Gene Summary

Gene:DAPK1; death-associated protein kinase 1
Aliases: DAPK
Summary:Death-associated protein kinase 1 is a positive mediator of gamma-interferon induced programmed cell death. DAPK1 encodes a structurally unique 160-kD calmodulin dependent serine-threonine kinase that carries 8 ankyrin repeats and 2 putative P-loop consensus sites. It is a tumor suppressor candidate. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2013]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:death-associated protein kinase 1
Source:NCBIAccessed: 06 August, 2015


What does this gene/protein do?
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Cancer Overview

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Publications Per Year (1990-2015)
Graph generated 07 August 2015 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 06 August, 2015 using data from PubMed, MeSH and CancerIndex

Latest Publications: DAPK1 (cancer-related)

Arantes LM, de Carvalho AC, Melendez ME, et al.
Validation of methylation markers for diagnosis of oral cavity cancer.
Eur J Cancer. 2015; 51(5):632-41 [PubMed] Related Publications
PURPOSE: Activation of proto-oncogenes and inactivation of tumour suppressor genes are the major genetic alterations involved in carcinogenesis. The increase in methylation at the promoter region of a tumour suppressor gene can lead to gene inactivation, selecting cells with proliferative advantage. Thus, promoter hypermethylation is considered a marker in a variety of malignant tumours, including oral cavity.
EXPERIMENTAL DESIGN: The methylation pattern of eight genes was evaluated in 40 oral cavity squamous cell carcinomas (OSCCs) and 40 saliva samples from healthy individuals by Q-MSP. Different combinations of genes were also assessed in order to identify gene panels that could better distinguish between OSCC and saliva samples.
RESULTS: CCNA1, DAPK, DCC and TIMP3 methylation were highly specific for being found in the OSCC samples. Moreover, the combination of these genes improved detection when compared with single markers, reaching values of 92.5% for sensitivity and specificity (when using the panel CCNA1, DCC, TIMP3). Moreover, DAPK, DCC and TIMP3 were hypermethylated in nearly 90% of clinically T1 and T2 cases.
CONCLUSION: The pursuing of this panel of hypermethylated genes is an important tool for the detection of individuals with OSCC. Moreover, the identification of these markers in early stages of OSCC shows the feasibility of using the panel on saliva as possible biomarkers for early diagnosis. The lack of association between the methylation status of these genes and clinical characteristics shows that they are able to distinguish OSCC cases irrespective of social and clinical factors (gender, age, human papillomavirus (HPV) status, clinical stage, vascular embolisation and perineural invasion).

Chen KM, Stephen JK, Havard S, et al.
IGSF4 methylation as an independent marker of human papillomavirus-positive oropharyngeal squamous cell carcinoma.
JAMA Otolaryngol Head Neck Surg. 2015; 141(3):257-63 [PubMed] Related Publications
IMPORTANCE: Human papillomavirus (HPV) is a known causative agent for oropharyngeal squamous cell carcinoma (OPSCC). Whereas it is becoming more firmly established that HPV-positive head and neck squamous cell carcinoma is associated with better survival outcomes, believed to be because of better response to chemoradiation therapy, the specific mechanisms for these improved survival outcomes remain underexplored.
OBJECTIVE: To examine the relationship between HPV status and promoter methylation in an OPSCC cohort.
DESIGN, SETTING, AND PARTICIPANTS: Real-time quantitative polymerase chain reaction was used to examine oncogenic HPV type 16 in a retrospective cohort of 121 patients with primary OPSCC. Aberrant promoter methylation of IGSF4, DAPK1, and ESR1 genes, known to be methylated in head and neck squamous cell carcinoma, including OPSCC, was examined by means of quantitative methylation-specific polymerase chain reaction.
INTERVENTIONS: Patients received standard therapy.
MAIN OUTCOMES AND MEASURES: Univariate associations between HPV and methylation were analyzed using Fisher exact tests followed by multivariable logistic regression. Cox proportional-hazards regression was used to model the risk of death given age, race, sex, HPV status, methylation, stage, smoking, and treatment.
RESULTS: In univariate logistic regression analyses, HPV-positive status was significantly associated with Caucasian race (P = .02), treatment (radiotherapy only, P = .01; chemoradiotherapy, P = .007), and IGSF4 methylation (P = .005). The final multivariate logistic model, after controlling for patient characteristics (sex, age, smoking, race, and treatment) with backward variable selection among genes, retained IGSF4 methylation (OR, 4.5 [95% CI, 1.6-12.8]; P = .005), Caucasian race (OR, 2.9 [95% CI, 1.0-8.3]; P = .053), treatment (radiotherapy only vs neither: OR, 11.62 [95% CI, 2.02-66.82]; P = .02; chemoradiotherapy vs neither: OR, 11.15 [95% CI, 1.92-64.65]; P = .01), male sex (OR, 4.7 [95% CI, 1.3-17.0]; P = .02), and younger age (OR, 0.9 [95% CI, 0.90-1.0]; P = .008) as independent predictors of HPV-positive status. Cox regression modeling indicated HPV-negative status, age, male sex, smoking, and radiation treatment as independent predictors of mortality.
CONCLUSIONS AND RELEVANCE: Methylation of IGSF4 is an independent predictor of HPV-positive status. DNA methylation in conjunction with HPV infection appears to play a role in OPSCC.

