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. 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.