Transcriptome Analysis Identifies an Attenuated Local Immune Response in Invasive Nonfunctioning Pituitary Adenomas

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.

Value of DAPK Gene Methylation Patterns in the Diagnosis of Leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To screen the differential methylation patterns of tumor suppressor gene DAPK and evaluate its value as a biomarker for the diagnosis of leukemia.</p><p><b>METHODS</b>The 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).</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>The 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.</p>

Effect of DAPK overexpression on biological behaviors and caspase-3 expression in HL-60 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of DAPK overexpression on the biological behaviors and caspase-3 expression in HL-60 cells.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>DAPK 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.</p><p><b>CONCLUSION</b>DAPK 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.</p>

Expressions of DAPK3 and c-Myc in endometrial cancer and their relationship with the patients' prognosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expressions of DAPK3 and c-Myc and their prognostic value in endometrial carcinoma (EC).</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>Immunohistochemical 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).</p><p><b>CONCLUSIONS</b>A 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.</p>

Promoter hypermethylation patterns of P16, DAPK and MGMT in Oral Squamous Cell Carcinoma: A systematic review and meta-analysis.

Background: Oral squamous cell carcinoma (OSCC) is a common cancer world‑wide that is highly lethal due to its recurrence and metastasis. Methylation is a common epigenetic mechanism that leads to gene silencing in tumors and could be a useful biomarker in OSCC. The prevalence of P16, death‑associated protein kinase (DAPK) and O6‑methylguanine‑DNA‑methyltransferase (MGMT) promoter hypermethylation in OSCC has been evaluated for several years while the results remain controversial. Objective: The aim of this systematic review is to critically analyze and perform a meta‑analysis on the various studies in the literature that have reported the promoter hypermethylation of P16, DAPK and MGMT genes in OSCC. Search Strategy: Articles were searched and selected through PubMed. Hand search from the relevant journals was also performed. Articles were reviewed and analyzed. Results: The estimated prevalence of P16 methylation was 43%, DAPK methylation was 39.7% and MGMT methylation was 39.8%. Heterogeneity in methylation prevalences and correlations with the clinical outcomes of the disease prevailed in various studies. Conclusion: We can conclude from our systematic review that a higher prevalence of methylation of P16, DAPK and MGMT occur in OSCC. Further studies are required to substantiate the role of methylation of P16, DAPK and MGMT as a marker in OSCC.

Triptolide affect the methylation status of HL-60cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the effect of triptolide (TP) on the methylation status of human promyelocytic leukemia cells (HL-60) and explore a preliminary demethylation mechanism.</p><p><b>METHODS</b>Normal 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).</p><p><b>RESULTS</b>Compared 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.</p><p><b>CONCLUSION</b>TP 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.</p>

Function of death associated protein kinase(DAPK) in colorectal cancer chemoresistance / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the role of death associated protein kinase(DAPK) in colon cancer drug-resistance.</p><p><b>METHODS</b>Immunohistochemistry was used to detect DAPK expression in colon carcinoma tissues of 61 cases and adjacent tissues of 32 cases. 5-fluorouracil (5-FU)-induced drug-resistant colon cancer cell lines HCT116/5-FU model was established. DAPK-siRNA was transfected into cells to down-regulate the DAPK gene expression (DAPK-siRNA grouyp), FAM-siRNA was transfected as control group, and DAPK over-expression plasmid vectors were constructed to up-regulate the DAPK gene expression(DAPK over-expression group). Real-time quantitative PCR and Western blotting were used to examine the mRNA and protein expression levels of DAPK, multidrug resistance protein (MRP) and P- glycoprotein (P-gp). MTT and flow cytometry were used to detect cell proliferation and apoptosis for cells treated with 5-FU (8 mg/L) and cells without treatment of 5-FU in 3 groups respectively.</p><p><b>RESULTS</b>Positive expression rate of DAPK in colon cancer tissues was significantly lower than that in adjacent normal tissues [18.0% (11/61) vs. 90.6% (29/32), P < 0.05]. Compared with FAM-siRNA group, DAPK mRNA and protein expression levels were significantly lower in DAPK-siRNA group, but significantly higher in DAPK over-expression group (P<0.05). After treatment of 5-FU, cell proliferation was significantly inhibited, but cell apoptosis was significantly increased in DAPK over-expression group compared to FAM-siRNA group (P < 0.05). Cell proliferation and apoptosis were not significantly different between DAPK siRNA and FAM-siRNA groups (all P < 0.05). Compared with FAM-siRNA group, DAPK over-expression could significantly reduce the mRNA and protein levels of MRP and P-gp, whereas DAPK siRNA had no obvious such effects.</p><p><b>CONCLUSION</b>DAPK can inhibit the proliferation and promote the apoptosis in drug-resistant colon cancer cells, and it probably enhances the sensitivity of cancer cells to drugs by down-regulating the mRNA and protein levels of MRP and P-gp.</p>

Expression of death-associated protein kinase gene and methylation status of promoter region in acute leukemia / 中国实验血液学杂志

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.

