Project description:In this study, we used a doxycycline (DOX) inducible gene expression system to introduce MyD88, a gene associated with lymphoma, into the U2932 lymphoma cell line. We performed a transcriptomic analysis (RNA-seq) to identify differentially expressed genes due to the MyD88 L265P oncogenic mutation. This study aimed to investigate the impact of MyD88 L265P oncogenic signaling on lymphoma cells by analyzing the transcriptomic response of model cell lines.
Project description:We compared gene expression profiles of CLL patients with and without MYD88 L265P mutations, taking into consideration IGHV mutation status.
Project description:To elucidate the differences occurring in the B cell composition between WM patients, we performed single cell RNA sequencing on CD19 + sorted cells from patients with MYD88 L265P versus MYD88 WT phenotype and compared them with two healthy controls.
Project description:The ABC subtype of diffuse large B cell lymphoma (DLBCL) remains the least curable form of this lymphoma despite recent advances in therapy. We have combined structural and functional genomics to triangulate on new oncogenic mechanisms and devise new therapeutic strategies. RNA interference screen revealed a dependence of ABC DLBCL cell lines on MYD88 and IRAK1. High throughput resequencing of RNA (RNA-Seq) revealed frequent somatic mutations in MYD88 that preferentially occurred in the ABC DLBCL subtype. Remarkably, one third of ABC DLBCL tumor samples harbored the same amino acid substitution, L265P, in the MYD88 TIR domain at an evolutionarily invariant residue in its hydrophobic core. This mutation was rare or absent in two other DLBCL subtypes, but was observed in 9% of MALT lymphomas. At a lower frequency, multiple other mutations were observed in the MYD88 TIR domain, occurring in both the ABC and GCB subtypes of DLBCL. Survival of ABC DLBCL lines bearing the L265P mutation was sustained by the mutant but not wild type MYD88 isoform, demonstrating that this MYD88 mutant is oncogenic and gain-of-function. The MYD88 L265P mutant assembled a protein complex that spontaneous triggers the phosphorylation of IRAK1, leading to NF-kB signaling, secretion of the cytokines IL-6, IL-10 and interferon-b, and JAK kinase signaling. These findings demonstrate that the MYD88 signaling pathway is integral to the pathogenesis of ABC DLBCL, providing a genetic rationale for therapeutic targeting of the MYD88 signaling pathway in this lymphoma subtype.
