Japanese nationwide observational multicenter study of tumor BRCA1/2 variant testing in advanced ovarian cancer.

The association between germline BRCA1 and BRCA2 pathogenic variants (mutations: gBRCAm) and ovarian cancer risk is well established. Germline testing alone cannot detect somatic BRCA1/2 pathogenic variants (sBRCAm), which is calculated based on the proportion of tumor BRCAm (tBRCAm) from tumor samples and gBRCAm. Homologous recombination deficiency (HRD) results mainly from genetic/epigenetic alterations in homologous recombination repair-related genes and can be evaluated by genomic instability status. In Japan, the prevalence of tBRCAm, sBRCAm, and HRD remains unclear. This multicenter, cross-sectional, observational study, CHaRacterIzing the croSs-secTional approach to invEstigate the prevaLence of tissue BRCA1/2 mutations in newLy diagnosEd advanced ovarian cancer patients (CHRISTELLE), evaluated the prevalence of tBRCAm, sBRCAm, and HRD in tumor specimens from newly diagnosed patients with ovarian cancer who underwent gBRCA testing. Of the 205 patients analyzed, 26.8% had a tBRCAm, including tBRCA1m (17.6%) and tBRCA2m (9.3%). The overall prevalence of tBRCAm, gBRCAm, sBRCAm, and HRD-positive status was 26.8%, 21.5%, 6.3%, and 60.0%, respectively. The calculated sBRCAm/tBRCAm ratio was 23.6% (13/55), and the prevalence of gBRCA variant of uncertain significance was 3.9%. These results suggest gBRCA testing alone cannot clearly identify the best course of treatment, highlighting the importance of sBRCA testing in Japan. The present results also suggest that testing for tBRCA and HRD should be encouraged in advanced ovarian cancer patients to drive precision medicine.

The Prevalence and Diagnostic Ratio of Familial Hypercholesterolemia (FH) and Proportion of Acute Coronary Syndrome in Japanese FH Patients in a Healthcare Record Database Study.

BACKGROUND: Familial hypercholesterolemia (FH) is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C). Because of underdiagnosis, acute coronary syndrome (ACS) is often the first clinical manifestation of FH. In Japan, there are few reports on the prevalence and diagnostic ratios of FH and the proportion of ACS among FH patients in clinical settings. METHODS: This retrospective, observational study used anonymized data from electronic healthcare databases between April 2001 and March 2015 of patients who had ≥2 LDL-C measurements recorded after April 2009. The index date was defined as the date of the first LDL-C measurement after April 2009. The primary endpoint was the prevalence of definite or suspected FH; secondary endpoints included the proportion of FH patients hospitalized for ACS, the proportion of patients using lipid-lowering drugs (LLDs), and LDL-C levels. RESULTS: Of the 187,781 patients screened, 1547 had definite or suspected FH (0.8%) based on data from the entire period; 832 patients with definite (n = 299, 0.16%) or suspected FH (n = 533, 0.28%) before the index date were identified in the main analysis cohort. LLDs were used in 214 definite FH patients (71.6%) and 137 suspected FH patients (25.7%). Among definite or suspected FH patients with ACS (n = 84) and without ACS (n = 748), 32.1% and 30.1% with definite FH and 3.2% and 2.4% with suspected FH had LDL-C levels < 2.6 mmol/L (<100 mg/dL), respectively. Sixty patients (7.2%) were hospitalized due to ACS at the index date. CONCLUSIONS: The prevalence of FH in this Japanese cohort of patients with ≥2 LDL-C measurements at hospitals was 0.8%, which is higher than that currently reported in epidemiological studies (0.2-0.5%). Patients with suspected FH, with or without ACS, had poorly controlled LDL-C levels and were undertreated. The proportion of FH patients who were hospitalized due to ACS was 7.2%.

Association of gBRCA1/2 mutation locations with ovarian cancer risk in Japanese patients from the CHARLOTTE study.