Flatley JE, Sargent A, Kitchener HC, et al.
Tumour suppressor gene methylation and cervical cell folate concentration are determinants of high-risk human papillomavirus persistence: a nested case control study.
BMC Cancer. 2014; 14:803 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Persistent infection with one or more high-risk human papillomavirus [HR-HPV] types increases the risk of intraepithelial neoplasia and cervical cancer. A nested case-control study was conducted to investigate the importance of cervical cell folate concentration and tumour suppressor gene methylation as risk factors for HR-HPV persistence.
METHODS: Cervical cell samples from 955 women with HR-HPV infection and normal, borderline or mild dyskaryosis were retrieved from the archive of a population-based screening trial. Women were classified as cases or controls, reflecting the presence or absence [respectively] of any HR-HPV infection at a follow-up clinic at least 6 months from baseline. Cervical cell folate concentration and promoter methylation of five tumour suppressor genes were measured in independent samples from cases and controls.
RESULTS: A higher cervical cell folate concentration [P = 0.015] was an independent predictor of infection at follow-up, together with infection with HPV-16 or infection with multiple HR-HPV types. Methylation of the tumour suppressor gene DAPK was associated with a 2.64-fold [95% CI, 1.35-5.17] increased likelihood of HPV infection whilst CDH1 methylation was associated with a 0.53-fold [95% CI, 0.331-0.844] likelihood of HR-HPV infection at follow-up. When considering women with normal or abnormal cytology, the predictive effect of higher cervical cell folate was only seen in women with mild cytology [P = 0.021]; similarly the effect of DAPK methylation was seen in women with mild or borderline cytology [P < 0.05].
CONCLUSIONS: Higher cervical cell folate concentration and promoter methylation of the tumour suppressor gene, DAPK, in women with cervical cell dyskaryosis, are associated with increased risk of HR-HPV persistence.

Dauksa A, Gulbinas A, Endzinas Z, et al.
DNA methylation at selected CpG sites in peripheral blood leukocytes is predictive of gastric cancer.
Anticancer Res. 2014; 34(10):5381-8 [PubMed] Related Publications
BACKGROUND/AIM: Recently, a set of studies addressed the question of the prevalence of aberrant methylation in surrogate tissues, such as peripheral blood leukocytes. Toward this aim, we conducted a case-control pilot study to investigate aberrant methylation in leukocytes of gastric cancer patients.
MATERIALS AND METHODS: The SNuPE combined with ion pair reverse phase HPLC (SIRPH method) was used to examine site-specific methylation status at selected CpG sites of the promoter regions of APC, ACIN1, BCL2, CD44, DAPK1, CDKN2A, RARB, TNFRSF10C HS3ST2 and of LINE-1, Alu repeats.
RESULTS: We observed that in the patients, tumor suppressor genes were slightly but significantly higher methylated at several CpG sites, while DNA repetitive elements were slightly less methylated compared to controls. This was found to be significantly associated with higher prevalence for gastric cancer.
CONCLUSION: These results suggest that larger studies must be carried-out to explore the biological significance and clinical usefulness of leukocyte DNA as non-invasive detection tool for gastric cancer.

