An exploratory study of factors associated with long-term, high-dose opioid prescription in cancer patients in Japan based on a medical claims database.

PURPOSE: As the cancer survivors increase, patients using long-term and high-dose opioids are also increasing. Therefore, the promotion of appropriate use is important. This study investigated the actual status of opioid prescriptions in Japan and identified factors associated with long-term, high-dose prescription. METHODS: We conducted a case-control study using a hospital-based administrative claims database. Patients with a diagnosis of cancer and prescriptions of opioids were included. Patients who received continuous opioid for less than 183 days were defined as the "control," and patients who received continuous opioid at higher dose levels (≥ 120 mg/day of oral morphine equivalent) for 183 days or more were defined as the "case." The case was subdivided into two groups: those with the duration of less than 730 days (case I) and 730 days or more (case II). After describing factors possibly associated with long-term, high-dose opioid prescription, ordinal logistic regression analysis was conducted. RESULTS: We included 19,176 patients; of these, 13,517 were in the control, 111 were in the case I, and 682 were in the case II. The analysis showed that distant metastasis, back pain, dose of opioids, non-opioid analgesics, prescription, and chemotherapy during the opioid prescriptions were significantly associated with long-term, high-dose opioid prescription. CONCLUSION: Four percent of the study population were prescribed long-term, high-dose opioids, and several comorbidities and concomitant medications were identified as associated factors. Opioids might be also prescribed for non-cancer chronic pain. It is necessary to properly distinguish the type of pain and to use opioids safely and appropriately.

The Burden of Undiagnosed Adults With Attention-Deficit/Hyperactivity Disorder Symptoms in Japan: A Cross-Sectional Study.

Background Symptoms experienced by adult patients with attention-deficit/hyperactivity disorder (ADHD) frequently result in functional impairment across academic/occupational functioning, daily life, and social functioning. A substantial proportion of undiagnosed and untreated ADHD has been suggested in Japan. This study aims to better understand the potential undiagnosed ADHD population in Japan by quantifying the burden associated with ADHD symptoms through a comparison of the prevalence of comorbidities, health-related quality of life (HRQoL), work productivity and activity impairment (WPAI), and healthcare resource utilization (HRU) between undiagnosed potential ADHD respondents who were screened positive and negative using Adult ADHD Self-Report Scale (ASRS)-v1.1. Methodology Respondents from Japan National Health and Wellness Survey 2016 who answered ASRS-v1.1 without an ADHD diagnosis were included. Respondents checking ≥4 items from ASRS-A and ≥9 from ASRS-A+B were classified as ASRS A+ (n = 309) and ASRS AB+ (n = 227), respectively. ASRS negative (n = 9,280) were respondents who were neither ASRS A+ nor ASRS AB+. Data on the presence of comorbidities, HRQoL, WPAI, and HRU were compared. Results ASRS A+ and ASRS AB+ respondents reported higher coexistence of mental comorbidities (depression, generalized anxiety disorder, bipolar disorder, obsessive-compulsive disorder, etc.), sleep problems (insomnia, narcolepsy, sleep apnea, etc.), and physical comorbidities (non-alcoholic steatohepatitis, allergy, and asthma). They also reported greater WPAI and HRU and lower HRQoL than matched ASRS-negative respondents. Conclusions A significantly higher burden was identified among undiagnosed adults with potential ADHD symptoms. Appropriate diagnosis may help those at risk or those who present with symptoms overlapping with ADHD.

Change in Antidepressant Use After Initiation of ADHD Medication in Japanese Adults with Comorbid Depression: A Real-World Database Analysis.