Whether germline (g) breast cancer susceptibility gene (BRCA) mutations are located within or outside the ovarian cancer cluster region (OCCR) (1380-4062 bp for gBRCA1, and between 3249-5681 bp and 6645-7471 bp for gBRCA2) may influence risk variations for ovarian cancers. This ad hoc analysis of the CHARLOTTE epidemiological study in Japan assessed the distribution of gBRCA1/2 mutations in patients with newly diagnosed ovarian cancer, and investigated an association between gBRCA1/2 mutation locations and ovarian cancer risk. Differences in patient background and clinical characteristics in subgroups stratified by gBRCA1/2 mutation locations were also evaluated. We analyzed the data of 93 patients (14.7%) from the CHARLOTTE study who were positive for gBRCA1/2 mutations. After excluding 16 cases with L63X founder mutation, 28 (65.1%) of gBRCA1 mutations were within the OCCR. Of 30 gBRCA2 mutations, 15 (50.0%) were within the OCCR. Of 27 patients (one patient excluded for unknown family history) with gBRCA1 mutations located in the OCCR, 11 (40.7%) had a family history of ovarian cancer; the proportion of patients with a family history of ovarian cancer and gBRCA1 mutations outside the OCCR was lower (13.3%). Sixty percent of patients with gBRCA1 mutations outside the OCCR had a family history of breast cancer; the proportion of patients with a family history of breast cancer and gBRCA1 mutations within the OCCR was relatively lower (33.3%). Understanding the mutation locations may contribute to more accurate risk assessments of susceptible individuals and early detection of ovarian cancer among gBRCA mutation carriers.

Evolocumab vs. Ezetimibe in Statin-Intolerant Hyperlipidemic Japanese Patients: Phase 3 GAUSS-4 Trial.

AIM: In patients with hyperlipidemia, intolerance to statins presents a challenge in reducing the risk of events associated with cardiovascular disease. This phase 3, randomized, double-blind trial in Japanese patients with statin intolerance aimed to evaluate the efficacy and safety of evolocumab vs. ezetimibe in lowering low-density lipoprotein-cholesterol (LDL-C). METHODS: This study was conducted in a 12-week, double-blind period followed by an open-label extension designed to characterize 1 year of evolocumab treatment. Statin intolerance was defined as failure of two or more statins due to myalgia, myositis, or rhabdomyolysis. Eligible patients were randomized at 2:2:1:1 into four groups: 420 mg evolocumab every 4 weeks (Q4W)＋oral placebo daily, 140 mg evolocumab every 2 weeks (Q2W)＋oral placebo daily, subcutaneous (SC) placebo Q4W＋10 mg ezetimibe daily, and SC placebo Q2W＋ 10 mg ezetimibe daily. RESULTS: Sixty-one patients were randomized to evolocumab (n=40) or ezetimibe (n=21). For the co-primary endpoints of percent change from the baseline in mean LDL-C to the mean of weeks 10 and 12 and to week 12, the evolocumab-ezetimibe treatment differences were -39.4% (95% CI, -47.2% to -31.5%) and -40.1% (95% CI, -48.7% to -31.6%), respectively (adjusted p＜0.0001). The most common adverse events were diarrhea (9.5%) and nasopharyngitis (12.5%) in the ezetimibe and evolocumab groups, respectively, during the double-blind period and nasopharyngitis (29%) during the open-label extension. CONCLUSION: Evolocumab was superior to ezetimibe in reducing LDL-C during the 12-week double-blind period in this population of Japanese patients with statin intolerance, with efficacy and safety results maintained for 1 year. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02634580.

Long-Term Treatment With Evolocumab Among Japanese Patients　- Final Report of the OSLER Open-Label Extension Studies.

