Non-coding RNA analysis in IgM monoclonal gammopathies: an underrecognized role of microRNA and long non-coding RNA differentiating Waldenström macroglobulinemia from IgM-MGUS
Waldenström macroglobulinemia (WM), is a rare non-Hodgkin lymphoma preceded by a clinically asymptomatic benign monoclonal gammopathy of undetermined significance (IgM-MGUS). The factors underlying the malignant progression between these two IgM-monoclonal gammopathies remain poorly understood. The non-coding genome is increasingly recognized as an important driver of disease pathogenesis, and there remains a lack of exploration of the influence of non-coding RNAs within the IgM-monoclonal gammopathy disease spectrum. The present study explores the role of microRNA (miRNA) and long non-coded RNA (lncRNA) in IgM-gammopathies and specifically elucidates potentially regulated protein-coding genes and pathways. A comprehensive analysis of miRNA, lncRNA and protein-coding coding genes was conducted on 28 subjects, 17 patients with WM, 6 patients with IgM-MGUS, and 5 normal controls. Differential expression analysis revealed a number of dysregulated miRNA and lncRNA between IgM-gammopathies compared to normal controls and specifically between IgM-MGUS and WM. Pathway analysis was conducted utilizing differentially expressed mRNA with correlated biological expression of targeting miRNA. Here, a number of pathways were implicated influencing a gamut of cellular functions, including cell signaling, metabolism, replication, and immune regulation in both WM compared to IgM-MGUS and IgM-gammopathies compared to controls. This report is additionally one of the first published analyses of lncRNAs in WM, where we demonstrate a number of lncRNA associated with transcription and apoptosis regulation genes in WM compared to IgM-MGUS. This study highlights the role of non-coding RNA in IgM-gammopathies and the potential to recognize novel targets which may halt or slow the malignant progression between these two diseases. Overall design: The study included samples from 28 subjects, 17 patients with WM, 6 patients with IgM-MGUS, and 5 normal controls. Bone marrow samples were collected and selection for CD19+ and/or CD138+ B cells was performed. mRNA and miRNA analyses were peformed on the isolated cells.