PURPOSE: To better understand the treatment of comorbid depression in adults with attention-deficit/hyperactivity disorder (ADHD) by investigating the prescription patterns of antidepressants, anxiolytics, and hypnotics after commencing ADHD medication. PATIENTS AND METHODS: In this retrospective observational study in Japan, the data of patients initiating ADHD medication while already receiving antidepressants (ADHD group) and of patients prescribed antidepressants but not diagnosed with ADHD (control group) were extracted from an electronic medical record database. Additionally, one-to-one matching for patients in both groups was performed using sex, age, baseline dosage of antidepressants, and any comorbid psychiatric disorders as covariates. The observation period included a 1-month baseline period and a 6-month follow-up period. The percentage of patients prescribed antidepressants and the mean prescribed dosages were compared between matched-cohort groups. Prescriptions for anxiolytics and hypnotics were also assessed. RESULTS: In the matched cohorts, consisting of 239 patients in the ADHD group and 239 patients from the unmatched control cohort of 10,485, the percentage of patients prescribed antidepressants decreased from baseline in both groups to 94.1% in the ADHD group and 89.5% in the control group during the first month of follow-up, and 77.0% and 78.7%, respectively, during the last month. There were no significant differences between groups in the percentages of patients prescribed antidepressants or in the mean prescribed dosages of antidepressants at any time point over the follow-up period. Prescribed dosages of anxiolytics and hypnotics tended to be lower in the ADHD group. CONCLUSION: The two groups were medicated similarly with respect to their depressive symptoms over 6 months. Our results suggest that in patients with ADHD and comorbid depression, which is more likely to be more severe than in depression without ADHD, depressive symptoms are managed following initiation of add-on ADHD medication, without requiring higher antidepressant dosages than in patients with depression only.

Efficacy and safety of guanfacine extended-release in Japanese adults with attention-deficit/hyperactivity disorder: Exploratory post hoc subgroup analyses of a randomized, double-blind, placebo-controlled study.

AIM: Previously, we reported on the efficacy and safety of guanfacine extended-release (GXR) in Japanese adults with attention-deficit/hyperactivity disorder (ADHD) from a phase 3, double-blind, placebo-controlled, randomized trial. In this exploratory post hoc analysis, we assessed the efficacy and/or safety of GXR in the following subgroups: ADHD-combined (ADHD-C) and ADHD-predominantly inattentive (ADHD-I) subtypes, age (≥31, <31 years), sex (male, female), and body weight (≥50, <50 kg). METHODS: The primary efficacy endpoint was change from baseline in the Japanese version of the investigator-rated ADHD-Rating Scale-IV (ADHD-RS-IV) with adult prompts (total scores) at week 10. RESULTS: The efficacy analysis population included 200 patients (GXR, 100; placebo, 100). ADHD-RS-IV total score effect sizes (GXR vs placebo) were similar across all subgroups (total population: 0.52, ADHD-C: 0.51, ADHD-I: 0.52, ≥31 years: 0.61, <31 years: 0.47, male: 0.50, female: 0.57). There were no major differences in the incidence/types of treatment-emergent adverse events (TEAEs) across the subgroups. The incidence of significant TEAEs (34.3%, 10.6%) and TEAEs leading to discontinuation (34.3%, 12.1%) were approximately three times higher in females than males, respectively. The incidence of TEAEs in patients weighing <50 kg and ≥50 kg was 100% and 73.6% during dose optimization and 40% and 24.4% during the maintenance period, respectively. CONCLUSION: Findings from this post hoc analysis in adults with ADHD support the efficacy and safety of GXR regardless of ADHD subtype, age, or sex and suggest that careful monitoring for TEAEs and GXR dose optimization is considered for all patients, as needed.

[Pharmacological properties and clinical effects of the ADHD drug, Lisdexamfetamine (Vyvanse® capsules 20†mg and 30†mg)].

Lisdexamfetamine dimesylate (hereinafter referred to as "lisdexamfetamine"; brand name, Vyvanse®), was developed for the treatment of attention-deficit/hyperactivity disorder (ADHD). This drug, which is classified as a central nervous system (CNS) stimulant for once-daily oral administration, received marketing approval in March 2019 and was launched in December 2019 in Japan. Lisdexamfetamine is a prodrug that is hydrolyzed to its active form d-amphetamine in the blood following oral administration. Pharmacologically, d-amphetamine competitively inhibits the dopamine transporter (DAT) and the noradrenaline transporter (NAT) to increase dopamine (DA) and noradrenaline (NA) concentrations in the synaptic cleft. In addition to inhibiting the reuptake of DA and NA, d-amphetamine has also an effect in promoting the release of these neurotransmitters by being taken up into neuronal cells and then acting on the vesicular monoamine transporter. The mechanisms of action by which d-amphetamine exerts a therapeutic effect on ADHD may be based on the above-described effects. Clinical studies conducted in Japan and overseas have demonstrated the efficacy of lisdexamfetamine over placebo in the treatment of pediatric ADHD patients. The most of the adverse events with a higher incidence than in the placebo were mild, and long-term administration of the drug was not associated with an increase in the incidence of adverse events or the rate of treatment discontinuation. Lisdexamfetamine, which is designated as raw material for stimulants and therefore requires strict distribution control in Japan, is expected to be effective in the treatment of ADHD patients with inadequate responses to existing therapeutic agents.

