Ubiquitin-proteasome System Is a Promising Target for Killing Cisplatin-resistant Bladder Cancer Cells

BACKGROUND/AIM

Activation of the ubiquitin-proteasome system (UPS) has been shown to be associated with drug resistance in cancer. Using bladder cancer cells, we investigated the association between UPS activation and cisplatin resistance and also the efficacy of UPS-targeting drugs.

MATERIALS AND METHODS

We established cisplatin-resistant bladder cancer cells (J82-cisR, T24-cisR) and examined the activation status of the UPS and the efficacy of MLN7243, oprozomib, ixazomib, and RTS-V5.

RESULTS

The UPS in cisplatin-resistant bladder cancer cells was activated compared to that in their parental controls. All the UPS-targeting drugs induced apoptosis and inhibited growth more effectively in the cisplatin-resistant bladder cancer cells than they did in the parental controls. Furthermore, these UPS-targeting drugs induced endoplasmic reticulum stress by causing unfolded protein accumulation at lower concentrations in the cisplatin-resistant bladder cancer cells.

CONCLUSION

Targeting the UPS could be an effective strategy for treating cisplatin-resistant bladder cancer.

Simvastatin-romidepsin combination kills bladder cancer cells synergistically

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Simvastatin-romidepsin combination kills bladder cancer cells synergistically.

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The combination induces histone acetylation by activating AMPK.

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AMPK activation and histone acetylation are associated with ER stress induction.

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Positive feedback cycle between ER stress induction and PPARγ expression.

The HMG-CoA reductase inhibitor simvastatin activates AMP-activated protein kinase (AMPK) and thereby induces histone acetylation. We postulated that combining simvastatin with the histone deacetylase (HDAC) inhibitor romidepsin would kill bladder cancer cells by inducing histone acetylation cooperatively. The combination of romidepsin and simvastatin induced robust apoptosis and killed bladder cancer cells synergistically. In murine subcutaneous tumor models using MBT-2 cells, a 15-day treatment with 0.5 mg/kg romidepsin and 15 mg/kg simvastatin was well tolerated and inhibited tumor growth significantly. Mechanistically, the combination induced histone acetylation by activating AMPK. The combination also decreased the expression of HDACs, thus further promoting histone acetylation. This AMPK activation was essential for the combination's action because compound C, an AMPK inhibitor, suppressed the combination-induced histone acetylation and the combination's ability to induce apoptosis. We also found that the combination increased the expression of peroxisome proliferator-activated receptor (PPAR) γ, leading to reactive oxygen species production. Furthermore, the combination induced endoplasmic reticulum (ER) stress and this ER stress was shown to be associated with increased AMPK expression and histone acetylation, thus playing an important role in the combination's action. Our study also suggests there is a positive feedback cycle between ER stress induction and PPARγ expression.

Inhibition of checkpoint kinase 1 potentiates anticancer activity of gemcitabine in bladder cancer cells

Checkpoint kinases (CHKs) are involved in the DNA damage response in many cancer cells. CHK inhibitors have been used in clinical trials in combination with chemotherapeutics; however, their effect against bladder cancer remains unclear. Here, we investigated the efficacy of combining gemcitabine with MK-8776, a novel CHK1 inhibitor, in four bladder cancer cell lines. The effects of gemcitabine and MK-8776 on cell viability, clonogenicity, cell cycle, and apoptosis were examined alongside in vivo efficacy using murine xenograft tumor models. Combined treatment inhibited the viability and colony formation of bladder cancer cells compared to either single treatment. Although gemcitabine (10 nM) alone increased the cell number in S-phase, it increased the cell number in sub-G1 phase when combined with MK-8776 (0.5 µM). Combined treatment enhanced cleaved poly[ADP-ribose]-polymerase expression alongside the number of annexin-V-positive cells, indicating the induction of apoptosis. In vivo, administration of gemcitabine and MK-8776 was well tolerated and suppressed tumor growth. Mechanistically, the combined treatment elevated γH2A.X and suppressed Rad51 expression. Our study demonstrates that MK-8776 and gemcitabine combined induces apoptosis and suppresses proliferation in bladder cancer cells by inhibiting CHKs and DNA repair. Therefore, CHK1 inhibition combined with gemcitabine may be a potential treatment for bladder cancer.

