DS-5670a, a novel mRNA-encapsulated lipid nanoparticle vaccine against severe acute respiratory syndrome coronavirus 2: Results from a phase 2 clinical study.

BACKGROUND: DS-5670a is a vaccine candidate for coronavirus disease 2019 (COVID-19) harnessing a novel modality composed of messenger ribonucleic acid (mRNA) encoding the receptor-binding domain (RBD) from the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encapsulated in lipid nanoparticles. Here, we report the safety, immunogenicity, and pharmacokinetic profile of DS-5670a from a phase 2 clinical trial in healthy adults who were immunologically naïve to SARS-CoV-2. METHODS: The study consisted of an open-label, uncontrolled, dose-escalation part and a double-blind, randomized, uncontrolled, 2-arm, parallel-group part. A total of 80 Japanese participants were assigned to receive intramuscular DS-5670a, containing either 30 or 60 µg of mRNA, as two injections administered 4 weeks apart. Safety was assessed by characterization of treatment-emergent adverse events (TEAEs). Immunogenicity was assessed by neutralization titers against SARS-CoV-2, anti-RBD immunoglobulin (Ig)G levels, and SARS-CoV-2 spike-specific T cell responses. Plasma pharmacokinetic parameters of DS-5670a were also evaluated. RESULTS: Most solicited TEAEs were mild or moderate with both the 30 and 60 µg mRNA doses. Four participants (10 %) in the 60 µg mRNA group developed severe redness at the injection site, but all cases resolved without treatment. There were no serious TEAEs and no TEAEs leading to discontinuation. Humoral immune responses in both dose groups were greater than those observed in human convalescent serum; the 60 µg mRNA dose produced better responses. Neutralization titers were found to be correlated with anti-RBD IgG levels (specifically IgG1). DS-5670a elicited antigen-specific T helper 1-polarized cellular immune responses. CONCLUSIONS: The novel mRNA-based vaccine candidate DS-5670a provided favorable immune responses against SARS-CoV-2 with a clinically acceptable safety profile. Confirmatory trials are currently ongoing to evaluate the safety and immunogenicity of DS-5670a as the primary vaccine and to assess the immunogenicity when administered as a heterologous or homologous booster. TRIAL REGISTRY: https://jrct.niph.go.jp/latest-detail/jRCT2071210086.

TAS4464, A Highly Potent and Selective Inhibitor of NEDD8-Activating Enzyme, Suppresses Neddylation and Shows Antitumor Activity in Diverse Cancer Models.

NEDD8-activating enzyme (NAE) is an essential E1 enzyme of the NEDD8 conjugation (neddylation) pathway, which controls cancer cell growth and survival through activation of cullin-RING ubiquitin ligase complexes (CRL). In this study, we describe the preclinical profile of a novel, highly potent, and selective NAE inhibitor, TAS4464. TAS4464 selectively inhibited NAE relative to the other E1s UAE and SAE. TAS4464 treatment inhibited cullin neddylation and subsequently induced the accumulation of CRL substrates such as CDT1, p27, and phosphorylated IκBα in human cancer cell lines. TAS4464 showed greater inhibitory effects than those of the known NAE inhibitor MLN4924 both in enzyme assay and in cells. Cytotoxicity profiling revealed that TAS4464 is highly potent with widespread antiproliferative activity not only for cancer cell lines, but also patient-derived tumor cells. TAS4464 showed prolonged target inhibition in human tumor xenograft mouse models; weekly or twice a week TAS4464 administration led to prominent antitumor activity in multiple human tumor xenograft mouse models including both hematologic and solid tumors without marked weight loss. As a conclusion, TAS4464 is the most potent and highly selective NAE inhibitor reported to date, showing superior antitumor activity with prolonged target inhibition. It is, therefore, a promising agent for the treatment of a variety of tumors including both hematologic and solid tumors. These results support the clinical evaluation of TAS4464 in hematologic and solid tumors.

