Thymic Extranodal Marginal Zone Lymphoma of Mucosa-associated Lymphoid Tissue: A Gene Methylation Study.

Thymic Extranodal Marginal Zone Lymphoma of Mucosa-associated Lymphoid Tissue: A Gene Methylation Study.

Jan 2013

Takino H, Li C, Yamada S, Sato F, Masaki A, Fujiyoshi Y, Hattori H, Inagaki H.

Abstract

Although rare, thymic mucosa-associated lymphoid tissue (MALT) lymphoma is considered to be a distinct clinicopathological entity. Using a methylation-specific polymerase chain reaction, we analyzed thymic MALT lymphomas (n=18) for their methylation of the following seven tumor suppressor genes: DAPK1, p16(INK4A), p14(ARF), CDH1, RARB, TIMP3, and MGMT. Reactive lymph nodes (n=16) were used as a control. Of the seven genes examined, thymic MALTlymphomas had an increased number of genes that were methylated (2.9 genes) as compared with reactive lymph nodes (0.63, p=0.0003). In particular, thymic MALT lymphomas showed a frequent methylation of DAPK1, CDH1, TIMP3, and p14(ARF). In addition, gene methylation of the p14(ARF) was associated with a larger tumor size while that of the other three genes was not associated with any clinicopathological features examined. This study suggests that methylation of tumor suppressor genes may play an important role in thymic MALT lymphoma.

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