Markers of mRNA stabilization and degradation, and, RNAi within astrocytoma GW bodies

GW bodies (GWBs) are unique cytoplasmic structures that contain the mRNA binding protein GW182 and other proteins involved in mRNA processing pathways. The rationale for this study arose from clinical studies indicating that 33% of patients with GWB autoantibodies have a motor/sensory neuropathy and/or ataxia. The novelty of this study is the identification of GWBs in astrocytes and astrocytoma cells within cell bodies and cytoplasmic projections. Astrocytoma GWBs exhibit complex heterogeneity with combinations of LSm4 and XRN1 as well as Ago2 and Dicer, key proteins involved in mRNA degradation and RNA interference, respectively. GWB subsets contained the mRNA transport and stabilization proteins SYNCRIP, hnRNPA1, and FMRP, not previously described as part of the GWB complex. Immunoprecipitation of astrocytoma GWBs suggested that Dicer, hDcp, LSm4, XRN1, SYNCRIP, and FMRP form a multiprotein complex. GWBs are likely involved in a number of regulatory mRNA pathways in astrocytes and astrocytoma cells. (C) 2007 Wiley-Liss, Inc.