Chronotherapy of maxacalcitol on skin inflammation induced by topical 12-O-tetradecanoylphorbol-13-acetate in mice.

In general, chronotherapy is desirable for a more effective and/or safe dosage regimen. In this study, a daily rhythm of skin vitamin D receptor (VDR) and chronotherapeutic profiles of maxacalcitol, a vitamin D analogue, were evaluated using mice with skin inflammation induced by topical 12-O-tetradecanoylphorbol-13-acetate (TPA). This study showed that skin nuclear VDR expression in TPA-treated mice has a daily rhythm with the peak at the middle of active period. The effects of maxacalcitol were greater after dosing during early to middle of active period than those after dosing during early to middle of inactive period. These data suggest that chronotherapeutic profiles of maxacalcitol partly depend on the daily rhythm of skin nuclear VDR in TPA-treated mice. Because TPA-treated mice are considered as one of animal models of psoriasis, these animal data might be helpful for establishing chronotherapeutic approach of maxacalcitol in clinical practice.

Muscle RAS oncogene homolog (MRAS) recurrent mutation in Borrmann type IV gastric cancer.

The prognosis of patients with Borrmann type IV gastric cancer (Type IV) is extremely poor. Thus, there is an urgent need to elucidate the molecular mechanisms underlying the oncogenesis of Type IV and to identify new therapeutic targets. Although previous studies using whole-exome and whole-genome sequencing have elucidated genomic alterations in gastric cancer, none has focused on comprehensive genetic analysis of Type IV. To discover cancer-relevant genes in Type IV, we performed whole-exome sequencing and genome-wide copy number analysis on 13 patients with Type IV. Exome sequencing identified 178 somatic mutations in protein-coding sequences or at splice sites. Among the mutations, we found a mutation in muscle RAS oncogene homolog (MRAS), which is predicted to cause molecular dysfunction. MRAS belongs to the Ras subgroup of small G proteins, which includes the prototypic RAS oncogenes. We analyzed an additional 46 Type IV samples to investigate the frequency of MRAS mutation. There were eight nonsynonymous mutations (mutation frequency, 17%), showing that MRAS is recurrently mutated in Type IV. Copy number analysis identified six focal amplifications and one homozygous deletion, including insulin-like growth factor 1 receptor (IGF1R) amplification. The samples with IGF1R amplification had remarkably higher IGF1R mRNA and protein expression levels compared with the other samples. This is the first report of MRAS recurrent mutation in human tumor samples. Our results suggest that MRAS mutation and IGF1R amplification could drive tumorigenesis of Type IV and could be new therapeutic targets.

Influence of dioxin on the daily variation of insulin sensitivity in mice.

To evaluate an influence of dioxin on a daily variation of insulin sensitivity, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (100ng/kg) was given for 3 weeks in mice. Insulin tolerance test and oral glucose tolerance test were performed. TCDD decreased insulin sensitivity at an active period, but not at a rest period. TCDD elevated plasma TNF-α, and the value was significantly higher during an active period than during a rest period. These data suggest that TCDD blunts insulin sensitivity, mainly during an active period. Higher elevation in plasma TNF-α during an active period might be involved in this phenomenon.

Selenoprotein P as a diabetes-associated hepatokine that impairs angiogenesis by inducing VEGF resistance in vascular endothelial cells.