Xiong J, Li Y, Huang K, et al.
Association between DAPK1 promoter methylation and cervical cancer: a meta-analysis.
PLoS One. 2014; 9(9):e107272 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Death-associated protein kinase1 (DAPK1) is an important tumor suppressor gene. DNA methylation can inactivate genes, which has often been observed in the carcinogenesis of cervical cancer. During the past several decades, many studies have explored the association between DAPK1 promoter methylation and cervical cancer. However, many studies were limited by the small samples size and the findings were inconsistent among them. Thus, we conducted a meta-analysis to assess the association between DAPK1 promoter methylation and cervical cancer.
METHODS: We systematically searched eligible studies in the PubMed, Web of Science, EMBASE and CNKI databases. Using meta-regression, subgroup analysis and sensitivity analysis, we explored the potential sources of heterogeneity. The odds ratio (OR) and 95% confidence interval (95% CI) were calculated by Meta-Analysis in R.
RESULTS: A total of 15 studies from 2001 to 2012, comprising 818 tumor tissues samples and 671 normal tissues samples, were analyzed in this meta-analysis. The frequencies of DAPK1 promoter methylation ranged from 30.0% to 78.6% (median, 59.3%) in cervical cancer tissue and 0.0% to 46.7% (median, 7.8%) in normal cervical tissue. The pooled OR was 19.66 (95%CI = 8.72-44.31) with the random effects model, and heterogeneity was found through the sensitivity analysis. The I2 = 60% (P = 0.002) decreased to I2 = 29.2% (P = 0.144) when one heterogeneous study was excluded, and the pooled OR increased to 21.80 (95%CI = 13.44-35.36) with the fixed effects model.
CONCLUSION: The results suggested a strong association between DAPK1 promoter methylation and cervical cancer. This study also indicated that DAPK1 promoter methylation may be a biomarker during cervical carcinogenesis that might serve as an early indication of cervical cancer.

Kristensen LS, Asmar F, Dimopoulos K, et al.
Hypermethylation of DAPK1 is an independent prognostic factor predicting survival in diffuse large B-cell lymphoma.
Oncotarget. 2014; 5(20):9798-810 [PubMed] Free Access to Full Article Related Publications
Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. Improvements in overall survival have been observed with the introduction of rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), however, prognostic markers are still needed. Methylation of the death associated protein kinase (DAPK or DAPK1) gene and TP53 mutations are likely to have prognostic value in DLBCL. We have assessed TP53 mutations and allelic DAPK1 methylation patterns in a cohort of 119 DLBCL patients uniformly treated with R-CHOP-like regimens. We found that DAPK1 promoter methylation was associated with shorter overall survival (p=0.017) and disease-specific survival (p=0.023). In multivariate analyses DAPK1 methylation remained as an independent prognostic factor predicting disease-specific survival (p=0.038). When only considering individuals heterozygous for the rs13300553 SNP monoallelic methylation of the A-allele was associated with shorter overall- and disease-specific survival (p<0.001). Patients carrying both DAPK1 methylation and a TP53 mutation had an inferior survival compared to patients carrying only one of these molecular alterations, however, this was borderline statistically significant. Allele-specific DAPK1 methylation patterns were also studied in a cohort of 67 multiple myeloma patients, and all of the methylated multiple myeloma samples heterozygous for the rs13300553 SNP were methylated on both alleles.

Yang X, Dai W, Kwong DL, et al.
Epigenetic markers for noninvasive early detection of nasopharyngeal carcinoma by methylation-sensitive high resolution melting.
Int J Cancer. 2015; 136(4):E127-35 [PubMed] Related Publications
Nasopharyngeal carcinoma (NPC) is a human malignancy that is closely associated with Epstein-Barr Virus (EBV). Early diagnosis of NPC will greatly improve the overall survival. However, current EBV DNA marker detection still lacks the predictive value to perform well in high-risk populations for early detection of NPC. Since aberrant promoter hypermethylation of tumor suppressor genes (TSGs) is widely considered to be an important epigenetic change in early carcinogenesis, this study identified a panel of methylation markers for early detection of NPC and also assessed the clinical usefulness of these markers with noninvasive plasma specimens instead of biopsies. MS-HRM assays were carried out to assess the methylation status of a selected panel of four TSGs (RASSF1A, WIF1, DAPK1 and RARβ2) in biopsies, NP brushings and cell-free plasma from NPC patients. High-risk and cancer-free groups were used as controls. DNA methylation panel showed higher sensitivity and specificity than EBV DNA marker in cell-free plasma from NPC patients at early Stages (I and II) and in addition to the EBV DNA marker, MS-HRM test for plasma and NP brushing DNA methylation significantly increased the detection rate at all NPC stages as well as local recurrence, using this selected four-gene panel (p<0.05). MS-HRM assay on a selected gene panel has great potential to become a noninvasive and complementary test for NPC early and recurrent detection in combination with the EBV DNA test to increase the sensitivity for NPC detection at an early stage.

