Variation in Utilization of Postoperative Rehabilitation After Total Hip Arthroplasty in Japan.

OBJECTIVE: The use of rehabilitation after arthroplasty in Japan is unknown. We aimed to identify utilization of postoperative rehabilitation after total hip arthroplasty (THA) and to explore the factors associated with rehabilitation usage. DESIGN: A retrospective cohort study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB). SETTING: Hospitals nationwide. PARTICIPANTS: Patients aged >40 years who underwent primary THA between 2017 and 2018 (N=51,332). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The proportion of patients who underwent postoperative rehabilitation and the number of rehabilitation days were also calculated. Patient demographic characteristics, hospital case volumes, and regions associated with continuing postoperative rehabilitation were analyzed using a Cox proportional hazards model. RESULTS: Eligible patients were selected from 3033 hospitals, of whom 41,192 (80%) were women. Of these, 94% used inpatient rehabilitation, and 20% received outpatient rehabilitation. The mean durations of rehabilitation were 47±72 days for inpatient and 195±109 days for outpatient, respectively. Large-scale hospitals performing more than 200 procedures annually had the shortest duration of inpatient rehabilitation (36-65 days) and the longest duration of outpatient rehabilitation (220-109 days) compared with smaller hospitals. The regression model consistently showed that rehabilitation continued longer at hospitals with over 200 patients per year (HR 0.96, 95% CI 0.93-0.99, P<.007). CONCLUSION: The Japanese health care system provided higher access to inpatient rehabilitation after THA than other countries. One limitation of this study is that long-term care insurance data were not analyzed. However, outpatient rehabilitation vary according to hospital case volume. Further research is needed to determine the causes of variation in rehabilitation use and the effect of variation on patient outcomes.

Effect of intravenous fluid therapy for acute alcohol intoxication on length of time from arrival at the emergency department until awakening: A prospective observational cohort study.

Aim: To evaluate the association of intravenous fluid (IVF) therapy on the length of time from arrival at the emergency department (ED) until awakening in cases of acute alcohol intoxication. Methods: This single-center, prospective, observational study was conducted in the ED of the Self-Defense Forces Central Hospital during October 1, 2018 to July 31, 2019. Patients with 1,000 mL bolus of lactated Ringer's solution and those without bolus were compared. The primary outcome was the length of time until awakening. Secondary outcomes were the length of stay in the ED and occurrence of conditions requiring extra care. Predictors of the occurrence of any event requiring extra care were identified. Results: We included 201 patients, of whom 109 received IVF and 92 did not. No significant difference existed in the baseline characteristics between the groups. The median length of time until awakening did not significantly differ between the groups (P = 0.77). Multivariable regression analysis adjusted by age, sex, hemoglobin, blood alcohol concentration, and initial Glasgow Coma Scale (GCS) score demonstrated that the regression coefficient of IVF for length of time until awakening was -9.55 (95% confidence interval [CI], -36.2 to 17.2). Hemoglobin (regression coefficient, 10.1; 95% CI, 0.38-19.9) and initial GCS score (regression coefficient, -7.51; 95% CI, -10.8 to -4.21) were significantly associated with length of time. Conclusion: IVF therapy was not associated with the length of time until awakening in patients with acute alcohol intoxication in the ED. Routine IVF administration was unnecessary.

In vitro evaluation of (S)-2-amino-3-[3-(2-18F-fluoroethoxy)-4-iodophenyl]-2-methylpropanoic acid (18F-FIMP) as a positron emission tomography probe for imaging amino acid transporters.