AIMS/HYPOTHESIS: Impaired angiogenesis induced by vascular endothelial growth factor (VEGF) resistance is a hallmark of vascular complications in type 2 diabetes; however, its molecular mechanism is not fully understood. We have previously identified selenoprotein P (SeP, encoded by the SEPP1 gene in humans) as a liver-derived secretory protein that induces insulin resistance. Levels of serum SeP and hepatic expression of SEPP1 are elevated in type 2 diabetes. Here, we investigated the effects of SeP on VEGF signalling and angiogenesis. METHODS: We assessed the action of glucose on Sepp1 expression in cultured hepatocytes. We examined the actions of SeP on VEGF signalling and VEGF-induced angiogenesis in HUVECs. We assessed wound healing in mice with hepatic SeP overexpression or SeP deletion. The blood flow recovery after ischaemia was also examined by using hindlimb ischaemia model with Sepp1-heterozygous-knockout mice. RESULTS: Treatment with glucose increased gene expression and transcriptional activity for Sepp1 in H4IIEC hepatocytes. Physiological concentrations of SeP inhibited VEGF-stimulated cell proliferation, tubule formation and migration in HUVECs. SeP suppressed VEGF-induced reactive oxygen species (ROS) generation and phosphorylation of VEGF receptor 2 (VEGFR2) and extracellular signal-regulated kinase 1/2 (ERK1/2) in HUVECs. Wound closure was impaired in the mice overexpressing Sepp1, whereas it was improved in SeP (-/-)mice. SeP (+/-)mice showed an increase in blood flow recovery and vascular endothelial cells after hindlimb ischaemia. CONCLUSIONS/INTERPRETATION: The hepatokine SeP may be a novel therapeutic target for impaired angiogenesis in type 2 diabetes.

Temsirolimus induces surfactant lipid accumulation and lung inflammation in mice.

Interstitial lung disease (ILD) is a well-known adverse effect of mammalian target of rapamycin (mTOR) inhibitors. However, it remains unknown how lung toxicities are induced by mTOR inhibitors. Here, we constructed a mouse model of mTOR inhibitor-induced ILD using temsirolimus and examined the pathogenesis of the disease. Male ICR mice were treated with an intraperitoneal injection of different doses of temsirolimus (3 or 30 mg·kg(-1)·wk(-1)) or vehicle. Temsirolimus treatment increased capillary-alveolar permeability and induced neutrophil infiltration and fibrinous exudate into the alveolar space, indicating alveolar epithelial and/or endothelial injury. It also induced macrophage depletion and the accumulation of excessive surfactant phospholipids and cholesterols. Alveolar macrophage depletion is thought to cause surfactant lipid accumulation. To further examine whether temsirolimus has cytotoxic and/or cytostatic effects on alveolar macrophages and alveolar epithelial cells, we performed in vitro experiments. Temsirolimus inhibited cell proliferation and viability in both alveolar macrophage and alveolar epithelial cells. Temsirolimus treatment caused some signs of pulmonary inflammation, including upregulated expression of several proinflammatory cytokines in both bronchoalveolar lavage cells and lung homogenates, and an increase in lymphocytes in the bronchoalveolar lavage fluid. These findings indicate that temsirolimus has the potential to induce alveolar epithelial injury and to deplete alveolar macrophages followed by surfactant lipid accumulation, resulting in pulmonary inflammation. This is the first study to focus on the pathogenesis of mTOR inhibitor-induced ILD using an animal model.

α-Lipoic acid protects against arsenic trioxide-induced acute QT prolongation in anesthetized guinea pigs.

Clinical use of arsenic trioxide (As2O3), which can induce the remission of relapsed or refractory acute promyelocytic leukemia, is often limited because of its cardiotoxicity. Symptoms of cardiotoxicity include acute cardiac conduction disturbances, such as QT prolongation. The present study was undertaken to evaluate the effects of α-lipoic acid (LA) on acute As2O3-induced ECG abnormalities (QTc interval prolongation) in anesthetized guinea pigs. Intravenous injection of As2O3 in guinea pigs caused QTc interval prolongation, which was significantly attenuated by co-treatment with LA (0.35, 3.5 and 35 mg/kg) in a dose-dependent manner. In isolated guinea pig cardiomyocytes, the decrease in IKs current induced by As2O3 (1 µM) was rapidly restored to the basal level by the addition of LA (10 µM). Consistent with this finding, the As2O3-induced QTc interval prolongation was also improved rapidly by post-treatment with LA in guinea pigs. Electrospray ionization time-of-flight mass spectrometry analysis detected an expected peak of arsenic-LA complex in vitro, indicating that LA and As2O3 form a new compound in vivo. In addition, pre-treatment with a chelating agent, British anti-Lewisite (BAL, 3.5 or 35 mg/kg), also attenuated the As2O3-induced QTc interval prolongation. In this study, co- and post-treatments with LA and pre-treatment with BAL ameliorated As2O3-induced acute QT prolongation in anesthetized guinea pigs. Because LA and probably BAL may bind to As2O3, these agents may exert protective effects through their chelating activity. Further studies are needed to determine whether LA is beneficial as a prophylactic or rescue agent for acute promyelocytic leukemia patients treated with As2O3.