Sesame lignans suppress age-related disorders of the kidney in mice

OBJECTIVE

Sesamin is a functional ingredient in sesame (Sesamum indicum) seeds and has many physiological effects. This study investigated whether sesame lignans, sesamin and episesamin (1:1), can suppress age-related disorders of the kidney.

MATERIALS AND METHODS

Twenty-month-old mice were divided into three groups, and each group received a regular diet (O-C), diet containing sesame lignans (O-SE), and diet containing sesame lignans and α-tocopherol (VE; O-SE+VE), respectively, for 5 months. Six-month-old young mice (Y-C) were compared to the older mice.

RESULTS

Renal lipofuscin deposition was increased in the O-C group compared to that in the Y-C group and its deposition with aging was significantly decreased in both O-SE and O-SE+VE groups. Plasma blood urea nitrogen levels in the O-C group increased compared to those in the Y-C group; however, those in both O-SE and O-SE+VE groups did not differ from those in the Y-C group. The number of podocytes in the O-C group decreased compared to that in the Y-C group and this effect was attenuated in the O-SE and O-SE+VE groups. The effect was strongest in the O-SE+VE group. Histological examinations showed that glomerular hypertrophy accompanied by mesangial hyperplasia and renal tubular degeneration was less severe in the O-SE and O-SE+VE groups than in the O-C group. Moreover, age-related increases in the mRNA expression of NADPH oxidase- and inflammation-related genes, including p67phox, p40phox, TNFα, and IL-6, in the kidney were suppressed in the O-SE and O-SE+VE groups.

CONCLUSIONS

Sesame lignans might be useful to suppress age-related kidney disorders, and these effects could be enhanced with VE.

Associations between Socioeconomic Status, Social Participation, and Physical Activity in Older People during the COVID-19 Pandemic: A Cross-Sectional Study in a Northern Japanese City

Physical activity (PA) is a key determinant of health in older adults. However, little is known about the effect of social factors on PA among older adults during the coronavirus disease 2019 (COVID-19) pandemic. Therefore, we aimed to clarify the association between socioeconomic status, social participation, and PA during the pandemic. A cross-sectional study was conducted on 999 community-dwelling residents aged 65-90 years. A self-administered questionnaire was used to collect socioeconomic status, social participation, and PA data in August 2020. Multivariable logistic regression analyses were used to calculate the odds ratios (ORs) for the associations between socioeconomic status, social participation, and maintaining PA. For both sexes, PA was reduced by approximately 5%-10% after the onset of COVID-19-related distancing restrictions. Men with a low socioeconomic status were less physically active (OR = 0.49, 95% CI: 0.30-0.82). Women who reported social participation had higher odds of maintaining PA (OR = 1.67, 95% CI: 1.13-2.45) during the restrictions. Higher socioeconomic status and social participation levels before the COVID-19 pandemic may have helped older adults to maintain PA during the COVID-19 pandemic. Further research is needed to clarify the potential effects of these factors on the health of older adults.

Comparing predictive ability of QSAR/QSPR models using 2D and 3D molecular representations

Quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) models predict biological activity and molecular property based on the numerical relationship between chemical structures and activity (property) values. Molecular representations are of importance in QSAR/QSPR analysis. Topological information of molecular structures is usually utilized (2D representations) for this purpose. However, conformational information seems important because molecules are in the three-dimensional space. As a three-dimensional molecular representation applicable to diverse compounds, similarity between a test molecule and a set of reference molecules has been previously proposed. This 3D representation was found to be effective on virtual screening for early enrichment of active compounds. In this study, we introduced the 3D representation into QSAR/QSPR modeling (regression tasks). Furthermore, we investigated relative merits of 3D representations over 2D in terms of the diversity of training data sets. For the prediction task of quantum mechanics-based properties, the 3D representations were superior to 2D. For predicting activity of small molecules against specific biological targets, no consistent trend was observed in the difference of performance using the two types of representations, irrespective of the diversity of training data sets.