BACKGROUND: (S)-2-amino-3-[3-(2-18F-fluoroethoxy)-4-iodophenyl]-2-methylpropanoic acid (18F-FIMP) as a promising PET probe for imaging the tumor-specific L-type amino acid transporter (LAT) 1. Our previous study revealed that 18F-FIMP had a higher affinity for LAT1 than for LAT2 abundantly expressed even in normal cells. 18F-FIMP showed high accumulation in LAT1-positive tumor tissues and low accumulation in inflamed lesions in tumor-bearing mice. However, the affinity of 18F-FIMP for other amino acid transporters was not determined yet. Here, we aimed to determine whether 18F-FIMP has affinity for other tumor-related amino acid transporters, such as sodium- and chloride-dependent neutral and basic amino acid transporter B(0 +) (ATB0,+), alanine serine cysteine transporter 2 (ASCT2), and cystine/glutamate transporter (xCT). PROCEDURES: Cells overexpressing LAT1, ATB0,+, ASCT2, or xCT were established by the transfection of expression vectors for LAT1, ATB0,+, ASCT2, or xCT. Protein expression levels were determined by western blot and immunofluorescent analyses. Transport function was evaluated by a cell-based uptake assay using 18F-FIMP and 14C-labeled amino acids as substrates. RESULTS: Intense signals were observed only for expression vector-transfected cells on western blot and immunofluorescent analyses. These signals were strongly reduced by gene-specific small interfering ribonucleic acid treatment. The uptake values for each 14C-labeled substrate were significantly higher in the transfected cells than in the mock-transfected cells and were significantly inhibited by the corresponding specific inhibitors. The 18F-FIMP uptake values were significantly higher in the LAT1- and ATB0,+-overexpressing cells than in the corresponding mock cells, but no such increase was seen in the ASCT2- or xCT-overexpressing cells. These 18F-FIMP uptake values were significantly decreased by the specific inhibitors for LAT1- and ATB0,+. CONCLUSIONS: We demonstrated that 18F-FIMP has affinity not only for LAT1, but also for ATB0,+. Our results may be helpful for understanding the mechanisms of the whole-body distribution and tumor accumulation of 18F-FIMP.

Comparison of [18F]FIMP, [11C]MET, and [18F]FDG PET for early-phase assessment of radiotherapy response.

Several limitations of [18F]FDG have been reported, such as nonspecific uptake of inflammation foci. Moreover, [11C]MET has been found to accumulate in normal and inflammatory tissues as well as tumors. To increase specificity to tumor tissues, PET probes with tumor-specific molecular targets have been actively developed. [18F]FIMP was found to be highly accumulated in LAT1-positive tumors but not in inflamed tissue. The aim of this study was to explore whether [18F]FIMP can be used for the early-phase evaluation of radiotherapy accompanied by inflammation, and compare its effectiveness with those of [11C]MET and [18F]FDG. Tumor uptake of [18F]FIMP decreased at day 1 after irradiation, and remained low until day 14. Comparatively, that of [18F]FDG initially decreased at day 3 but was transiently elevated at day 7 and then decreased again at day 10. Decreased tumor uptake of [11C]MET was observed at day 10. In line with the uptake of [18F]FIMP, the ratio of Ki-67 immuno-positive cells in tumor tissues significantly decreased at day 1, 7, and 10 as compared with that in the control. These findings suggest that [18F]FIMP may be a PET probe involved in the early detection and prediction of radiotherapy efficacy, although further clarification is needed.

First-in-human assessment of the novel LAT1 targeting PET probe 18F-FIMP.

In the first-in-human PET study, we evaluated the biodistribution and tumor accumulation of the novel PET probe, (S)-2-amino-3-[3-(2-18F-fluoroethoxy)-4-iodophenyl]-2-methylpropanoic acid (18F-FIMP), which targets the tumor-related L-type amino acid transporter 1 (LAT1), and compared it with L-[methyl-11C]methionine (11C-MET) and 2-Deoxy-2-18F-fluoro-D-glucose (18F-FDG). 18F-FIMP biodistribution was revealed by whole-body and brain scans in 13 healthy controls. Tumor accumulation of 18F-FIMP was evaluated in 7 patients with a brain tumor, and compared with those of 11C-MET and 18F-FDG. None of the subjects had significant problems due to probe administration, such as adverse effects or abnormal vital signs. 18F-FIMP was rapidly excreted from the kidneys to the urinary bladder. There was no characteristic physiological accumulation in healthy controls. 18F-FIMP PET resulted in extremely clear images in patients with suspected glioblastoma compared with 11C-MET and 18F-FDG. 18F-FIMP could be a useful novel PET probe for LAT1-positive tumor imaging including glioblastoma.

Neural correlates of beneficial effects of young plasma treatment in aged mice: PET-SPM analyses and neuro-behavioural/molecular biological studies.

