplifier. More PEP patients had the GGT1 SNP rs5751901 risk allele (C) than that of non-PEP patients at Hokkaido University Hospital. Additionally, GGT1 expression and IL-6 amplifier activation were increased in PEP pancreas samples with the risk allele. A mechanistic analysis showed that IL-6-mediated STAT3 nuclear translocation and STAT3 phosphorylation were suppressed in GGT1-deficient cells. Furthermore, GGT1 directly associated with gp130, the signal-transducer of IL-6. Importantly, GGT1-deficiency suppressed inflammation development in a STAT3/NF-κB-dependent disease model. Thus, the risk allele of GGT1-SNP rs5751901 is involved in the pathogenesis of PEP via IL-6 amplifier activation. Therefore, the GGT1-STAT3 axis in pancreas may be a prognosis marker and therapeutic target for PEP.

Exercise effect on pain is associated with negative and positive affective components: A large-scale internet-based cross-sectional study in Japan.

Pain is a global health problem that leads to sedentary behavior and tends to cause negative emotion. In contrast, exercise is widely recommended for a health promotion, while pain often worsens with physical activity. Although exercise therapy is often prescribed to people with pain, the mechanisms of exercise effect on pain remains unclear. In this study, we tried to identify a universal association factor between regular exercise and pain intensity utilizing a cross-sectional web-based survey involving 52,353 adult participants from a large national study conducted in Japan. Using principal component analysis, we uncovered a mediation model of exercise effect on pain through psychological components. Analyses were performed in half of the population with pain (n = 20,330) and validated in the other half (n = 20,330), and showed that high-frequency exercise had a significant association with reduction in pain intensity. We also found Negative Affect and Vigor, two psychological components, are fully associating the exercise effect on pain (indirect effect = - 0.032, p < 0.001; association proportion = 0.99) with a dose-dependent response corresponding to the frequency of exercise. These findings were successfully validated (indirect effect of high-frequency exercise = - 0.028, p < 0.001; association proportion = 0.85). Moreover, these findings were also identified in subpopulation analyses of people with low back, neck, knee pain, and the tendency of the exercise effect on pain was increased with older people. In conclusion, the effect of exercise on pain is associated with psychological components and these association effects increased in parallel with the frequency of exercise habit regardless pain location.

High-precision rapid testing of omicron SARS-CoV-2 variants in clinical samples using AI-nanopore.

A digital platform that can rapidly and accurately diagnose pathogenic viral variants, including SARS-CoV-2, will minimize pandemics, public anxiety, and economic losses. We recently reported an artificial intelligence (AI)-nanopore platform that enables testing for Wuhan SARS-CoV-2 with high sensitivity and specificity within five minutes. However, which parts of the virus are recognized by the platform are unknown. Similarly, whether the platform can detect SARS-CoV-2 variants or the presence of the virus in clinical samples needs further study. Here, we demonstrated the platform can distinguish SARS-CoV-2 variants. Further, it identified mutated Wuhan SARS-CoV-2 expressing spike proteins of the delta and omicron variants, indicating it discriminates spike proteins. Finally, we used the platform to identify omicron variants with a sensitivity and specificity of 100% and 94%, respectively, in saliva specimens from COVID-19 patients. Thus, our results demonstrate the AI-nanopore platform is an effective diagnostic tool for SARS-CoV-2 variants.

Derivation of a new model of lung adenocarcinoma using canine lung cancer organoids for translational research in pulmonary medicine.

Canine primary lung cancer (cPLC) is a rare malignant tumor in dogs, and exhibits poor prognosis. Effective therapeutic drugs against cPLC have not been established yet. Also, cPLC resembles human lung cancer in histopathological characteristics and gene expression profiles and thus could be an important research model for this disease. Three-dimensional organoid culture is known to recapitulate the tissue dynamics in vivo. We, therefore, tried to generate cPLC organoids (cPLCO) for analyzing the profiles of cPLC. After samples from cPLC and the corresponding normal lung tissue were collected, cPLCO were successfully generated, which recapitulated the tissue architecture of cPLC, expressed lung adenocarcinoma marker (TTF1), and exhibited tumorigenesis in vivo. The sensitivity of cPLCO to anti-cancer drugs was different among strains. RNA-sequencing analysis showed significantly upregulated 11 genes in cPLCO compared with canine normal lung organoids (cNLO). Moreover, cPLCO were enriched with the MEK-signaling pathway compared with cNLO. The MEK inhibitor, trametinib decreased the viability of several strains of cPLCO and inhibited the growth of cPLC xenografts. Collectively, our established cPLCO model might be a useful tool for identifying novel biomarkers for cPLC and a new research model for dog and human lung cancer.

