Genome-wide DNA Methylation Analysis along the Progression of Gastric Marginal Zone B-cell Lymphoma of MALT Type

Extranodal marginal zone B-cell lymphoma (MZBL) of the mucosa-associated lymphoid tissue (MALT) is an indolent lymphoma mostly affecting the gastrointestinal tract. In the stomach, MZBL of MALT initially has small cell morphology (SC-MZBL) and arises in the background of Helicobacter pylori induced gastritis. Clonal malignant progression to large cell morphology (LC-MZBL) is observed. During this progression an intermediate stage consisting of both the small cell and large cell morphology is present, called "composite lymphoma". To gain insight into the DNA methylation changes associated with progression of gastric MZBL of MALT, we performed genome-wide DNA methylation profiling using the Illumina Infinium MethylationEPIC BeadChip array for 30 microdissected samples of gastric MZBL of MALT. Bisulphite converted DNA from 30 gastric MZBL of MALT samples were amplified, fragmented and hybridised to Illumina Infinium MethylationEPIC BeadChip.