Effect of 5-aza-2'-deoxycytidine on DAPK gene expression in human HL-60 cells / 中国实验血液学杂志

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.

Inhibitory effect of arsenic trioxide combined with cisplatin on human nasopharyngeal carcinoma xenograft and DAPK in nude mice / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study the inhibitory effect of Arsenic Trioxide (As2O3) combined with diamminedichloroplatinum (DDP) on the growth of human nasopharyngeal carcinoma cell strain CNE-2Z xenograft in nude mice, and to explore the possible effect mechanisms of the antitumor.@*METHOD@#The models of human poorly differentiated nasopharyngeal carcinoma in nude mice were established and randomly divided into four groups, control group, As2O3 group, DDP group and As2O3 + DDP group. The effect of antitumor on each group was studied. The specimen obtained from the mice were detected by optical microscope and tdt-mediated dutp rock end labeling (tunel) method. Expression of DAPK was detected by real time-PCR and immunohistochemistry.@*RESULT@#As2O3 group and AS2O3 + DDP group could obviously inhibit the growth of tumor, induce the apoptosis of human naso pharyngeal carcinoma cell and up-regulate the expression of RASSF1A.@*CONCLUSION@#As2O3 can greatly inhibit the growth of human nasopharyngeal carcinoma cell strain CNE-2Z xenograft in nude mice, which were related to the induced apoptosis of human nasopharyngeal carcinoma cell and up-regulated expression of DAPK Combination of As2O3 with DDP seem to be more effective.

Death-associated protein kinase promoter (DAPK) hypermethylation in uterine cervical cancer and intraepithelial neoplasia in Uyghur nationality women / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the methylation levels of death-associated protein kinase (DAPK) in Uyghur female patients with different cervical lesions in Xinjiang, and to discuss the relationship of the expression and significance of DAPK in normal cervix, chronic cervicitis, cervical intraepithelial neoplasia (CINI, CIN II/III) and invasive cervical squamous cell carcinoma.</p><p><b>METHODS</b>30 cases of normal cervix and chronic cervicitis, 30 cases of CINI, 30 cases of CINII/III and 30 cases of cervical squamous cell carcinoma were tested by methylation specific PCR (MSP). Expressions of DAPK in 30 cases of normal cervix and chronic cervicitis, 30 cases of CINI, 30 cases of CINII/III and 30 cases of cervical squamous cell carcinoma were assayed using immunohistochemical SP staining.</p><p><b>RESULTS</b>The methylation rate of DAPK gene in normal cervix and chronic cervicitis was 3.33%, 10% in cervical intraepithelial neoplasia CINI, 36.7% in CINII/III, and 63.3% in invasive cervical squamous cell carcinoma. The methylation rate of DAPK in the SCC group was significantly higher than that in the other groups (P < 0.05). Aberrant promoter methylation of the DAPK gene was positively correlated with the degree of cervical lesions. The positive rate of DAPK protein in normal cervix and chronic cervicitis was 93.3%, 83.3% in cervical intraepithelial neoplasia CINI, 60.0% in CINII/III, and 33.3% in invasive cervical squamous cell carcinoma. The expression of DAPK in the SCC group was significantly lower than that in the other groups (P < 0.05). The positive rate of DAPK protein was negatively correlated with the degree of cervical lesions (r(s) = -0.603, P < 0.001).</p><p><b>CONCLUSIONS</b>Methylation of DAPK is involved in the cervical carcinogenesis and DAPK gene promoter methylation occurs in the early development of cervical cancer in Uyghur women in Xinjiang. Detection of DAPK gene methylation may provide a basis for use in early detection of cervical cancer. DAPK protein expression is decreasing even disappears along with the progression of cervical lesions.</p>