Efficacy of cardiac rehabilitation with motion assistance from wearable cyborg hybrid assistive limb in patients with chronic heart failure: a randomized controlled trial

Background

Recent Cochrane Systematic Review suggested that the participation in cardiac rehabilitation is associated with approximately 20% lower cardiovascular mortality and morbidity. Exercise therapy is the key component of cardiac rehabilitation programs. In recent years, innovative technologies have been introduced into the field of rehabilitation, and a typical example is the wearable cyborg Hybrid Assistive Limb (HAL). The wearable cyborg HAL provides motion assistance based on detection of bioelectrical signals on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in performing usual cardiac rehabilitation programs, such as bicycle pedaling or walking.

Purpose

We aim to compare the efficacy of exercise therapy performed with motion assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure.

Methods

This clinical trial is a randomized, non-blinded, and controlled study. Twenty-eight heart failure patients (73.1±13.8 years) who have difficulty in walking at the usual walking speed of healthy subjects were randomly assigned to 2 groups (HAL group or control group) with a 1:1 allocation ratio and performed sit-to stand exercise either with HAL or without HAL for 5 to 30 minutes once a day, and 6 to 10 days during the study period. The brain natriuretic peptide (BNP), isometric knee extensor strength, standing ability (30-seconds chair-stand test: CS-30), short physical performance battery (SPPB) and 6-minute walking distance (6MWD) were measured before and after the completion of cardiac rehabilitation. Cardiac events such as death, re-hospitalization, myocardial infarction and worsening of angina pectoris and heart failure during 1 year after discharge were evaluated.

Results

There was no significant difference in the number of days of exercise therapy between the two groups. BNP, SPPB and 6MWD were improved in both groups. In the HAL group, the isometric knee extensor strength (0.29±0.11 vs 0.35±0.11 kgf/kg, p=0.003) significantly improved and CS-30 (5.5±5.1 vs 8.2±5.3, p=0.054) tended to improve. However, in the control group, either the isometric knee extensor strength (0.35±0.11 vs 0.36±0.14 kgf/kg, p=0.424) or CS-30 (6.0±4.3 vs 9.2±6.2, p=0.075) did not significantly change. HAL group showed significantly more improvement in the isometric knee extensor strength than control group (p=0.045). Cardiac events occurred in 20% in the HAL group and 43% in the control group.

Conclusion

The improvement in isometric knee extensor strength with the assistance from lumbar-type HAL suggests that exercise therapy using this device may be useful in chronic heart failure patients with flail or sarcopenia, a strong poor prognostic factor in these patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (JSPS KAKENHI grant number JP17K09485) and funded by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) (grant number 2017-PM05-03-01).

Impact of coronary plaque characteristics on periprocedural myocardial injury after elective percutaneous coronary intervention -MDCT and CMR analysis-

Background

Percutaneous coronary intervention (PCI) is often complicated by periprocedural myocardial injury (PMI) manifested by elevated cardiac biomarkers. The occurrence of PMI has been shown to be associated with worse clinical outcome over short- and long-term.

Purpose

We performed multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (CMR) to evaluate the relationship between culprit plaque characteristics and PMI.

Methods

A total of 90 patients who underwent elective PCI were underwent CMR and multidetector coronary tomography before PCI. The high intensity plaque (HIP) on CMR was defined as a coronary plaque to myocardium signal intensity ratio (PMR) of >1.4. The plaque characteristics and the presence of napkin-ring sign (NRS) were analyzed on MDCT. PMI was defined as an increase in cardiac Troponin T levels to more than 5 times the upper limit of normal at 24 h after PCI. Patients were divided into 2 groups according to the presence (Group I, n=26) or absence (Group II, n=64) of PMI.

Results

Spotty calcification, positive remodeling, low attenuation plaque and NRS on MDCT were significantly more observed in Group I than in Group II. HIP on CMR was significantly more observed in Group I than in Group II. In the multivariable logistic regression analysis, the presence of NRS and HIP were significantly independent predictors of PMI (odds ratio (OR) 4.82, 95% confidence interval 1.13–20.60, P=0.034 and OR 3.66, 95% CI 1.09–12.30, P=0.036, respectively). Moreover, for prediction of PMI, NRS and HIP showed a high positive predictive value of 81%, and their absence showed a high negative predictive value of 91%.

