BACKGROUND: Promoter methylation of tumor suppressor genes is one of the key epigenetic changes in many human cancers. The aim of this study was to evaluate the promoter methylation status of the Death-associated protein(DAP) kinase gene, which played an important role in lung cancer, in the serum DNA of primary lung cancer patients. METHODS: This study investigated the aberrant methylation of DAP kinase in the serum of 65 primary lung cancer patients by methylation-specific PCR (MSP). RESULTS: Methylation in the serum was detected in 29 of 65(44.6%) for DAP kinase. There was no statistical association between methylation of DAP kinase and age, smoking history, histologic type, or stage. Methylation of DAP kinase was found more frequently in men (p=0.044). CONCLUSIONS: This study suggests that the aberrant methylation of the DAP kinase promoter is readily detectable in the serum DNA of lung cancer patients using MSP analysis.
Death-Associated Protein Kinases ; DNA* ; Epigenomics ; Genes, Tumor Suppressor ; Humans ; Lung Neoplasms* ; Lung* ; Male ; Methylation* ; Phosphotransferases ; Polymerase Chain Reaction ; Protein Kinases* ; Smoke ; Smoking

This study was aimed to investigate the effect of methylation transferase inhibitor 5-aza-2'-deoxycytidine (5-aza-2dC) of different concentrations on the apoptosis of human acute myeloid leukemia (AML) cell line HL-60 and the expression of DAPK gene in HL-60 cells, as well as to explore the possible anti-AML mechanism of 5-aza-2dC. HL-60 cells were treated by 5-aza-2dC of different concentrations. The effect of 5-aza-2dC on the HL-60 cell morphology was observed by Wright's staining. The effect of 5-aza-2dC on HL-60 cell apoptosis and DAPK mRNA expression was detected by flow cytometry and reverse transcription-polymerize chain reaction (RT-PCR) respectively. The results showed that the 5-aza-2dC induced the apoptosis of HL-60 cells in a concentration-dependent manner; the 5-aza-2dC increased the expression levels of DAPK mRNA in HL-60 cells in a concentration-dependent manner. It is concluded that the apoptosis rate of HL-60 cells and DAPK mRNA expression level displayed a rising trend with 5-aza-2dC concentration increasing. Therefore, DAPK gene may participate in HL-60 cell apoptosis induced by 5-aza-2dC.
Apoptosis ; drug effects ; Death-Associated Protein Kinases ; genetics ; Deoxycytidine ; pharmacology ; Gene Expression ; drug effects ; HL-60 Cells ; Humans

OBJECTIVETo study the effects of sodium butyrate (NaBu) on cell cycle checkpoint and the apoptosis sensitivity in U937 cells.

METHODSTwo mutant U937 cell lines, U937-ASPI3K (ATM negative) and U937-pZeosv2(+) (ATM wild-type), were used as the cell model system. Immunoprecipitation and kinase assay were used to examine the p38 MAPK and ERK1 kinase activities. Western blot was used to analyze the phosphorylation of Bad protein.

RESULTSU937-pZeosv2(+) pretreated with NaBu exhibited enhanced apoptotic response in a NaBu dose dependent fashion upon (137)Cs irradiation, which could be abolished by olomoucine (OLM), a p38 MAPK specific inhibitor. On the other hand, Cyclin dependent kinase 2 (CDK2) specific inhibitor CDK2-I and p34cdc2/cyclinB inhibitor alsterpaullone (ALP) failed to block the effects of NaBu. Similar results were also observed in U937-ASPI3K. The effect of irradiation on p38 MAPK and ERK1 was strikingly potentiated by NaBu. Furthermore, inactivation of irradiated Bad protein via phosphorylation on serine 136 was also enhanced.

CONCLUSIONNaBu is able to enhance the apoptotic response in U937 cells, which is mediated by p38 MAPK activation but not ATM status.

