Peptide mimetic NC114 induces growth arrest by preventing PKCδ activation and FOXM1 nuclear translocation in colorectal cancer cells

The peptide mimetic, NC114, is a promising anticancer compound that specifically kills colorectal cancer cells without affecting normal colon epithelial cells. In our previous study, we observed that NC114 inhibited the Wnt/β-catenin pathway, with significant downregulation of both Ser 675-phosphorylated β-catenin and its target genes, cyclin D1 and survivin. However, the molecular mechanism responsible for its cytotoxic effect has not yet been fully characterized. In the present study, we demonstrated that NC114 prevented cell cycle progression from S to G2/M phase by downregulating cell cycle-related gene expression, and also induced growth arrest in SW480 and HCT-116 colorectal cancer cells. A novel covariation network analysis combined with transcriptome analysis revealed a series of signaling cascades affected by NC114 treatment, and identified protein kinase C-δ (PKCδ) and forkhead box protein M1 (FOXM1) as important regulatory factors for NC114-induced growth arrest. NC114 treatment inhibits the activation of PKCδ and its kinase activity, which suppresses MEK/ERK signaling. Attenuated MEK/ERK signaling then results in a reduction in FOXM1 phosphorylation and subsequent nuclear translocation of FOXM1 and β-catenin. Consequently, formation of a T-cell factor-4 (TCF4)/β-catenin transcription complex in the nucleus is inhibited and transcription of its target genes, such as cell cycle-related genes, is downregulated. The efficacy of NC114 on tumor growth was confirmed in a xenograft model. Collectively, elucidation of the mechanism by which NC114 induces growth arrest in colorectal cancer cells should provide a novel therapeutic strategy for colorectal cancer treatment.

Prognosis of hypertrophic cardiomyopathy in Japanese patients with an implantable cardioverter defibrillator -focus on apical hypertrophic cardiomyopathy

Background

Patients with hypertrophic cardiomyopathy (HCM) are at high risk of lethal arrhythmias, and implantable cardioverter defibrillators (ICD) are widely used for prevention of sudden cardiac death (SCD). Apical HCM is a phenotype variant of HCM, with hypertrophy predominantly affecting apex, that was initially described 30 years ago. Apical HCM patients may have different clinical prognosis compared with other subsets of HCM. In previous studies, apical HCM patients seem to have a more benign prognosis than other types of HCM. However, little is known about the long-term outcomes of apical HCM patients and there are many unclear points. Moreover, there are few reports about the clinical prognosis in apical HCM patients with an ICD.

Objective

The aim of this study is to identify the difference between the prognosis of apical and the other types of HCM patients with an ICD.

Methods

We retrospectively analyzed the database of our ICD clinic. All subjects underwent ICD implantation between October 2006 and September 2018. We classified HCM patients into LV outflow tract obstruction (LVOTO) and midventricular obstruction (MVO), apical HCM and other non-obstructive types. We divided all the patients into apical and other types of HCM, and examined their background, incidence of appropriate ICD therapies, hospitalization for heart failure, electrical storm and death.

Results

A total of consecutive 64 Japanese HCM patients with an ICD (follow-up period, 86±24 months; age, 65±14 years; male sex, 83%; left ventricular ejection fraction, 56±14%; LV max wall-thickness, 19±7mm; LV apical aneurysm, 9.4%; 5-year risk of SCD, 4.4±2.1) were enrolled in this study. We classified them into 14 apical HCM and 50 other types of HCM patients. The clinical characteristics and major clinical events of these patients are shown in the Table 1. During the follow-up periods, there were no significant differences in the incidence of electrical storm, hospitalization for heart failure and death between the 2 groups (p=0.11; p=0.60; p=0.39). Appropriate ICD therapies occurred in 6 of 14 (43%) patients with apical HCM and 5 of 50 (10%) patients with other types of HCM (p=0.010). The risk factors of patients with apical HCM patients are shown in Table 2.

Conclusions

Appropriate ICD therapy was more prevalent in patients with apical HCM, compared to patients with other types of HCM. Aggressive intervention such as catheter ablation for ventricular tachycardia and ventricular fibrillation may be considered in patients with apical HCM and higher score of 5-year risk of SCD. Further studies are needed to clarify the manifestations and long-term outcome of apical HCM patients.

Funding Acknowledgement

Type of funding sources: None.

Long-term clinical course and prognostic factors of heart failure with reduced ejection fraction (HFrEF) patients underwent primary prophylactic implantable cardioverter defibrillator (ICD)

Background

For decades, ICD is a well-established therapy for improving prognosis of structural heart disease with severe cardiac dysfunction, and ICD for primary prophylaxis against sudden cardiac death were routinely provided. However, long-term prognosis and clinical course are different in each individual patient with an ICD, and it is moreover unclear what kind of factors might have influences on their clinical outcomes.

Purpose

The aim of this study is to clarify long-term prognosis and predictors of future major adverse cardiac events (MACEs) in HFrEF patients with an ICD as primary prophylaxis in Japanese population.

Methods

We retrospectively analyzed our ICD database. Patients underwent primary prophylactic ICD implantation from 2006 to 2020 at our institute and met the criteria of ICD recommendation of the latest Japanese guideline. Its requirements are receiving optimal medication therapy, symptomatic heart failure (New York Heart Association classification II or greater), and severe cardiac dysfunction (left ventricular ejection fraction (LVEF) is 35% or less). Additionally, prior NSVT is considered Class I ICD recommendation. In the case of ischemic cardiomyopathy (ICM), ICD implantation was done at least 40 days after myocardial infarction and at least 90 days after revascularization. MACEs were defined as composite outcome of cardiovascular death, heart failure hospitalization, and appropriate ICD therapies.

Results

A total of 148 consecutive patients were enrolled (male, 120 (81%); age, 62.1±11.8 years; LVEF, 23.0±5.86%; left ventricular end-diastolic diameter (LVDd), 67.6±9.26mm; paroxysmal or persistent atrial fibrillation (AF), 38 (26%); NSVT, 113 (76%); use of class III antiarrhythmic drugs, 48 (32%); ICM, 49 (33%); cardiac resynchronization therapy (CRT), 63 (43%)). One hundred twenty patients (81%) were programmed with a shock-only zone over 200 beats per minute. The median follow-up duration was 58.5 months. Among those 148 patients, MACEs were occurred to 60 patients (41%). As a result of dividing all patients into two groups by the occurrence of MACE, LVEF and LVDd were worse in MACE(+) group, whereas, MACE(−) had greater number of co morbidities. The results of cox-regression analysis showed LVDd (HR: 1.07, 95% CI: 1.03–1.12, p<0.001), AF (HR: 2.88, 95% CI: 1.56–5.31, p<0.001) and ICM (HR: 1.78, 95% CI: 1.00–3.16, p=0.049) were the independent predictors of MACEs (Table). However, initial ICD programming was not related to the occurrence of MACE.

Conclusions

The incidence of MACEs in patients with an ICD and severe HFrEF was substantially high in this Japanese population. Etiology of ICM, left ventricle size, and AF were the potential risk factors for future MACEs.