BACKGROUND: Treatment with evolocumab reduces mean low-density lipoprotein cholesterol (LDL-C) up to 75% and cardiovascular events by 16% in the first year and 25% thereafter. Methods and Results: Japanese patients with hypercholesterolemia enrolled in the parent YUKAWA-1-2 studies could enroll, once eligible, in the OSLER studies (n=556). OSLER re-randomized patients 2:1 to evolocumab plus standard of care (SOC; evolocumab+SOC) or SOC alone for 1 year; after year 1, patients could enter the all-evolocumab+SOC open-label extension of OSLER. Patients received evolocumab+SOC from the 2nd year through up to 5 years. Long-term efficacy and safety, including antidrug antibodies, were evaluated. Of 556 patients, 532 continued to the all-evolocumab+SOC extension: mean (standard deviation [SD]) age 61 (10) years, 39% female. A total of 91% of 532 patients completed the studies. Mean (SD) LDL-C change from parent-study baseline with evolocumab from a mean (SD) baseline of 142.3 (21.3) and 105.0 (31.1) mg/dL in OSLER-1 and OSLER-2, respectively, was maintained through the end of the study: -58.0% (19.1%) at year 5 in OSLER-1, -62.7% (25.6%) at year 3 in OSLER-2. The overall safety profile of the evolocumab+SOC periods was similar to that of the year-1 controlled period. Antidrug antibodies were detected transiently in 3 patients. No neutralizing antibodies were detected. CONCLUSIONS: Japanese patients who continued evolocumab+SOC for up to 5 years experienced sustained high LDL-C level reduction. Long-term evolocumab+SOC exposure showed no new safety signals.

12-Week Effectiveness and Safety of Low-Density Lipoprotein Cholesterol-Lowering Therapy by Proprotein Convertase Subtilisin/Kexin Type 9 Inhibition in Patients With Familial Hypercholesterolemia and Hypercholesterolemia　- Data From a Real-World Observational Study of Evolocumab in Japan.

Background: Evolocumab is the first monoclonal antibody against proprotein convertase subtilisin/kexin type 9 (PCSK9) approved in Japan for the treatment of patients with familial hypercholesterolemia (FH) and hypercholesterolemia (HC). This study assessed the 12-week effectiveness and safety of low-density lipoprotein cholesterol (LDL-C)-lowering therapy by PCSK9 inhibition in patients with FH (homozygous [HoFH] or heterozygous [HeFH]) and HC by analyzing evolocumab data collected in the real-world setting in Japan. Methods and Results: Overall, 427 patients (mean±SD age, 61.6±13.8 years; female, 38.4%; 28 HoFH, 320 HeFH, 79 HC), enrolled from 299 clinical sites, were included in the safety analysis set. The major cardiovascular risk factors were coronary artery disease (77.3%), diabetes mellitus/impaired glucose tolerance (38.6%), and hypertension (65.1%). Median follow-up duration was 85.0 days. After 12 weeks of evolocumab treatment, the mean±SD percent change from baseline in LDL-C was -45.5%±27.0% (n=23) in HoFH (P<0.001 vs. baseline; t-test), -54.2%±29.0% (n=280) in HeFH (P<0.001), and -64.6%±22.4% (n=72) in HC (P<0.001) patients. The incidence of adverse drug reactions was 5.4% (23/427). Conclusions: Results suggest that patients receiving evolocumab treatment in the real-world setting were predominantly those with FH and HC in the secondary prevention group. LDL-C-lowering effectiveness with evolocumab was observed in FH (both HoFH and HeFH) and HC patients.

Treatment Patterns, Statin Intolerance, and Subsequent Cardiovascular Events Among Japanese Patients With High Cardiovascular Risk Initiating Statin Therapy.

BACKGROUND: This study examined treatment patterns, possible statin intolerance, and incidence of cardiovascular events (CVEs) in 2 cohorts of patients with high cardiovascular risk (i.e., patients with atherosclerotic cardiovascular disease [ASCVD] and patients with diabetes mellitus).Methods and Results:A retrospective cohort study examined adults initiating either a statin or ezetimibe from 1 January 2006 to 31 May 2014 in the Japan Medical Data Center database. The first observed statin or ezetimibe prescription defined the index date. Patients had ≥12 months of pre- and post-index date plan enrollment. Two high-risk cohorts, the ASCVD cohort and diabetes cohort, were created based on diagnoses observed during the 12 months' pre-index date. Treatment patterns, possible statin intolerance, and incidence of CVEs were reported. In the ASCVD cohort (n=5,302), 32.9% discontinued therapy, 7.7% switched to a non-index statin or non-statin lipid-lowering therapy, and 11.2% augmented index therapy in the 12 months' post-index date; only 0.3% were using high-intensity statins and 10% had possible statin intolerance. Also, 8.1% had any new CVE during the follow-up period. Treatment patterns and incidence of CVEs among the diabetes cohort were similar to those of the ASCVD cohort. CONCLUSIONS: High cardiovascular risk Japanese patients had frequent treatment modifications, although use of high-intensity statin doses was rare. These patterns may indicate that alternative therapies for lipid lowering are needed.