PURPOSE: To investigate the in vivo neurofunctional changes and therapeutic effects of young blood plasma (YBP) in aged mice, as well as the molecular mechanisms underlying the therapeutic effects of YBP ex vivo and in vitro. METHODS: Aged C57/BL6 mice received systemic administrations of phosphate-buffered saline (PBS) or YBP twice a week, for 4 weeks. In vivo 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) under conscious state and cognitive behavioural tests were performed after 4-week treatment. In addition, an in vitro senescent model was established, and the expressions of key cognition-associated proteins and/or the alterations of key neuronal pathways were analysed in both brain tissues and cultured cells. RESULTS: Aged mice treated with YBP demonstrated higher glucose metabolism in the right hippocampus and bilateral somatosensory cortices, and lower glucose metabolism in the right bed nucleus of stria terminalis and left cerebellum. YBP treatment exerted beneficial effects on the spatial and long-term social recognition memory, and significantly increased the expressions of several cognition-related proteins and altered the key neuronal signalling pathways in the hippocampus and somatosensory cortex. Further in vitro studies suggested that YBP but not aged blood plasma significantly upregulated the expressions of several cognition-associated proteins. CONCLUSION: Our results highlight the role of the hippocampus and somatosensory cortex in YBP-induced beneficial effects on recognition memory in aged mice. 18F-FDG PET imaging under conscious state provides a new avenue for exploring the mechanisms underlying YBP treatment against age-related cognitive decline.

A nationwide survey on participation in cardiac rehabilitation among patients with coronary heart disease using health claims data in Japan.

Poor implementation and variable quality of cardiac rehabilitation (CR) for coronary heart disease (CHD) have been a global concern. This nationwide study aimed to clarify the implementation of and participation in CR among CHD patients and associated factors in Japan. We conducted a retrospective cohort study using data extracted from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Patients who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in 2017-2018 were included. Aspects of CR were assessed in terms of (1) participation in exercise-based CR, (2) pharmacological education, and (3) nutritional education. Of 87,829 eligible patients, 32% had participated in exercise-based CR, with a mean program length of 40 ± 71 days. CABG was associated with higher CR participation compared to PCI (OR 10.2, 95% CI 9.6-10.8). Patients living in the Kyushu region were more likely to participate in CR (OR 2.59, 95% CI 2.39-2.81). Among patients who participated in CR, 92% received pharmacological education, whereas only 67% received nutritional education. In Japan, the implementation of CR for CHD is insufficient and involved varying personal, therapeutic, and geographical factors. CR implementation needs to be promoted in the future.

Redox-Active Tin Metal-Organic Framework with a Thiolate-Based Ligand.

Metal-organic frameworks (MOFs) and coordination polymers composed of thiolates as coordinating functional groups are interesting materials with unique optical and electronical properties. Herein, we report the preparation of KGF-4 and KGF-10, two Sn-MOF crystal structures with bonds between Sn and thiolate. KGF-10 was isolated as a pure phase and found to exhibit redox properties and a semiconducting band structure, as confirmed by first-principles (density functional theory) calculations.

18F-FIMP: a LAT1-specific PET probe for discrimination between tumor tissue and inflammation.

Positron emission tomography (PET) imaging can assist in the early-phase diagnostic and therapeutic evaluation of tumors. Here, we report the radiosynthesis, small animal PET imaging, and biological evaluation of a L-type amino acid transporter 1 (LAT1)-specific PET probe, 18F-FIMP. This probe demonstrates increased tumor specificity, compared to existing tumor-specific PET probes (18F-FET, 11C-MET, and 18F-FDG). Evaluation of probes by in vivo PET imaging, 18F-FIMP showed intense accumulation in LAT1-positive tumor tissues, but not in inflamed lesions, whereas intense accumulation of 18F-FDG was observed in both tumor tissues and in inflamed lesions. Metabolite analysis showed that 18F-FIMP was stable in liver microsomes, and mice tissues (plasma, urine, liver, pancreas, and tumor). Investigation of the protein incorporation of 18F-FIMP showed that it was not incorporated into protein. Furthermore, the expected mean absorbed dose of 18F-FIMP in humans was comparable or slightly higher than that of 18F-FDG and indicated that 18F-FIMP may be a safe PET probe for use in humans. 18F-FIMP may provide improved specificity for tumor diagnosis, compared to 18F-FDG, 18F-FET, and 11C-MET. This probe may be suitable for PET imaging for glioblastoma and the early-phase monitoring of cancer therapy outcomes.