Funding Acknowledgement

Type of funding sources: None.

Targeting Podoplanin for the Treatment of Osteosarcoma

PURPOSE

Osteosarcoma, the most common bone malignancy in children, has a poor prognosis, especially when the tumor metastasizes to the lungs. Therefore, novel therapeutic strategies targeting both proliferation and metastasis of osteosarcoma are required. Podoplanin (PDPN) is expressed by various tumors and is associated with tumor-induced platelet activation via its interaction with C-type lectin-like receptor 2 (CLEC-2) on platelets. We previously found that PDPN contributed to osteosarcoma growth and metastasis through platelet activation; thus, in this study, we developed an anti-PDPN humanized antibody and evaluated its effect on osteosarcoma growth and metastasis.

EXPERIMENTAL DESIGN

Nine osteosarcoma cell lines and two osteosarcoma patient-derived cells were collected, and we evaluated the efficacy of the anti-DPN-neutralizing antibody PG4D2 and the humanized anti-PDPN antibody AP201, which had IgG4 framework region. The antitumor and antimetastasis effect of PG4D2 and AP201 were examined in vitro and in vivo. In addition, growth signaling by the interaction between PDPN and CLEC-2 was analyzed using phospho-RTK (receptor tyrosine kinase) array, growth assay, or immunoblot analysis under the supression of RTKs by knockout and inhibitor treatment.

RESULTS

We observed that PG4D2 treatment significantly suppressed tumor growth and pulmonary metastasis in osteosarcoma xenograft models highly expressing PDPN. The contribution of PDGFR activation by activated platelet releasates to osteosarcoma cell proliferation was confirmed, and the humanized antibody, AP201, suppressed in vivo osteosarcoma growth and metastasis without significant adverse events.

CONCLUSIONS

Targeting PDPN with a neutralizing antibody against PDPN-CLEC-2 without antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity is a novel therapeutic strategy for PDPN-positive osteosarcoma.

Evaluation of risk factors for chemotherapy-induced nausea and vomiting in cisplatin and gemcitabine treatment for biliary tract cancer: acid suppressants do not prevent nausea

Chemotherapy-induced nausea and vomiting (CINV) is one of the most serious adverse effects of cancer therapy. Cancer patients frequently use acid suppressants (AS) for palliation of gastrointestinal symptoms associated with malignancy and/or anticancer therapy. AS are suggested as an additional option for CINV management in several antiemetic guidelines, although their efficacy remains unknown. The aim of this study was to determine whether AS administration affects CINV incidence in cisplatin and gemcitabine treatment for biliary tract cancer. The primary endpoint was to evaluate whether AS administration was associated with the incidence of all-grade nausea in the first administration by logistic analysis. The secondary endpoints were to assess factors associated with anorexia. Prophylactic antiemetics were based on current guidelines. Nausea occurred in 34.2% of patients (grade 1, 31.7%; grade 2, 2.5%). Patients exhibiting vomiting and anorexia represented 4.2% and 39.1%, respectively, without grade 3/4 symptoms. Multivariate analysis suggested that the independent risk factors for nausea as female sex, and no- or less-alcohol drinking habit and regular narcotics administration were associated with anorexia. In contrast, AS administration was not associated with nausea and anorexia incidence (odds ratio, 95% confidence interval: 1.43, 0.64-3.23; P =0.38 for nausea, 1.62, 0.71-3.68; P =0.25 for anorexia). In conclusion, we found that AS administration is not associated with CINV incidence, and female sex is a risk factor for nausea, and non-alcohol drinking habits and regular narcotic use are factors associated with anorexia in cisplatin and gemcitabine treatment for biliary tract cancer. We should correctly administer AS depending on the patient's situation. Successful CINV management needs effective monitoring and administration of prophylactic antiemetics and counter-measure medicines for patients at risk.

Association between right ventricular dysfunction and appropriate icd therapy

Funding Acknowledgements

Type of funding sources: None.

Background

Right ventricular fractional area change (RVFAC) as right ventricular function is recently referred as an independent predictor of sudden cardiac death (SCD). The purpose of this study was to evaluate the association of RVFAC and appropriate ICD therapy in order to determine the cut-off value of RVFAC.

Methods

Consecutive patients who underwent initial ICD implantation for any diseases except for non-dilated phase hypertrophic cardiomyopathy and channelopathy were retrospectively enrolled from 2012 to 2018. Primary endpoint was an initial appropriate ICD therapy. Transthoracic echocardiographic parameters before ICD implantation were evaluated by one physician and one echocardiologist to be validated. Right ventricular dimensions and function were also measured to be analyzed.

Results

In total, 172 patients (60.3±13.6 years, 131 males) including 63 ischemic cardiomyopathy were enrolled. Ninety patients received an ICD as a secondary prophylaxis. Mean LVEF and RVFAC were 38.3±14.3% and 35.8±8.82%, respectively. There was little correlation between RVFAC and LVEF (correlation coefficient =0.274). Regarding appropriate ICD therapy events, the best cut-off value of RVFAC was 34.8%. The odds ratio of low RVFAC was 2.731 (95%CI: 1.456-5.121, P=0.00174). Secondary prophylactic cohort with low RVFAC showed highest incidence of appropriate ICD therapy as shown in the figure. In multivariate analysis, only low RVFAC is an independent predictor of appropriate ICD therapy (HR: 3.53, 95%CI:1.78- 6.99, P=0.0003).

Conclusion

Low RVFAC seemed independently associated with increased appropriate ICD therapy.

Negative prognostic implications of non-sustained ventricular tachycardias in patients after prophylactic defibrillator implantation

Funding Acknowledgements

Type of funding sources: None.

Background

Non-sustained ventricular tachycardia (NSVT) is frequent phenomenon in severe heart failure with reduced ejection fraction (HFrEF) patients, and causes any negative impacts on such patients. In the Japanese Circulation Society (JCS) and Japanese Heart Rhythm Society (JHRS) guidelines, NSVT is regarded as a major component of indication for implantable cardioverter defibrillator (ICD) implantation. However, the long-term prognostic significance of NSVT in severe HFrEF is incompletely resolved.

Purpose

The aim of this study is to investigate the relation between prior NSVT episodes and major adverse cardiac events (MACEs) in HFrEF patients with an ICD as primary prophylaxis.

Methods

We retrospectively analyzed our ICD database. Patients underwent primary prophylactic ICD implantation from 2007 to 2018 following ICD recommendation of JCS and JHRS guidelines. Patients met the criteria of receiving optimal medication therapy, symptomatic heart failure (New York Heart Association classification II or greater), and severe cardiac dysfunction (left ventricular ejection fraction (LVEF) is 35% or less). In the case of ischemic cardiomyopathy (ICM), implantation of ICD was done at least 40 days after myocardial infarction and at least 90 days after revascularization. Incidence of NSVT episodes were identified through daily electrocardiogram (ECG), Holter ECG or monitor ECG in the hospital. MACEs were defined as composite outcome of cardiovascular death, heart failure hospitalization, and appropriate ICD therapies.