Expression and clinical significance of DAPK1 and CD147 in esophageal squamous cell carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the amplification and expression status of DAPK1 and CD147 in esophageal squamous cell carcinoma (ESCC) and their relationship with the prognosis of ESCC.</p><p><b>METHODS</b>Immunohistochemical staining and RT-PCR were used to detect the expression and amplification of DAPK1 and CD147 in esophageal squamous carcinoma tissue and normal esophageal mucosa. Statistical analysis of the clinocopathological data was performed with SPSS 11.5 software package.</p><p><b>RESULTS</b>The positive rates of expression of DAPK1 protein and CD147 protein in the specimens of esophageal carcinoma were 31.3% and 58.5%, and in normal esophageal mucosa 57.5% and 25.0%, respectively, with a statistically significant difference (P < 0.001). The expressions of DAPK1 and CD147 were significant correlated with invasion depth, lymph node metastasis, TNM stage and the degree of cancer differentiation. (P < 0.05). The negative expression of DAPK1 and positive expression of CD147 indicated a poor prognosis. In 52 ESCC cases, the expression of DAPK1 in cancer tissues was 0.236 ± 0.049, and 0.395 ± 0.058 in normal esophageal mucosa, while that of CD147 mRNA expression was 0.942 ± 0.204 and 0.821 ± 171, respectively, statistically both with a very significant difference (P < 0.01). There was a higher expression level of DAPK1 mRNA in the cancer tissue in patients with no lymph node metastasis, well differentiation, and earlier pathological stage, and a higher expression level of CD147 mRNA in the cancer tissues in patients with lymph node metastasis, poor differentiation, and later pathological stage.</p><p><b>CONCLUSIONS</b>The expression of DAPK1 and CD147 proteins is closely correlated with the clinicopathological characteristics of ESCC. The genes DAPK1 and CD147 may participate in the metastasis and apoptosis of ESCC. The expression of DAPK1 and CD147 may be used as important prognostic predictors in ESCC.</p>

Relationship between promoter methylation of p16, DAPK and RAR beta genes and the clinical data of non-small cell lung cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the effects of promoter methylation of p16, death-associated protein kinase (DAPK) and retinoic acid receptor-beta (RAR beta) genes on clinical data in non-small cell lung cancers, and to study the effect of smoking on the risk of gene methylation.</p><p><b>METHODS</b>The promoter methylation of p16, DAPK and RAR beta genes in 200 primary non-small cell lung cancers and the corresponding nonmalignant lung tissues were determined by methylation-specific PCR.</p><p><b>RESULTS</b>Methylation in the tumor tissues was detected in 51.0% for p16, 60.0% for DAPK, and 58.0% for RAR beta gene, with significant differences (P < 0.05) when compared with those in the corresponding nonmalignant tissues(12.5%, 11.5% and 15.0%) respectively. p16 gene methylation in tumor tissue was associated with age significantly in unconditional logistic regression analysis (P < 0.01) and histologic type (P < 0.05). DAPK gene methylation in tumor tissue was associated significantly with age (P < 0.05), gender (P < 0.05) and clinical type (P < 0.05). RAR beta gene methylation in tumor tissue was associated with clinical type (P < 0.05) and tumor stage (P < 0.05) significantly. The interaction odds ratio (OR) for the gene-gene interaction in tumor tissue between p16 and DAPK was 1.987 (95%CI:1.055-3.743). The results of the gene-smoking analyses revealed that a relationship existed between cigarette smoking and p16 gene methylation (OR = 3.139, 95%CI: 1.046-9.419), the OR for the relationship of DAPK gene methylation and cigarette smoking was 3.585(95%CI: 1.270-10.123) in tumor tissue. The RAR beta gene methylation did not differ based on the smoking status of patients in tumor tissue.</p><p><b>CONCLUSION</b>The p16, DAPK and RAR beta genes methylation are strongly associated with clinical data of non-small cell lung cancer, and methylation of p16 and DAPK genes are associated with tobacco smoking.</p>