Apoptosis ; Butyrates ; pharmacology ; Carrier Proteins ; metabolism ; Humans ; MAP Kinase Signaling System ; Mitogen-Activated Protein Kinase 3 ; Mitogen-Activated Protein Kinases ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; U937 Cells ; bcl-Associated Death Protein ; p38 Mitogen-Activated Protein Kinases

OBJECTIVETo study the effect of triptolide (TP) on the methylation status of human promyelocytic leukemia cells (HL-60) and explore a preliminary demethylation mechanism.

METHODSNormal HL-60 cells as control group, the cell proliferation level of HL-60 cells was detected by MTT assay, being treated by different concentration TP (3.125, 6.25, 12.5, 25 nmol/L) for 24 h or 48 h respectively; Choosing the 3.125 nmol/L and the 6.25 nmol/L TP affected HL-60 cells for 48 h, the cell apoptosis rate and cell cycle were determined by flow cytometry, the expressions of death-associated protein kinase 1 (DAPK-1) and methyltransferase DNMT1, DNMT3B mRNA were measured by real time-PCR (RT-PCR), LINE-1, DAPK-1 genes'methylation variations were analyzed by methylation specific PCR (MSP).

RESULTSCompared with control group, the different concentration TP could significantly inhibit the proliferation of HL-60 in a time-dose dependent manner (P<0.05, P<0.01). After being treated by TP for 48 h, the cell early apoptosis rate of control group and 6.250 nmol/L TP group were (2.07 ± 1.91)%, (9.77 ± 3.52)%, respectively (P<0.05); When the TP concentration increased, DAPK-1mRNA expression increased (P<0.01), DNMT1, DNMT3B mRNA expression significantly dampened (P<0.01); the promoter of LINE-1, DAPK-1 genes were hypermethylation state in the control group, after being treated by TP for 48 h, the brightness of LINE-1, DAPK-1 genes'methylation strips weakened, and the non-methylation strips enhanced all in a dose-dependent manner.

CONCLUSIONTP could down-regulate the transcriptional expression of methyltransferase DNMT1/3B genes, indirect action to reduce the degree of DAPK-1, LINE-1 genes mathylation, thus promote DAPK-1 gene expression level and inhibit the HL 60 cell growth.

DNA (Cytosine-5-)-Methyltransferases ; DNA Methylation ; drug effects ; Death-Associated Protein Kinases ; Diterpenes ; pharmacology ; Epoxy Compounds ; pharmacology ; HL-60 Cells ; Humans ; Phenanthrenes ; pharmacology ; Promoter Regions, Genetic ; RNA, Messenger

OBJECTIVETo explore the effect of DAPK overexpression on the biological behaviors and caspase-3 expression in HL-60 cells.

METHODSThe expression of DAPK mRNA was detected by RT-PCR leukemia cell lines K562, Molt4, U937, and HL-60 cells. HL-60 cells were transfected by a eukaryotic expression vector pReceiver-M29-DAPK via LipofectamineTM 2000, and the impact of DAPK overexpression on cell apoptosis, cell cycle, cell differentiation and caspase-3 expression were analyzed.

RESULTSDAPK mRNA expression was positive in K562, Molt4 and U937 cells but negative in HL-60 cells. Significantly increased cell apoptosis was observed in pReceiver-M29-DAPK-transfected HL-60 cells by flow cytometry and Hoechst33342 staining. The cell cycle distribution and differentiation showed no significant changes after the transfection. The expression of caspase-3 was significantly increased in the cells after transfection.

CONCLUSIONDAPK gene overexpression promotes apoptosis of HL-60 cells without affecting the cell cycle and differentiation. Caspase-3 may be involved in the regulation of cell apoptosis.