Comparative effects of statins on murine cardiac gene expression profiles in normal mice.

Recent clinical data suggest that the efficacy of statin treatment in patients with heart failure varies depending on the drugs administered. The present study was undertaken to compare murine cardiac gene expression profiles following treatment with four different statins. In normal male C57BL/6J mice, 4 weeks of treatment with or without a statin (pitavastatin, pravastatin, rosuvastatin, or atorvastatin) did not affect any biochemical parameters, including the lipid profile. However, cardiac gene expression profiling by microarray analysis revealed distinct patterns among the five groups. Several genes that might be involved in cardiac function, including Ccnd2, Klf7 and Timp3, were differentially regulated by treatment with a specific statin. In the primary cultured neonatal mouse cardiomyocytes, statin-induced changes in the expression of these genes were largely unaffected by supplementation with mevalonic acid. These data indicate that statins directly regulate cardiac gene expression in a drug-specific manner in normal mice. Additional studies are needed to determine whether these differences influence the clinical efficacy in particular patients, such as those with heart failure.

Tissue-dependent alterations of the clock gene expression rhythms in leptin-resistant Zucker diabetic fatty rats.

Recent studies have demonstrated that circadian clocks are impaired in liver and adipose tissue of both leptin-deficient ob/ob and leptin-resistant KK-A(y) mice. Because impairment of peripheral clocks precedes metabolic abnormalities in ob/ob mice, leptin signaling might be important for modulating peripheral clocks. To assess this hypothesis, the authors determined daily mRNA expression profiles of clock genes Clock, Arntl, Per1, Per2, Cry1, Dbp, and Nr1d1 in several tissues of leptin-receptor-deficient Zucker diabetic fatty (ZDF) rats. Transcript levels of some of these genes around the respective peak times decreased significantly in the liver, but not in the suprachiasmatic nucleus, mesenteric adipose tissue, and heart, compared to those in control rats. In contrast, mRNA levels of Per1 and Dbp around the peak time increased in the aorta of ZDF rats. However, expression rhythms of these clock genes in serum-stimulated cultured cells isolated from the aorta of ZDF rats were quite similar to those in serum-stimulated aortic cells of control rats. These results show that systemic leptin signaling defect influences peripheral clocks in a tissue-dependent manner, suggesting the possibility that leptin indirectly modulates the clocks in at least a subset of peripheral tissues.

Influence of dosing time on the efficacy and safety of finasteride in rats.

Finasteride (FIN), a widely used medication for the treatment of androgen-dependent diseases, blocks the conversion of testosterone to a more potent androgen, dihydrotestosterone (DHT). In this study, we investigated a dosing time-dependent effect and safety of FIN in rats. Androgen receptor (AR) mRNA and nuclear protein levels exhibited clear daily rhythms with the peak during the dark period in the prostate and during the light period in the liver. Repeated oral administration of FIN (5 or 100 mg/kg) at 3 h after lights on (HALO) for 2 weeks decreased serum DHT concentration throughout a 24-h period, whereas the dosing of the agent at 15 HALO decreased its level only transiently even in the higher dose group. FIN caused laboratory abnormalities in the 3 HALO group but not in the 15 HALO group. However, the effect of FIN on the prostate weight was not influenced by the dosing time. These results suggest that the safety, but not effect, of FIN depends on its dosing time in rats. The dosing of FIN in the active period might be a rational dosage regimen, which is needed to be confirmed in human subjects.

