Acute myeloid leukemia (AML) is a heterogeneous group of diseases with respect to biology and clinical course. Through genome-wide scanning, we can have an improvement of the diagnosis and assay system of AML. Microarray was performed for the identification of acute myeloid leukemia prognosis. We divided patients into two groups (good prognosis group, GPG and poor prognosis group, PPG) based on differences in the individual reactions to treatment. Gene expression profiles were analyzed using microarray. Among genes up-regulated at least two-fold and down-regulated at least 0.5-fold in HL-60, we chose three up-regulated genes (PPP2CA, ME3, and CCDN2) and three down-regulated genes (GLO1, ANXA2, and BMI1) and confirmed the expression of these six genes by RT-PCR. We created a leukemia-specific subclass microarray, based on the gene expression profiles. Clinical samples from the bone marrow of four patients were hybridized on this microarray. Among the genes selected by the microarray technology, NB4, silenced TRIB3 and overexpressed XRN2 were not differentiated in spite of treatment with ATRA. This indicates that XRN2 and TRIB3 play an important role in cell differentiation. These data provided an expression profile for the diagnosis and prognosis of AML patients and identified candidate genes that might allow the prognosis of AML through the relative comparison of the expression level of genes between GPG and PPG.

The study of ES cell-mediated neuronal differentiation allows elucidating the mechanism of neuronal development in spite of the complexity and the difficult accessibility. During the differentiation of embryonic stem cells into neuronal cell, the expression profiles in the level of protein were extensively investigated by proteomic analysis. These cells were analyzed for charges in proteome during the differentiation of ES cells by 2-dimensional electrophoresis (2-DE) and MALDI-TOF MS. Seven unique proteins were identified, some of which were differentially expressed at each stage. A complex system of neuronal differentiation can be activated in cultured embryonic stem cells and our two dimensional electrophoresis data should be useful for investigating some of the mechanism that regulates neuronal differentiation.

The PC12 is the widely used cell line to study neuronal differentiation. We had extensively investigated the details of protein expression in differentiated PC12 cells by proteomic analysis. The cells were incubated at the presence of nerve growth factor. We had analyzed the expression changes in the differentiating PC12 cells by 2-dimensional electrophoresis and the identification of the proteins using MALDI-TOF MS. By comparing expression pattern in the time course, we identified the candidate genes which are associated with neuronal differentiation. Among these genes, we performed real-time PCR analysis to validate Idh3α expression by the time course. To identify the function of Idh3α in neuronal differentiation stage, the transfection of Idh3α to PC12 cells was performed. As a result, we proved that up-regulation of Idh3α causes reduction in neural differentiation of PC12 cells. Based on these data, we suggest that Idh3α plays a role to the neuronal differentiation. [BMB reports 2010; 43(5): 369-374]