Association of TAP1 and TAP2 Gene Polymorphisms with Hematological Malignancies
ABSTRACT Transporter associated with antigen presenting (TAP) 1 and TAP2 genes are localized in the major histocompatability complex (MHC) class II region and form a heterodimer playing a key role in endogenous pathways for antigen presentation. Defects of these genes have been reported to be common in different types of cancer. Polymorphisms identified in these loci have also been investigated and reported to be associated with several autoimmune disorders, viral infections and neoplasms. In the present study, for the first time, the allele and genotype frequencies of TAP1-333, TAP2-565, TAP2-651 and TAP2-665 were determined in patients with hematological malignancies (HM) using a PCR-RFLP method and compared with the frequencies in the control group. Our results suggested an association of TAP1-333 polymorphism with multiple myeloma-MM and TAP2- 565 polymorphism with chronic lymphoid leukemia-CLL. In addition, it could be concluded that the TAP2-665 GG genotype might be a risk factor for all types of hematological malignancies included in this study.
Full-textDOI: · Available from: Sacide Pehlivan, May 19, 2015
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ABSTRACT: Memory B cells (MBCs) remain in a quiescent state for years, expressing pro-survival and anti-apoptotic factors while repressing cell proliferation and activation genes. During their differentiation into plasma cells (PCs), their expression pattern is reversed, with a higher expression of genes related to cell proliferation and activation, and a lower expression of pro-survival genes. To determine whether myelomatous PCs (mPCs) share characteristics with normal PCs and MBCs and to identify genes involved in the pathophysiology of multiple myeloma (MM), we compared gene expression patterns in these three cell sub-types. We observed that mPCs had features intermediate between those of MBCs and normal PCs, and identified 3455 genes differentially expressed in mPCs relative to normal PCs but with a similar expression pattern to that in MBCs. Most of these genes are involved in cell death and survival, cell growth and proliferation and protein synthesis. According to our findings, mPCs have a gene expression pattern closer to a MBC than a PC with a high expression of genes involved in cell survival. These genes should be physiologically inactivated in the transit from MBC to PC, but remain overexpressed in mPCs and thus may play a role in the pathophysiology of the disease.