Superoxide Scavenging Activity of Gold, Silver, and Platinum Nanoparticles Capped with Sugar-based Nonionic Surfactants.

Metal nanoparticles have the ability to remove superoxide via changes in the surface electronic states at the large surface area. Gold, silver, and platinum nanoparticles were prepared in the presence of three sugar-based nonionic surfactants using NaBH4 as a reducing agent. The surfactants (glycosyloxyethyl methacrylate: xGEMA) contain sugar oligomers of various lengths (x), are biodegradable, and act as protecting groups for the nanoparticles. Three types of xGEMA were used: dodecyl and hexadecyl chains containing amphiphilic oligomers (C12-3.0GEMA and C16-3.2GEMA) and multi-dodecyl chain with multiple sugar side chains (1.8C12-4.7GEMA). We found that the type of nonionic surfactant affected the size of the nanoparticles. The average size of the gold, silver, and platinum nanoparticles ranged from 1.9 to 6.6 nm depending on the surfactant. The trend in the size of gold nanoparticles in relation to the chosen surfactants was different from that for the silver and platinum nanoparticles. Moreover, the gold nanoparticles did not show effective antioxidant activity for superoxide, whereas the silver and platinum nanoparticles removed superoxide to a certain extent. The general order for superoxide scavenging activity increased in the following order: gold < platinum < silver. In particular, the largest size of silver nanoparticles capped with C16-3.2GEMA had a similar ability for the removal of superoxide as superoxide dismutase (ca. 3999 unit/mg) on the basis of the mass concentration.

Ecrg4 deficiency extends the replicative capacity of neural stem cells in a Foxg1-dependent manner.

The self-renewal activity of neural stem cells (NSCs) has been suggested to decrease with aging, resulting in age-dependent declines in brain function, such as presbyopia and memory loss. The molecular mechanisms underlying decreases in NSC proliferation with age need to be elucidated in more detail to develop treatments that promote brain function. We have previously reported that the expression of esophageal cancer-related gene 4 (Ecrg4) was upregulated in aged NSCs, whereas its overexpression decreased NSC proliferation, suggesting a functional relationship between Ecrg4 and NSC aging. Using Ecrg4-deficient mice in which the Ecrg4 locus was replaced with the lacZ gene, we here show that Ecrg4 deficiency recovered the age-dependent decline in NSC proliferation and enhanced spatial learning and memory in the Morris water-maze paradigm. We demonstrate that the proliferation of Ecrg4-deficient NSCs was partly maintained by the increased expression of Foxg1. Collectively, these results determine Ecrg4 as a NSC aging factor.

Disulfiram enhanced delivery of orally administered copper into the central nervous system in Menkes disease mouse model.

INTRODUCTION: Menkes disease (MD) is an X-linked recessive disorder caused by dysfunction of a copper-transporting protein, leading to severe neurodegeneration in early childhood. We investigated whether a lipophilic copper chelator, disulfiram, could enhance copper absorption from the intestine and transport copper across the blood-brain barrier in MD model mice. METHODS: Wild type and MD model mice were pretreated with disulfiram for 30 min before oral administration of 64CuCl2. Each organ was sequentially analyzed for radioactivity with γ counting. Copper uptake into the brain parenchyma was assessed by ex vivo autoradiography. RESULTS: In wild type mice, orally administered copper was initially detected in the intestine within 2 h, reaching a maximum level in the liver (19.6 ± 3.8 percentage injected dose per gram [%ID/g]) at 6 h. In MD model mice, the copper reached the maximum level in the liver (5.3 ± 1.5 %ID/g) at 4 h, which was lower than that of wild type mice (19.0 ± 7.4 %ID/g) (P < 0.05). Pretreatment of disulfiram in MD model mice increased the copper level in the brain (0.59 ± 0.28 %ID/g) at 24 h compared with MD model mice without disulfiram (0.07 ± 0.05 %ID/g) (P < 0.05). Ex vivo autoradiography revealed that high levels of copper uptake was observed in the cerebral cortex upon disulfiram pretreatment. CONCLUSION: Our data demonstrated that disulfiram enhanced the delivery of orally administered copper into the central nervous system in MD model mice. The administration of disulfiram will enable patients to avoid unpleasant subcutaneous copper injection in the future.

