A gene trap mutagenesis screen for genes underlying cellular response to the mood stabilizer lithium
Article first published online: 12 APR 2013
© 2013 The Authors Journal of Cellular and Molecular Medicine Published by Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Journal of Cellular and Molecular Medicine
Volume 17, Issue 5, pages 657–663, May 2013
How to Cite
Gow, M., Mirembe, D., Longwe, Z. and Pickard, B. S. (2013), A gene trap mutagenesis screen for genes underlying cellular response to the mood stabilizer lithium. Journal of Cellular and Molecular Medicine, 17: 657–663. doi: 10.1111/jcmm.12048
- Issue published online: 27 MAY 2013
- Article first published online: 12 APR 2013
- Manuscript Accepted: 31 JAN 2013
- Manuscript Received: 5 SEP 2012
- gene trap;
- mood stabilizer;
Identifying the biological pathways mediating the action of a therapeutic compound may help the development of more specific treatments while also increasing our understanding of the underlying disease pathology. Salts of the metal lithium are commonly used as a front-line mood stabilizing treatment for bipolar disorder. Lithium's action has been variously linked to inositol phosphate metabolism and the WNT/Glycogen Synthase Kinase 3β (GSK3β)/β-Catenin signalling cascade, but, to date, little is known about which of these provides the principal therapeutic benefit for patients and, more specifically, which constituent genes, through presumed sequence variation, determine differences in patient response to treatment. Here, we describe a functional screen in which SH-SY5Y neuroblastoma cells were randomly mutated through genomic integration of the pMS1 poly A ‘gene trap’ plasmid vector. Lithium normally induces differentiation of neuroblastoma cells, but a small proportion of mutated cells continued to proliferate and formed colonies. Rapid amplification of cDNA ends (RACE)-PCR was used to identify the ‘trapped’ gene in each of these lithium-resistant colonies. Heterozygous, gene trap integrations were identified within ten genes, eight of which are likely to produce loss-of-function mutations including MED10, MSI2 and three long intergenic non-coding (LINC) RNAs. Both MED10 and MSI2 have been previously linked with WNT/GSK3β/β-Catenin pathway function suggesting that this is an important mediator of lithium action in this screen. The methodology applied here provides a rapid, objective and economic approach to define the genetic contribution to drug action, but could also be readily adapted to any desired in vitro functional selection/screening paradigm.