Distinct pattern of gene expression in pyothorax-associated lymphoma (PAL), a lymphoma developing in long-standing inflammation.

Pyothorax-associated lymphoma (PAL) is a unique lymphoma developing in the pleural cavity after long-standing pyothorax. They are diffuse large B-cell lymphomas (DLBCLs), frequently with immunoblastic morphology, and show a strong association with Epstein-Barr virus (EBV) infection. In this study, cDNA microarray analysis was performed in six cases with PAL and 12 with nodal DLBCL.

Association of PTEN mutation with HPV-negative adenocarcinoma of the uterine cervix.

Serous, mucinous, endometrioid, and clear cell adenocarcinomas arise from reproductive organs of mullerian origin. Although the mutation of PTEN, a tumor suppressor, is known to be involved in tumorigenesis of endometrioid adenocarcinomas of the endometrium and ovary, the role of PTEN alteration in endometrioid adenocarcinoma of the cervix remains to be investigated. To elucidate the molecular pathogenesis of cervical adenocarcinoma and adenosquamous carcinoma, and in particular to examine the potential role of PTEN mutation in endometrioid-type cancer of the cervix, we analyzed 32 cervical adeno- or adenosquamous carcinomas (8 endometrioid adenocarcinomas, 14 mucinous adenocarcinomas and 10 adenosquamous carcinomas) for PTEN mutations and HPV infections.

Microarray analysis of gene-expression profiles in diffuse large B-cell lymphoma: identification of genes related to disease progression.

To identify genes that are associated with progression of malignant lymphoma, the expression profiles of 18,432 genes were analyzed in diffuse large B-cell lymphomas at early (stages I and II, 6 cases) and advanced stages (stages III and IV, 9 cases) by means of cDNA microarrays. By comparing expression profiles between localized and advanced lymphomas, a number of genes that were differentially expressed were identified: 48 genes with increased expression and 30 genes with reduced expression in advanced-stage diffuse large B-cell lymphomas. Increased expression of MPHOSPH1, RUVBL1, CHN2, PSA and CDC10 genes, and reduced expression of COL1A2, COL4A1, FBLN5, CLECSF6, MIC2, CAV1 and S100A10 genes in the advanced lymphoma group were confirmed by semi-quantitative reverse transcription-PCR.

Hypermethylation of death-associated protein (DAP) kinase CpG island is frequent not only in B-cell but also in T- and natural killer (NK)/T-cell malignancies.

Death-associated protein (DAP) kinase is a pro-apoptotic serine/threonine kinase with a death domain, which is involved in apoptosis induced by interferon-gamma, tumor necrosis factor-alpha, and Fas ligand. Down-regulation of DAP kinase gene expression by hypermethylation of its promoter region might result in resistance to apoptotic cell death, and could provide a basis for tumor development. In the present study, we employed methylation-specific polymerase chain reaction to examine the methylation status of CpG islands in the DAP kinase gene in 19 cases of T-cell malignancies (including eight adult T-cell leukemia/lymphoma), 24 of natural killer (NK)/T-cell, and 34 of B-cell.

Methylation of promoter region in p27 gene plays a role in the development of lymphoid malignancies.

p27 belong to the cyclin-dependent kinase inhibitor family and plays an important role in regulation of cell cycle progression. Expression of these genes is epigenetically suppressed by methylation of their promoter regions. In this study, we examined protein expression and methylation status of the promoter region of p27 in 70 cases with non-Hodgkin's lymphoma and their relationship with proliferative activity of the tumor cells as revealed by Ki-67 index.

Enhanced expression of neuron-specific enolase (NSE) in pyothorax-associated lymphoma (PAL).

Pyothorax-associated lymphoma (PAL) is a B-cell lymphoma of mostly large cell type developing in the pleural cavity of patients with long-standing pyothorax. Neuron-specific enolase (NSE) is an enolase comprising gamma subunit and is located at high levels in neuronal and neuroendocrine cells, together with their neoplasias. Expression of NSE at protein and mRNA levels was examined in PAL and other types (non-PAL) of non-Hodgkin's lymphomas.

Gene mutations in lymphoproliferative disorders of T and NK/T cell phenotypes developing in renal transplant patients.

Post-transplantation lymphoproliferative disorder (PT-LPD) is characterized by lymphoid proliferation after organ or bone marrow transplantation. In Western countries, most cases of PT-LPD are B-cell-derived and Epstein-Barr virus-associated, in which alterations of c-myc, p53, and N-ras genes might play a role in disease progression. In Japan, PT-LPD of T- and NK/T-cell types are not uncommon in renal transplant patients.