Objective To investigate the effect of mitogen-activated protein kinase(MAPK)pathway on the transcriptional expression of mdr1 gene induced by doxorubicin ( DOX)and study the transcription regulation of mdr1 gene.Methods K562 cells were treated with DOX(0.01 μg/ml)with the initial concentration of 0.01 μg/ml for 24 hours,then change the culture media without DOX.K562 cells were cultured until the its status wag recovered.Subsequently the cells were treated with DOX(0.02μg/ml)for 24 hours again.The concentration of DOX was increaged until 0.05 μg/ml by following the protocol above.K562 cells were collected at the concentration of 0.01 μg/ml,0.03μg/ml and 0.05μS/ml DOX.Expression of mdr1 gene were examined by reverse transcription-polymerase chain reaction(RT-PCR).Pglycoprotein(P-gP)wag detected by flow cytometry.Western blot wag performed to detect ERK and P-ERk.K562 cells were pretreated with MAPK inhibitor PD98059 for 1 hour.and then DOX was added.RT-PCR and FCM were used to detect the expression of mdr1 mRNA and P-gp.Results When K562 cells were exposured to DOX.the phosphorylation of ERK wag increaged.the mdr1 gene wag highly expressed as well as its corresponding protein P-gp.When the concentration of DOX was 0.05μg/ml,the expression of mdr1 gene and P-gp were increased over 5 fold.When K562 cells were pretreated with MAPK inhibitor PD98059,the expression of mdr1 gene induced by DOX(the concentration was 0.03 μg/ml and 0.05 μg/m1)was effectively inhibited by(74.1±0.11)%and(70.2±0.14)%respectively.Conclusions DOX could induce the expression of mdr1 gene in K562 cells accompanied by the activation of MAPK/ERK pathway.The block of activation of ERK could inhibit the induced expression of mdr1 gene.

OBJECTIVETo identify differentially expressed genes between chronic phase and blast crisis in chronic myeloid leukemia, explore the mechanism and screen potential biomarkers of disease progression.

METHODSThe differences in the gene expression profiles of bone marrow mononuclear cells between chronic phase and blastic crisis were examined using DNA microarray. PANTHER database, Genomatix database and Bibliosphere software were used to analyze and predict the critical genes or transcription factors during disease progression. Some of the genes or transcription factors were selected for verification by semi-quantitative RT-PCR.

RESULTSIn blastic crisis, 68 of the 1176 tested genes were obviously up-regulated. Sixteen of these differential genes were selectively expressed in leukocyte membranes. CD40, CCR3, LGALS3, RGS3, CEACAM3 and the related transcription factors RAC1, CTNNB1, TP53, and NF-κB, all as the nodes of the entire regulatory network, were presumed to play key roles in disease progression. The results of RT-PCR were consistent with the microarray data and showed high expression of CEACAM3, RGS3, CTNNB1 and RAC1 in blastic crisis.

CONCLUSIONA group of genes have been identified to very likely play key roles or serve as biomarkers in the transition from the chronic phase to blastic crisis in chronic myeloid leukemia.

Blast Crisis ; genetics ; Computational Biology ; Gene Expression Profiling ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Oligonucleotide Array Sequence Analysis ; Transcriptome

OBJECTIVETo investigate the cytogenetic differences between children and adults with acute lymphoblastic leukemia (ALL) using eight-probe fluorescence in situ hybridization and karyotype analysis.

METHODSEight-probe (MYC, P16, E2A, TEL/AML1, BCR/ABL , MLL , IGH, and hyperdiploidy) fluorescence in situ hybridization and karyotype analysis were performed for 86 adults and 39 children with acute lymphoblastic leukemia.

RESULTSEight-probe fluorescence in situ hybridization showed significant differences in the positivity rate of TEL/AML1, BCR/ABL, and hyperdiploidy between adult patients and children with ALL. By karyotype analysis, the positivity rate of t(9;22) and hyperdiploidy differed significantly between the children and adult patients (P<0.05).

CONCLUSIONAdults and children with ALL have different expression profiles of the fusion genes. Eight-probe fluorescence in situ hybridization is time-saving, accurate and efficient in detecting common genetic abnormalities in ALL patients, and can be well complementary to karyotype analysis in clinical diagnosis of ALL.

Adolescent ; Adult ; Child ; Child, Preschool ; Cytogenetics ; Female ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Infant ; Karyotype ; Karyotyping ; Male ; Middle Aged ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; diagnosis ; genetics ; Young Adult