Results

A total of 148 consecutive patients were enrolled (male, 120 (81%); age, 62.1±11.8 years; LVEF, 23.0±5.86%; left ventricular end-diastolic diameter (LVDd), 67.6±9.26mm; paroxysmal or persistent atrial fibrillation (AF), 38 (26%); NSVT, 113 (76%); use of class III antiarrhythmic drugs, 48 (32%); ICM, 49 (33%); cardiac resynchronization therapy (CRT), 63 (43%)). The median follow-up duration was 58.5 months. As a result of comparison of the Kaplan-Meier curve between NSVT group (n=113) and non-NSVT group (n=35), cardiovascular death, heart failure hospitalization, and appropriate ICD therapy were not statistically different (Figures). Of those, MACEs were occurred to 60 patients (41%). The results of cox-regression analysis showed LVDd (HR: 1.07, 95% CI: 1.03-1.12, p<0.001), AF (HR: 2.88, 95% CI: 1.56-5.31, p<0.001) and ICM (HR: 1.78, 95% CI: 1.00-3.16, p=0.049) were the independent predictors of MACEs, however NSVT was not (Table).

Conclusions

In this Japanese population, the long-term prognosis of severe HFrEF patients is considered to be comparable regardless of prior NSVT episodes. However, the incidence of MACEs in patients with severe HFrEF after ICD implantation was substantially high. ICM, left ventricle size, and atrial fibrillation were the potential risk factors for MACEs as the previous reports showed.

Mitochondrial complex I inhibitors suppress tumor growth through concomitant acidification of the intra- and extracellular environment

The disruption of the tumor microenvironment (TME) is a promising anti-cancer strategy, but its effective targeting for solid tumors remains unknown. Here, we investigated the anti-cancer activity of the mitochondrial complex I inhibitor intervenolin (ITV), which modulates the TME independent of energy depletion. By modulating lactate metabolism, ITV induced the concomitant acidification of the intra- and extracellular environment, which synergistically suppressed S6K1 activity in cancer cells through protein phosphatase-2A-mediated dephosphorylation via G-protein-coupled receptor(s). Other complex I inhibitors including metformin and rotenone were also found to exert the same effect through an energy depletion-independent manner as ITV. In mouse and patient-derived xenograft models, ITV was found to suppress tumor growth and its mode of action was further confirmed. The TME is usually acidic owing to glycolytic cancer cell metabolism, and this condition is more susceptible to complex I inhibitors. Thus, we have demonstrated a potential treatment strategy for solid tumors.

Prognosis of apical hypertrophic cardiomyopathy in patients with an implantable cardioverter defibrillator

Background

Prophylactic use of implantable cardioverter-defibrillators (ICDs) to prevent sudden cardiac death (SCD) is widely spread all over the world in patients with hypertrophic cardiomyopathy (HCM). Apical HCM is a phenotype variant of HCM, with hypertrophy predominantly affecting apex, that was initially described 30 years ago. Apical HCM patients may have different clinical prognosis compared with other subsets of HCM. In previous studies, apical HCM patients seem to have a more benign prognosis than other types of HCM. However, little is known about the long-term outcomes of apical HCM and there are many unclear points. Moreover, there are few reports about the clinical prognosis in apical HCM patients with an ICD.

Objective

The aim of this study is to identify the difference between the prognosis of apical and the other HCM patients with an ICD.

Methods

We retrospectively analyzed the database of our ICD clinic. All subjects had been implanted with an ICD from October 2006 to August 2017. We classified HCM patients into LV outflow tract obstruction (LVOTO) and midventricular obstruction (MVO), apical HCM and other non-obstructive types. We divided all the patients into apical and other types of HCM, and examined their background, incidence of appropriate ICD therapies, hospitalization for heart failure, electrical storm and death.

Results

A total of consecutive 62 Japanese HCM patients with an ICD (follow-up period, 86±25 months; age, 67±14 years; male sex, 85%; left ventricular ejection fraction, 57±12%; LV max wall-thickness, 19±5mm; LV apical aneurysm, 9.7%; HCM Risk-SCD, 4.4±3.0) were enrolled in this study. We classified them into 14 apical HCM and 48 other types of HCM patients. The clinical characteristics and major events of these patients are shown in the Figure. During the follow-up periods, there were no significant differences in the incidence of hospitalization for heart failure, electrical storm and death between the 2 groups (p=0.40; p=0.22; p=0.23). Appropriate therapies occurred in 5 of 14 (36%) patients with apical HCM and 4 of 48 (8.3%) patients with other types of HCM (p=0.022).

Conclusions

Appropriate ICD therapy was more prevalent in patients with apical HCM, compared to patients with other types of HCM. However, the incidences of hospitalization for heart failure, electrical storm and death were not significantly different between two groups.

Funding Acknowledgement

Type of funding sources: None.

Risk stratification for ischemic stroke and major bleeding in patients without atrial fibrillation – application of CHA2DS2-VASc and HAS-BLED scores

Background

Atrial fibrillation (AF) is the most common arrhythmia. AF-related stroke tends to be more severe, and the mortality rate is higher compared with stroke without AF. Recent cardiac implantable electronic devices (CIEDs) have led to an improvement in the early detection of AF episodes. Previous studies showed that AF episodes detected by CIEDs are associated with ischemic stroke. However, little is known about the relationship between new-onset AF and ischemic stroke events in Japanese patients with CIEDs who have no prior AF and take no anticoagulant therapy. ESC guidelines for the management of AF recommend the use of CHA2DS2-VASc score as class I to predict the risk of ischemic stroke in patients with AF. However, the validity of the CHA2DS2-VASc and HAS-BLED scores to predict ischemic stroke and major bleeding events in patients without AF remains unclear.

Objective

The purpose of this study was to identify the incidence of ischemic stroke and major bleeding events in CIEDs patients without AF and assess the validity of CHA2DS2-VASc and HAS-BLED scores in this population.

Methods

We retrospectively analyzed the database of our CIEDs clinic. Every 6 months, CIEDs were checked using remote monitoring system. We examined the characteristics and incidence of ischemic stroke and bleeding events. In addition, we investigated the relationship between CHA2DS2-VASc and HAS-BLED scores and the incidence of these events.

Results

We enrolled 620 consecutive patients who were followed up at our CIED clinic. We excluded patients who had a history of AF or had received anticoagulant therapies, 348 patients (follow-up period, 65±58 months; age, 70±16 years; male sex; 64%; defibrillator, 55%) were included in this study. The mean CHA2DS2-VASc and HAS-BLED scores were 2.8±1.5 points and 1.7±1.6 points, respectively. During the follow-up, 23 (6.6%) and 12 (3.4%) of 348 patients had ischemic stroke and major bleeding events, respectively. The incidence of ischemic stroke and major bleeding events stratified by the CHA2DS2-VASc and HAS-BLED scores were shown in Figure 1.

