We previously demonstrated that the transcription factor NF-E2-related factor2 (Nrf2), expressed abundantly in non-small-cell lung cancer (NSCLC) cells, plays a pivotal role in the proliferation and ...chemoresistance of NSCLC. Here we show that Nrf2-mediated NSCLC cell proliferation is dually regulated by epidermal growth factor receptor (EGFR) signaling and an Nrf2 repressor protein Keap1 (Kelch-like ECH-associated protein-1). NSCLC cells expressing wild-type EGFR and Keap1 genes show enhanced proliferation on stimulation with EGFR ligand under non-stress conditions. Exposure to cigarette smoke extract (CSE) enhanced cell proliferation by modification of the Nrf2/Keap1 interaction. Although EGFR-tyrosine kinase inhibitor (TKI) inhibited the proliferation of these cells, exposure to CSE attenuated its efficacy. In NSCLC cells with Keap1 gene mutations, Nrf2 was constitutively activated owing to dysfunction of Keap1 and cells proliferated independently of EGFR signaling. Furthermore, EGFR-TKI was unable to inhibit their proliferation. In NSCLC cells with EGFR gene mutations, Nrf2 was constitutively activated by EGFR signaling. In these cells, proliferation was largely dependent on the EGFR signaling pathway. Although these cells were highly sensitive to EGFR-TKI, exposure to CSE or knockdown of Keap1 mRNA reduced sensitivity to EGFR-TKI. We found a case of NSCLC showing resistance to EGFR-TKI despite having EGFR-TKI-sensitive EGFR gene mutation because of dysfunctional mutation in Keap1 gene. Results indicate that oxidative stress reduces the anticancer effects of EGFR-TKI in wild-type Keap1 NSCLC cells. Analysis of Keap1 dysfunction may become a novel molecular marker to predict resistance to EGFR-TKI in NSCLC cells having EGFR-TKI-sensitive EGFR mutations. Finally, as the downstream molecule of both EGFR and Keap1 signaling, Nrf2 is an important molecular target for the treatment of NSCLC, where cells have mutations in EGFR, KRAS or Keap1 genes.
Background: Factor Xa (FXa), a key serine protease that converts prothrombin to thrombin in the coagulation cascade, is a promising target enzyme for the prophylaxis and treatment of thromboembolic ...diseases. DU‐176b is a novel antithrombotic agent that directly inhibits FXa activity. Objective: To evaluate the in vitro pharmacological profiles and in vivo effects of DU‐176b in animal models of thrombosis and bleeding. Methods: In vitro, FXa inhibition, specificity and anticoagulant activities were examined. Oral absorption was studied in rats and cynomolgus monkeys. In vivo effects were studied in rat and rabbit models of venous thrombosis and tail bleeding. Results: DU‐176b inhibited FXa with Ki values of 0.561 nm for free FXa, 2.98 nm for prothrombinase, and exhibited >10 000‐fold selectivity for FXa. In human plasma, DU‐176b doubled prothrombin time and activated partial thromboplastin time at concentrations of 0.256 and 0.508 μm, respectively. DU‐176b did not impair platelet aggregation by ADP, collagen or U46619. DU‐176b was highly absorbed in rats and monkeys, as demonstrated by more potent anti‐Xa activity and higher drug concentration in plasma following oral administration than a prototype FXa inhibitor, DX‐9065a. In vivo, DU‐176b dose‐dependently inhibited thrombus formation in rat and rabbit thrombosis models, although bleeding time in rats was not significantly prolonged at an antithrombotic dose. Conclusions: DU‐176b is a more potent and selective FXa inhibitor with high oral bioavailability compared with its prototype, DX‐9065a. DU‐176b represents a promising new anticoagulant for the prophylaxis and treatment of thromboembolic diseases.