Noorlag R, van Kempen PM, Moelans CB, et al.
Promoter hypermethylation using 24-gene array in early head and neck cancer: better outcome in oral than in oropharyngeal cancer.
Epigenetics. 2014; 9(9):1220-7 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
Silencing of tumor suppressor genes (TSGs) by DNA promoter hypermethylation is an early event in carcinogenesis and a potential target for personalized cancer treatment. In head and neck cancer, little is known about the role of promoter hypermethylation in survival. Using methylation specific multiplex ligation-dependent probe amplification (MS-MLPA) we investigated the role of promoter hypermethylation of 24 well-described genes (some of which are classic TSGs), which are frequently methylated in different cancer types, in 166 HPV-negative early oral squamous cell carcinomas (OSCC), and 51 HPV-negative early oropharyngeal squamous cell carcinomas (OPSCC) in relation to clinicopathological features and survival. Early OSCC showed frequent promoter hypermethylation in RARB (31% of cases), CHFR (20%), CDH13 (13%), DAPK1 (12%), and APC (10%). More hypermethylation (≥ 2 genes) independently correlated with improved disease specific survival (hazard ratio 0.17, P = 0.014) in early OSCC and could therefore be used as prognostic biomarker. Early OPSCCs showed more hypermethylation of CDH13 (58%), TP73 (14%), and total hypermethylated genes. Hypermethylation of two or more genes has a significantly different effect on survival in OPSCC compared with OSCC, with a trend toward worse instead of better survival. This could have a biological explanation, which deserves further investigation and could possibly lead to more stratified treatment in the future.

Drilon A, Sugita H, Sima CS, et al.
A prospective study of tumor suppressor gene methylation as a prognostic biomarker in surgically resected stage I to IIIA non-small-cell lung cancers.
J Thorac Oncol. 2014; 9(9):1272-7 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
INTRODUCTION: While retrospective analyses support an association between early tumor recurrence and tumor suppressor gene promoter methylation in early-stage non-small-cell lung cancers (NSCLCs), few studies have investigated this question prospectively.
METHODS: Primary tumor tissue from patients with resected pathologic stage I to IIIA NSCLCs was collected at the time of surgery and analyzed for promoter methylation via methylation-specific reverse transcriptase polymerase chain reaction (MethyLight). The primary objective was to determine an association between promoter methylation of 10 individual tumor suppressor genes (CDKN2A, CDH13, RASSF1, APC, MGMT, GSTP1, DAPK1, WIF1, SOCS3, and ADAMTS8) and recurrence-free survival (RFS), with the secondary objectives of determining association with overall survival (OS), and relation to clinical or pathologic features.
RESULTS: A total of 107 patients had sufficient tumor tissue for successful promoter methylation analysis. Majority of patients were former/current smokers (88%) with lung adenocarcinoma (78%) and pathologic stage I disease (62%). Median follow-up was 4 years. When controlled for pathologic stage, promoter methylation of the individual genes CDKN2A, CDH13, RASSF1, APC, MGMT, GSTP1, DAPK1, WIF1, and ADAMTS8 was not associated with RFS. Promoter methylation of the same genes was not associated with OS except for DAPK1 which was associated with improved OS (p = 0.03). The total number of genes with methylated promoters did not correlate with RFS (p = 0.89) or OS (p = 0.55).
CONCLUSION: Contrary to data established by previous retrospective series, tumor suppressor gene promoter methylation (CDKN2A, CDH13, RASSF1, APC, MGMT, GSTP1, DAPK1, WIF1, and ADAMTS8) was not prognostic for early tumor recurrence in this prospective study of resected NSCLCs.

Millares L, Rosell A, Setó L, et al.
Variability in the measurement of the methylation status of lung cancer-related genes in bronchial secretions.
Oncol Rep. 2014; 32(4):1435-40 [PubMed] Related Publications
Assessment of the methylation status of genes related to the development of lung cancer (LC) in bronchial secretions has been proposed as a biomarker for early detection. Several techniques are available to detect gene methylation, and the method chosen may have an effect on the results. A cross-sectional study was conducted in which the methylation status of DAPK, CDKN2A (p16) and RASSF1A genes in sputum and bronchial washing (BW) from subjects at risk for LC was analyzed. The methylation results of both samples were compared, considering BW as the reference. Results obtained by methylation-sensitive PCR (MSP) were validated by methylation-sensitive high-resolution melting (MS-HRM). The methylation results obtained in sputum and BW samples did not show statistically significant differences for any of the three genes analyzed in 65 subjects (McNemar test>0.05). Concordant results between sputum and BW were found in 40 patients for DAPK (61%), in 52 patients for p16 (80%) and in 63 patients for RASSF1 (97%). More methylated samples were found in BW, however, and sputum sensitivities and specificities for the identification of methylation status were 44 and 72% for DAPK gene, 21 and 94% for p16 and 100 and 98% for RASSF1A, respectively. When MSP results were validated by MS-HRM, DAPK and p16 gene samples methylated by MSP appeared to be unmethylated by MS-HRM. One sample showing methylation of RASSF1A gene also showed methylation when tested following MS-HRM procedure. Sputum and BW samples may be considered equally valid for the identification of methylated genes in bronchial secretions. The low sensitivity of sputum for the assessment of the methylation status of DAPK and p16 genes, however, suggests that the analysis of two or more sputum samples, or of a BW obtained semi-invasively, would be needed to attain higher reliability, together with the use of confirmatory techniques for positive results.