One-Year Efficacy and Safety of Evolocumab in Japanese Patients　- A Pooled Analysis From the Open-Label Extension OSLER Studies.

BACKGROUND: Evolocumab, a fully human monoclonal antibody against PCSK9, significantly reduced low-density lipoprotein-cholesterol (LDL-C) levels in Japanese patients by up to 76% when administered with a statin. We evaluated the efficacy and safety of 1 year of evolocumab in a pooled analysis of patients from the 12-week YUKAWA studies who continued into the open-label extension (OLE) OSLER studies.Methods and Results:YUKAWA-1 and YUKAWA-2 were conducted in hypercholesterolemic, high-cardiovascular-risk Japanese patients who were receiving statin therapy. Patients completing these studies were eligible for an OLE study. At OLE entry, patients were re-randomized 2:1 to evolocumab+standard of care (SOC) or SOC alone (OSLER-1: evolocumab 420 mg monthly; OSLER-2: evolocumab 140 mg biweekly or 420 mg monthly). A 1-year analysis was performed on patients enrolled from the YUKAWA studies into OSLER. At parent-study baseline (YUKAWA-1 or YUKAWA-2 patients continuing into OSLER), mean (SD) age was 61 (10) years; 39% were female; mean (SD) baseline LDL-C (on statin) was 119.7 (33.0) mg/dL. Overall rates of adverse events were comparable between evolocumab+SOC and SOC alone. In YUKAWA patients receiving evolocumab+SOC, mean (SE) reductions in LDL-C from parent-study baseline to OLE 1 year were 69.1% (1.2%; OSLER-1) and 65.1% (2.2%; OSLER-2). CONCLUSIONS: In a pooled 1-year analysis of Japanese patients in the ongoing OSLER studies, treatment with evolocumab+SOC was well tolerated and resulted in sustained LDL-C reductions at 1 year.

IQGAP1 links PDGF receptor-ß signal to focal adhesions involved in vascular smooth muscle cell migration: role in neointimal formation after vascular injury.

Platelet-derived growth factor (PDGF) stimulates vascular smooth muscle cell (VSMC) migration and neointimal formation in response to injury. We previously identified IQ-domain GTPase-activating protein 1 (IQGAP1) as a novel VEGF receptor 2 binding scaffold protein involved in endothelial migration. However, its role in VSMC migration and neointimal formation in vivo is unknown. Here we show that PDGF stimulation rapidly promotes IQGAP1 association with PDGF receptor-ß (PDGFR) as well as IQGAP1 tyrosine phosphorylation in cultured VSMC. Overexpression or knockdown of IQGAP1 enhances or inhibits PDGFR autophosphorylation (p-PDGFR), respectively. Immunofluorescence and cell fractionation analysis reveals that PDGF-induced p-PDGFR localized in focal adhesions (FAs), but not caveolae/lipid rafts, is inhibited by IQGAP1 knockdown with siRNA. PDGF stimulation promotes IQGAP1 association with PDGFR/FA signaling protein complex. Functionally, IQGAP1 siRNA inhibits PDGF-induced FA formation as well as VSMC migration induced by PDGF. In vivo, IQGAP1 expression is markedly increased at neointimal VSMC in wire-injured femoral arteries. Mice lacking IQGAP1 exhibit impaired neointimal formation in response to vascular injury. In summary, IQGAP1, through interaction with PDGFR and FA signaling proteins, promotes activation of PDGFR in FAs as well as FA formation, which may contribute to VSMC migration and neointimal formation after injury. Our findings provide insight into IQGAP1 as a potential therapeutic target for vascular migration-related diseases.

Role of nox2-based NADPH oxidase in bone marrow and progenitor cell function involved in neovascularization induced by hindlimb ischemia.