Although it is known that human leukocyte antigen (HLA)-DPB1 disparity has a strong impact on outcomes in unrelated hematopoietic transplantation with induction of acute graft-versus-host disease ...(GVHD) and a graft-versus-leukemia (GVL) effect, its role in unrelated umbilical cord blood transplantation (UR-CBT) has yet to be fully clarified. Our current study is being conducted to elucidate the impact of HLA-DPB1 mismatch, along with the effect of other HLA loci mismatches at the allele level. HLA six loci alleles were retrospectively typed in 1157 Japanese donors and patients with leukemia or myelodysplastic syndrome who underwent transplantation with a single unit of cord blood. HLA-DPB1 mismatch was associated with a significant reduction in leukemia relapse (hazard ratio 0.61, P<0.001), whereas the other HLA loci allele-level mismatches did not. No significant effect of HLA-DPB1 mismatch was observed in the risk of acute GVHD, engraftment or mortality. This HLA-DPB1 GVL effect without induction of severe acute GVHD or deterioration of survival rate has not been reported in unrelated bone marrow or peripheral blood stem cell transplantations, suggesting apparent advantages of UR-CBT. Accordingly, selection of an HLA-DPB1 mismatch cord blood might be the preferable choice for single-unit UR-CBT.
The effect of graft-versus-host disease (GVHD) on transplant outcomes after unrelated cord blood transplantation (UCBT) has not been fully elucidated. We analyzed the impact of acute and chronic GVHD ...on outcomes in adult patients with acute leukemia or myelodysplastic syndrome who underwent their first UCBT (n=2558). The effect of GVHD on outcomes was analyzed after adjusting for other significant variables. The occurrence of GVHD was treated as a time-dependent covariate. The occurrence of grade 1-2 or 3-4 acute GVHD was significantly associated with a lower relapse rate. Grade 3-4 acute GVHD was associated with a higher risk of non-relapse and overall mortality than no acute GVHD, whereas grade 1-2 acute GVHD was associated with a lower risk of non-relapse and overall mortality than no acute GVHD. Limited or extensive chronic GVHD was significantly associated with a lower relapse rate. Limited chronic GVHD was associated with a lower overall and non-relapse mortality than no chronic GVHD. In conclusion, mild acute or chronic GVHD was associated not only with a low risk of relapse but also with a low risk of non-relapse mortality, and provides a survival benefit in UCBT.
To elucidate the impact of pretransplant body mass index (BMI) on the clinical outcome, we performed a retrospective study with registry data including a total of 12 050 patients (age ⩾18 years) who ...received allogeneic hematopoietic SCT (HSCT) between 2000 and 2010. Patients were stratified as follows: BMI<18.5 kg/m(2), Underweight, n=1791; 18.5⩽BMI<25, Normal, n=8444; 25⩽BMI<30, Overweight, n=1591; BMI⩾30, Obese, n=224. The median age was 45 years (range, 18-77). A multivariate analysis showed that the risk of relapse was significantly higher in the underweight group and lower in the overweight and obese groups compared with the normal group (hazard ratio (HR), 1.16, 0.86, and 0.74, respectively). The risk of GVHD was significantly higher in the overweight group compared with the normal group. The risk of non-relapse mortality (NRM) was significantly higher in the overweight and obese group compared with the normal group (HR 1.19 and HR 1.43, respectively). The probability of OS was lower in the underweight group compared with the normal group (HR 1.10, P=0.018). In conclusion, pretransplant BMI affected the risk of relapse and NRM after allogeneic HSCT. Underweight was a risk factor for poor OS because of an increased risk of relapse. Obesity was a risk factor for NRM.