Conclusions

MDCT and CMR may play an important role in detecting which lesions are high risks for myocardial necrosis after PCI in elective coronary stenting.

Funding Acknowledgement

Type of funding source: None

Association of coronary high-intensity plaque on T1-weighted magnetic resonance imaging and circulating malondialdehyde-modified low-density lipoprotein levels with cardiac events

Background

Although elevated oxidized low-density lipoprotein could play critical roles in vulnerable plaque, there are no studies that compared coronary high-intensity plaque (HIP) on non-contrast T1-weighted magnetic resonance imaging (T1WI_MRI) and circulating malondialdehyde-modified low-density lipoprotein (MDA-LDL) levels for the prediction of cardiac events.

Methods and results

A total of 139 patients with coronary artery stenosis (>70%) were examined with non-contrast T1WI using a 1.5-T MRI (HIP: n=63, non-HIP: n=76). Scheduled percutaneous coronary intervention (PCI) for culprit lesions was performed within 48 h after MRI. HIP was defined as a signal intensity of coronary plaque to cardiac muscle ratio (PMR) of ≥1.4. At admission, circulating levels of MDA-LDL and other lipid-related markers were measured. We evaluated the subsequent cardiac events, which were defined as major adverse cardiac events (MACE; cardiac death, myocardial infarction, and/or ischemia-driven PCI) during follow-up periods (5.6±1.3 years). Circulating MDA-LDL levels were significantly higher in patients with HIP than in those without HIP (p<0.0001). MDA-LDL levels were significantly correlated with PMR (r=0.490, p<0.0001). In multivariable logistic regression analysis, MDA-LDL levels were independently associated with the presence of HIP (OR 1.05; 95% CI, 1.02–1.08, p<0.0001). The incidence of MACE was significantly higher in patients with HIP (27%) than in those without HIP (5%; p=0.011 by the log-rank test). In the multivariable Cox proportional hazard analysis, the MDA-LDL levels (HR 1.03; 95% CI:1.01–1.05, p=0.007) and PMR (HR 2.39; 95% CI:1.19–4.65, p=0.016) were significantly associated with MACE. For MACE prediction, the C-statistic values for MDA-LDL, PMR, and PMR+MDA-LDL were 0.724, 0.791, and 0.800, respectively. Compared with MDA-LDL alone, the addition of PMR to MDA-LDL increased the net reclassification improvement by 0.78 (p=0.012).

Conclusions

MDA-LDL levels might be associated with the presence of HIP in patients with coronary artery disease. Furthermore, adding PMR to MDA-LDL levels markedly improved MACE prediction.

Funding Acknowledgement

Type of funding source: None

Pulmonary vein isolation for atrial fibrillation patients with reduced left ventricular ejection fraction

 

Background/Introduction Pulmonary vein isolation (PVI) is a cornerstone of curable treatment for atrial fibrillation (AF). Left ventricular (LV) ejection fraction (EF) occasionally improves after PVI in AF patients with reduced LVEF (rEF), the mechanism of which is not fully understood. CASTLE-AF trial have demonstrated that PVI with radiofrequency (RF) catheter for AF patients with rEF can reduce their mortality and heart failure. Nevertheless there are limited data about the clinical outcome of the PVI for patients with impaired LV function.

Purpose

This study was to evaluate the efficacy of PVI and improvement of LVEF after the procedure in AF patients with rEF.

Methods

A total of 2709 consecutive AF patients (age 65±39 y/o, male 67%) underwent their first PVI with cryoballoon or RF catheter in our facility from April 2014 to March 2019, and retrospectively analyzed. All the patients underwent echocardiogram before and half to one year after the procedure. Patients with LVEF under 40% before the PVI were selected (n=111) and divided into two groups based on whether there were specific etiologies of LV function impairment (group A) or not (group B).

