Mutation of the MYD88 gene has recently been identified in activated B-cell-like diffuse cell lymphoma and enhanced Janus kinase/signal transducer and activator of transcription (JAK-STAT) and nuclear factor κB (NF-κB) signaling pathways.
In order to evaluate whether the presence of the recently described MYD88L265P mutation in patients with Waldenström's macroglobulinemia (WM) is contributory to SS-associated lymphomagenesis, a quantitative allele-specific PCR method was performed in peripheral blood derived from 90 SS patients as well as in minor salivary gland tissues derived from 12 primary SS patients with or without lymphoma.
MYD88L265P mutation has been reported in ∼90% of Waldenström's Macroglobulinemia (WM) patients and immunoglobulin M (IgM) monoclonal gammopathies of uncertain significance (MGUS), as well as in some cases of lymphoma and chronic lymphocytic leukemia.
This review discusses the molecular and biological mechanisms underlying MYD88 mutations in LPL/WM, the role of MYD88 mutations as molecular biomarker for the refinement of diagnosis and the improvement classification of LPL/WM, and novel targeted therapeutic strategies for LPL/WM based on the pharmacological manipulation of MYD88 signaling to which this lymphoma is addicted.
MYD88 mutations were identified in 20 of 29 (69%) clinically, histologically, and molecularly confirmed VRL, including 6 cases of the test cohort initially diagnosed as reactive (3/6) or suspicious (3/6) for lymphoma.
Myeloid differentiation primary response 88 (MYD88) is a common adaptor protein that is responsible for signaling from several receptors; mutations in this gene may play a role in the pathogenesis of lymphoma.
Individuals with tumors positive for MYD88 mutations also harbored the same mutations at a low frequency in peripheral blood mononuclear cells, suggesting that MYD88 mutation-positive precancerous cells originate outside of the CNS and develop into lymphoma after additional genetic hits that confer adaptation to the CNS environment.
Toll-like receptors (TLRs) and interleukin 1 receptors (IL-1R) can recognize microbes or endogenous ligands and then recruit MyD88 to activate the MyD88-dependent pathway, while MyD88 mutation associated with lymphoma development and altered MyD88 signaling also involved in cancer-associated cell intrinsic and extrinsic inflammation progression and carcinogenesis.