van Kempen PM, van Bockel L, Braunius WW, et al.
HPV-positive oropharyngeal squamous cell carcinoma is associated with TIMP3 and CADM1 promoter hypermethylation.
Cancer Med. 2014; 3(5):1185-96 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
Oropharyngeal squamous cell carcinoma (OPSCC) is associated with human papillomavirus (HPV) in a proportion of tumors. HPV-positive OPSCC is considered a distinct molecular entity with a prognostic advantage compared to HPV-negative cases. Silencing of cancer-related genes by DNA promoter hypermethylation may play an important role in the development of OPSCC. Hence, we examined promoter methylation status in 24 common tumor suppressor genes in a group of 200 OPSCCs to determine differentially methylated genes in HPV-positive versus HPV-negative primary OPSCC. Methylation status was correlated with HPV status, clinical features, and patient survival using multivariate methods. Additionally, methylation status of 16 cervical squamous cell carcinomas (SCC) was compared with HPV-positive OPSCC. Using methylation-specific probe amplification, HPV-positive OPSCC showed a significantly higher cumulative methylation index (CMI) compared to HPV-negative OPSCC (P=0.008). For the genes CDH13, DAPK1, and RARB, both HPV-positive and HPV-negative OPSCC showed promoter hypermethylation in at least 20% of the tumors. HPV status was found to be an independent predictor of promoter hypermethylation of CADM1 (P < 0.001), CHFR (P = 0.027), and TIMP3 (P < 0.001). CADM1 and CHFR showed similar methylation patterns in OPSCC and cervical SCC, but TIMP3 showed no methylation in cervical SCC in contrast to OPSCC. Methylation status of neither individual gene nor CMI was associated with survival. These results suggest that HPV-positive tumors are to a greater extent driven by promotor hypermethylation in these tumor suppressor genes. Especially CADM1 and TIMP3 are significantly more frequently hypermethylated in HPV-positive OPSCC and CHFR in HPV-negative tumors.

Leong KJ, Beggs A, James J, et al.
Biomarker-based treatment selection in early-stage rectal cancer to promote organ preservation.
Br J Surg. 2014; 101(10):1299-309 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND: Total mesorectal excision (TME) remains commonplace for T1-2 rectal cancer owing to fear of undertreating a small proportion of patients with node-positive disease. Molecular stratification may predict cancer progression. It could be used to select patients for organ-preserving surgery if specific biomarkers were validated.
METHODS: Gene methylation was quantified using bisulphite pyrosequencing in 133 unirradiated rectal cancer TME specimens. KRAS mutation and microsatellite instability status were also defined. Molecular parameters were correlated with histopathological indices of disease progression. Predictive models for nodal metastasis, lymphovascular invasion (LVI) and distant metastasis were constructed using a multilevel reverse logistic regression model.
RESULTS: Methylation of the retinoic acid receptor β gene, RARB, and that of the checkpoint with forkhead and ring finger gene, CHFR, was associated with tumour stage (RARB: 51·9 per cent for T1-2 versus 33·9 per cent for T3-4, P < 0·001; CHFR: 5·5 per cent for T1-2 versus 12·6 per cent for T3-4, P = 0·005). Gene methylation associated with nodal metastasis included RARB (47·1 per cent for N- versus 31·7 per cent for N+; P = 0·008), chemokine ligand 12, CXCL12 (12·3 per cent for N- versus 8·9 per cent for N+; P = 0·021), and death-associated protein kinase 1, DAPK1 (19·3 per cent for N- versus 12·3 per cent for N+; P = 0·022). RARB methylation was also associated with LVI (45·1 per cent for LVI- versus 31·7 per cent for LVI+; P = 0·038). Predictive models for nodal metastasis and LVI achieved sensitivities of 91·1 and 85·0 per cent, and specificities of 55·3 and 45·3 per cent, respectively.
CONCLUSION: This methylation biomarker panel provides a step towards accurate discrimination of indolent and aggressive rectal cancer subtypes. This could offer an improvement over the current standard of care, whereby fit patients are offered radical surgery.