Question Synchronized brain oscillations are considered a basis for inter-regional neuronal communication ( Engel, 2001; Buzsáki, 2000 ). However, the causal role of synchronized neural oscillations ...in regulating the efficacy of signal transmission in brain networks has so far not been directly demonstrated. Methods To address this relationship, we employed the simultaneous use of transcranial alternating current stimulation (tACS), TMS and EEG. Through tACS we entrained theta oscillatory activity in two regions of the human frontoparietal network; the dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC). We applied 6 Hz tACS to the DLPFC and PPC simultaneously in an in-phase or anti-phase manner. For assessing resultant changes in transmission in the network, we simultaneously applied weak single-pulse TMS over the DLPFC at four different phases of tACS (90°, 180°, 270°, 360°) and measured the spread of TMS-evoked EEG potentials (TEPs). The amount of current spread is modulated by the functional status of the neural network, and thereby provides a measure of changes in signaling efficacy ( Ilmoniemi, 1997 ). Results We found that the amplitude of TEPs depended on the phase of the entrained 6 Hz activity. The phase-dependent changes of TEPs propagated to the occipital area in the in-phase condition, while, in the anti-phase condition, the phase-dependency of TEPs disappeared in the occipital area, suggesting that the tACS-induced de-synchronization of the frontoparietal network limited the communication of the network. Conclusions A recent study has shown that introducing synchronized theta activity in the frontoparietal network with tACS modulates working memory performance ( Polanía, 2012 ). Our results add to the neurophysiological explanation of these findings. We demonstrate that tACS-induced theta oscillations modulate signaling efficacy in a phase-dependent manner, and that the induced state of phase-synchrony across the frontoparietal network further modulates signaling efficacy. This supports the causal role of synchronized endogenous oscillatory activity in modulating neuronal communication.
This retrospective study was conducted in Japan to determine the incidence, risk factors and outcomes of sinusoidal obstruction syndrome (SOS) after allogeneic hematopoietic stem cell transplantation ...(HSCT). Among 4290 patients undergoing allogeneic HSCT between 1999 and 2010, 462 were diagnosed with SOS according to the Seattle criteria (cumulative incidence, 10.8%). The cumulative incidence of SOS diagnosed by the modified Seattle criteria was 9.3%. Of 462 patients, 107 met the Baltimore criteria and 168 had severe SOS with renal and/or respiratory failure. The median onset for SOS was 12 days after HSCT (range, -2-30). Overall survival at day 100 was 32% for SOS and 15% for severe SOS. Multivariate analyses showed that significant independent risk factors for SOS were the number of HSCTs, age, performance status, hepatitis C virus-seropositivity, advanced disease status and myeloablative regimen. SOS was highly associated with overall mortality (hazard ratio, 2.09; P<0.001). Our retrospective survey showed that the cumulative incidence of SOS in Japan was 10.8%, similar to that previously reported in Western countries, and that the overall survival of patients who developed SOS was low. Furthermore, several risk factors were identified. Preventive and therapeutic strategies for high-risk SOS patients must be established to improve overall survival.
To improve the clinical outcome of allogeneic hematopoietic stem cell transplantation from an unrelated donor, the identification of human leukocyte antigen (HLA) alleles responsible for immunologic ...events such as graft-versus-host disease (GVHD), engraftment failure, and graft-versus-leukemia effect is essential. Genomic typing of HLA-A, -B, -C, -DRB1, and -DQB1 was retrospectively performed in 1298 donor-patient pairs in cases where marrow was donated from serologically HLA-A, -B, and -DR compatible donors. Single disparities of the HLA-A, -B, -C, or -DRB1 allele were independent risk factors for acute GVHD, and the synergistic effect of the HLA-C allele mismatch with other HLA allele mismatches on acute GVHD was remarkable. HLA-A and/or HLA-B allele mismatch was found to be a significant factor for the occurrence of chronic GVHD. HLA class I (A, B, and/or C) allele mismatch caused a significantly higher incidence of engraftment failure than HLA match. Significant association of HLA-C allele mismatch with leukemia relapse was not observed. As the result of these events, HLA-A and/or HLA-B allele mismatch reduced overall survival remarkably in both standard-risk and high-risk leukemia cases, whereas the HLA-C mismatch or HLA-class II (DRB1 and/or DQB1) mismatch did not. Furthermore, multiple mismatch of the HLA locus was found to reduce survival in leukemia cases. Thus, the role of the HLA class I allele in unrelated bone marrow transplantation was elucidated. Notably, HLA-C alleles had a different mode from HLA-A or -B alleles for acute GVHD and survival.
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