Results

There were no significant difference in mean LVEF between group A (n=40) and group B (n=71) (32±6% vs 33±6%, p=0.12). The major etiology of rEF in group A were old myocardial infarction (n=20, 18%), hypertensive heart disease (n=6, 5.4%), and dilated cardiomyopathy (n=5, 4.5%). After mean follow-up of 2.7 years, there were no significant difference in clinical outcome after the procedure between two groups (1-year Kaplan–Meier event rate estimates; 72.2% vs 72.9%; p=0.85). The change amounts of LVEF after the PVI were significantly higher in group B (20±14%) compared to group A (2±10%) (p<0.001). Multivariable Cox regression analysis revealed that age was the independent significant predictors of EF improvement over 10% in group B (p=0.048).

Conclusions

In AF patients with reduced LVEF, there were no significant difference in efficacy of PVI between those who have specific etiologies of LV function impairment other than AF and who have not. The improvement of LVEF after PVI was significantly larger in patients without specific etiologies compared to those with.

Funding Acknowledgement

Type of funding source: None

Effect of continuous saline bladder irrigation with concomitant single instillation of chemotherapy after transurethral resection on intravesical recurrence in patients with non‑muscle‑invasive bladder cancer

A single immediate instillation of chemotherapy following transurethral resection of bladder tumor (TURBT) is effective in preventing intravesical recurrence (IVR) in patients with non-muscle-invasive urothelial bladder carcinoma (NMIBC). However, continuous saline bladder irrigation (CSBI) is also performed with a single instillation of chemotherapy (SIC), but its inhibitory effect on IVR remains unclear. In the present study, the effect of CSBI with concomitant SIC following TUR on IVR was evaluated in patients with NMIBC. A retrospective review of 253 patients who underwent TURBT and were clinically and histologically diagnosed with NMIBC at National Defense Medical College Hospital was performed. Doxorubicin (DXR) was administered to all patients. Methods of DXR administration included a single instillation of DXR (60 mg in 30-40 ml saline) in 34 patients (group A), continuous irrigation of the bladder with saline including DXR (80 mg in 1 liter saline) in 40 patients (group B) and overnight CSBI after a single instillation of DXR in 179 patients (group C). The difference in IVR-free survival rates was compared after adjusting for significant differences in several covariates between the groups by nearest-neighbor propensity score matching. Prior to propensity score matching, it was identified that time to IVR was significantly longer in group A than in groups B and C; however, it was observed that several factors significantly differed among the three groups. By using nearest neighbor matching, 18 pairs were matched between groups A and B and 33 pairs between the groups A and C. No significant difference was identified in any covariates between these two matched group pairsTime to IVR was significantly longer in the matched group A than in the matched groups B and C (P=0.0255 and P=0.0023, respectively). In conclusion, SIC alone could provide a higher IVR-free survival rate than CSBI with DXR or CSBI with SIC.

Fluvastatin potentiates anticancer activity of vorinostat in renal cancer cells

Drug repositioning is an emerging approach to developing novel cancer treatments. Vorinostat is a histone deacetylase inhibitor approved for cancer treatment, but it could attenuate its anticancer activity by activating the mTOR pathway. The HMG‐CoA reductase inhibitor fluvastatin reportedly activates the mTOR inhibitor AMP‐activated protein kinase (AMPK), and we thought that it would potentiate vorinostat's anticancer activity in renal cancer cells. The combination of vorinostat and fluvastatin induced robust apoptosis and inhibited renal cancer growth effectively both in vitro and in vivo. Vorinostat activated the mTOR pathway, as evidenced by the phosphorylation of ribosomal protein S6, and fluvastatin inhibited this phosphorylation by activating AMPK. Fluvastatin also enhanced vorinostat‐induced histone acetylation. Furthermore, the combination induced endoplasmic reticulum (ER) stress that was accompanied by aggresome formation. We also found that there was a positive feedback cycle among AMPK activation, histone acetylation, and ER stress induction. This is the first study to report the beneficial combined effect of vorinostat and fluvastatin in cancer cells.

P3098Association with coronary high-intensity plaque on T1-weighted magnetic resonance imaging and circulating levels of malondialdehyde-modified low-density lipoprotein

Objectives

This study aimed to evaluate the association with coronary high-intensity plaque (HIP) on non-contrast T1-weighted magnetic resonance imaging (T1WI) and circulating levels of malondialdehyde-modified low-density lipoprotein (MDA-LDL).