Chung CL, Tsai HP, Tsai CY, et al.
Differential hypermethylation of death-associated protein kinase promoter in central neurocytoma and oligodendroglioma.
Biomed Res Int. 2014; 2014:506458 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND: Central neurocytoma and oligodendroglioma are rare tumors of the central nervous system. However, diagnosis between these two types of tumors is challenging due to their many cytological and histological similarities. Death-associated protein kinase (DAPK) is a calcium/calmodulin-regulated serine/threonine protein kinase involved in many apoptosis pathways, and repressed expression of DAPK by promoter hypermethylation has been found in a variety of human cancers. The purpose of this study was to assess DAPK protein expression and promoter hypermethylation in central neurocytoma and oligodendroglioma.
METHOD: Central neurocytoma and oligodendroglioma samples were obtained from age- and sex-matched patients. DAPK protein expression was performed using immunohistochemical assays in formalin-fixed, paraffin-embedded sections. DAPK promoter hypermethylation was carried out using bisulfite-modified genomic DNA in methylation-specific PCR followed by separation in agarose gels.
FINDINGS: A statistically significant difference (P = 0.021) in DAPK promoter hypermethylation between central neurocytoma (76.9%) and oligodendroglioma (20%) was observed. High levels of DAPK protein expression were generally found in oligodendroglioma (90%), compared with 38.5% in central neurocytoma (P = 0.054; not statistically significant). There was an inverse correlation between DAPK protein expression and DAPK promoter hypermethylation in the cohort of 23 patients (P = 0.002).
CONCLUSIONS: The results show that DAPK promoter hypermethylation and repressed expression of DAPK protein were more common in central neurocytoma than in oligodendroglioma. Thus, DAPK promoter hypermethylation could be useful for differential diagnosis between these two types of tumors, whereas DAPK protein expression might be less predictive. The role of DAPK promoter hypermethylation in the pathogenesis of central neurocytoma warrants further study.

Krajnović M, Jovanović MP, Mihaljević B, et al.
Hypermethylation of p15 gene in diffuse - large B-cell lymphoma: association with less aggressiveness of the disease.
Clin Transl Sci. 2014; 7(5):384-90 [PubMed] Related Publications
In this study, methylation-specific polymerase chain reaction was used to investigate the potential prognostic significance of the methylation status of p15, p16, MGMT, and DAPK genes in 51 specimens of diffuse large B-cell lymphoma (DLBCL). Hypermethylation of p15 gene was significantly more prevalent in patients without relapse (p = 0.001) and there was a trend toward more frequent presence of p15 methylation in patients without death outcome within 5-year follow-up period (p = 0.086) Also, there was a trend toward accumulation of p15 methylation with favorable clinicopathological parameters including: age ≤ 60 years (p = 0.091), normal levels of lactate dehydrogenase (p = 0.090), Eastern Cooperative Oncology Group performance status < 2 (p = 0.095), and low/intermediate low International Prognostic Index (p = 0.076). In the female group and group of the patients without bulky tumor mass, treated with chemotherapeutic regimens including rituximab, methylation of p15 was significantly related to longer overall survival (p = 0.036 and 0.027, respectively). Our results suggest that promoter methylation of p15 gene could have prognostic value in DLBCL patients treated with rituximab when used in combination with gender and tumor size.

Giachelia M, Bozzoli V, D'Alò F, et al.
Quantification of DAPK1 promoter methylation in bone marrow and peripheral blood as a follicular lymphoma biomarker.
J Mol Diagn. 2014; 16(4):467-76 [PubMed] Related Publications
Hypermethylation of DAPK1 promoter gene was found to be a frequent epigenetic alteration in follicular lymphoma (FL). We evaluated whether the quantification of DAPK1 methylation in the bone marrow (BM) and peripheral blood of FL patients at diagnosis and during follow-up provides important prognostic information. DAPK1 methylation was quantitated by real-time MethyLight PCR in 107 patients at diagnosis, at end of therapy, and during follow-up. Information on BCL2-IGH rearrangement and clinical characteristics were available for all patients. Aberrant DAPK1 methylation was found in 22 of 26 (85%) lymph node biopsy samples, 62 of 107 (58%) BM specimens, and 25 of 63 (40%) peripheral blood samples at diagnosis. DAPK1 methylation was greater in patients with BM infiltration and a higher Follicular Lymphoma International Prognostic Index score. The presence of aberrant DAPK1 methylation in BM significantly reduced progression-free survival following immunochemotherapy, independent of Follicular Lymphoma International Prognostic Index score. Residual or increased methylation after treatment was associated with an increased risk for relapse. With watchful waiting, greater DAPK1 methylation at diagnosis was associated with a shorter time to antilymphoma treatment. Our study indicates that quantification of DAPK1 methylation represents a prognostically relevant FL biomarker, with promising implications for risk assessment.