Anti-cancer activity of Chaga mushroom (Inonotus obliquus) against dog bladder cancer organoids.

Despite its disadvantages, chemotherapy is still commonly used for the treatment of bladder cancer (BC). Developing natural supplements that can target cancer stem cells (CSCs) which cause drug resistance and distant metastasis is necessary. Chaga mushrooms are popular to have several health-promoting and anti-cancer potentials. Organoid culture can recapitulate tumor heterogeneity, epithelial environment, and genetic and molecular imprints of the original tissues. In the previous study, we generated dog bladder cancer organoids (DBCO) as a novel experimental model of muscle-invasive BCO. Therefore, the present study aimed to examine the anti-tumor potentials of Chaga mushroom extract (Chaga) against DBCO. Four strains of DBCO were used in the present study. Treatment with Chaga inhibited the cell viability of DBCO in a concentration-dependent way. Treatment of DBCO with Chaga has significantly arrested its cell cycle and induced apoptosis. Expression of bladder CSC markers, CD44, C-MYC, SOX2, and YAP1, declined in the Chaga-treated DBCO. Also, Chaga inhibited the phosphorylation of ERK in DBCO. Expression of downstream signals of ERK, C-MYC, and Cyclins (Cyclin-A2, Cyclin-D1, Cyclin-E1, and CDK4) was also inhibited by Chaga in DBCO. Interestingly, the combinational treatment of DBCO with Chaga and anti-cancer drugs, vinblastine, mitoxantrone, or carboplatin, showed a potentiating activity. In vivo, Chaga administration decreased tumor growth and weight of DBCO-derived xenograft in mice with the induction of necrotic lesions. In conclusion, Chaga diminished the cell viability of DBCO by inhibiting proliferation-related signals and stemness conditions as well as by arresting the cell cycle. Collectively, these data suggest the value of Chaga as a promising natural supplement that could potentiate the effect of adjuvant chemotherapy, lower its adverse effects, and thus, limit the recurrence and metastasis of BC.

GM-CSF Promotes the Survival of Peripheral-Derived Myeloid Cells in the Central Nervous System for Pain-Induced Relapse of Neuroinflammation.

We recently discovered a (to our knowledge) new neuroimmune interaction named the gateway reflex, in which the activation of specific neural circuits establishes immune cell gateways at specific vessel sites in organs, leading to the development of tissue-specific autoimmune diseases, including a multiple sclerosis (MS) mouse model, experimental autoimmune encephalomyelitis (EAE). We have reported that peripheral-derived myeloid cells, which are CD11b+MHC class II+ and accumulate in the fifth lumbar (L5) cord during the onset of a transfer model of EAE (tEAE), play a role in the pain-mediated relapse via the pain-gateway reflex. In this study, we investigated how these cells survive during the remission phase to cause the relapse. We show that peripheral-derived myeloid cells accumulated in the L5 cord after tEAE induction and survive more than other immune cells. These myeloid cells, which highly expressed GM-CSFRα with common ß chain molecules, grew in number and expressed more Bcl-xL after GM-CSF treatment but decreased in number by blockade of the GM-CSF pathway, which suppressed pain-mediated relapse of neuroinflammation. Therefore, GM-CSF is a survival factor for these cells. Moreover, these cells were colocalized with blood endothelial cells (BECs) around the L5 cord, and BECs expressed a high level of GM-CSF. Thus, GM-CSF from BECs may have an important role in the pain-mediated tEAE relapse caused by peripheral-derived myeloid cells in the CNS. Finally, we found that blockade of the GM-CSF pathway after pain induction suppressed EAE development. Therefore, GM-CSF suppression is a possible therapeutic approach in inflammatory CNS diseases with relapse, such as MS.

Computer model of IL-6-dependent rheumatoid arthritis in F759 mice.

