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result(s) for
"Keiichi Ota"
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Immunostimulatory oncolytic activity of coxsackievirus A11 in human malignant pleural mesothelioma
2023
Malignant pleural mesothelioma (MPM) is an aggressive solid cancer with a poor prognosis, whereas coxsackievirus A11 (CVA11) is a potential oncolytic virus for cancer treatment. We here investigated the oncolytic activity of CVA11 with human MPM cell lines. CVA11 infection was cytotoxic in all six MPM cell lines examined and showed no or minimal cytotoxicity toward normal human normal cell lines. MPM cells with a higher surface level of intercellular adhesion molecule‐1 (ICAM‐1) expression tended to be more susceptible to CVA11‐induced cytotoxicity, and a neutralizing antibody to ICAM‐1 attenuated such cytotoxicity. CVA11 infection activated signaling by Akt and extracellular signal‐regulated kinase (ERK) pathways, and inhibitors of such signaling also abrogated CVA11‐mediated cytotoxicity. Furthermore, CVA11 infection‐triggered multiple modes of tumor cell death including apoptosis, pyroptosis, and necroptosis, and such death was accompanied by the release or exposure of the proinflammatory cytokine interleukin‐1β and damage‐associated molecular patterns such as calreticulin, high‐mobility group box‐1, annexin A1, and heat shock protein 70, which are hallmarks of immunogenic cell death. Notably, in vivo treatment of human MPM xenografts with intratumoral CVA11 injection resulted in significant suppression of tumor growth in SCID mice, and all mice infected with CVA11 showed no significant change in body weight. Our findings collectively suggest that the oncolytic activity of CVA11 for MPM is dependent on ICAM‐1 as a virus receptor, as well as on Akt and ERK signaling, and that oncolytic virotherapy with CVA11 is a promising treatment modality with immunostimulatory activity for human MPM. The authors found that coxsackievirus A11 (CVA11) infection exhibited a marked oncolytic activity in multiple human malignant pleural mesothelioma cell lines in vitro, and that serial intratumoral CVA11 injections into mesothelioma xenografts resulted in significant suppression of tumor growth in SCID mice with tolerability. The authors successfully identified ICAM‐1 as a receptor for CVA11 infection. CVA11 infection‐triggered cytotoxicity was partially dependent on MEK/ERK and PI3K/Akt signaling pathways and manifested multimodal immunogenic cell death with proinflammatory cytokine and DAMPs.
Journal Article
AKT and EZH2 inhibitors kill TNBCs by hijacking mechanisms of involution
2024
Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and has the highest rate of recurrence
1
. The predominant standard of care for advanced TNBC is systemic chemotherapy with or without immunotherapy; however, responses are typically short lived
1
,
2
. Thus, there is an urgent need to develop more effective treatments. Components of the PI3K pathway represent plausible therapeutic targets; more than 70% of TNBCs have alterations in PIK3CA, AKT1 or PTEN
3
–
6
. However, in contrast to hormone-receptor-positive tumours, it is still unclear whether or how triple-negative disease will respond to PI3K pathway inhibitors
7
. Here we describe a promising AKT-inhibitor-based therapeutic combination for TNBC. Specifically, we show that AKT inhibitors synergize with agents that suppress the histone methyltransferase EZH2 and promote robust tumour regression in multiple TNBC models in vivo. AKT and EZH2 inhibitors exert these effects by first cooperatively driving basal-like TNBC cells into a more differentiated, luminal-like state, which cannot be effectively induced by either agent alone. Once TNBCs are differentiated, these agents kill them by hijacking signals that normally drive mammary gland involution. Using a machine learning approach, we developed a classifier that can be used to predict sensitivity. Together, these findings identify a promising therapeutic strategy for this highly aggressive tumour type and illustrate how deregulated epigenetic enzymes can insulate tumours from oncogenic vulnerabilities. These studies also reveal how developmental tissue-specific cell death pathways may be co-opted for therapeutic benefit.