Methods

A total of 139 patients with coronary artery stenosis (>70%) were imaged with non-contrast T1WI by using a 1.5-T magnetic resonance system (HIP: n=60, non-HIP: n=79). HIP was defined as a signal intensity of coronary plaque to cardiac muscle ratio (PMR) of ≥1.4. At admission, circulating levels of MDA-LDL and other lipid-related markers (triglyceride, HDL, LDL, Lp(a), RLP-C, and EPA/AA) were measured.

Results

Circulating levels of MDA-LDL (p=0.001) and LDL (p=0.041) were significantly higher in patients with HIP than those without, whereas the other lipid-related markers were not significantly different between both groups. In multivariable logistic regression analysis, MDA-LDL levels were independently associated with the presence of HIP (OR 1.03; 95% CI, 1.00–1.06, p=0.015) after adjusting for cofounding factors (age, sex, triglyceride, LDL, Lp(a), RLP-C, and EPA/AA). The optimal MDA-LDL threshold for predicting coronary HIP was 90.4 U/L, identified by the receiver operating characteristic curve.

Conclusion

MDA-LDL levels might be associated with the presence of HIP in patients with coronary artery disease.

P737Endothelial ERK2/thromboxane receptor pathway induces endothelial dysfunction, insulin resistance and steatohepatosis through superoxide with high fat high sucrose diet

Introduction

Metabolic syndrome (MetS) is well known as the risk of cardiovascular diseases associated with endothelial dysfunction and induces steatohepatosis. Insulin resistance is a major character of MetS, which affects intracellular signaling pathways and endothelial function. Extracellular signal-regulated kinase (ERK) is a major component of insulin signal and many of vasoactive peptides, which were released in MetS, can activate it in endothelium. However, the role of endothelial ERK in nitric oxide (NO) bioactivity in MetS in in vivo has been unknown.

Purpose

The aim of this study is to clarify the role of endothelial ERK2 on NO bioactivity in mice model of MetS.

Methods and results

We created endothelial specific ERK2 knock out mice (EE2KO) crossing Tie2-Cre mice and ERK2 flox mice and fed them with normal or high-fat/high-sucrose diet (HFHSD) for 24 weeks. Serum glucose and insulin levels and HOMA-IR were lowered in EE2KO with HFHSD without changing body weight. In wild type mice (WT) with HFHSD, nonalcoholic fatty liver disease (NAFLD) activity score, fibrosis score and serum ALT level were increased, all of which were blunted in EE2KO. EE2KO with HFHSD lowered systolic blood pressure (WT: 123.7±5.83 mmHg, EE2KO: 101.4±3.66 mmHg, P<0.01, N=8) without changing heart rate, which was increased to the same levels with L-NAME, an endothelial NO synthase inhibitor, in both groups. Serum NO levels measured with serum nitrite/nitrate concentrations were increased in EE2KO with HFHSD (WT: 23.10±3.74 μmol/l, EE2KO: 41.71±6.73 μmol/l, P<0.05, N=12). Endothelial function was assessed with the isometric tension measurement of aortic rings with acetylcholine (ACh). ACh-induced relaxation was improved in EE2KO with HFHSD. Superoxide production of aorta from EE2KO was lowered than WT with HFHSD in dihydroethidium (DHE) staining. S18886, an antagonist of the thromboxane A2-prostanoid (TP) receptor, decreased superoxide production of aorta in DHE staining resulting in improving endothelial function in the isometric tension measurement of aortic rings. Oral administrations of S18886 decreased systolic blood pressure, serum fasting glucose and insulin levels, and surprisingly improved steatohepatosis by decreasing NAFLD activity score and fibrosis score.

Relaxation of aortic rings with ACh

Conclusions

Endothelial ERK2/TP receptor pathway increases superoxide production and decreased NO bioactivity, resulting in deteriorating endothelial function, insulin resistance and steatohepatosis, which were improved by antagonist of the TP receptor in mice model of MetS. The present study indicates that ERK2/TP pathway could be a therapeutic target for complications of MetS.