CAMK2A supported tumor initiating cells of lung adenocarcinoma by upregulating SOX2 through EZH2 phosphorylation
CELL DEATH & DISEASE
Authors: Wang, Si-Qi; Liu, Jing; Qin, Jing; Zhu, Yun; Tin, Vicky Pui-Chi; Yam, Judy Wai Ping; Wong, Maria Pik; Xiao, Zhi-Jie
Abstract
Tumor initiating cells (TIC) of lung cancer are mainly induced by stress-related plasticity. Calcium/Calmodulin dependent protein kinase II alpha (CAMK2A) is a key calcium signaling molecule activated by exogenous and endogenous stimuli with effects on multiple cell functions but little is known about its role on TIC. In human lung adenocarcinomas (AD), CAMK2A was aberrantly activated in a proportion of cases and was an independent risk factor predicting shorter survivals. Functionally, CAMK2A enhanced TIC phenotypes in vitro and in vivo. CAMK2A regulated SOX2 expression by reducing H3K27me3 and EZH2 occupancy at SOX2 regulatory regions, leading to its epigenetic de-repression with functional consequences. Further, CAMK2A caused kinase-dependent phosphorylation of EZH2 at T487 with suppression of EZH2 activity. Together, the data demonstrated the CAMK2A-EZH2-SOX2 axis on TIC regulation. This study provided phenotypic and mechanistic evidence for the TIC supportive role of CAMK2A, implicating a novel predictive and therapeutic target for lung cancer.
Exome sequencing in 57 patients with self-limited focal epilepsies of childhood with typical or atypical presentations suggests novel candidate genes
EUROPEAN JOURNAL OF PAEDIATRIC NEUROLOGY
Authors: Rudolf, Gabrielle; de Bellescize, Julitta; Martin, Anne de Saint; Arzimanoglou, Alexis; Hirsch, Maria Paola Valenti; Labalme, Audrey; Boulay, Clotilde; Simonet, Thomas; Boland, Anne; Deleuze, Jean Francois; Nitschke, Patrick; Ollivier, Emmanuelle; Sanlaville, Damien; Hirsch, Edouard; Chelly, Jamel; Lesca, Gaetan
Abstract
Objective: Self-limited focal epilepsies of childhood (SFEC) are amongst the best defined and most frequent epilepsy syndromes affecting children with usually normal developmental milestones. They include core syndromes such as Rolandic epilepsy or "-Benign-" epilepsy with Centro-Temporal Spikes and the benign occipital epilepsies, the early onset Panayiotopoulos syndrome and the late-onset Gastaut type. Atypical forms exist for all of them. Atypical Rolandic epilepsies are conceptualized as belonging to a continuum reaching from the "benign" RE to the severe end of the Landau-Kleffner (LKS) and Continuous Spike-Waves during Sleep syndromes (CSWS). GRIN2A has been shown to cause the epilepsy-aphasia continuum that includes some patients with atypical Rolandic epilepsy with frequent speech disorders, LKS and CSWS. In the present study, we searched novel genes causing SFEC with typical or atypical presentations. Methods: Exome sequencing was performed in 57 trios. Patients presented with typical or atypical SFEC, negative for GRIN2A pathogenic variant. Results: We found rare candidate variants in 20 patients. Thirteen had occurred de novo and were mostly associated to atypical Rolandic Epilepsy. Two of them could be considered as disease related: a null variant in GRIN2B and a missense variant in CAMK2A. Others were considered good candidates, including a substitution affecting a splice site in CACNG2 and missense variants in genes encoding enzymes involved in chromatin remodeling. Significance: Our results further illustrate the fact that atypical SFEC are more likely to have Mendelian inheritance than typical SFEC. (C) 2020 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.