AKT inhibitors synergize with agents that suppress the histone methyltransferase EZH2 and promote robust tumour regression in multiple triple-negative breast cancer models in vivo by triggering an involution-like process.
Journal Article
MicroRNA ‐326 negatively regulates CD155 expression in lung adenocarcinoma
by
Iwama, Eiji
,
Yoshizumi, Tomoharu
,
Okamoto, Isamu
in
3' Untranslated regions
,
Adenocarcinoma
,
Apoptosis
2023
Treatment with immune checkpoint inhibitors induces a durable response in some patients with non‐small‐cell lung cancer, but eventually gives rise to drug resistance. Upregulation of CD155 expression is implicated as one mechanism of resistance to programmed death receptor‐1 (PD‐1)/PD‐1 ligand (PD‐L1) inhibitors, and it is therefore important to characterize the mechanisms underlying regulation of CD155 expression in tumor cells. The aim of this study was to identify microRNAs (miRNAs) that might regulate CD155 expression at the posttranscriptional level in lung cancer. Comprehensive miRNA screening with target prediction programs and a dual‐luciferase reporter assay identified miR‐346, miR‐328‐3p, miR‐326, and miR‐330‐5p as miRNAs that bind to the 3′‐UTR of CD155 mRNA. Forced expression of these miRNAs suppressed CD155 expression in lung cancer cell lines. Immunohistochemical staining of CD155 in tissue specimens from 57 patients with lung adenocarcinoma revealed the median tumor proportion score for CD155 to be 68%. The abundance of miR‐326 in these specimens with a low level of CD155 expression was significantly greater than in specimens with a high level ( p < 0.005). Our results thus suggest that miR‐326 negatively regulates CD155 expression in lung adenocarcinoma and might therefore play a role in the development of resistance to PD‐1/PD‐L1 inhibitors.
Journal Article
Paired analysis of tumor mutation burden for lung adenocarcinoma and associated idiopathic pulmonary fibrosis
by
Isamu Okamoto
,
Kentaro Tanaka
,
Mitsuhiro Takenoyama
in
631/208/69
,
631/67/1612
,
692/4028/67/1612/1350
2021
Genetic alterations underlying the development of lung cancer in individuals with idiopathic pulmonary fibrosis (IPF) have remained unclear. To explore whether genetic alterations in IPF tissue contribute to the development of IPF-associated lung cancer, we here evaluated tumor mutation burden (TMB) and somatic variants in 14 paired IPF and tumor samples from patients with IPF-associated lung adenocarcinoma. We also determined TMB for 22 samples of lung adenocarcinoma from patients without IPF. TMB for IPF-associated lung adenocarcinoma was significantly higher than that for matched IPF tissue (median of 2.94 vs. 1.26 mutations/Mb,
P
= 0.002). Three and 102 somatic variants were detected in IPF and matched lung adenocarcinoma samples, respectively, with only one pair of specimens sharing one somatic variant. TMB for IPF-associated lung adenocarcinoma was similar to that for lung adenocarcinoma samples with driver mutations (median of 2.94 vs. 2.51 mutations/Mb) and lower than that for lung adenocarcinoma samples without known driver mutations (median of 2.94 vs. 5.03 mutations/Mb,
P
= 0.130) from patients without IPF. Our findings suggest that not only the accumulation of somatic mutations but other factors such as inflammation and oxidative stress might contribute to the development and progression of lung cancer in patients with IPF.
Journal Article
Regulation of PD-L1 expression in non–small cell lung cancer by interleukin-1β
by
Yoneshima, Yasuto
,
Iwama, Eiji
,
Okamoto, Isamu
in
Apoptosis
,
B7-H1 Antigen - metabolism
,
Carcinoma, Non-Small-Cell Lung - drug therapy
2023
Programmed cell death-ligand 1 (PD-L1) is a biomarker for prediction of the clinical efficacy of immune checkpoint inhibitors in various cancer types. The role of cytokines in regulation of PD-L1 expression in tumor cells has not been fully characterized, however. Here we show that interleukin-1β (IL-1β) plays a key role in regulation of PD-L1 expression in non-small cell lung cancer (NSCLC).
