%0 Journal Article
%T AR-A 014418 Used against GSK3beta Downregulates Expression of hnRNPA1 and SF2/ASF Splicing Factors
%A Ajay K. Yadav
%A Vidhi Vashishta
%A Nidhi Joshi
%A Pankaj Taneja
%J Journal of Oncology
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/695325
%X Glioblastoma is one of the most aggressive forms of primary brain tumors of glial cells, including aberrant regulation of glycogen synthase kinase 3¦Â (GSK3¦Â) and splicing factors deregulation. Here, we investigate the role of small molecule AR-A014418 and Manzamine A against GSK3 kinase with factual control on splicing regulators. AR-A 014418, 48£¿hrs posttreatment, caused dose (25¨C100£¿¦ÌM) dependent inhibition in U373 and U87 cell viability with also inhibition in activating tyrosine phosphorylation of GSK3alpha (Tyr 279) and beta (Tyr 216). Furthermore, inhibition of GSK3 kinase resulted in significant downregulation of splicing factors (SRSF1, SRSF5, PTPB1, and hnRNP) in U87 cells with downregulation of antiapoptotic genes such as BCL2, BCL-xL, Survivin, MCL1, and BMI1. Similarly, downregulation of splicing factors was also observed in U373 glioma cell after using SiRNA against AKT and GSK3beta kinase. In addition, potential roles of AR-A014418 in downregulation of splicing factors were reflected with decrease in Anxa7 (VA) variant and increase in Anxa7 WT tumor suppressor transcript and protein. The above results suggest that inhibition of GSK3beta kinase activation could be the beneficial strategy to inhibit the occurrence of alternative cancer escape pathway via downregulating the expression of splicing regulators as well as apoptosis. 1. Introduction Glioblastoma remains challenging to us being a devastating aggressive brain tumor. Patients median survival is found to be around 15 months and 10% less will survive 5 years after diagnosis [1, 2]. GBM¡¯s heterogeneous genome wide landscape and resistance against multimodal therapy make this even more challenging to treat or to at least extend the survival of patient beyond expectancy. Although a lot of progress is being made to revive the multigene targeted approaches to restrict the tumor growth, it is going to be limited due to its biological complexity and tumor heterogeneity [3]. Moreover finding a better target for GBM could be possible by studying the regulation of splicing factors involved in evolving alternative splicing event with diversified encoded protein product in cancer to escape apoptotic pathway. Cooperative and competitive association between splicing factor enhancer and silencer is under exploration area; its functional consequences lead to misregulated alternative splice variant expression which could affect biology of survival signalling in various scales of function such as mRNA stability, oncogenic gain, and loss in tumor suppressor function. However, few of splicing factors such
%U http://www.hindawi.com/journals/jo/2014/695325/