Anti-CALM3 monoclonal antibody, clone FQS6139

Background-Calmodulin (CaM) mutations are associated with severe forms of long QT syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT). CaM mutations are found in 13% of genotype-negative long QT syndrome patients, but the prevalence of CaM mutations in genotype-negative CPVT patients is unknown. Here, we identify and characterize CaM mutations in 12 patients with genotype-negative but clinically diagnosed CPVT. Methods and Results-We performed mutational analysis of CALM1, CALM2, and CALM3 gene-coding regions, in vitro measurement of CaM-Ca2+ (Ca)-binding affinity, ryanodine receptor 2-CaM binding, Ca handling, L-type Ca current, and action potential duration. We identified a novel CaM mutation-A103V-in CALM3 in 1 of 12 patients (8%), a female who experienced episodes of exertion-induced syncope since age 10, had normal QT interval, and displayed ventricular ectopy during stress testing consistent with CPVT. A103V modestly lowered CaM Ca-binding affinity (3-fold reduction versus WT-CaM), but did not alter CaM binding to ryanodine receptor 2. In permeabilized cardiomyocytes, A103V-CaM (100 nmol/L) promoted spontaneous Ca wave and spark activity, a cellular phenotype of ryanodine receptor 2 activation. Even a 1: 3 mixture of A103V-CaM: WT-CaM activated Ca waves, demonstrating functional dominance. Compared with long QT syndrome D96V-CaM, A103V-CaM had significantly less effects on L-type Ca current inactivation, did not alter action potential duration, and caused delayed afterdepolarizations and triggered beats in intact cardiomyocytes. Conclusions-We discovered a novel CPVT mutation in the CALM3 gene that shares functional characteristics with established CPVT-associated mutations in CALM1. A small proportion of A103V-CaM is sufficient to evoke arrhythmogenic Ca disturbances via ryanodine receptor 2 dysregulation, which explains the autosomal dominant inheritance.

MicroRNAs (miRNAs or miRs) contribute to the development of various malignant neoplasms, including glioblastoma multiforme (GBM). The present study aimed to explore the pathogenesis of GBM and to identify latent therapeutic agents for patients with GBM, based on an in silico analysis. Gene chips that provide miRNA expression profiling in GBM were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed miRNAs (DEMs) were also determined via the RobustRankAggreg algorithm. The target genes of DEMs were predicted and then intersected with GBM-associated genes that were collected from the Gene Expression Profiling Interactive Analysis. Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of the overlapping genes were then performed. Simultaneously, a connectivity map (CMap) analysis was performed to screen for potential therapeutic agents for GBM. A total of 10 DEMs (hsa-miR-196a, hsa-miR-10b, hsa-miR-196b, hsa-miR-18b, hsa-miR-542-3p, hsa-miR-129-3p, hsa-miR-1224-5p, hsa-miR-876-3p and hsa-miR-770-5p) were obtained from three GEO gene chips (GSE25631, GSE42657 and GSE61710). Then, 1,720 target genes of the 10 miRNAs and 4,185 differently expressed genes in GBM were collected. By intersecting the aforementioned gene clusters, the present study identified 390 overlapping genes. GO and KEGG analyses of the 390 genes demonstrated that these genes were involved in certain cancer-associated biological functions and pathways. Eight genes [(GTPase NRas (NRAS), calcium/calmodulin-dependent protein kinase type II subunit Gamma (CAMK2G), platelet-derived growth factor receptor alpha (PDGFRA), calmodulin 3 (CALM3), cyclin-dependent kinase 6 (CDK6), calcium/calmodulin-dependent protein kinase type II subunit beta (CAMK2B), retinoblastoma-associated protein (RB1) and protein kinase C beta type (PRKCB)] that were centralized in the glioma pathway were selected for CMap analysis. Three chemicals (W-13, gefitinib and exemestane) were identified as putative therapeutic agents for GBM. In summary, the present study identified three miRNA-based chemicals for use as a therapy for GBM. However, more experimental data are needed to verify the therapeutic properties of these latent drugs in GBM.