We performed comprehensive screening of cytokine gene expression in NSCLC tissue using available single-cell RNA-Sequence data. Then we examined the role of IL-1β
to elucidate its induction of PD-L1 on NSCLC cells.
The IL-1β gene is highly expressed in the tumor microenvironment, particularly in macrophages. The combination of IL-1β and interferon-γ (IFN-γ) induced a synergistic increase in PD-L1 expression in NSCLC cell lines. IL-1β and IFN-γ also cooperatively activated mitogen-activated protein kinase (MAPK) signaling and promoted the binding of downstream transcription factors to the PD-L1 gene promoter. Furthermore, inhibitors of MAPK signaling blocked upregulation of PD-L1 by IL-1β and IFN-γ.
Our study reports high levels of IL-1β in the tumor microenvironment may cooperate with IFN-γ to induce maximal PD-L1 expression in tumor cells
activation of MAPK signaling, with the IL-1β-MAPK axis being a promising therapeutic target for attenuation of PD-L1-mediated suppression of antitumor immunity.
Journal Article
Sensitivity and kinase activity of epidermal growth factor receptor (EGFR) exon 19 and others to EGFR‐tyrosine kinase inhibitors
by
Iwama, Eiji
,
Wang, Shuo
,
Giaccone, Giuseppe
in
Antineoplastic Agents - pharmacology
,
Breast Neoplasms - drug therapy
,
Breast Neoplasms - enzymology
2013
The presence of epidermal growth factor receptor (EGFR) somatic mutations in non‐small‐cell lung cancer patients is associated with response to treatment with EGFR‐tyrosine kinase inhibitors, such as gefitinib and erlotinib. More than 100 mutations in the kinase domain of EGFR have been identified. In particular there are many variations of deletion mutations in exon 19. In this study, using yellow fluorescent protein‐tagged fragments of the EGFR intracellular domain, we examined the differences in sensitivity to gefitinib, erlotinib and afatinib between several exon 19 mutants and other common EGFR mutations. We also used serum of patients undergoing treatment with EGFR‐tyrosine kinase inhibitors in this system. In addition, we examined the relative kinase activity of these mutants by measuring relative fluorescent intensity after immunofluorescence staining. We found that both sensitivity to EGFR‐tyrosine kinase inhibitors and relative kinase activity differed among several EGFR mutations found in the same region of the kinase domain. This study underscores the importance of reporting the clinical outcome of treatment in relation to different EGFR mutations.
Journal Article
Evaluation of slope stability by finite element method using observed displacement of landslide
2012
To monitor land deformation in detail, we ran a large-scale field test in which an artificial landslide was induced by the application of a load to a natural slope. The measured landslide displacement was reproduced numerically through the use of finite element model analysis with a two-dimensional elasto-viscoplastic model. The analysis suggested that the strength of the sliding surface decreased as the landslide mass moved. We propose a simple method for estimating safety factors. The method involves back-calculation of shear strength parameters through reproduction of observed landslide displacements and calculating the ratio of driving force to resisting force acting on the sliding surface as modeled by joint elements. This ratio, the \"stability index\", shows the same trend as safety factors calculated by a two-dimensional limit equilibrium method and a shear strength reduction method that use back-calculated shear strength parameters estimated from the limit equilibrium state. The results indicate that the stability index may be applicable to the assessment of slope stability.