The interleukin-6 (IL-6) amplifier, which describes the simultaneous activation of signal transducer and activator of transcription 3 (STAT3) and NF-κb nuclear factor kappa B (NF-κB), in synovial fibroblasts causes the infiltration of immune cells into the joints of F759 mice. The result is a disease that resembles human rheumatoid arthritis. However, the kinetics and regulatory mechanisms of how augmented transcriptional activation by STAT3 and NF-κB leads to F759 arthritis is unknown. We here show that the STAT3-NF-κB complex is present in the cytoplasm and nucleus and accumulates around NF-κB binding sites of the IL-6 promoter region and established a computer model that shows IL-6 and IL-17 (interleukin 17) signaling promotes the formation of the STAT3-NF-κB complex followed by its binding on promoter regions of NF-κB target genes to accelerate inflammatory responses, including the production of IL-6, epiregulin, and C-C motif chemokine ligand 2 (CCL2), phenotypes consistent with in vitro experiments. The binding also promoted cell growth in the synovium and the recruitment of T helper 17 (Th17) cells and macrophages in the joints. Anti-IL-6 blocking antibody treatment inhibited inflammatory responses even at the late phase, but anti-IL-17 and anti-TNFα antibodies did not. However, anti-IL-17 antibody at the early phase showed inhibitory effects, suggesting that the IL-6 amplifier is dependent on IL-6 and IL-17 stimulation at the early phase, but only on IL-6 at the late phase. These findings demonstrate the molecular mechanism of F759 arthritis can be recapitulated in silico and identify a possible therapeutic strategy for IL-6 amplifier-dependent chronic inflammatory diseases.

Establishment of an experimental model of canine malignant mesothelioma organoid culture using a three-dimensional culture method.

Canine malignant mesothelioma (cMM) is a rare and drug-resistant malignant tumor. Due to few patients and experimental models, there have not been enough studies to demonstrate the pathogenesis of the disease and novel effective treatment for cMM. Since cMM resembles human MM (hMM) in histopathological characteristics, it is also considered a promising research model of hMM. Compared with conventional 2-dimensional (2D) culture methods, 3-dimensional (3D) organoid culture can recapitulate the properties of original tumor tissues. However, cMM organoids have never been developed. In the present study, we for the first time generated cMM organoids using the pleural effusion samples. Organoids from individual MM dogs were successfully generated. They exhibited the characteristics of MM and expressed mesothelial cell markers, such as WT-1 and mesothelin. The sensitivity to anti-cancer drugs was different in each strain of cMM organoids. RNA sequencing analysis showed cell adhesion molecule pathways were specifically upregulated in cMM organoids compared with their corresponding 2D cultured cells. Among these genes, the expression level of E-cadherin was drastically higher in the organoids than that in the 2D cells. In conclusion, our established cMM organoids might become a new experimental tool to provide new insights into canine and human MM therapy.

Zoobiquity experiments show the importance of the local MMP9-plasminogen axis in inflammatory bowel diseases in both dogs and patients.

Using a zoobiquity concept, we directly connect animal phenotypes to a human disease mechanism: the reduction of local plasminogen levels caused by matrix metalloproteinase-9 (MMP9) activity is associated with the development of inflammation in the intestines of dogs and patients with inflammatory bowel disease. We first investigated inflammatory colorectal polyps (ICRPs), which are a canine gastrointestinal disease characterized by the presence of idiopathic chronic inflammation, in Miniature Dachshund (MD) and found 31 missense disease-associated SNPs by whole-exome sequencing. We sequenced them in 10 other dog breeds and found five, PLG, TCOF1, TG, COL9A2 and COL4A4, only in MD. We then investigated two rare and breed-specific missense SNPs (T/T SNPs), PLG: c.477G > T and c.478A>T, and found that ICRPs with the T/T SNP risk alleles showed less intact plasminogen and plasmin activity in the lesions compared to ICRPs without the risk alleles but no differences in serum. Moreover, we show that MMP9, which is an NF-κB target, caused the plasminogen reduction and that intestinal epithelial cells expressing plasminogen molecules were co-localized with epithelial cells expressing MMP9 in normal colons with the risk alleles. Importantly, MMP9 expression in patients with ulcerous colitis or Crohn's disease also co-localized with epithelial cells showing enhanced NF-κB activation and less plasminogen expression. Overall, our zoobiquity experiments showed that MMP9 induces the plasminogen reduction in the intestine, contributing to the development of local inflammation and suggesting the local MMP9-plasminogen axis is a therapeutic target in both dogs and patients. Therefore, zoobiquity-type experiments could bring new perspectives for biomarkers and therapeutic targets.