Bone marrow (BM) is the major reservoir for endothelial progenitor cells (EPCs). Postnatal neovascularization depends on not only angiogenesis but also vasculogenesis, which is mediated through mobilization of EPCs from BM and their recruitment to the ischemic sites. Reactive oxygen species (ROS) derived from Nox2-based NADPH oxidase play an important role in postnatal neovascularization; however, their role in BM and EPC function is unknown. Here we show that hindlimb ischemia of mice significantly increases Nox2 expression and ROS production in BM-mononuclear cells (BMCs), which is associated with an increase in circulating EPC-like cells. Mice lacking Nox2 show reduction of ischemia-induced flow recovery, ROS levels in BMCs, as well as EPC mobilization from BM. Transplantation of wild-type (WT)-BM into Nox2-deficient mice rescues the defective neovascularization, whereas WT mice transplanted with Nox2-deficient BM show reduced flow recovery and capillary density compared to WT-BM transplanted control. Intravenous infusion of WT- and Nox2-deficient BMCs into WT mice reveals that neovascularization and homing capacity are impaired in Nox2-deficient BMCs in vivo. In vitro, Nox2-deficient c-kit+Lin- BM stem/progenitor cells show impaired chemotaxis and invasion as well as polarization of actins in response to stromal derived factor (SDF), which is associated with blunted SDF-1-mediated phosphorylation of Akt. In conclusion, Nox2-derived ROS in BM play a critical role in mobilization, homing, and angiogenic capacity of EPCs and BM stem/progenitor cells, thereby promoting revascularization of ischemic tissue. Thus, NADPH oxidase in BM and EPCs is potential therapeutic targets for promoting neovascularization in ischemic cardiovascular diseases.

Role of protein tyrosine phosphatase 1B in vascular endothelial growth factor signaling and cell-cell adhesions in endothelial cells.

Vascular endothelial growth factor (VEGF) binding induces phosphorylation of VEGF receptor (VEGFR)2 in tyrosine, which is followed by disruption of VE-cadherin-mediated cell-cell contacts of endothelial cells (ECs), thereby stimulating EC proliferation and migration to promote angiogenesis. Tyrosine phosphorylation events are controlled by the balance of activation of protein tyrosine kinases and protein tyrosine phosphatases (PTPs). Little is known about the role of endogenous PTPs in VEGF signaling in ECs. In this study, we found that PTP1B expression and activity are markedly increased in mice hindlimb ischemia model of angiogenesis. In ECs, overexpression of PTP1B, but not catalytically inactive mutant PTP1B-C/S, inhibits VEGF-induced phosphorylation of VEGFR2 and extracellular signal-regulated kinase 1/2, as well as EC proliferation, whereas knockdown of PTP1B by small interfering RNA enhances these responses, suggesting that PTP1B negatively regulates VEGFR2 signaling in ECs. VEGF-induced p38 mitogen-activated protein kinase phosphorylation and EC migration are not affected by PTP1B overexpression or knockdown. In vivo dephosphorylation and cotransfection assays reveal that PTP1B binds to VEGFR2 cytoplasmic domain in vivo and directly dephosphorylates activated VEGFR2 immunoprecipitates from human umbilical vein endothelial cells. Overexpression of PTP1B stabilizes VE-cadherin-mediated cell-cell adhesions by reducing VE-cadherin tyrosine phosphorylation, whereas PTP1B small interfering RNA causes opposite effects with increasing endothelial permeability, as measured by transendothelial electric resistance. In summary, PTP1B negatively regulates VEGFR2 receptor activation via binding to the VEGFR2, as well as stabilizes cell-cell adhesions through reducing tyrosine phosphorylation of VE-cadherin. Induction of PTP1B by hindlimb ischemia may represent an important counterregulatory mechanism that blunts overactivation of VEGFR2 during angiogenesis in vivo.

Identification of quantitative trait loci for cardiac hypertrophy in two different strains of the spontaneously hypertensive rat.