Apoptosis ; Caspase 3 ; metabolism ; Cell Cycle ; Cell Differentiation ; Cell Line, Tumor ; Death-Associated Protein Kinases ; metabolism ; HL-60 Cells ; Humans ; RNA, Messenger ; metabolism ; Transfection ; U937 Cells

This study was purpose to investigate the expression of death-associated protein kinase (DAPK) gene in acute leukemia (AL) patients and the methylation status of its promoter region through experiments of DAPK methylation and expression, and to analyze the relation between them. The expression of DAPK gene in leukemia cells and normal bone marrow cells was detected by RT-PCR; the methylation status of DAPK gene promoter region in cells from AL patients and leukemia cell lines HL-60 and U937 was detected by nested methylation specific PCR (n-MSP); 2 randomly primers selected from randomly amplified products of second round nMS-PCR were cloned and sequenced in professional company. The results showed that the DAPK gene expressed in bone marrow specimens of all 10 normal controls, with average value of expression 0.92 ± 0.18, while the average value of DAPK expression in bone marrow specimens of AL patients was 0.61 ± 0.40 which was lower than that in normal controls (P < 0.05). The low or deletion of DAPK mRNA expression were found in bone marrow specimens of 9/17 (52.94%) cases of ALL and 42/102 (41.18%) cases of AML. The cell line U937 showed normal expression of DAPK gene, while cell line HL-60 showed the expression detection of DAPK gene. The methylation of DAPK promoter region existed in 33 out of bone marrow specimens of 102 AML patients and in 8 out of bone marrow specimens of 17 ALL patients, the methylation rates were 32.4% (33/102) and 47% respectively. The DAPK promoter region in bone marrow of 7 normal controls was unmethylated, while DAPK promoter region in U937 cells and HL-60 cells were unmethylated and methylated respectively. The DAPK mRNA expression in ALL and AML patients significantly negatively correlated with the methylation of its promoter region (r = -0.855, P < 0.05, in AML patients and r = -0.343, P < 0.05, in AML patients) suggesting the close relationship between them. It is concluded that the methylation of DAPK gene promoter region relates with abnormal expression or detection of DAPK mRNA in AL patients.
Acute Disease ; Case-Control Studies ; DNA Methylation ; Death-Associated Protein Kinases ; genetics ; HL-60 Cells ; Humans ; Leukemia ; genetics ; Promoter Regions, Genetic ; RNA, Messenger ; genetics

OBJECTIVETo screen the differential methylation patterns of tumor suppressor gene DAPK and evaluate its value as a biomarker for the diagnosis of leukemia.

METHODSThe methylation status of DAPK gene promoter's CpG island was analyzed in the genomes of normal human white blood cells and HL-60, U937 and Jurkat cell lines by bisulfite sequencing PCR (BSP). The effectiveness of differential methylation patterns of DAPK gene for diagnosis of leukemia was verified in the leukemia cell lines and peripheral blood samples by methylation specific PCR (MSP).

RESULTSThe methylation pattern of DAPK gene in different cell genomes displayed that the degree of unmethylation in normal cell genome was higher than that of leukemia cell lines. The differential CpG sites were found and could be used to differentiate HL-60 and the other 3 cell lines by MSP. Meanwhile, the differential methylation patterns in clinical specimens could distinguish acute non-lymphocytic leukemia (ANLL) and other types of leukemia by MSP. The diagnostic sensitivity, specificity and accuracy were 59.1%, 100% and 82.7% respectively. No relationship was found between MSP diagnosis results and clinical pathological typing.

CONCLUSIONThe differential methylation patterns of DAPK gene as potential tumor biomarker for diagnosis of leukemia can enrich the means of diagnosis of leukemia, provide idea and basis for finding all kinds of tumor's DNA methylation biomarkers in the future.

Biomarkers, Tumor ; genetics ; CpG Islands ; DNA Methylation ; Death-Associated Protein Kinases ; genetics ; HL-60 Cells ; Humans ; Jurkat Cells ; Leukemia ; diagnosis ; genetics ; Polymerase Chain Reaction ; Promoter Regions, Genetic

OBJECTIVETo investigate the expressions of DAPK3 and c-Myc and their prognostic value in endometrial carcinoma (EC).

METHODSThe expressions of DAPK3 and c-Myc were detected immunohistochemically in 132 surgical specimens. The relationship between DAPK3 and c-Myc protein expressions and the clinicopathological features of the patients was evaluated.