Detection of anti-feline infectious peritonitis virus activity of a Chinese herb extract using geneLEAD VIII, a fully automated nucleic acid extraction/quantitative PCR testing system.

The geneLEAD VIII is a fully-automated nucleic acid extraction/quantitative PCR equipment developed by Precision System Science Co., Ltd., (PSS). To take advantage of its capability, we developed a quantitative assay system to measure growth of animal viruses. The system was used to assay one of the Chinese herbal extracts whose anti-malarial activities were previously reported and demonstrated its dose-dependent anti-viral activity against feline infectious peritonitis virus (FIPV), a feline coronavirus causing the fatal diseases in cats, and relatively low cell toxicity. The assay developed in this study is useful to screen antiviral drugs and the anti-FIPV activity of the herbal extract identified have a potential to lead to development of new drugs against FIPV and other coronaviruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Improvement in Disability Mediates the Effect of Self-Efficacy on Pain Relief in Chronic Low Back Pain Patients with Exercise Therapy.

Background: The biopsychosocial mechanism by which exercise leads to improvement in chronic low back pain (CLBP) remains unstudied. This prospective cohort study was performed to examine the effectiveness of exercise on pain, disability, and psychological status for CLBP. We also tested path analytic models in which changes in these variables were included. Methods: CLBP patients who visited the Interdisciplinary Pain Center of Keio University Hospital from July 2018 to April 2020 were included. The propensity score matching was performed between patients who underwent exercise (the exercise group) and those who did not (the control group). At the first visit and at the 3-month follow-up, pain (Numerical Rating Scale (NRS)), disability (Pain Disability Assessment Scale (PDAS)), and psychological status (Pain Self-Efficacy Questionnaire (PSEQ), and Pain Catastrophizing Scale (PCS)) were assessed. Changes in pain and disability at the follow-up were compared between the groups. The relationships between changes in pain, disability, and psychological variables were examined using Pearson's correlation and mediation analysis. Results: A significantly larger decrease in the PDAS was observed in the exercise group (N = 49) than in the control (N = 49) (p < 0.05). Increased PSEQ scores were significantly correlated with decreased NRS scores in both groups. In the exercise group, decreased PDAS fully mediated the relationship between increased PSEQ and decreased NRS (P < 0.05). Conclusion: Exercise improved disability, and the improved disability by exercise mediated the effect of increased self-efficacy on pain relief in CLBP patients.

Clinical Trial for Evaluating the Effectiveness and Safety of a New Dental Plaque Removal Device: Microscale Mist Unit.

This study evaluates the effectiveness and safety of a microscale mist unit (MSM-UNIT) that sprays high-speed fine water droplets to remove dental plaque adhering to the oral mucosa (tongue and palate) and tooth surface. Fifteen patients who had difficulty self-managing sufficient oral care were included in this study. Effectiveness was evaluated for at least five patients' tongues, palate mucosas, and tooth surfaces, and safety evaluation was conducted at all three sites for all patients. Effectiveness was evaluated using the rate of degree of dental plaque removal. Safety was evaluated using a numerical rating scale (NRS) for pain and symptoms of inflammation. An operator who performed treatment and an evaluator who evaluated effectiveness and safety were designated. In addition, an image judgment committee judged effectiveness. Although evaluation of the tongue varied between the evaluators and the image judgment committee, the rates of degree for all plaque removal increased in all regions. In addition, low pain NRS results and minimal symptoms of inflammation were observed and within an acceptable range. The MSM-UNIT can be used effectively and safely for removing oral plaque not only from teeth, but also from the oral mucosa.

Establishment of an experimental model of normal dog bladder organoid using a three-dimensional culture method.