Cardiac hypertrophy and left ventricular hypertrophy are known to be substantially controlled by genetic factors. As an experimental model, we undertook genome-wide screens for cardiac mass in F2 populations bred from the stroke-prone spontaneously hypertensive rats (SHRSP) and normal spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) of a Japanese colony. Two F2 cohorts were independently produced: F2(SHRSP x WKY) (110 male and 110 female rats) and F2(SHR x WKY) (151 male rats). The ratio of heart weight to body weight (Hw/Bw) was evaluated at 12 months of age in F2(SHRSP x WKY) after salt-loading for 7 months, and at around 15 weeks of age in F2(SHR x WKY) who had been fed a normal rat chow diet. Subsequent to an initial screen with 251 markers in F2(SHRSP x WKY) male progeny, 170 and 161 markers were selected and characterized in F2(SHRSP x WKY) female progeny and F2(SHR x WKY) male progeny, respectively. Markers from four chromosomal regions showed suggestive or significant linkage to Hw/Bw. The strongest and the most consistent linkage was found in the vicinity of D3Mgh16 on rat chromosome (RNO) 3 (a maximal log of the odds score reached 4.0 to 6.6 across the F2 populations studied). In the other three regions on RNO6, RNO10 and RNO13, the degree of linkage was more prominent in either males or females. These data provide solid evidence for a "principal" RNO3 quantitative trait loci regulating Hw/Bw in SHRSP and SHR, and also suggest the possible presence of sexual dimorphism in regard to genetic susceptibility for cardiac hypertrophy.

Evaluation of insulin resistance linkage to rat chromosome 4 in SHR of a Japanese colony.

The spontaneously hypertensive rat (SHR) is a model of human insulin resistance syndrome. Quantitative trait loci for cellular defects in glucose and fatty acid metabolism have been mapped to an overlapping region of rat chromosome (RNO) RNO4 in SHR of the National Institute of Health colony, where a deletion in the Cd36 gene has been implicated as the causative mutation of insulin resistance. The present study has examined the potential presence of RNO4 linkage to a series of metabolic phenotypes in F(2) progeny derived from SHR of a Japanese colony (SHR/Izm) without the Cd36 mutation. Our data demonstrate that 'major' insulin resistance gene(s) are unlikely to exist on RNO4 in SHR/Izm and in vitro phenotypes measured in isolated adipocytes do not cosegregate in the F(2) population studied. Thus, it seems to be difficult to explain the underlying genetic mechanisms of insulin resistance by a single major gene on RNO4.

Isolation of a chromosome 1 region affecting blood pressure and vascular disease traits in the stroke-prone rat model.

Recently, a genome-wide screen has shown a major quantitative trait locus (QTL) for a stroke-associated phenotype on rat chromosome 1 (RNO1) independent of QTL for blood pressure (BP) in the stroke-prone spontaneously hypertensive rat (SHRSP) of a Heidelberg colony. However, it remains to be elucidated whether these observations reflect the existence of different genes predisposing to each of the disorders. To address this issue, we performed comprehensive approaches in a Japanese colony, Izm, as follows. First, we undertook genome-wide searches in F1(SHRSP/IzmxWKY/Izm)xSHRSP/Izm back-cross (n=63) to pursue a causal relation between hypertension and stroke. Although the strongest linkage to BP (LOD score of 3.4) was identified on RNO1, its relevance to stroke was not supported in the F1 back-cross studied. Second, we also investigated linkage to BP in F2 progeny (n=175) involving the stroke-resistant (or normal) spontaneously hypertensive rat (SHR). In F2 studies of SHR/Izm, this locus did not appear to constitute a principal BP QTL. Third, we constructed congenic animals with detailed phenotype characterization. Transfer of a chromosomal fragment between markers Klk1 and D1Rat116 from WKY/Izm onto the SHRSP/Izm background lowered systolic BP by 20 to 80 mm Hg, prevented development of apparent stroke, and exaggerated impaired glucose tolerance. In conclusion, we have successfully isolated an RNO1 region affecting BP, stroke, and glucose tolerance in SHRSP/Izm-derived congenic rats. The size of the introgressed region is large, but our novel congenic strain should help delineate complex, genetic impairments underlying BP and associated vascular disease phenotypes.