Conclusion

The risk stratification for ischemic stroke and major bleeding using the CHA2DS2-VASc and HAS-BLED scores is valid in patients without AF.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Right ventricular function as a predictor of appropriate therapy of implantable cardioverter defibrillator

Funding Acknowledgements

Type of funding sources: None.

Aim

The purpose of this study was to evaluate the association of RV function and appropriate therapy of ICD.Methods: This study was a single-center retrospective cohort study. Consecutive patients who underwent ICD implantation for any diseases were enrolled except for non-dilated phase hypertrophic cardiomyopathy and channelopathy. Transthoracic echocardiographic parameters including left ventricular ejection fraction (LVEF), RV basal diameter, RV end-diastolic area, and right ventricular fractional area change (RVFAC) were evaluated. RV systolic dysfunction was defined as RVFAC <35%. Cox regression analysis was used to analyze the effects of those parameters on appropriate ICD therapy after the implantation.

Results

In total, 151 patients (60.9 ± 13.6 years, 117 males) consisting of 67 old myocardial infarction, 34 dilated cardiomyopathy, 19 cardiac sarcoidosis, and 31 others were enrolled. Eighty patients received an ICD as a secondary prophylaxis. Mean LVEF and RVFAC were 37.8 ± 13.9% and 33.2 ± 10.8%, respectively. RV systolic dysfunction was present in 86 (57.0%) patients, which was significantly associated with ICD therapy (odds ratio 2.313; 95% confidence interval 1.067-5.014; P = 0.034) according to a univariate analysis. There was no correlation between RVFAC and LVEF (correlation coefficient =0.064). Regarding the subjects LVEF > 35%, RV systolic dysfunction was an independent predictor of ICD therapy in a multivariate analysis.

Conclusion

RV systolic dysfunction was independently associated with increased ICD therapy despite of relatively preserved LVEF.

Cancer-Specific Targeting of Taurine-Upregulated Gene 1 Enhances the Effects of Chemotherapy in Pancreatic Cancer

Overcoming drug resistance is one of the biggest challenges in cancer chemotherapy. In this study, we examine whether targeting the long noncoding RNA taurine upregulated gene 1 (TUG1) could be an effective therapeutic approach to overcome drug resistance in pancreatic ductal adenocarcinoma (PDAC). TUG1 was expressed at significantly higher levels across 197 PDAC tissues compared with normal pancreatic tissues. Overall survival of patients with PDAC who had undergone 5-FU-based chemotherapy was shorter in high TUG1 group than in low TUG1 group. Mechanistically, TUG1 antagonized miR-376b-3p and upregulated dihydropyrimidine dehydrogenase (DPD). TUG1 depletion induced susceptibility to 5-FU in BxPC-3 and PK-9 pancreatic cell lines. Consistently, the cellular concentration of 5-FU was significantly higher under TUG1-depleted conditions. In PDAC xenograft models, intravenous treatment with a cancer-specific drug delivery system (TUG1-DDS) and 5-FU significantly suppressed PDAC tumor growth compared with 5-FU treatment alone. This novel approach using TUG1-DDS in combination with 5-FU may serve as an effective therapeutic option to attenuate DPD activity and meet appropriate 5-FU dosage requirements in targeted PDAC cells, which can reduce the systemic adverse effects of chemotherapy. SIGNIFICANCE: Targeting TUG1 coupled with a cancer-specific drug delivery system effectively modulates 5-FU catabolism in TUG1-overexpressing PDAC cells, thus contributing to a new combinatorial strategy for cancer treatment. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/7/1654/F1.large.jpg.

Platelet-derived lysophosphatidic acid mediated LPAR1 activation as a therapeutic target for osteosarcoma metastasis

Osteosarcoma is the most common primary malignant bone cancer, with high rates of pulmonary metastasis. Osteosarcoma patients with pulmonary metastasis have worse prognosis than those with localized disease, leading to dramatically reduced survival rates. Therefore, understanding the biological characteristics of metastatic osteosarcoma and the molecular mechanisms of invasion and metastasis of osteosarcoma cells will lead to the development of innovative therapeutic intervention for advanced osteosarcoma. Here, we identified that osteosarcoma cells commonly exhibit high platelet activation-inducing characteristics, and molecules released from activated platelets promote the invasiveness of osteosarcoma cells. Given that heat-denatured platelet releasate maintained the ability to promote osteosarcoma invasion, we focused on heat-tolerant molecules, such as lipid mediators in the platelet releasate. Osteosarcoma-induced platelet activation leads to abundant lysophosphatidic acid (LPA) release. Exposure to LPA or platelet releasate induced morphological changes and increased invasiveness of osteosarcoma cells. By analyzing publicly available transcriptome datasets and our in-house osteosarcoma patient-derived xenograft tumors, we found that LPA receptor 1 (LPAR1) is notably upregulated in osteosarcoma. LPAR1 gene KO in osteosarcoma cells abolished the platelet-mediated osteosarcoma invasion in vitro and the formation of early pulmonary metastatic foci in experimental pulmonary metastasis models. Of note, the pharmacological inhibition of LPAR1 by the orally available LPAR1 antagonist, ONO-7300243, prevented pulmonary metastasis of osteosarcoma in the mouse models. These results indicate that the LPA-LPAR1 axis is essential for the osteosarcoma invasion and metastasis, and targeting LPAR1 would be a promising therapeutic intervention for advanced osteosarcoma.

γ-Glutamyltranspeptidase (GGT)-Activatable Fluorescence Probe for Durable Tumor Imaging

γ-Glutamyltranspeptidase (GGT) is overexpressed in several types of cancer. Existing GGT-targeting fluorescence probes can image these cancers, but the fluorescent hydrolysis product leaks from the target cancer cells during prolonged incubation or fixation. Here, we present a functionalized fluorescence probe for GGT, 4-CH₂ F-HMDiEtR-gGlu, which is designed to generate an azaquinone methide intermediate during activation by GGT; this intermediate reacts with intracellular nucleophiles to generate a fluorescent adduct that is trapped inside the cells, without loss of the target enzyme activity. Application of the probe to patient-derived xenograft (PDX) mice enabled in vivo cancer imaging for a prolonged period and was also compatible with fixation and immunostaining of the cancer tissue.

SAT0057 PREDICTING INADEQUATE RESPONSE TO JAK INHIBITORS BY CLUSTER ANALYSIS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Oral Janus kinase inhibitors (JAKi) have dramatically altered outcomes in patients with rheumatoid arthritis (RA). However, there remains some proportion of patients who respond to inadequately JAKi treatment (JAKi-IR) [1,2]. The characteristics in RA patients associated with JAKi-IR have not been fully demonstrated.

Objectives:

To clarify the characteristics of JAKi-IR in patients with RA by cluster analysis.

