Citations

Background: Hydrogen peroxide (H2O2)-induced oxidative stress has been demonstrated to induce afterdepolarizations and triggered activities in isolated myocytes, but the underlying mechanisms remain not fully understood. We aimed to explore whether protein kinase C (PKC) activation plays an important role in oxidative stress-induced afterdepolarizations. Methods: Action potentials and ion currents of isolated rabbit cardiomyocytes were recorded using the patch clamp technique. H2O2 (1 mM) was perfused to induce oxidative stress and the specific classical PKC inhibitor, Gö 6983 (1 μM), was applied to test the involvement of PKC. Results: H2O2 perfusion prolonged the action potential duration and induced afterdepolarizations. Pretreatment with Gö 6983 prevented the emergence of H2O2-induced afterdepolarizations. Additional application of Gö 6983 with H2O2 effectively suppressed H2O2-induced afterdepolarizations. H2O2 increased the late sodium current (INa,L) (n = 7, p < 0.01) and the L-type calcium current (ICa,L) (n = 5, p < 0.01), which were significantly reversed by Gö 6983 (p < 0.01). H2O2 also increased the transient outward potassium current (Ito) (n = 6, p < 0.05). However, Gö 6983 showed little effect on H2O2-induced enhancement of Ito. Conclusions: H2O2 induced afterdepolarizations via the activation of PKC and the enhancement of ICa,L and INa,L. These results provide evidence of a link between oxidative stress, PKC activation and afterdepolarizations.

152 Background: Plasma cfDNA ARcopy number variations (CNV) have been suggested to have prognostic significance in mCRPC stage. We compared plasma AR amplification ( ARamp) with CTC counts (the only FDA approved prognostic marker in mCRPC stage) in a prospective trial of patients (pts) progressing on androgen deprivation therapy. Methods: Plasma and CTC counts were obtained concurrently as part of a prospective clinical trial in mCRPC stage pts initiating abiraterone acetate (NCT# 01953640). Plasma cfDNA was purified using DNA Blood Mini Kit (Qiagen, Valencia, CA) and AR CNVs were detected using QuantStudio3D digital PCR system (Life Technologies, Carlsbad, CA, USA). CTC enumeration was performed using the FDA cleared CellSearch platform. The distributions of overall survival (OS) time based on ARamp status and CTC counts ( < 5 vs ≥ 5 cells) were estimated using the Kaplan-Meier method. Log-rank tests were used to test association of ARamp status and CTC counts with overall survival (OS). Univariate and multivariate logistic regression models and ROC evaluated association of OS at 24 months by ARamp status and CTCs ≥ 5. Results: Between 05/2013 and 09/2015, 92 pts were enrolled of which complete CTC, plasma and outcome data was available for 70 pts. Median age of the cohort (range) was 72 yrs (39-91); Median PSA–16.2 ng/ml (range: 0.9-2026.0); Median CTC count was 2.0 (range: 0-372); 58/70 pts had bone metastases; 38/70 had high volume and 32/70 had low volume metastatic disease at the time of sample collection. The median (range) follow up time at the time of this analysis was: 26.5 (7.9-37.0) months at which time 28/70 patients had died. ARamp was present in 19/70 pts while 51/70 did not have amplification. 24/70 had CTCs ≥ 5. A significant association of increased ARamp status with OS (p < 0.0001, log-rank test; AUC: 0.66) as well as with CTC counts ≥ 5 (p = 0.001, log-rank test; AUC: 0.67) was observed. Combining CTC status and plasma ARamp status the AUC was 0.75. Conclusions: Plasma cfDNA ARamp status and CTC counts have comparable and clinically meaningful prognostic marker value in mCRPC stage patients.

TPS474 Background: In pts with APC, the distal common bile duct is frequently obstructed, which can lead to elevated bilirubin levels. Normalization of bilirubin by stenting can take weeks, so treatment options that could be initiated in pts with elevated bilirubin are desirable. In a phase III trial of pts with metastatic PC, nab-P + Gem demonstrated superior efficacy vs Gem alone for all endpoints, including overall survival (OS; median, 8.7 vs 6.6 months; hazard ratio, 0.72; P < 0.001). This study will be the first to analyze safety and PK profiles of nab-P + Gem in pts with APC and CH secondary to bile duct obstruction. Methods: Treatment-naive pts (≈ 12 to 40) with APC, Karnofsky performance status ≥ 70, and CH due to bile duct obstruction are eligible. Pts with a biliary stent must have 2 stable (within 20% of each other) bilirubin readings within 48 to 72 hours of each other taken between 5 and 21 days after stenting. Exclusion criteria consist of brain metastases, any other active malignancy, infection requiring systemic therapy, a history of myocardial infarction, or current use of medications known to be strong inducers of CYP3A4 and CYP2C8. Pts will enter 1 of 2 cohorts based on bilirubin level: cohort 1, > 1.5 to 3 × upper limit of normal (ULN), or cohort 2, > 3 to 5 × ULN. Cohort 2 will proceed only after review of safety and PK data from cohort 1 by a safety monitoring committee (SMC) and a decision has been made to proceed. The starting doses are nab-P 100 mg/m2 and Gem 800 mg/m2 for cohort 1 and nab-P 75 mg/m2 and Gem 600 mg/m2 for cohort 2. Treatment will be administered on days 1, 8, and 15 of each 28-day cycle. Doses in each cohort will be modified according to tolerability as determined by the SMC. The primary endpoints are determination of maximum tolerated dose for each cohort and PK profile. Secondary endpoints include investigator-assessed objective response rate, progression-free survival, OS, PK profile of Gem, and safety. The exploratory endpoint is change in serum CA19-9 level from baseline. Enrollment is ongoing. ClinicalTrials.gov: NCT02267707. Clinical trial information: NCT02267707.