Dog bladder cancer (BC) is mostly muscle-invasive (MI) with poor prognosis, and its pathogenesis is close to human MIBC. Three-dimensional (3D) organoid culture ensures novel knowledge on cancer diseases including BC. Recently, we have established dog BC organoids (BCO) using their urine samples. BCO recapitulated the epithelial structures, characteristics, and drug sensitivity of BC-diseased dogs. However, organoids from dog normal bladder epithelium are not established yet. Therefore, the present study aimed to establish dog normal bladder organoids (NBO) for further understanding the pathogenesis of dog BC and human MIBC. The established NBO underwent various analyzes including cell marker expressions, histopathological structures, cancer-related gene expression patterns, and drug sensitivity. NBO could be produced non-invasively with a continuous culturing and recapitulated the structures and characteristics of the dog's normal bladder mucosal tissues. Different drug sensitivities were observed in each NBO. The analysis of RNA sequencing revealed that several novel genes were changed in NBO compared with BCO. NBO showed a higher expression of p53 and E-cadherin, but a lower expression of MDM2 and Twist1 compared with BCO. These results suggest that NBO could be a promising experimental 3D model for studying the developmental mechanisms of dog BC and human MIBC.

Effect of the liquid form of traditional Chinese medicine, Hozen-S, on gastric motility in dogs.

Juzen-taiho-to, a traditional Chinese herbal medicine, is used for patients with anorexia and fatigue in human medicine. In our previous study, granulated Juzen-taiho-to improved vincristine-induced gastrointestinal adverse effects through increasing gastric motility in dogs. As the effect of Hozen-S, the sweet liquid form of Juzen-taiho-to, on dog gastric motility has not been investigated, we examined the effect of administration of Hozen-S on gastric motility. Furthermore, we assessed dog plasma ghrelin level to further elucidate the mechanism of the effect of Hozen-S on gastric contraction. Finally, we assessed the palatability of Hozen-S compared to granulated Juzen-taiho-to and its effect on body weight in dogs. Administration of Hozen-S significantly increased gastric motility, plasma ghrelin concentration, and body weight. A palatability evaluation revealed that the dogs preferred Hozen-S to granulated Juzen-taiho-to. In conclusion, Hozen-S administration to dogs promoted gastric motility by raising plasma ghrelin levels. Considering these functional and palatability data, Hozen-S may replace granulated type Juzen-taiho-to and become a prominent traditional Chinese veterinary medicament.

Impact of Dental Referral Prior to Elective Surgery on Postoperative Outcomes.

OBJECTIVES: Oral bacteria may contribute to postoperative infectious complications including postoperative pneumonia or surgical site infection. The aim of this study was to investigate the impact of preoperative dental care on postoperative outcomes among surgical patients under general anesthesia. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: We analyzed clinical records of major surgical patients at a university hospital between 2016 and 2018. Subjects were categorized into either the preoperative dental care group, those being referred to dentists by their surgeons based on an individual surgeon's judgment for dental care before surgery, or the control group. METHODS: The primary outcome was postoperative infectious complications. Secondary outcomes were postoperative inflammation markers (C-reactive protein and fever), and economic outcomes (postoperative length of hospital stay and medical expenses). As the main analysis, the average treatment effects of the preoperative dental care were obtained from the augmented inverse-probability weighting (AIPW) method with consideration of demographics and perioperative risk factors to estimate causal effect of the intervention from the observational data. Then, stratified analyses by age and surgical sites were conducted with the inverse-probability weighting and linear regression methods, respectively. RESULTS: In the AIPW estimation, compared with the control group, the care group saw a significantly lower rate of postoperative infection (average treatment effect -3.02) and shorter fever duration (-2.79 days). The stratified analysis by age revealed significant positive impact of dental care in all age groups, including the highest treatment effects observed among patients younger than 60. Also, treatment effect was observed in wider surgical sites than previously known. CONCLUSION/IMPLICATIONS: This study indicates a significant impact of preoperative dental care on preventing postoperative infection and inflammation. Along with old age or certain types of surgeries in which advantages of dental referral have been already known, preoperative dental referral could be beneficial for broader types of patients.

Rewired Cellular Metabolic Profiles in Response to Metformin under Different Oxygen and Nutrient Conditions.

Metformin is a metabolic disruptor, and its efficacy and effects on metabolic profiles under different oxygen and nutrient conditions remain unclear. Therefore, the present study examined the effects of metformin on cell growth, the metabolic activities and consumption of glucose, glutamine, and pyruvate, and the intracellular ratio of nicotinamide adenine dinucleotide (NAD+) and reduced nicotinamide adenine dinucleotide (NADH) under normoxic (21% O2) and hypoxic (1% O2) conditions. The efficacy of metformin with nutrient removal from culture media was also investigated. The results obtained show that the efficacy of metformin was closely associated with cell types and environmental factors. Acute exposure to metformin had no effect on lactate production from glucose, glutamine, or pyruvate, whereas long-term exposure to metformin increased the consumption of glucose and pyruvate and the production of lactate in the culture media of HeLa and HaCaT cells as well as the metabolic activity of glucose. The NAD+/NADH ratio decreased during growth with metformin regardless of its efficacy. Furthermore, the inhibitory effects of metformin were enhanced in all cell lines following the removal of glucose or pyruvate from culture media. Collectively, the present results reveal that metformin efficacy may be regulated by oxygen conditions and nutrient availability, and indicate the potential of the metabolic switch induced by metformin as combinational therapy.