Methods:

This retrospective study comprised 120 RA patients who were treated with JAKi (Tofacitinib or Baricitinib) between July 2013 and September 2019 in five facilities. The disease status at the baseline, at 12 weeks after JAKi treatment and at the time point of withdrawing JAKi was assessed using the Disease Activity Score (DAS28) and the American College of Rheumatology (ACR) response criteria. JAKi-IR was defined as follows, primary non-response at 12 weeks after JAKi treatment: withdrawal of JAKi with ACR20 non-response or non-improvement in DAS28-CRP (ΔDAS28-CRP<1.2 from baseline), secondary non-response: withdrawal of JAKi without clinical remission after 12 weeks. Hierarchical cluster analysis was performed with the following variables: gender, age, disease duration, bone erosion, ACR functional classification (Class ≥3), comcomitant rheumatoid arthritis related interstitial lung disease (RA-ILD) or other autoimmune disease (AID), anti-citrullinated protein antibody (ACPA) positivity, rheumatoid factor (RF) at baseline, use/dose of methotrexate (MTX) and prednisolone (PSL), serum ESR/CRP, tender/swollen joint counts (TJC/SJC), visual analog scale by patients (VAS-Pt), and prior of biologic DMARDs.

Results:

The 120 enrolled patients were classified into 4 groups by cluster analysis(Figure1), The characteristics of each group are as follows, Group A(n=21): female + bone erosion + RF/ACPA positive + AID + MTX non-user, Group B(n=36): male + older age + RA-ILD + RF/ACPA positive + MTX non-user, Group C(n=35): RF/ACPA positive + absence of RA-ILD + MTX user, Group D (n=28): seronegative + MTX user + absence of RA-ILD + history of biologic DMARDs failure. The rate of JAKi-IR was A:9%, B:8%, C:20%, D:32%, and the significant difference between Group B and D was identified (p=0.02). In multiple comparison of 4 groups, no significant difference was identified (p=0.06) (Figure2).

Conclusion:

JAKi-IR would be more likely to be seronegative, MTX use, absence of RA-ILD and history of biologic DMARDs failure. Cluster analysis is an exploratory tool that aids in the analysis of huge amount of data.

References:

[1] Takeuchi T, Yamanaka H, Yamaoka K, Arai S, Toyoizumi S, DeMasi R, et al. Efficacy and safety of tofacitinib in Japanese patients with rheumatoid arthritis by background methotrexate dose: A post hoc analysis of clinical trial data. Mod Rheumatol. 2019;29(5):756-66.

[2] Tanaka Y, Atsumi T, Amano K, Harigai M, Ishii T, Kawaguchi O, et al. Efficacy and safety of baricitinib in Japanese patients with rheumatoid arthritis: Subgroup analyses of four multinational phase 3 randomized trials. Mod Rheumatol. 2018;28(4):583-91.

Disclosure of Interests:

Masanari Sugawara: None declared, Yuichiro Fujieda: None declared, Atsushi Noguchi: None declared, Shun Tanimura: None declared, Yuka Shimizu: None declared, Ikuma Nakagawa: None declared, Michihito Kono: None declared, Masaru Kato: None declared, Kenji Oku: None declared, Tatsuya Atsumi Grant/research support from: Eli Lily Japan K.K., Alexion Pharmaceuticals, Inc., Bristol-Myers Squibb Co., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Astellas Pharma Inc., Consultant of: Gilead Sciences, Inc., Eli Lilly Japan K.K., UCB Japan Co. Ltd., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Speakers bureau: Eli Lilly Japan K.K., UCB Japan Co. Ltd., Bristol-Myers Squibb Co., AbbVie Inc., Eisai Co. Ltd., Otsuka Pharmaceutical Co., Ltd., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Takeda Pharmaceutical Co., Ltd., Astellas Pharma Inc.

138 Effects of different treatments of donors on the efficiency of embryo production and conception in bovine ovum pickup-in vitro production

An in vitro-produced bovine embryo has a low conception rate compared with that of an in vivo embryo. The present study was conducted to examine the effects of different treatments delivered to donors before ovum pickup (OPU) sessions to improve the conception rate of in vitro-produced bovine embryos. In total, 351 OPU sessions were performed on 138 Holstein and 213 Japanese Black cows from January to December 2017. Donors were divided into 4 groups based on their pretreatment before OPU: (1) single injection of 2.5 AU of FSH 40h before OPU; (2) CIDR insertion on Day 0, injection of 2mg of oestradiol benzoate on Day 1, 4 injections of FSH (each 2.5 AU) every 12h beginning from Day 5 to 7, followed by removal of CIDR and OPU on Day 9; (3) injection of 50μg of gonadotropin-releasing hormone 72h before OPU; or (4) no pretreatment. The collected cumulus-oocyte complexes were matured for 22h in 25mM of HEPES buffered TCM-199 supplemented with 5% newborn calf serum and 0.02 AU mL−1 FSH. After 6h of gamete co-culture (5.0×106 sperm mL−1), the presumptive zygotes were washed and the remaining cumulus cells were denuded by pipetting. The presumptive zygotes were then cultured in KSOMaa supplemented with 5% newborn calf serum for 9 days in a micro-well culture dish (Dai Nippon Printing, Tokyo, Japan). Blastocyst formation rates were analysed 9 days after insemination, and the formed blastocysts were transferred to oestrous synchronized recipients on the seventh or eighth day after oestrus. The data were analysed by Chi-squared test with Yates correction. The average numbers of collected oocytes were 57.7±17.4 (n=136), 25.3±12.8 (n=20), 28.8±12.5 (n=18) and 24.3±12.9 (n=177) in groups 1 to 4, respectively. Groups 1 and 2 showed significantly (P&lt;0.01) high percentages of Grade-1 oocytes (52.1 and 49.6%, respectively) compared with groups 3 and 4 (37.3 and 39.9%, respectively). The proportion of blastocysts in groups 1 (38.6%) was significantly different compared with that in groups 2 (32.1%) and 4 (35.3%), but the difference was insignificant in the case of group 3 (36.4%). The conception rates in groups 1 (43.5%, n=868) and 2 (59.1%, n=44) were significantly (P&lt;0.05) higher than those in groups 3 (35.1%, n=57) and 4 (34.9%, n=768). These results suggest that although the efficiency of embryo production did not differ largely between donors pretreated with 4 FSH injections and those without any pretreatment, the conception rate in donors pretreated with 4 FSH injections was significantly higher than that in donors without pretreatment. Moreover, donors pretreated with a single injection of FSH showed significantly high efficiency of embryo production and conception rate than donors without pretreatment.

Abstract 1954: Functional analyses of CLDN18-ARHGAP26 fusion gene in gastric cancers

[Introduction]Comprehensive molecular analyses by TCGA have classified Gastric Cancers (GC) into 4 groups: EB virus -associated (EBV), Microsatellite instability (MSI), Genomically stable (GS) and Chromosomal instability (CIN). Among these 4 subtypes, patients with GS subtype have few actionable genetic alterations and thus a limited number of molecular-targeted treatments are available. A fusion gene between CLDN18 and ARHGAP26 was first reported by TCGA to be enriched in GS subtype (13.8%), but the prospective functions of this gene product remain unknown.

