嶋田 明

The human herpes virus, Epstein-Barr virus (EBV), is a known oncogenic virus and plays important roles in life-threatening T/NK-cell lymphoproliferative disorders (T/NK-cell LPD) such as hypersensitivity to mosquito bite (HMB), chronic active EBV infection (CAEBV), and NK/T-cell lymphoma/leukemia. During the clinical courses of HMB and CAEBV, patients frequently develop malignant lymphomas and the diseases passively progress sequentially. In the present study, gene expression of CD16(-)CD56(+)-, EBV(+) HMB, CAEBV, NK-lymphoma, and NK-leukemia cell lines, which were established from patients, was analyzed using oligonucleotide microarrays and compared to that of CD56brightCD16dim/- NK cells from healthy donors. Principal components analysis showed that CAEBV and NK-lymphoma cells were relatively closely located, indicating that they had similar expression profiles. Unsupervised hierarchal clustering analyses of microarray data and gene ontology analysis revealed specific gene clusters and identified several candidate genes responsible for disease that can be used to discriminate each category of NK-LPD and NK-cell lymphoma/leukemia.

Annually, it is estimated that approximately 150-200 children aged 0-16 years are diagnosed with acute myeloid leukemia (AML). In Japan, clinical studies with ANLL91, AML99, CCLSG-AML9805, and JPLSG-AML05 protocols were performed historically, and the risk stratification with a combination of chemotherapy and hematopoietic stem cell transplantation resulted in the improvement of clinical outcomes. Regarding the onset of pediatric AML at the molecular level, mutations in FLT3-ITD or KIT (Class I mutation) showed a poor prognosis, but the ratio of mutations in Class III-V genes was smaller than that in adult AML. In contrast, several pediatric AML cases are complicated due to chromosome fragility syndrome or congenital bone marrow failure syndrome. To improve the clinical outcomes, clinical application of next generation sequencing may allow for personalized therapy in each patient in the future.

Myeloid malignancy with Down syndrome (ML-DS) is estimated to have a step-wise leukemogenesis including GATA1 mutation. Trisomy 21 is essential for ML-DS; however, we do not know exactly which gene or genes located on chromosome 21 are necessary for the ML-DS. We report a female infant with transient myeloproliferative disorder (TMD) and partial trisomy 21. SNP array analysis showed 10 Mb amplification of 21q22.12-21q22.3, which included DYRK1A, ERG, and ETS but not the RUNX1 gene. With two other reported TMD cases having partial trisomy 21, DYRK1A, ERG, and ETS were the most likely genes involved in collaboration with the GATA1 mutation.