Pathogenesis of Gastric MALT Lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is a heterogeneous form of a B-cell non-Hodgkin’s lymphoma with extranodal location.In the view of molecular biology, there are two types of MALT lymphoma: translocationnegative MALT lymphoma and translocation-positive MALT lymphoma. The pathogenesis of translocation-negative MALT lymphoma is driven by an active immune response to Helicobacter pylori infection. Thismost probably underscores the tumor cell survival and proliferation, and thus determines their response to Helicobacter pylorieradication. The oncogenic products of t(1;14) (p22;q32)/CL10-IGH, t(14;18)(q32;21)/IGH-MALT1 and t(11;18)(q21;q21)/API2MALT1, found in translocation-positive MALT lymphoma, are all potent activators of the NF-κB activation pathway. They activate the canonical NFκB activation pathway, and also potentially trigger directly and /r indirectly activation of the non-canonical NF-κB pathway. Inactivation of the global NFκB inhibitor A20 also impacts upon multiple signaling pathways leading to NF-κB activation and thus potentially exacerbates the effect of stimulation of surface receptors. This review discusses the recent advances in the molecular pathogenesis of MALT lymphoma, and explores how the above genetic abnormalities cooperate with immunological stimulation in the development of lymphoma. (Korean J Helicobacter Up Gastrointest Res 2011;11: 145-155)