Attenuated Edmonston lineage measles virus (MV-Edm) vaccine strains can preferentially infect and lyse a wide variety of cancer cells. Oncolytic MV-Edm derivatives are genetically engineered to express the human carcinoembryonic antigen (MV-CEA virus) or the human sodium iodide symporter (MV-NIS virus) and are currently being tested in clinical trials against ovarian cancer, glioblastoma multiforme, multiple myeloma, mesothelioma, head and neck cancer, breast cancer and malignant peripheral nerve sheath tumors. This review describes the basic and preclinical data that facilitated the clinical translation of MV-Edm strains, and summarizes the clinical results of this oncolytic platform to date. Furthermore, we discuss the latest clinically relevant MV-Edm vector developments and creative strategies for future translational steps.

ABSTRACT Angiogenesis and inflammation are regarded as important factors in the pathogenesis of chronic inflammation, cancer, and wound healing. Recent studies have supported prior evidence that common signaling pathways are involved in angiogenesis and inflammatory responses; however, key factors controlling both processes remain unclear. Although tripartite motif‐containing (TRIM)‐28 is known to have an immunosuppressive role in immune cells, its expression level and role in endothelial cells (ECs) are still unclear. In this study, we investigated the role of TRIM28 in inflammatory responses and angiogenic activity of ECs for the first time. We showed that TRIM28 is the most abundant TRIM family member and is localized in nuclei of ECs. Small interfering RNA‐mediated knockdown of TRIM28 strikingly suppressed expression of TNF receptor (TNFR)‐1 and −2, decreased TNFα‐induced phosphorylation of IKKα/β and IκBα and degradation of IκBα and nuclear translocation of p65, and suppressed basal level and TNF‐α‐induced expression of chemokines and adhesion molecules, including VCAM‐1, IL‐6, ICAM‐1, E‐selectin, and monocyte chemoattractant protein (MCP)‐1. Unexpectedly, IL‐8 was potentiated by TRIM28 knockdown in ECs in an NF‐κB‐inducing kinase–dependent manner. Meanwhile, knockdown of TRIM28 inhibited expression of VEGF receptor 2 and suppressed VEGF‐induced proliferation and tube formation by ECs. Finally, knockdown of TRIM28 suppressed recruitment of ECs in vivo in a murine synthetic basement membrane model. In summary, we found that TRIM28 acts as a central factor in controlling endothelial inflammatory responses and angiogenic activities by retaining expression of TNFR‐1 and −2 and VEGF receptor 2 in ECs.—Wang, Y., Li, J., Huang Y., Dai, X., Liu, Y., Liu, Z., Wang, Y., Wang, N., Zhang, P. Tripartite motif–containing 28 bridges endothelial inflammation and angiogenic activity by retaining expression of TNFR1 and −2 and VEGFR2 in endothelial cells. FASEB J. 31, 2026–2036 (2017). www.fasebj.org

AbstractBackgroundGastric motility is coordinated by bioelectrical slow waves, and gastric dysrhythmias are reported in motility disorders. High‐resolution (HR) mapping has advanced the accurate assessment of gastric dysrhythmias, offering promise as a diagnostic technique. However, HR mapping has been restricted to invasive surgical serosal access. This study investigates the feasibility of HR mapping from the gastric mucosal surface.MethodsExperiments were conducted in vivo in 14 weaner pigs. Reference serosal recordings were performed with flexible‐printed‐circuit (FPC) arrays (128‐192 electrodes). Mucosal recordings were performed by two methods: (i) FPC array aligned directly opposite the serosal array, and (ii) cardiac mapping catheter modified for gastric mucosal recordings. Slow‐wave propagation and morphology characteristics were quantified and compared between simultaneous serosal and mucosal recordings.Key ResultsSlow‐wave activity was consistently recorded from the mucosal surface from both electrode arrays. Mucosally recorded slow‐wave propagation was consistent with reference serosal activation pattern, frequency (P≥.3), and velocity (P≥.4). However, mucosally recorded slow‐wave morphology exhibited reduced amplitude (65‐72% reduced, P<.001) and wider downstroke width (18‐31% wider, P≤.02), compared to serosal data. Dysrhythmias were successfully mapped and classified from the mucosal surface, accorded with serosal data, and were consistent with known dysrhythmic mechanisms in the porcine model.Conclusions & InferencesHigh‐resolution gastric electrical mapping was achieved from the mucosal surface, and demonstrated consistent propagation characteristics with serosal data. However, mucosal signal morphology was attenuated, demonstrating necessity for optimized electrode designs and analytical algorithms. This study demonstrates feasibility of endoscopic HR mapping, providing a foundation for advancement of minimally invasive spatiotemporal gastric mapping as a clinical and scientific tool.