Ng HY, Wan TS, So CC, Chim CS
Epigenetic inactivation of DAPK1, p14ARF, mir-34a and -34b/c in acute promyelocytic leukaemia.
J Clin Pathol. 2014; 67(7):626-31 [PubMed] Related Publications
AIM: TP53 mutation frequently occurs in solid cancers but not haematological cancers including acute promyelocytic leukaemia (APL) characterised by t(15;17). Both DAPK1 and p14(ARF) positively regulate p53 whereas miR-34a and -34b/c are direct transcriptional targets of p53. We studied if DNA methylation might contribute to inactivation of gene/microRNA (miRNA) in the TP53 tumour suppressor network.
METHODS: Promoter methylation of DAPK1, p14(ARF), miR-34a and -34b/c were studied in 10 normal bone marrow samples, NB4 cell line and 60 APL primary samples at diagnosis by methylation-specific PCR (MSP).
RESULTS: DAPK1, p14(ARF), miR-34a and -34b/c were completely unmethylated in normal bone marrow samples. DAPK1, miR-34a and -34b/c were completely methylated in NB4. Treatment of NB4 by 5'-Aza-2'-deoxyctidine resulted in promoter demethylation together with re-expression of DAPK1 and both miRNAs. In primary APL samples, methylation of miR-34b/c was detected in 43% in contrast to absence of methylation of DAPK1, p14(ARF) or miR-34a. Overexpression of miR-34b in NB4 resulted in inhibition of proliferation.
CONCLUSIONS: Methylation of DAPK1, miR-34a and -34b/c is tumour-specific, and associated with gene/miRNAs silencing. miR-34b/c is a tumour suppressor miRNA in APL. Methylation of miR-34b/c may contribute to APL leukaemogenesis.

Zhang Q, Hu H, Shi X, Tang W
Knockdown of S100P by lentiviral-mediated RNAi promotes apoptosis and suppresses the colony-formation ability of gastric cancer cells.
Oncol Rep. 2014; 31(5):2344-50 [PubMed] Related Publications
S100P is a putative candidate oncogene in several types of human tumors. However, expression of S100P, its potential role and its clinical significance in gastric cancer remain unclear. In the present study, S100P expression was examined by immunohistochemistry using a tissue microarray. Positive staining for S100P was noted in 77.1% of the cases while 22.9% were negative. In two gastric cancer cell lines, MGC-803 and SGC-7901, S100P expression was knocked down by a lentiviral short hairpin delivery system. The RNA interference-mediated downregulation of S100P expression markedly promoted cell apoptosis and inhibited cell colony-formation ability of the gastric cancer cells. In addition, knockdown of S100P significantly regulated the expression of 12 apoptosis-associated genes with a >1.5-fold change compared with the negative control. Among them, FOS, DDIT3 and FN1 were significantly upregulated, while FASLG, DAPK1, CTNNB1 and CASP2 were notably downregulated following S100P silencing. These results suggest that S100P acts as an oncogenic factor in gastric cancer and is a potential molecular target for gastric cancer gene therapy.

Li FF, Yang Y, Wang XL, et al.
Promoter methylation of DAPK gene may contribute to the pathogenesis of nonsmall cell lung cancer: a meta-analysis.
Tumour Biol. 2014; 35(6):6011-20 [PubMed] Related Publications
We performed a meta-analysis of cohort studies to determine whether promoter methylation of the death-associated protein kinase (DAPK) gene contributes to the pathogenesis of nonsmall cell lung cancer (NSCLC). A range of electronic databases were searched: MEDLINE (1966 ∼ 2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980 ∼ 2013), CINAHL (1982 ∼ 2013), Web of Science (1945 ∼ 2013), and the Chinese Biomedical Database (CBM; 1982 ∼ 2013) without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Crude odds ratio (OR) with 95 % confidence interval (95 % CI) was calculated. Our meta-analysis integrated results from 12 clinical cohort studies that met all inclusion criteria with a total of 1,027 NSCLC patients. We observed that the frequency of DAPK gene methylation in cancer tissues were significantly higher than that in the adjacent normal and benign tissues (cancer tissues vs. benign tissues: OR=8.50, 95 % CI=5.88 ∼ 12.28, P<0.001; cancer tissues vs. adjacent tissues: OR=5.95, 95 % CI=4.11 ∼ 8.60, P<0.001; cancer tissues vs. normal tissues: OR=4.75, 95 % CI=3.28 ∼ 6.87, P<0.001; respectively). Subgroup analysis by ethnicity demonstrated that DAPK gene methylation was closely associated with the development and progression of NSCLC among both Asians and Caucasians (all P<0.05). Furthermore, we conducted a subgroup analysis based on sample source and discovered that DAPK gene methylation was implicated in the pathogenesis of NSCLC in both blood and tissue subgroups (all P<0.05). Our results suggest that DAPK promoter methylation may be involved in NSCLC carcinogenesis. Thus, the detection of aberrant DAPK methylation may be helpful in the diagnosis and prognosis of NSCLC.