Detection of methylation levels of multi-genes by real-time PCR in patients with myelodysplastic syndrome / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the promoter methylation levels of p15, CDH1, DAPK and HICI genes of patients with myelodysplastic syndrome (MDS) and explore the relationship between the level of methylation and clinical features.</p><p><b>METHODS</b>DNA methylation levels of p15, CDH1, DAPK and HICI in peripheral blood (PB) or bone marrow (BM) samples from 52 MDS patients were detected by real-time quantitative PCR. The correlation of the methylation level with clinical features and hematological findings was analyzed. 38 de novo AML patients and 46 normal individuals served as controls.</p><p><b>RESULTS</b>The methylation levels of p15, CDH1, DAPK and HICI were 16.23 ± 21.69, 6.59 ± 9.39, 0.14 ± 0.11 and 7.81 ± 9.70 in BM, and 14.96 ± 20.16, 6.00 ± 9.26, 0.12 ± 0.14 and 6.74 ± 9.72 in PB, respectively from 18 MDS patients, and the difference between BM and PB was not statistically significant (P > 0.05). The methylation levels of p15 (14.70 ± 18.17) and CDH1 (6.61 ± 8.79) genes in high risk (RAEBI/II) MDS were significantly higher than in low risk (RCMD/RARS/5q-, p15: 1.99 ± 1.59, CDH1: 1.23 ± 1.14 and RCMD, p15: 3.02 ± 3.42, CDH1:1.53 ± 2.06) MDS or control (p15: 1.69 ± 1.82, CDH1: 1.01 ± 1.12) (P < 0.05). The methylation levels of DAPK gene had no difference among subtypes of MDS, and that of HIC1 gene only differed between RAEB I/II (9.16 ± 11.95) and control (2.49 ± 2.26) (P = 0.042). The difference of methylation levels of p15, CDH1, DAPK and HICI in BM was statistically significant among subtypes of MDS (P = 0.001, 0.003, 0.039, 0.023, respectively). And so did of p15 and DAPK in PB (P = 0.013, 0.006, respectively). The methylation level of p15 and CDH1 was significantly correlated with IPSS classification and blasts percentage in BM.</p><p><b>CONCLUSIONS</b>p15 and CDH1 genes are special hypermethylation genes in MDS. Methylation level of HIC1 gene showed an upward tendency from low risk to high risk MDS.</p>

Alteration of methylation status of death-associated protein kinase (dapk) gene promoter in patients with acute myeloid leukemia / 中国实验血液学杂志

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.

Reversion transcriptional expression of DAPK in bladder cancer T24 cells 5-aza-2'-deoxycytidine / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the methylation status of the promoter of resion death associated protein kinase (DAPK) gene in bladder cancer cell (T24), and study the effect of 5-aza-2'-deoxycytidine (5-aza-dc) on DAPK gene reactive expression in T24 and its inhibitory effect on T24.</p><p><b>METHODS</b>The bladder cancer cell T24 was treated with different doses of 5-aza-dc. The inhibitory effect and apoptosis rate were detected by MTT and flow cytometry, and the changes of DAPK mRNA and protein expression and the methylation status of DAPK promoter were assessed by RT-PCR, Western blotting, and methylation specific PCR, respectively.</p><p><b>RESULTS</b>The growth of bladder cancer cell was inhibited significantly and the maximal apoptosis rate detected by flow cytometry was (24.12-/+1.4)%. DAPK mRNA was not expressed in bladder cancer cell T24 in normal conditions. DAPK mRNA and protein re-expressed after 5-aza-dc (12.5 micromol/L) treatment in cell line T24 for 24 h, and DAPK promoter became unmethylated.</p><p><b>CONCLUSIONS</b>The promoter methylation can be an important factor for silencing the expression of DAPK in bladder cancer cell. 5-aza-dc can inhibit the growth and induce apoptosis of bladder cancer cells through reversing unmethylation status of DAPK promoter.</p>

O papel do gene p16 e do gene Dapk no controle do ciclo celular e na via carcinogênese vulvar / The role of p16 and Dark genes in cell cycle control and in the pathways of vulvar carcinogenesis

O câncer vulvar é o quarto tipo de câncer mais comum nas mulheres e representa 4,8% dos cânceres do trato genital inferior. O carcinoma de células escamosas é responsável por 80 a 90% de todos os cânceres de vulva. O carcinoma escamoso vulvar e suas lesões pré-malignas parecem desenvolver-se por dois caminhos distintos, baseados em características etiológicas e histopatológicas, tendo assim uma etiologia heterogênea. Um dos caminhos está relacionado com a infecção pelo HPV, e o outro, com as desordens epiteliais, tais como líquen escleroso e hiperplasia epitelial. O HPV é um importante fator causal das neoplasias do trato genital inferior. Ele está presente em cerca de 90% dos cânceres do colo uterino e 30 a 40% dos cânceres de vulva. O tipo mais prevalente é o 16, seguido pelos tipos 18, 45, 31 e 33. O estudo das alterações genéticas e epigenéticas, por meio da análise de metilação e imunoexpressão gênica, tem demonstrado uma grande versatilidade para o monitoramento molecular de pacientes com câncer, o que impulsiona pesquisas de métodos diagnósticos e terapêuticos do câncer. Nesta atualização pretendeu-se demonstrar as funções dos genes p16 e DAPK e as recentes pesquisas sobre a expressão destes genes nas vias da carcinogênse vulvar.