Anti-malarial activity in a Chinese herbal supplement containing Inonotus obliquus and Panax notoginseng.

Plasmodium falciparum, the most virulent human malaria parasite, causes serious diseases among the infected patients in the world and is particularly important in African regions. Although artemisinin combination therapy is recommended by the WHO for treatment of P. falciparum-malaria, the emergence of artemisinin-resistant parasites has become a serious issue which underscores the importance of sustained efforts to obtain novel chemotherapeutic agents against malaria. As a part of such efforts, thirty-nine herbal extracts from traditional Chinese medicine (TCM) were assayed for their anti-malarial activity using 3D7 strain of P. falciparum. Three herbal supplements appeared to possess higher specific anti-malarial activity than the others. One of them (D3) was separated by two sequential fractionations with reverse-phase (the first step) and normal-phase (the second step) liquid chromatography, in which some fractions resulted in higher specific activities than those of D3 or the previous fractions. Cell toxicity assay was performed with the fractions of the first fractionation and demonstrated no obvious cell toxicity. These results suggest that structure determination of the major compound for the anti-malarial activity in D3 may help the development of more potent chemicals in the future.

Hypoxically cultured cells of oral squamous cell carcinoma increased their glucose metabolic activity under normoxic conditions.

OBJECTIVE: The oxygen concentration within cancer tissue is known to be low, but is expected to increase rapidly when oxygen is supplied by angiogenesis and hematogenous metastasis, suggesting that rapid increases in oxygen levels might influence cancer cell physiology. Therefore, we investigated the effects of oxygen concentration fluctuations on the glucose metabolism of cancer cells. METHODS: The glucose metabolism of oral squamous cell carcinoma (HSC-2 and HSC-3) and normal epithelial (HaCaT) cells cultured under normoxic (21% oxygen) or hypoxic (1% oxygen) conditions was measured using a pH-stat system under normoxic or hypoxic conditions. The acidic end-products and reactive oxygen species (ROS) generated by glucose metabolism were also measured. RESULTS: Under normoxic conditions, the metabolic activity of hypoxically cultured cancer cells was significantly increased, and the production of acids other than lactate was upregulated, while the normal cells did not respond to rapid increases in oxygen levels. ROS production was higher in normoxic conditions in all cells, especially the hypoxically cultured HSC-3 cells. CONCLUSIONS: Rapid increases in oxygen levels might enhance the glucose metabolism of hypoxically cultured cancer cells by mainly activating the TCA cycle and electron transport system, which might activate cancer cells through the ATP and ROS generation.

Evaluation of the Safety and Feasibility of Apheresis in Dogs: For Application in Metastatic Cancer Research.

In patients with solid tumors, circulating tumor cells (CTCs) spread in their blood and function as a seed for metastases. However, the study of CTCs has been limited by their rarity, low frequency, and heterogeneity. The efficient collection of CTCs will contribute to further research of metastatic cancers. Apheresis is a process in which the whole blood of an individual is passed through a machine that isolates a particular constituent and returns the remainder to the circulation. In the present study, we investigated the safety and feasibility of apheresis to separate peripheral blood monocytes (PBMCs), whose density is closely similar to that of CTCs, and to capture intravenously administered human breast cancer cells, MCF7s, from the dogs. No life-threatening events were observed in dogs during the apheresis process. The changes in the hemogram were transient and recovered gradually within a few days after apheresis. During apheresis, 50 mL of PBMCs could be collected from each dog. Notably, a thrombus was formed along the circuit wall during apheresis, which decreased the blood collection pressure. MCF7 cells were successfully captured by the apheresis machine. The captured cells were regrown in vitro and characterized compared with the original cells. In conclusion, apheresis could be safely performed in dogs to isolate CTCs with precautions to maintain hemodynamic stability.