Data on the effect of target temperature management at 32-34 °C in cardiac arrest patients considering assessment by regional cerebral oxygen saturation: A multicenter retrospective cohort study.

This data article contains raw data and supplementary analyzed data regarding to the article entitled "Effect of target temperature management at 32-34 °C in cardiac arrest patients considering assessment by regional cerebral oxygen saturation: A multicenter retrospective cohort study". We examined the effectiveness of target temperature management (TTM) at 32-34 °C considering degrees of patients' cerebral injury and cerebral circulation assessed by regional cerebral oxygen saturation (rSO2). The research is a secondary analysis of prospectively collected registry, in which comatose patients who were transferred to 15 hospitals in Japan after out-of-hospital cardiac arrest (OHCA), and we included 431 study patients. Propensity score analysis revealed that TTM at 32-34 °C decreased all-cause mortality in patients with rSO2 41-60%, and increased favorable neurological outcomes in patients with rSO2 41-60% in the original research article. With regard to the balance of covariates of propensity-score matching (PSM) and inverse-probability weighting (IPW) analyses, some covariates were not well balanced after the analyses between groups. The overlap plots indicate the overlap of densities of the propensity scores are low in group rSO2 41-60% and group rSO2 ≥ 61%. When patients were limited to those who achieved return of spontaneous circulation (ROSC) until/on hospitals arrival, TTM still tended to decrease all-cause mortality and increase favorable outcomes in group rSO2 41-60%.

PET Imaging Analysis of Vitamin B1 Kinetics with [11C]Thiamine and its Derivative [11C]Thiamine Tetrahydrofurfuryl Disulfide in Rats.

PURPOSE: Thiamine is an essential component of glucose metabolism and energy production. The disulfide derivative, thiamine tetrahydrofurfuryl disulfide (TTFD), is better absorbed than readily-available water-soluble thiamine salts because it does not require the rate-limiting transport system required for thiamine absorption. However, the detailed pharmacokinetics of thiamine and TTFD under normal and pathological conditions have not yet been clarified. C-11-labeled thiamine and TTFD were recently synthesized by our group. In this study, to clarify the differences in pharmacokinetics and metabolism of these probes, a quantitative PET imaging study and radiometabolite analysis of C-11-labeled thiamine and TTFD were performed in the rat heart. PROCEDURES: Positron emission tomography (PET) imaging with [11C]thiamine and [11C]TTFD was performed in normal rats to determine the pharmacokinetics of these probes, and the radiometabolites of both probes from the blood and heart tissue were analyzed by thin-layer chromatography. RESULTS: Accumulation of [11C]TTFD was significantly higher than that of [11C]thiamine in the rat heart. Moreover, as a result of the radiometabolite analysis of heart tissue at 15 min after the injection of [11C]TTFD, thiamine pyrophosphate, which serves as a cofactor for the enzymes involved in glucose metabolism, was found as the major radiometabolite and at a significantly higher level than in the [11C]thiamine-injected group. CONCLUSIONS: PET imaging techniques for visualizing the kinetics and metabolism of thiamine using [11C]thiamine and [11C]TTFD were developed in this study. Consequently, noninvasive PET imaging for the pathophysiology of thiamine-related cardiac function may provide novel information about heart failure and related disorders.

Effect of target temperature management at 32-34 °C in cardiac arrest patients considering assessment by regional cerebral oxygen saturation: A multicenter retrospective cohort study.