[Methods]We have previously established 124 GC-Patient derived xenografts (PDXs) from surgically resected specimens in our institute. There are various types of GCs in the PDX panel, including intestinal and diffuse type tumors or tumors of primary and metastatic site. In an attempt to assess roles of CLDN18-ARHGAP26 fusion gene in gastric cancers, we used the cultured cells obtained from GC-PDXs. We first prepared tissue micro-array of formalin-fixed and paraffin-embedded (FFPE) specimen of PDXs and screened for the patients harboring a CLDN18-ARHGAP26 fusion genes by FISH and RT-PCR. In addition, fusion positive cases were sequenced to determine the breakpoints by direct sequencing. Then, we conducted several functional analyses, including assays for cellular proliferation and mobility, by RNAi-knockdown experiments.

[Results]Among 124 GC-PDXs, we detected two CLDN18-ARHGAP26 fusion positive cases. Both of these 2 cases were derived from tumors with diffuse-type GC patient and had identical breakpoint between CLDN18 (exon 5) and ARHGAP26 (exon 10). We successfully established cell lines of these 2 cases. Furthermore, we would verify that PDX derived cells preserved the original patient properties, as transplantation of the PDX-derived cells histologically recapitulated the original tumors. To address its function, we introduced siRNA into cultured cells to reduce their protein levels. Our data so far indicate that the CLDN18-ARHGAP26 fusion might promote anchorage independent cell growth.

[Conclusion] The CLDN18-ARHGAP26 fusion gene potentially contributes to malignant phenotypes of GC. Further analyses in vivo are awaited.

Citation Format: Izuma Nakayama, Eiji Shinozaki, Tetsuo Mashima, Tokuichi Kawaguchi, Seiji Sakata, Noriko Yamamoto, Satoko Baba, Akito Dobashi, Yuki Togashi, Minoru Sugawara, Shunji Takahashi, Kensei Yamaguchi, Kengo Takeuchi, Tetsuo Noda. Functional analyses of CLDN18-ARHGAP26 fusion gene in gastric cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1954.

Microscopic Observation of Leukocyte Kinesis in the Vascular Bed during Hemodialysis Using the Rabbit Ear Chamber Technique

Leukocyte kinesis in the capillary vascular bed during hemodialysis (HD) was investigated to elucidate the mechanism of transient leukopenia. Leukocyte movement was observed microscopically during HD using the rabbit ear chamber (REC) technique, which permits visualization of the movement of blood corpuscles in capillaries. Blood was drawn from the femoral artery and returned into the auricular and/or carotid artery so that the blood passing through the hollow fiber artificial kidney (HFAK) flowed into capillaries in the REC. Leukocyte counts of blood samples taken from the afferent and efferent limbs of the HD circuit, the right jugular vein and the right atrium were determined consecutively during HD. The difference in the leukocyte count was observed between the afferent and efferent limbs for the first 15 minutes and thereafter between the efferent limb and the jugular vein. The “transpulmonary” difference in the leukocyte count was not noticed throughout HD. Between 15 and 90 minutes after the start of HD, scarcely any circulating leukocytes were found in capillaries in the REC and some leukocytes were attached to the endothelial surface. Thereafter circulating leukocytes were seen again and detachment of leukocytes from the endothelial surface was observed. No leukocyte aggregation or embolization of aggregating leukocytes was noticed. This evidence suggests that leukopenia may be attributed to the transient shift of leukocytes to the marginal pool of the vessel lumen and this process may not be specific for the pulmonary vasculature, but may occur in the first capillary bed into which the blood passing through the HFAK flows. The attachment of leukocytes to the surface membrane of the HFAK may contribute to the transient leukopenia especially during the initial period of the HD.

193 Comparison of Superovulatory Responses to Single Subcutaneous FSH Injection and Twice-Daily Intramuscular FSH Injection Protocols in Japanese Black Cows

The conventional superovulation treatment using follicle-stimulating hormone (FSH) comprises 2 intramuscular injections per day for 3 to 4 days. This conventional method requires frequent handling of donors—which may cause increasing stress in donors—and high labour costs. Therefore, to alleviate these issues, a treatment protocol using a single FSH injection under on-farm conditions is needed. The objective of this study was to evaluate the feasibility of the single subcutaneous FSH injection protocol (Sugawara et al. 2017 Reprod. Fertil. Dev. 29, 209), compared with with the traditional twice-daily intramuscular FSH injection protocol, in Japanese Black cows. Japanese Black cows (n = 13) were superovulated using 2 treatments in a crossover design. All cows received an intravaginal progesterone device (CIDR) at random stages of the oestrous cycle (Day 0), and 2 mg of oestradiol benzoate on Day 1 (24 h after CIDR insertion). On Day 6, for the group receiving a single subcutaneous FSH injection (single-FSH), 20 armor units (AU) of pFSH dissolved in 30 mL of saline was subcutaneously injected in the neck region and 0.5 mg of prostaglandin F2α was intramuscularly injected simultaneously. For the control group, FSH administration was initiated at Day 6. A total dose of 20 AU of FSH was administered in 3 days (with decreasing doses of 5, 3, and 2 AU, respectively, per injection) with 2 intramuscular injections per day; 0.5 mg of prostaglandin F2α was injected 48 h after the first FSH injection. For both groups, CIDR was removed 60 h after FSH injection and AI was done 42 to 48 h after CIDR removal. Embryo collections were performed 7 days after AI. Data were analysed using t-test for the mean numbers of collected ova/embryos and transferable embryos, and chi-squared test for the proportion of transferable embryos. There were no significant differences in the mean numbers (single-FSH v. control) of ova/embryos collected (17.1 ± 12.1 v. 17.8 ± 9.3), or transferable embryos (8.4 ± 9.3 v. 10.3 ± 8.7), and proportion of transferable embryos (45.0 ± 34.0 v. 56.6 ± 36.5). These results showed that although a slightly higher number and proportion of transferable embryos were obtained in the control group, a superovulation treatment protocol involving a single subcutaneous FSH injection can be effectively used for Japanese Black cows, under on-farm conditions.

201 EFFECT OF A SINGLE SUBCUTANEOUS INJECTION OF FSH AND TIMING OF PROSTAGLANDIN F2α ADMINISTRATION ON SUPEROVULATORY RESPONSE IN JAPANESE BLACK COWS