Vulvar cancer is the fourth commonest kind of cancer in women and it represents 4.8% of cancers in the lower genital tract squamous cell carcinoma is responsible for 80-90% of all vulvar cancers. Squamous cell carcinoma and it's premalignant lesions seem to develop in two distinct pathways, based on etiological and histopathological characteristics, thus forming a heterogeneous etiology. Whereas one of the pathways is related to HPV infection, the other is related to epithelial disorders such as: lichen sclerousus and epithelial hyperplasia. HPV is an important contributing factor of neoplasia in the lower genital tract. It is found in 90% of cervical cancers and in 30-40 % of vulvar cancers. The most prevalent kind is 16, followed by 18, 45, 31, and 33. The study of genetic and epigenetic alterations by means of methylation and genic immunoexpression has demonstrated great versatility to the monitoring ofpatients with cancer, which boosts researches of diagnostic and therapeutic methods for cancer. This update intends to demonstrate the role of p16 and DAPK genes as well as the recent researches regarding the expression of these genes in the pathways of vulvar carcinogenesis.

Hypermethylation of the death-associated protein kinase promoter in laryngeal squamous cell cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the relationship between hypermethylation of the promoter of death-associated protein kinase (DAPK) gene and laryngeal squamous cell cancer.</p><p><b>METHODS</b>Promoter hypermethylation and mRNA expression of DAPK gene were detected by methylation-specific PCR, RT-PCR and gene sequencing.</p><p><b>RESULTS</b>Among the 58 patients with laryngeal squamous cell cancer, hypermethylation of DAPK promoter was detected in 39 cases (67.2%). There was no significant difference in hypermethylation in relation to pathological grade and clinical staging, but a highly significant difference was observed between patients with and without lymph node metastasis (N0 and N1) (P < 0.001). DAPK promoter hypermethylation was detected in tumor adjacent tissues in 6 of the 58 cases. DAPK mRNA was not expressed in all laryngeal squamous cell cancers having hypermethylation of DAPK promoter, whereas it was expressed in normal laryngeal mucosa, laryngeal squamous cell cancers without hypermethylation and tumor adjacent tissues.</p><p><b>CONCLUSION</b>Hypermethylation of DAPK promoter is associated with loss of its transcription in laryngeal squamous cell carcinoma. The high frequency hypermethylation of DAPK promoter illustrates its potential clinical application as tumor marker for diagnosis and prognosis.</p>

Aberrant Promoter Methylation of Death-Associated Protein Kinase in Serum DNA from Lung Cancer Patients / 결핵

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.

Aberrant Methylation of p16 Tumor Suppressor Gene and Death-Associated Protein Kinase in Non-Small Cell Lung Carcinoma / 결핵

BACKGROUND: The p16INK4a (p16) tumor suppressor gene is frequently inactivated in human non-small cell lung cancers (NSCLCs), predominantly through homozygous deletion or in association with aberrant promotor hypermethylation. Death-associated protein kinase (DAPK) gene influences interferon γ-induced apoptotic cell death and has important role in metastasis of lung cancer in animal model. Hypermethylation of promoter region of DAP kinase gene may suppress the expression of this gene. METHODS: This study was performed to investigate the aberrant methylation of p16 or DAP kinase in 35 resected primary NSCLCs by methylation-specific PCR (MSP), and demonstrated frequency, diagnostic value and clinical implication of aberrant methylation of two genes. RESULTS: Thirty-two cases were male patients, and 3 cases were female patients with an average age was 57.8±10.5 years. The histologic types of lung cancer were 22 of squamous cell carcinoma, 12 of adenocarcinoma, 1 of large cell carcinoma. Pathologic stages were 11 cases of stage I(1 IA,10 IB), 13 cases of stage II (1 IIA, 12 IIB), and 11 cases of stage III(9 IIIA, 2 IIIB). Regarding for the cancer tissue, p16 aberrant methylation was noted in 13 case of 33 cases (39.4%), DAP kinase in 21 cases of 35 cases (60%). Age over 55 year was associated with p16 aberrant methylation significantly (p<0.05). Methylation status of two genes was not different by smoking history, histologic type, size of tumor, lymph node metastasis and disease progression of lung cancer. There was no correlation between p16 and DAP kinase hypermethylation. CONCLUSION: This investigation demonstrates that aberrant methylation of p16 tumor suppressor gene or DAP kinase showed relatively high frequency (74.3%) in NSCLCs, and that these genes could be a biologic marker for early detection of lung cancer.