Protective effect of α-lipoic acid against arsenic trioxide-induced acute cardiac toxicity in rats.

The clinical use of arsenic trioxide (ATO) is often limited because of its adverse effects. We examined whether α-lipoic acid (LA) protects against the ATO-induced cardiac toxicity. In the chronic study, two of four rats suddenly died by the repeated dosing of ATO, whereas no deaths were observed in combination with LA. In the acute study, continuous ECG recording revealed that intravenous injection of ATO caused transient ST-T change, whereas pretreatment with LA abolished the ATO-induced ECG abnormality in all animals. These results suggest that LA protects against the ATO-induced acute cardiac toxicity and subsequent sudden death in rats.

Impairment of peripheral circadian clocks precedes metabolic abnormalities in ob/ob mice.

Recent studies have demonstrated relationships between the dysfunction of circadian clocks and the development of metabolic abnormalities, but the chicken-and-egg question remains unresolved. To address this issue, we investigated the cause-effect relationship in obese, diabetic ob/ob mice. Compared with control C57BL/6J mice, the daily mRNA expression profiles of the clock and clock-controlled genes Clock, Bmal1, Cry1, Per1, Per2, and Dbp were substantially dampened in the liver and adipose tissue, but not the hypothalamic suprachiasmatic nucleus, of 10-wk-old ob/ob mice. Four-week feeding of a low-calorie diet and administration of leptin over a 7-d period attenuated, to a significant and comparable extent, the observed metabolic abnormalities (obesity, hyperglycemia, hyperinsulinemia, and hypercholesterolemia) in the ob/ob mice. However, only leptin treatment improved the impaired peripheral clocks. In addition, clock function, assessed by measuring levels of Per1, Per2, and Dbp mRNA at around peak times, was also reduced in the peripheral tissues of 3-wk-old ob/ob mice without any overt metabolic abnormalities. Collectively these results indicate that the impairment of peripheral clocks in ob/ob mice does not result from metabolic abnormalities but may instead be at least partially caused by leptin deficiency itself. Further studies are needed to clarify how leptin deficiency affects peripheral clocks.

Protective Effect of α-Lipoic Acid Against Arsenic Trioxide-Induced Acute Cardiac Toxicity in Rats.

The clinical use of arsenic trioxide (ATO) is often limited because of its adverse effects. We examined whether α-lipoic acid (LA) protects against the ATO-induced cardiac toxicity. In the chronic study, two of four rats suddenly died by the repeated dosing of ATO, whereas no deaths were observed in combination with LA. In the acute study, continuous ECG recording revealed that intravenous injection of ATO caused transient ST-T change, whereas pretreatment with LA abolished the ATO-induced ECG abnormality in all animals. These results suggest that LA protects against the ATO-induced acute cardiac toxicity and subsequent sudden death in rats.

Associations of metabolic parameters and ethanol consumption with messenger RNA expression of clock genes in healthy men.

Recent studies suggest that the impairment of circadian clock function causes various pathological conditions, such as obesity, diabetes, and alcoholism, and an altered mRNA expression of clock genes was found under these conditions. However, it remains to be determined whether clock gene expression varies depending on metabolic conditions even in healthy people. To address this issue, we investigated the associations of metabolic parameters and alcohol consumption with mRNA expression of clock genes (CLOCK, BMAL1, PER1, PER2, and PER3) in peripheral blood cells obtained from 29 healthy non-obese elderly men (age 51-78 yrs) who adhered to a regular sleep-wake routine, through a single time-of-day venous blood sampling at approximately 09:00 h. There were significant correlations between (1) waist circumference and mRNA level of PER1 (r =-0.43), (2) plasma glucose concentration and PER2 (r =-0.50), (3) ethanol consumption and BMAL1 (r =-0.43), and (4) serum gamma-GTP concentration (a sensitive marker of alcohol consumption) and PER2 (r =-0.40). These results suggest mRNA expression of clock genes is associated with obesity, glucose tolerance, and ethanol consumption even in healthy people.