AIM: Target temperature management (TTM) is used in comatose post-cardiac arrest patients, but the recommended temperature range is wide. This study aimed to assess the effectiveness of TTM at 32-34 °C while considering the degree of cerebral injury and cerebral circulation, as assessed by regional cerebral oxygen saturation (rSO2). METHODS: This is a secondary analysis of prospectively collected registry data from comatose patients who were transferred to 15 hospitals in Japan after out-of-hospital cardiac arrest (OHCA) from 2011 to 2013. The primary outcome was all-cause mortality at 90 days after OHCA, and the secondary outcome was favorable neurological outcomes as evaluated according to the Cerebral Performance Category. We monitored rSO2 noninvasively with near-infrared spectroscopy, which could assess cerebral perfusion and the balance of oxygen delivery and uptake. RESULTS: We stratified 431 study patients into three groups according to rSO2 on hospital arrival: rSO2 ≤40% (n = 296), rSO2 41-60% (n = 67), and rSO2 ≥61% (n = 68). Propensity score analysis revealed that TTM at 32-34 °C decreased all-cause mortality in patients with rSO2 41-60% (average treatment effect on treated [ATT] by propensity score matching [PSM] -0.51, 95%CI -0.70 to -0.33; ATT by inverse probability of treatment weighting [IPW] -0.52, 95%CI -0.71 to -0.34), and increased favorable neurological outcomes in patients with rSO2 41-60% (ATT by PSM 0.50, 95%CI 0.32-0.68; ATT by IPW 0.52, 95%CI 0.35-0.69). CONCLUSION: TTM at 32-34 °C effectively decreased all-cause mortality in comatose OHCA patients with rSO2 41-60% on hospital arrival in Japan.

Development of Diagnostic Techniques for Early Rheumatoid Arthritis Using Positron Emission Tomography with [11C]PK11195 and [11C]Ketoprofen Tracers.

PURPOSE: In vivo detection of pathological insults during the early stages of rheumatoid synovitis is essential to allow early anti-inflammatory treatment for prevention of joint destruction. Whether rheumatoid synovitis pathology and the efficacy of therapies can be visualized by positron emission tomography (PET) tracers specific to the inflammatory process was investigated. PROCEDURES: Using a collagen-induced experimental rat model of rheumatoid arthritis, in vivo imaging using the PET tracers [11C]PK11195, which binds to the translocator protein mainly expressed on myeloid cells, and [11C]ketoprofen, for cyclooxygenase imaging, was performed. To evaluate therapeutic efficacy, model animals were administered the tumour necrosis factor alpha blocker etanercept subcutaneously. RESULTS: [11C]PK11195 and [11C]ketoprofen uptakes were significantly higher in inflamed paws of collagen-induced arthritis rats than in normal rats. The data showed a correlation between tracer uptake values and paw swelling. After treatment with etanercept, [11C]ketoprofen uptake was significantly lower in treated animals than in untreated ones, whereas [11C]PK11195 uptake in the inflamed regions was comparable to that in the untreated group. CONCLUSIONS: With [11C]PK11195 and [11C]ketoprofen tracers, non-invasive in vivo PET imaging for rheumatoid synovitis can provide diagnostic evidence of early synovitis and allow monitoring inflammatory cell activity during treatment.

Eva1 Maintains the Stem-like Character of Glioblastoma-Initiating Cells by Activating the Noncanonical NF-κB Signaling Pathway.

Glioblastoma (GBM)-initiating cells (GIC) are a tumorigenic subpopulation that are resistant to radio- and chemotherapies and are the source of disease recurrence. Therefore, the identification and characterization of GIC-specific factors is critical toward the generation of effective GBM therapeutics. In this study, we investigated the role of epithelial V-like antigen 1 (Eva1, also known as myelin protein zero-like 2) in stemness and GBM tumorigenesis. Eva1 was prominently expressed in GICs in vitro and in stem cell marker (Sox2, CD15, CD49f)-expressing cells derived from human GBM tissues. Eva1 knockdown in GICs reduced their self-renewal and tumor-forming capabilities, whereas Eva1 overexpression enhanced these properties. Eva1 deficiency was also associated with decreased expression of stemness-related genes, indicating a requirement for Eva1 in maintaining GIC pluripotency. We further demonstrate that Eva1 induced GIC proliferation through the activation of the RelB-dependent noncanonical NF-κB pathway by recruiting TRAF2 to the cytoplasmic tail. Taken together, our findings highlight Eva1 as a novel regulator of GIC function and also provide new mechanistic insight into the role of noncanonical NF-κB activation in GIC, thus offering multiple potential therapeutic targets for preclinical investigation in GBM.