An Oncogenic Alteration Creates a Microenvironment that Promotes Tumor Progression by Conferring a Metabolic Advantage to Regulatory T Cells.

Only a small percentage of patients afflicted with gastric cancer (GC) respond to immune checkpoint blockade (ICB). To study the mechanisms underlying this resistance, we examined the immune landscape of GC. A subset of these tumors was characterized by high frequencies of regulatory T (Treg) cells and low numbers of effector T cells. Genomic analyses revealed that these tumors bore mutations in RHOA that are known to drive tumor progression. RHOA mutations in cancer cells activated the PI3K-AKT-mTOR signaling pathway, increasing production of free fatty acids that are more effectively consumed by Treg cells than effector T cells. RHOA mutant tumors were resistant to PD-1 blockade but responded to combination of PD-1 blockade with inhibitors of the PI3K pathway or therapies targeting Treg cells. We propose that the metabolic advantage conferred by RHOA mutations enables Treg cell accumulation within GC tumors, generating an immunosuppressive TME that underlies resistance to ICB.

Selective inhibition of low-affinity memory CD8+ T cells by corticosteroids.

Patients treated with immune checkpoint blockade (ICB) sometimes experience immune-related adverse events (irAEs), requiring immuno-suppressive drugs such as corticosteroids despite the possibility that immunosuppression may impair the antitumor effects of ICB. Here, we address the dilemma of using corticosteroids for the treatment of irAEs induced by ICB. ICB augments neoantigen-specific CD8+ T cell responses, resulting in tumor regression. In our model, simultaneous, but not late, administration of corticosteroids impaired antitumor responses with reduction of CD8+ T cell proliferation. Secondary challenge using tumors with/without the neoantigen showed selective progression in tumors lacking the neoantigen when corticosteroids were administered. Corticosteroids decreased low- but not high-affinity memory T cells by suppressing fatty acid metabolism essential for memory T cells. In a small cohort of human melanoma patients, overall survival was shorter after treatment with CTLA-4 blockade in patients who received early corticosteroids or had low tumor mutation burden. Together, low-affinity memory T cells are dominantly suppressed by corticosteroids, necessitating careful and thoughtful corticosteroid use.

Selective Cytotoxicity of Dihydroorotate Dehydrogenase Inhibitors to Human Cancer Cells Under Hypoxia and Nutrient-Deprived Conditions.

Human dihydroorotate dehydrogenase (HsDHODH) is a key enzyme of pyrimidine de novo biosynthesis pathway. It is located on the mitochondrial inner membrane and contributes to the respiratory chain by shuttling electrons to the ubiquinone pool. We have discovered ascofuranone (1), a natural compound produced by Acremonium sclerotigenum, and its derivatives are a potent class of HsDHODH inhibitors. We conducted a structure-activity relationship study and have identified functional groups of 1 that are essential for the inhibition of HsDHODH enzymatic activity. Furthermore, the binding mode of 1 and its derivatives to HsDHODH was demonstrated by co-crystallographic analysis and we show that these inhibitors bind at the ubiquinone binding site. In addition, the cytotoxicities of 1 and its potent derivatives 7, 8, and 9 were studied using human cultured cancer cells. Interestingly, they showed selective and strong cytotoxicity to cancer cells cultured under microenvironment (hypoxia and nutrient-deprived) conditions. The selectivity ratio of 8 under this microenvironment show the most potent inhibition which was over 1000-fold higher compared to that under normal culture condition. Our studies suggest that under microenvironment conditions, cancer cells heavily depend on the pyrimidine de novo biosynthesis pathway. We also provide the first evidence that 1 and its derivatives are potential lead candidates for drug development which target the HsDHODH of cancer cells living under a tumor microenvironment.