Influence of age on clock gene expression in peripheral blood cells of healthy women.

Recent studies have demonstrated a close relationship between circadian clock function and the development of obesity and various age-related diseases. In this study, we investigated whether messenger RNA (mRNA) levels of clock genes are associated with age, body mass index, blood pressures, fasting plasma glucose, or shift work. Peripheral blood cells were obtained from 70 healthy women, including 25 shift workers, at approximately 9:00 AM. Transcript levels of clock genes (CLOCK, BMAL1, PER1, and PER3) were determined by real-time quantitative polymerase chain reaction. Stepwise multiple regression analysis demonstrated that BMAL1 mRNA levels were correlated only with age (beta = -.50, p < .001). In contrast, PER3 levels were correlated with fasting plasma glucose (beta = -.29, p < .05) and shift work (beta = .31, p < .05). These results suggest that increased age, glucose intolerance, and irregular hours independently affect the intracellular clock in humans.

The hepatic circadian clock is preserved in a lipid-induced mouse model of non-alcoholic steatohepatitis.

Recent studies have correlated metabolic diseases, such as metabolic syndrome and non-alcoholic fatty liver disease, with the circadian clock. However, whether such metabolic changes per se affect the circadian clock remains controversial. To address this, we investigated the daily mRNA expression profiles of clock genes in the liver of a dietary mouse model of non-alcoholic steatohepatitis (NASH) using a custom-made, high-precision DNA chip. C57BL/6J mice fed an atherogenic diet for 5 weeks developed hypercholesterolemia, oxidative stress, and NASH. DNA chip analyses revealed that the atherogenic diet had a great influence on the mRNA expression of a wide range of genes linked to mitochondrial energy production, redox regulation, and carbohydrate and lipid metabolism. However, the rhythmic mRNA expression of the clock genes in the liver remained intact. Most of the circadianly expressed genes also showed 24-h rhythmicity. These findings suggest that the biological clock is protected against such a metabolic derangement as NASH.

[Improvement of epirubicin-induced phlebitis to switch from liquid preparation to lyophilized formulation].

Adjuvant chemotherapy containing epirubicin is commonly used to treat patients with pre- or post-operative breast cancer. It is known that the epirubicin(FarmorubicinRTU)preparation often caused phlebitis, whereas dexamethasone has been used to prevent that reaction. We examined whether the lyophilized formulation of epirubicin(Farmorubicin)can reduces the incidence of phlebitis compared with the preparation. All infusions were administered through a peripheral vein. Adverse drug reaction including phlebitis was evaluated after each infusion and at the subsequent visit to four or six cycles. Sixty-two patients were given the preparation and 35 the lyophilized formulation. Epirubicininduced phlebitis was observed in 45.7% of patients given the preparation and in 48.4% of those given the lyophilized formulation. There was no statistically significant difference between the two groups(p=0.41). However, the incidence of severe phlebitis requiring treatment with steroid ointment was significantly increased among patients treated with the preparation(27.4% vs 9.7%, p<0.05, respectively). There was no significant difference in the incidence of adverse drug reactions other than severe phlebitis between the two groups. In this study, lyophilized formulations of epirubicin significantly reduced the incidence of severe phlebitis compared with that among patients receiving the preparation. Using lyophilized formulations of epirubicin should be considered to prevent a reduction in QOL with epirubicin-induced phlebitis in patients with breast cancer.