Ceacam1L Modulates STAT3 Signaling to Control the Proliferation of Glioblastoma-Initiating Cells.

Glioblastoma-initiating cells (GIC) are a tumorigenic cell subpopulation resistant to radiotherapy and chemotherapy, and are a likely source of recurrence. However, the basis through which GICs are maintained has yet to be elucidated in detail. We herein demonstrated that the carcinoembryonic antigen-related cell adhesion molecule Ceacam1L acts as a crucial factor in GIC maintenance and tumorigenesis by activating c-Src/STAT3 signaling. Furthermore, we showed that monomers of the cytoplasmic domain of Ceacam1L bound to c-Src and STAT3 and induced their phosphorylation, whereas oligomerization of this domain ablated this function. Our results suggest that Ceacam1L-dependent adhesion between GIC and surrounding cells play an essential role in GIC maintenance and proliferation, as mediated by signals transmitted by monomeric forms of the Ceacam1L cytoplasmic domain.

Combination of a ptgs2 inhibitor and an epidermal growth factor receptor-signaling inhibitor prevents tumorigenesis of oligodendrocyte lineage-derived glioma-initiating cells.

Recent findings have demonstrated that malignant tumors, including glioblastoma multiforme (GBM), contain cancer-initiating cells (CICs; also known as cancer stem cells), which self-renew and are malignant. However, it remains controversial whether such CICs arise from tissue-specific stem cells, committed precursor cells, or differentiated cells. Here, we sought to examine the origin of the CICs in GBM. We first showed that the overexpression of oncogenic HRas(L61) transformed p53-deficient oligodendrocyte precursor cells (OPCs) and neural stem cells (NSCs) into glioma-initiating cell (GIC)-like cells in mice. When as few as 10 of these GIC-like cells were transplanted in vivo, they formed a transplantable GBM with features of human GBM, suggesting that these GIC-like cells were enriched in CICs. DNA microarray analysis showed that widespread genetic reprogramming occurred during the OPCs' transformation: they largely lost their OPC characteristics and acquired NSC ones, including the expression of prominin1, hmga2, ptgs2, and epiregulin. In addition, the combination of a Ptgs2 inhibitor and an epidermal growth factor receptor (EGFR)-signaling inhibitor prevented the tumorigenesis of transformed OPCs and human GICs (hGICs) obtained from anaplastic oligodendroglioma, but not of transformed NSCs or hGICs obtained from GBM. Together, these findings suggest that GBM can arise from either OPCs or NSCs and that the therapeutic targets for GBM might be different, depending on each GIC's cell-of-origin.

Sox11 prevents tumorigenesis of glioma-initiating cells by inducing neuronal differentiation.

Recent findings have shown that malignant tumors contain cancer-initiating cells (CIC), which self-renew and are tumorigenic. However, CICs have not been characterized properly due to lack of specific markers. We recently established a mouse glioma cell line, NSCL61, by overexpressing an oncogenic HRas(L61) in p53-deficient neural stem cells. Using limiting dilution assays, we show that only 2 of 24 NSCL61 clones retained their tumorigenicity in vivo, although the others also expressed oncogenic HRas(L61) and could proliferate in culture. A comparison of the gene expression profiles of tumorigenic and nontumorigenic clones showed that the tumorigenic clones had lost Sox11 expression. We show that overexpression of sox11 prevented tumorigenesis of NSCL61s by inducing their neuronal differentiation accompanied with decreased levels of plagl1. We also show that overexpression of plagl1 abolished neuronal commitment of nontumorigenic cells and induced them to become tumorigenic. Moreover, we show that human glioma-initiating cells lost sox11 expression, and overexpression of sox11 prevented their tumorigenesis in vivo. Together with the clinical evidence showing that downregulation of sox11 mRNA correlates with a significant decrease in survival, these findings suggest that Sox11 prevents gliomagenesis by blocking the expression of oncogenic plagl1.