Superovulation treatment using FSH requires injection twice a day, for 3 to 4 days. This conventional method requires frequent handling of donors and higher labour costs. Therefore, simplification of the superovulation treatment protocol is needed to reduce animal handling and labour costs. The objective of this study was to investigate the effect of a single subcutaneous FSH injection and the timing of prostaglandin F2α (PGF; cloprostenol) administration on the superovulatory response in Japanese Black cows (Hiraizumi et al. 2015 Theriogenology 83, 466–473) and to determine whether the superovulation treatment protocol can be used in on-farm conditions. A total of 270 Japanese Black cows were used in this study. Twenty Armour units of pFSH dissolved in 30 mL of saline was injected subcutaneously in the neck region. In Experiment 1, 32 cows received an intravaginal progesterone device (CIDR) at random stages of the oestrous cycle (Day 0), and 2 mg of oestradiol benzoate on Day 1 (24 h after CIDR insertion). On Day 6, FSH was injected subcutaneously, and 16 cows were simultaneously injected with 0.5 mg of PGF (0-h PGF, Group A); the other 16 cows were injected with 0.5 mg of PGF at 48 h (on Day 8) after FSH injection (48-h PGF, Group B). The CIDR was removed at 60 h after FSH injection and AI was done 42 to 48 h after CIDR removal. Embryo collections were performed 7 days after AI. In Experiment 2, 238 cows were used in farm conditions. The cows were superstimulated using the same protocol as that used for Group A. Data were analysed by ANOVA for the mean numbers of collected ova/embryos and transferrable embryos and chi-square test for the proportion of transferrable embryos. In Experiment 1, there were no differences in the mean numbers of ova/embryos collected (16.9 ± 12.3 v. 16.1 ± 17.1) or transferrable embryos (11.1 ± 9.5 v. 7.2 ± 6.2). However, the proportion of transferrable embryos for Group A was significantly higher than that of Group B (65.9 v. 44.7%; P < 0.01). In Experiment 2, the mean numbers of ova/embryos collected and transferrable embryos were 15.7 ± 13.3 and 6.8 ± 7.8, respectively. These results showed that a superovulation treatment protocol involving a single subcutaneous injection of FSH with simultaneous PGF injection can be effectively used for Japanese Black cows under on-farm conditions.

Development of detection method for novel fusion gene using GeneChip exon array

Background

Fusion genes have been recognized to play key roles in oncogenesis. Though, many techniques have been developed for genome-wide analysis of fusion genes, a more efficient method is desired.

Results

We introduced a new method of detecting the novel fusion gene by using GeneChip Exon Array that enables exon expression analysis on a whole-genome scale and TAIL-PCR. To screen genes with abnormal exon expression profiles, we developed computational program, and confirmed that the program was able to search the fusion partner gene using Exon Array data of T-cell acute lymphocytic leukemia (T-ALL) cell lines. It was reported that the T-ALL cell lines, ALL-SIL, BE13 and LOUCY, harbored the fusion gene NUP214-ABL1, NUP214-ABL1 and SET-NUP214, respectively. The program extracted the candidate genes with abnormal exon expression profiles: 1 gene in ALL-SIL, 1 gene in BE13, and 2 genes in LOUCY. The known fusion partner gene NUP214 was included in the genes in ALL-SIL and LOUCY. Thus, we applied the proposed program to the detection of fusion partner genes in other tumors. To discover novel fusion genes, we examined 24 breast cancer cell lines and 20 pancreatic cancer cell lines by using the program. As a result, 20 and 23 candidate genes were obtained for the breast and pancreatic cancer cell lines respectively, and seven genes were selected as the final candidate gene based on information of the EST data base, comparison with normal cell samples and visual inspection of Exon expression profile. Finding of fusion partners for the final candidate genes was tried by TAIL-PCR, and three novel fusion genes were identified.

Conclusions

The usefulness of our detection method was confirmed. Using this method for more samples, it is thought that fusion genes can be identified.

Noninvasive assessment of left ventricular force-frequency relationships by measuring carotid arterial wave intensity during exercise stress

BACKGROUND

Evaluation of the contractile state of the left ventricle during exercise is important in drawing up a protocol of cardiac rehabilitation. It has been demonstrated that color Doppler- and echo tracking-derived carotid arterial wave intensity is a sensitive index of global left ventricular (LV) contractility.

OBJECTIVES

We assessed the feasibility of measuring carotid arterial wave intensity and determining force-frequency (contractility-heart rate) relationships (FFR's) during exercise totally noninvasively.

METHODS

We measured carotid arterial wave intensity with a combined color Doppler and echo tracking system in 15 healthy young male volunteers (age 20.8 ± 1.3 years) at rest and during exercise. FFR's were constructed by plotting the maximum value of wave intensity (WD1) against heart rate (HR).

RESULTS

WD1 increased linearly with an increase in HR. The goodness-of-fit of the regression line of WD1 on HR in each subject was very high (r2 0.67 ~ 0.91, p < 0.0001 respectively). The slope of the WD1-HR relation ranged from 0.31 to 1.52 [m/s(3)(beat/min)].

CONCLUSIONS

A global LV FFR can be generated in healthy young volunteers with an entirely noninvasive combination of exercise and wave intensity. These data should show the potential usefulness of FFR in the context of cardiac rehabilitation.

Comparison of sensitivity of lung nodule detection between radiologists and technologists on low-dose CT lung cancer screening images

OBJECTIVES

The objective of this study was to compare the sensitivity of detection of lung nodules on low-dose screening CT images between radiologists and technologists.

METHODS

11 radiologists and 10 technologists read the low-dose screening CT images of 78 subjects. On images with a slice thickness of 5 mm, there were 60 lung nodules that were ≥5 mm in diameter: 26 nodules with pure ground-glass opacity (GGO), 7 nodules with mixed ground-glass opacity (GGO with a solid component) and 27 solid nodules. On images with a slice thickness of 2 mm, 69 lung nodules were ≥5 mm in diameter: 35 pure GGOs, 7 mixed GGOs and 27 solid nodules. The 21 observers read screening CT images of 5-mm slice thickness at first; then, 6 months later, they read screening CT images of 2-mm slice thickness from the 78 subjects.

RESULTS

The differences in the mean sensitivities of detection of the pure GGOs, mixed GGOs and solid nodules between radiologists and technologists were not statistically significant, except for the case of solid nodules; the p-values of the differences for pure GGOs, mixed GGOs and solid nodules on the CT images with 5-mm slice thickness were 0.095, 0.461 and 0.005, respectively, and the corresponding p-values on CT images of 2-mm slice thickness were 0.971, 0.722 and 0.0037, respectively.

CONCLUSION

Well-trained technologists may contribute to the detection of pure and mixed GGOs ≥5 mm in diameter on low-dose screening CT images.

Gene expression profiling of Escherichia coli in response to interactions with the lettuce rhizosphere

AIMS

The objective of this study was to examine transcriptional changes in Escherichia coli when the bacterium was growing in the lettuce rhizoshpere.

METHODS AND RESULTS

A combination of microarray analyses, colonization assays and confocal microscopy was used to gain a more complete understanding of bacterial genes involved in the colonization and growth of E. coli K12 in the lettuce root rhizosphere using a novel hydroponic assay system. After 3 days of interaction with lettuce roots, E. coli genes involved in protein synthesis, stress responses and attachment were up-regulated. Mutants in curli production (crl, csgA) and flagella synthesis (fliN) had a reduced capacity to attach to roots as determined by bacterial counts and by confocal laser scanning microscopy.

CONCLUSIONS

This study indicates that E. coli K12 has the capability to colonize lettuce roots by using attachment genes and can readily adapt to the rhizosphere of lettuce plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

Results of this study show curli production and biofilm modulation genes are important for rhizosphere colonization and may provide useful targets to disrupt this process. Further studies using pathogenic strains will provide additional information about lettuce-E. coli interactions.