Journal Article
Propensity score–weighted analysis of chemotherapy after PD-1 inhibitors versus chemotherapy alone in patients with non–small cell lung cancer (WJOG10217L)
2020
BackgroundStudies have suggested that chemotherapy after immune checkpoint inhibitors may confer an improved response for non–small cell lung cancer (NSCLC). However, potential selection bias in such studies has not been addressed. We therefore applied propensity score analysis to investigate the efficacy of chemotherapy after PD-1 inhibitor treatment (CAP) compared with chemotherapy alone.MethodsWe conducted a retrospective observational cohort study for patients treated at 47 institutions across Japan between April 1, 2014 and July 31, 2017. Eligible patients had advanced or recurrent NSCLC who have undergone chemotherapy. Patients subsequently treated with chemotherapy (docetaxel with or without ramucirumab, S-1 or pemetrexed) either after PD-1 inhibitor therapy (CAP cohort) or alone (control cohort) were included. The primary end point was objective response rate (ORR). Inverse probability weighting (IPW) was applied to adjust for potential confounding factors.ResultsA total of 1439 patients (243 and 1196 in the CAP and control cohorts, respectively) was available for unadjusted analysis. Several baseline characteristics—including age, histology, EGFR or ALK genetic alterations, and brain metastasis—differed significantly between the two cohorts. After adjustment for patient characteristics with the IPW method, ORR was 18.9% for the CAP cohort and 11.0% for the control cohort (ORR ratio 1.71; 95% CI 1.19 to 2.46; p=0.004). IPW-adjusted Kaplan-Meier curves showed that median progression-free survival (PFS) for the CAP and control cohorts was 2.8 and 2.7 months (IPW-adjusted HR 0.95; 95% CI 0.80 to 1.12; p=0.55), and median overall survival (OS) was 9.2 and 10.4 months (IPW-adjusted HR 1.05; 95% CI 0.86 to 1.28; p=0.63), respectively.ConclusionsAfter accounting for selection bias by propensity score analysis, CAP showed a significantly higher ORR compared with chemotherapy alone, with the primary end point of ORR being achieved. However, these results did not translate into a PFS or OS advantage, suggesting that prior administration of PD-1 inhibitors may result in a synergistic antitumor effect with subsequent chemotherapy, but that such an effect is transient. CAP therefore does not appear to achieve durable tumor control or confer a lasting survival benefit.
Journal Article
Effects of combined hot and hypoxic conditions on muscle blood flow and muscle oxygenation during repeated cycling sprints
by
Yamaguchi Keiichi
,
Hayashi Nanako
,
Goto Kazushige
in
Blood flow
,
Hypoxia
,
Infrared spectroscopy
2021
PurposeThe purpose of the present study was to determine muscle blood flow and muscle oxygenation during repeated-sprint exercise under combined hot and hypoxic conditions.MethodsIn a single-blind, cross-over research design, 11 active males performed three sets of 5 × 6-s maximal sprints with 30-s active recovery on a cycling ergometer under control (CON; 23 °C, 50% rH, 20.9% FiO2), normobaric hypoxic (HYP; 23 °C, 50% rH, 14.5% FiO2), or hot + normobaric hypoxic (HH; 35 °C, 50% rH, 14.5% FiO2) conditions. The vastus lateralis muscle blood flow after each set and muscle oxygenation during each sprint were evaluated using near-infrared spectroscopy methods.ResultsDespite similar repeated-sprint performance among the three conditions (peak and mean power outputs, percent decrement score), HH was associated with significantly higher muscle blood flow compared with CON after the first set (CON: 0.61 ± 0.10 mL/min/100 g; HYP: 0.81 ± 0.13 mL/min/100 g; HH: 0.99 ± 0.16 mL/min/100 g; P < 0.05). The tissue saturation index was significantly lower in HYP than in CON during the latter phase of the exercise (P < 0.05), but it did not differ between HH and CON.ConclusionThese findings suggest that a combination of normobaric hypoxia and heat stress partially facilitated the exercise-induced increase in local blood flow, but it did not enhance tissue desaturation.
Journal Article