RESULTSImmunohistochemical analysis revealed low DAPK3 expression in 60.61% (80/132) and high c-Myc expression in 53.79% (71/132) of the specimens of EC. Both DAPK3 expression and c-Myc expression were significantly correlated with FIGO stage (P=0.034 and 0.015, respectively) and lymph node metastasis (P=0.022 and 0.031, respectively). DAPK3 expression was closely correlated with the histological grade (P=0.027) and depth of myometrial invasion (P=0.011). Kaplan-Meier survival analysis indicated that patients with low DAPK3 expressions had a shorter overall survival rate than those with high DAPK3 expressions (P=0.023), while patients with high c-Myc expressions had poorer prognoses than those with low c-Myc expressions (P=0.002). Spearman correlation analysis showed that DAPK3 and c-Myc expressions were negatively correlated (P<0.001, r=?0.310). Multivariate analysis identified a high c-Myc expression as the independent predictor of the prognosis of EC (P=0.007).

CONCLUSIONSA low expression of DAPK3 and a high expression of c-Myc are associated with aggressive and metastatic behaviors of EC, and their detection may help to predict the prognosis of the EC patients.

Death-Associated Protein Kinases ; metabolism ; Endometrial Neoplasms ; diagnosis ; metabolism ; Female ; Humans ; Kaplan-Meier Estimate ; Lymphatic Metastasis ; Prognosis ; Proto-Oncogene Proteins c-myc ; metabolism ; Survival Rate

BACKGROUND: Invasive nonfunctioning pituitary adenomas (NFPAs) remain challenging due to their high complication rate and poor prognosis. We aimed to identify the distinctive molecular signatures of invasive NFPAs, compared with noninvasive NFPAs, using gene expression profiling by RNA sequencing. METHODS: We obtained frozen fresh tissue samples from 14 patients with NFPAs who underwent primary transsphenoidal surgery. Three non-invasive and 11 invasive NFPAs were used for RNA sequencing. The bioinformatics analysis included differential gene expression, gene ontology analysis, and pathway analysis. RESULTS: A total of 700 genes were differentially expressed (59 up-regulated and 641 down-regulated genes) between invasive and non-invasive NFPAs (false discovery rate <0.1, and |fold change| ≥2). Using the down-regulated genes in invasive NFPAs, gene ontology enrichment analyses and pathway analyses demonstrated that the local immune response was attenuated and that transforming growth factor-β (TGF-β) RII-initiated TGF-β signaling was down-regulated in invasive NFPAs. The overexpression of claudin-9 (CLDN9) and the down-regulation of insulin-like growth factor-binding protein 5 (IGFBP5), death-associated protein kinase 1 (DAPK1), and tissue inhibitor of metalloproteinase-3 (TIMP3) may be related with invasiveness in NFPAs. CONCLUSION: Invasive NFPAs harbor different gene expression profiles relative to noninvasive NFPAs. In particular, local suppression of the immune response and TGF-β signaling can make PAs prone to invasiveness.
Computational Biology ; Death-Associated Protein Kinases ; Down-Regulation ; Gene Expression ; Gene Expression Profiling ; Gene Ontology ; Humans ; Pituitary Neoplasms ; Prognosis ; Sequence Analysis, RNA ; Tissue Inhibitor of Metalloproteinase-3 ; Transcriptome

This study was purposed to analyze the methylation status of death-associated protein kinase (dapk) gene promoter in Chinese patients with acute myeloid leukemia (AML) and its relationship with clinical features. The methylation-specific PCR (MSP) technique was used to detect dapk promoter methylation in bone marrow samples from 112 cases of AML. The results indicated that gene dapk promoter hypermethylation was detected in 82 cases (73.2%), but not in 13 control group. There was no correlation of dapk gene hypermethylation with sex, age, WBC counts, platelet counts, hematologic parameters, chromosomal abnormalities and different subtypes of AML patients. It is concluded that dapk gene hypermethylation may be a common molecular event in AML.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Apoptosis Regulatory Proteins ; genetics ; Calcium-Calmodulin-Dependent Protein Kinases ; genetics ; Child ; Child, Preschool ; DNA Methylation ; Death-Associated Protein Kinases ; Female ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Male ; Middle Aged ; Promoter Regions, Genetic ; Young Adult