[Immunosuppressive Environment in Tumors].

Tumor cells establish a unique circumstance called tumor microenvironment(TME)suitable for tumor development and progression. One ofthe most important advantages ofTME for tumor cells is immunosuppressive environment such as higher presence ofregulatory T(Treg)cells, which play a central role for establishment and maintenance of immunological selftolerance and homeostasis. CTLA-4 expressed by Treg cells prevents the maturation ofAPCs resulting in suppression ofT -cell activation. Inhibitory cytokines and adenosine produced by Treg cells are also responsible for their suppressive functions. Indeed, high infiltration of Treg cells has been observed in many tumor tissues and is associated with poor clinical outcomes. Treg cells are recruited into tumors via chemokines secreted by tumor cells and immune cells, and further expand in TME. It has recently been shown that the metabolism oftumor cells and infiltrated immune cells in TME is also important component for tumor immunosuppressive environment. Effector T(Teff)cells rely on glycolysis for their proliferation and effector function, whereas Treg cells predominantly employ oxidative phosphorylation for suppressive function. In TME, tumor cells uptake and utilize large amounts ofglucose and glutamine and the concentration ofthose nutrients is much lower than that in normal tissues or peripheral blood. Under low glucose conditions, Teff cells fail to drive glycolysis for their survival and effector function. While the shortage of glutamine causes inhibition of Teff-cell proliferation and cytokines production, it is favorable for Treg cells. High consumption of glucose through glycolysis by tumor cells results in lactate accumulation in TME, resulting in suppression to proliferation and function of Teff cells. By contrast, high lactate level increases Treg cells with suppressive function. Furthermore, adenosine generated by tumor cells and Treg cells is known to impair the function of Teff cells. Together, various factors in TME including the metabolism of tumor cells and infiltrated immune cells allow Treg cells to infiltrate, proliferate and exhibit strong suppressive function, leading to dysfunction of Teff cells.

IBA57 mutations abrogate iron-sulfur cluster assembly leading to cavitating leukoencephalopathy.

OBJECTIVE: To determine the molecular factors contributing to progressive cavitating leukoencephalopathy (PCL) to help resolve the underlying genotype-phenotype associations in the mitochondrial iron-sulfur cluster (ISC) assembly system. METHODS: The subjects were 3 patients from 2 families who showed no inconsistencies in either clinical or brain MRI findings as PCL. We used exome sequencing, immunoblotting, and enzyme activity assays to establish a molecular diagnosis and determine the roles of ISC-associated factors in PCL. RESULTS: We performed genetic analyses on these 3 patients and identified compound heterozygosity for the IBA57 gene, which encodes the mitochondrial iron-sulfur protein assembly factor. Protein expression analysis revealed substantial decreases in IBA57 protein expression in myoblasts and fibroblasts. Immunoblotting revealed substantially reduced expression of SDHB, a subunit of complex II, and lipoic acid synthetase (LIAS). Levels of pyruvate dehydrogenase complex-E2 and α-ketoglutarate dehydrogenase-E2, which use lipoic acid as a cofactor, were also reduced. In activity staining, SDH activity was clearly reduced, but it was ameliorated in mitochondrial fractions from rescued myoblasts. In addition, NFU1 protein expression was also decreased, which is required for the assembly of a subset of iron-sulfur proteins to SDH and LIAS in the mitochondrial ISC assembly system. CONCLUSIONS: Defects in IBA57 essentially regulate NFU1 expression, and aberrant NFU1 ultimately affects SDH activity and LIAS expression in the ISC biogenesis pathway. This study provides new insights into the role of the iron-sulfur protein assembly system in disorders related to mitochondrial energy metabolism associated with leukoencephalopathy with cavities.

ECHS1 mutations cause combined respiratory chain deficiency resulting in Leigh syndrome.