Whole-exome sequencing of human pancreatic cancers and characterization of genomic instability caused by MLH1 haploinsufficiency and complete deficiency

Whole-exome sequencing (Exome-seq) has been successfully applied in several recent studies. We here sequenced the exomes of 15 pancreatic tumor cell lines and their matched normal samples. We captured 162,073 exons of 16,954 genes and sequenced the targeted regions to a mean coverage of 56-fold. This study identified a total of 1517 somatic mutations and validated 934 mutations by transcriptome sequencing. We detected recurrent mutations in 56 genes. Among them, 41 have not been described. The mutation rates varied widely among cell lines. The diversity of the mutation rates was significantly correlated with the distinct MLH1 copy-number status. Exome-seq revealed intensive genomic instability in a cell line with MLH1 homozygous deletion, indicated by a dramatically elevated rate of somatic substitutions, small insertions/deletions (indels), as well as indels in microsatellites. Notably, we found that MLH1 expression was decreased by nearly half in cell lines with an allelic loss of MLH1. While these cell lines were negative in conventional microsatellite instability assay, they showed a 10.5-fold increase in the rate of somatic indels, e.g., truncating indels in TP53 and TGFBR2, indicating MLH1 haploinsufficiency in the correction of DNA indel errors. We further analyzed the exomes of 15 renal cell carcinomas and confirmed MLH1 haploinsufficiency. We observed a much higher rate of indel mutations in the affected cases and identified recurrent truncating indels in several cancer genes such as VHL, PBRM1, and JARID1C. Together, our data suggest that MLH1 hemizygous deletion, through increasing the rate of indel mutations, could drive the development and progression of sporadic cancers.

The pH Dependent Uptake of Enoxacin by Rat Intestinal Brush-border Membrane Vesicles

The mechanism of the intestinal transport of enoxacin, an orally active fluoroquinolone antibiotic, has been investigated using brush-border membrane vesicles isolated from rat small intestine. The initial rate and time-course of enoxacin uptake were considerably dependent upon the medium pH (pH 5·5 &gt; pH 7·5) and upon the percent ionization of the carboxyl group (pKa 6·2, anionic charge), namely, the degree of uptake of cationic form was higher than that of the zwitterionic form. There was evidence of transport into the intravesicular space as shown by the effect of extravesicular medium osmolarity on enoxacin uptake at steady state (30 min). This transport across the brush-border membrane was stimulated by the valinomycin-induced K+-diffusion potential (interior negative) and an outward H+-diffusion potential. Furthermore, changing the pH of the medium from 5·5 to 7·5 significantly decreased the effect of valinomycin-induced K+-diffusion potential on the enoxacin uptake. These results suggest that the uptake behaviour of the cationic form of enoxacin plays an important role in the intestinal absorption process of enoxacin.

Transport Characteristics of Cephalosporin Antibiotics Across Intestinal Brush-border Membrane in Man, Rat and Rabbit

The uptake of orally active cephalosporins, ceftibuten and cephradine, by intestinal brush-border membrane vesicles isolated from man, rat and rabbit was studied. In the presence of an inward H+ gradient, ceftibuten but not cephradine was taken up into intestinal brush-border membrane vesicles of man and rat against the concentration gradient (overshoot phenomenon). In rabbit jejunal brush-border membrane vesicles, the uptake of both cephalosporins in the presence of an inward H+ gradient exhibited the overshoot phenomenon. In human and rat vesicles, the initial uptake of ceftibuten was strongly inhibited by compound V, an analogue of ceftibuten, but the uptake of cephradine was not affected by any of the cephalosporins tested, whereas in the rabbit brush-border membrane vesicles, initial uptake of both ceftibuten and cephradine were markedly inhibited by all cephalosporins and dipeptides used. These results suggest that the transport characteristics of human and rat intestinal brush-border membrane for cephalosporins are comparable, and that rabbit is an inadequate animal for investigating the transport characteristics of β-lactam antibiotics.

Workspace Analysis and Design Improvement of a Carotid Flow Measurement System

Heart and cerebrovascular diseases such as arteriosclerosis and myocardial ischemia dysfunction are currently among the main causes of death in developed countries. Recently, wave intensity (WI), which is an index used to obtain the force of cardiac contraction, has been investigated as a method for early-stage diagnosis of the above-mentioned diseases. Nevertheless, experimental tests have proven that the manual measurements of WI by means of commercial ultrasonic diagnostic systems require too much time and can be affected by the operator's skills. For this purpose, the introduction of robotic-assisted technology has advantages in terms of repetitiveness and accuracy of the measurement procedure. Therefore, at Waseda University, the development of a carotid blood flow measurement system has been proposed to support doctors while using ultrasound diagnostic equipment to measure the WI. This robotic system is composed of a serial robot with a wrist having a six-degree-of-freedom (6-DOF) parallel mechanism. The main focus is to obtain a suitable workspace performance of the 6-DOF parallel mechanism wrist. In this paper, a workspace analysis is carried out on a wrist prototype built for the Waseda-Tokyo Women's Medical Aloka Blood Flow Measurement System No.1 Refined (WTA-1R). Then, mechanical design enhancements are proposed and validated to provide a suitable workspace performance both as reachable workspace and dexterity, and a refined prototype WTA-1RII has been built.

Development of a method to control the water evaporation of hatching eggs during incubation

Three experiments were conducted to develop methods to control the amount of water loss and to evaluate the metabolic effects of water condition in the White Leghorn breeder eggs during incubation. One hundred twenty, 54, and 90 Julia strain White Leghorn breeder eggs were incubated at 37.8 degrees C, 60% RH in experiments 1, 2, and 3. In experiment 1, eggs were drilled with various bore diameters of 0, 0.5, 1, 2, 3, 4, and 5 mm on the blunt end of the eggshell. In experiment 2, 4 x 4 mm(2) windows were cut into the eggs or the eggs were drilled with 5 holes of bore diameter 2 mm on the blunt end of eggshell. In experiment 3, eggs were drilled with 1, 3, 5, and 7 holes of diameter 2 mm on the blunt end of eggshell. Eggs were treated on d 3 of each experiment and the amount of water loss was recorded on d 19 of incubation. Embryo growth was evaluated in experiments 2 and 3. In addition, the livers of embryos were collected in the 0-, 1-, 3-, and 5-hole treatment groups after weighing eggs to determine 3-hydroxy acyl coenzyme A dehydrogenase activity. In experiment 1, although higher water loss was observed in all windowed eggs than in control, there were no differences in amount of water loss among all bore diameters. Accordingly, that was not successful to control amount of water loss. In experiment 2, higher water loss was observed in drilled eggs at the same levels in windowed eggs as in control. Drilling holes was a more useful treatment to control amount of water loss on incubated eggs than windowing. In experiment 3, amount of water loss increased linearly with increasing number of holes on the blunt end of eggshell. Hepatic 3-hydroxy acyl coenzyme A dehydrogenase activity increased with increasing the number of drilled holes.