The human ECHS1 gene encodes the short-chain enoyl coenzyme A hydratase, the enzyme that catalyzes the second step of ß-oxidation of fatty acids in the mitochondrial matrix. We report on a boy with ECHS1 deficiency who was diagnosed with Leigh syndrome at 21 months of age. The patient presented with hypotonia, metabolic acidosis, and developmental delay. A combined respiratory chain deficiency was also observed. Targeted exome sequencing of 776 mitochondria-associated genes encoded by nuclear DNA identified compound heterozygous mutations in ECHS1. ECHS1 protein expression was severely depleted in the patient's skeletal muscle and patient-derived myoblasts; a marked decrease in enzyme activity was also evident in patient-derived myoblasts. Immortalized patient-derived myoblasts that expressed exogenous wild-type ECHS1 exhibited the recovery of the ECHS1 activity, indicating that the gene defect was pathogenic. Mitochondrial respiratory complex activity was also mostly restored in these cells, suggesting that there was an unidentified link between deficiency of ECHS1 and respiratory chain. Here, we describe the patient with ECHS1 deficiency; these findings will advance our understanding not only the pathology of mitochondrial fatty acid ß-oxidation disorders, but also the regulation of mitochondrial metabolism.

Homoplasmy of a mitochondrial 3697G>A mutation causes Leigh syndrome.

Herein we report on three siblings with Leigh syndrome (LS) harboring a homoplasmic m.3697G>A mutation (G131S) in the MT-ND1 gene. The siblings' phenotypically normal mother had the same, albeit heteroplasmic, mutation. Complex I deficiency (8% of average control values) was demonstrated in a biceps brachii muscle from one of the patients. Heteroplasmic m.3697G>A has been reported in patients with Leber's hereditary optic neuropathy, mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes and Stüve-Wiedemann syndrome. Because all three patients in this series carried m.3697G>A in a homoplasmic manner and had LS, we suggest that homoplasmy of m.3697G>A may cause the LS phenotype.

Inhibition of cancer cell growth by GRP78 siRNA lipoplex via activation of unfolded protein response.

Proteasome inhibitors are a novel class of molecular-targeted anti-cancer drugs that suppress the degradation of malfolded proteins, trigger endoplasmic reticulum (ER) stress, and activate apoptosis signals. Glucose-regulated protein 78 (GRP78), a major ER chaperone, is one of the most important molecules for transduction of unfolded protein response (UPR) signals. In accordance with past findings that expression of GRP78 is elevated in cancer cells and helps to resist stress-induced apoptosis, GRP78 knockdown could be effective in anticancer therapy. We tested this hypothesis and found that transfection of small interfering RNA (siRNA) targeting GRP78 inhibited the growth of RENCA renal carcinoma cells, in association with elevated gene expression of UPR downstream signaling molecules (CHOP, EDEM1, and ERdj4 mRNA). In addition, the combinatorial effect of GRP78 siRNA with ER stress inducers (tunicamycin, MG132, and 2-deoxyglucose) on survival was measured. Combination of GRP78 siRNA and the ER stress inducers more extensively reduced cell viability than combination with scrambled siRNA. Besides RENCA, B16BL6 melanoma cells were also shown to be sensitive to GRP78 siRNA. These results suggest that GRP78 knockdown might be an effective strategy for cancer therapy targeting UPR-induced apoptosis.

Type II Fp of human mitochondrial respiratory complex II and its role in adaptation to hypoxia and nutrition-deprived conditions.

The flavoprotein (Fp) subunit of human mitochondrial succinate-ubiquinone reductase (SQR, complex II) has isoforms (type I, type II). Type II Fp is predominantly expressed in some cancer and fetal tissues and those tissues are often exposed to ischemia. The present study shows that complex II with type II Fp has lower optimal pH than complex II with type I Fp, and type II Fp mRNA expression was induced by ischemia. The result suggests complex II with type II Fp may function in cells with low mitochondrial matrix pH caused by ischemia and its function is related to cellular adaptation to ischemia.

Mitochondrial complex III deficiency caused by a homozygous UQCRC2 mutation presenting with neonatal-onset recurrent metabolic decompensation.

Mitochondrial complex III (CIII) deficiency is a relatively rare disease with high clinical and genetic heterogeneity. CIII comprises 11 subunits encoded by one mitochondrial and 10 nuclear genes. Abnormalities of the nuclear genes such as BCS1L and TTC19 encoding mitochondrial assembly factors are well known, but an explanation of the majority of CIII deficiency remains elusive. Here, we report three patients from a consanguineous Mexican family presenting with neonatal onset of hypoglycemia, lactic acidosis, ketosis, and hyperammonemia. We found a homozygous missense mutation in UQCRC2 that encodes mitochondrial ubiquinol-cytochrome c reductase core protein II by whole-exome sequencing combined with linkage analysis. On the basis of structural modeling, the mutation (p.Arg183Trp) was predicted to destabilize the hydrophobic core at the subunit interface of the core protein II homodimer. In vitro studies using fibroblasts from the index patient clearly indicated CIII deficiency, as well as impaired assembly of the supercomplex formed from complexes I, III, and IV. This is the first described human disease caused by a core protein abnormality in mitochondrial CIII.

A homozygous mutation of C12orf65 causes spastic paraplegia with optic atrophy and neuropathy (SPG55).

BACKGROUND: Autosomal recessive hereditary spastic paraplegias (AR-HSP) constitute a heterogeneous group of neurodegenerative diseases involving pyramidal tracts dysfunction. The genes responsible for many types of AR-HSPs remain unknown. We attempted to identify the gene responsible for AR-HSP with optic atrophy and neuropathy. METHODS: The present study involved two patients in a consanguineous Japanese family. Neurologic examination and DNA analysis were performed for both patients, and a skin biopsy for one. We performed genome-wide linkage analysis involving single nucleotide polymorphism arrays, copy-number variation analysis, and exome sequencing. To clarify the mitochondrial functional alteration resulting from the identified mutation, we performed immunoblot analysis, mitochondrial protein synthesis assaying, blue native polyacrylamide gel electrophoresis (BN-PAGE) analysis, and respiratory enzyme activity assaying of cultured fibroblasts of the patient and a control. RESULTS: We identified a homozygous nonsense mutation (c.394C>T, p.R132X) in C12orf65 in the two patients in this family. This C12orf65 mutation was not found in 74 Japanese AR-HSP index patients without any mutations in previously known HSP genes. This mutation resulted in marked reduction of mitochondrial protein synthesis, followed by functional and structural defects in respiratory complexes I and IV. CONCLUSIONS: This novel nonsense mutation in C12orf65 could cause AR-HSP with optic atrophy and neuropathy, resulting in a premature stop codon. The truncated C12orf65 protein must lead to a defect in mitochondrial protein synthesis and a reduction in the respiratory complex enzyme activity. Thus, dysfunction of mitochondrial translation could be one of the pathogenic mechanisms underlying HSPs.

Mitochondrial fumarate reductase as a target of chemotherapy: from parasites to cancer cells.

Recent research on respiratory chain of the parasitic helminth, Ascaris suum has shown that the mitochondrial NADH-fumarate reductase system (fumarate respiration), which is composed of complex I (NADH-rhodoquinone reductase), rhodoquinone and complex II (rhodoquinol-fumarate reductase) plays an important role in the anaerobic energy metabolism of adult parasites inhabiting hosts. The enzymes in these parasite-specific pathways are potential target for chemotherapy. We isolated a novel compound, nafuredin, from Aspergillus niger, which inhibits NADH-fumarate reductase in helminth mitochondria at nM order. It competes for the quinone-binding site in complex I and shows high selective toxicity to the helminth enzyme. Moreover, nafuredin exerts anthelmintic activity against Haemonchus contortus in in vivo trials with sheep indicating that mitochondrial complex I is a promising target for chemotherapy. In addition to complex I, complex II is a good target because its catalytic direction is reverse of succinate-ubiquionone reductase in the host complex II. Furthermore, we found atpenin and flutolanil strongly and specifically inhibit mitochondrial complex II. Interestingly, fumarate respiration was found not only in the parasites but also in some types of human cancer cells. Analysis of the mitochondria from the cancer cells identified an anthelminthic as a specific inhibitor of the fumarate respiration. Role of isoforms of human complex II in the hypoxic condition of cancer cells and fetal tissues is a challenge. This article is part of a Special Issue entitled Biochemistry of Mitochondria, Life and Intervention 2010.