Zhang B, Liu S, Zhang Z, et al.
Analysis of BRAF(V600E) mutation and DNA methylation improves the diagnostics of thyroid fine needle aspiration biopsies.
Diagn Pathol. 2014; 9:45 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND: Thyroid nodules with indeterminate cytological features on fine needle aspiration biopsy specimens (FNABs) have a ~20% risk of thyroid cancer. BRAF(V600E) mutation and DNA methylation are useful markers to distinguish malignant thyroid neoplasm from benign. The aim of this study was to determine whether combined detection of BRAF(V600E) mutation and methylation markers on FNABs could improve the diagnostic accuracy of thyroid cancer.
METHODS: Using pyrosequencing and quantitative methylation-specific PCR (Q-MSP) methods, FNABs from 79 and 38 patients with thyroid nodules in training and test groups, respectively, were analyzed for BRAF(V600E) mutation and gene methylation.
RESULTS: BRAF(V600E) mutation was found in 30/42 (71.4%) and 14/20 (70%) FNABs in training and test groups, respectively. All BRAF(V600E)-positive samples were histologically diagnosed as papillary thyroid cancer (PTC) after thyroidectomy. As expected, BRAF mutation was not found in all benign nodules. Moreover, we demonstrated that the five genes, including CALCA, DAPK1, TIMP3, RAR-beta and RASSF1A, were aberrantly methylated in FNABs. Of them, methylation level of DAPK1 in PTCs was significantly higher than that in benign samples (P <0.0001). Conversely, methylation level of RASSF1A in PTCs was significantly lower than that in benign samples (P =0.003). Notably, compared with BRAF mutation testing alone, combined detection of BRAF mutation and methylation markers increased the diagnostic sensitivity and accuracy of PTC with excellent specificity.
CONCLUSION: Our data have demonstrated that combine analysis of BRAF mutation and DNA methylation markers on FNABs may be a useful strategy to facilitate the diagnosis of malignant thyroid neoplasm, particularly PTC.
VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6080878071149177.

Stamatelli A, Vlachou C, Aroni K, et al.
Epigenetic alterations in sporadic basal cell carcinomas.
Arch Dermatol Res. 2014; 306(6):561-9 [PubMed] Related Publications
Basal cell carcinoma (BCC) is the most common malignant human neoplasm characterized by slow growth and virtual absence of metastases. Recently, it has become evident that along with genetic mutations epigenetic alterations play a key role in the pathogenesis of human cancer. We searched for promoter methylation of hMLH1, RASSF1A, DAPK, APC, DCR1 and DCR2 genes and BRAF mutations in BCCs in association with the clinicopathological parameters and the histological subtypes of the tumours. Fifty-two BCCs, 17 FFPE along with 35 fresh tissue samples with matching normal tissues for 26 cases were analyzed by methylation-specific PCR to assess the methylation status of hMLH1, RASSF1A, DAPK, APC, DCR1 and DCR2 genes after sodium bisulfite treatment of the tumour and normal DNA. hMLH1 and DCR1 gene expression was investigated by immunohistochemistry. BRAF mutations were studied by high resolution melting analysis. Methylation was detected at a variable frequency of 44, 33, 32.5, 32 and 14 % of DCR2, APC, DCR1, RASSF1 and DAPK promoters, respectively, whereas methylation of hMLH1 promoter was absent. No BRAF mutations were found. There was no correlation between the frequency of the promoter methylation of the above-mentioned genes and the clinicopathological features or the histological subtypes of the tumours. The relatively high frequency of RASSF1A, DCR1, DCR2 and APC promoter methylation may imply that methylation constitutes an important pathway in the tumourigenesis of BCC that could provide new opportunities in developing epigenetic therapies for BCC patients. Nevertheless, further studies are needed to establish the above-mentioned hypothesis.

Wang LQ, Kwong YL, Wong KF, et al.
Epigenetic inactivation of mir-34b/c in addition to mir-34a and DAPK1 in chronic lymphocytic leukemia.
J Transl Med. 2014; 12:52 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND: TP53 mutation/deletion is uncommon in chronic lymphocytic leukemia (CLL). We postulated that components of TP53-centered tumor suppressor network, miR-34b/c, in addition to DAPK1 and miR-34a might be inactivated by DNA hypermethylation. Moreover, we tested if miR-34b/c methylation might correlate with miR-203 or miR-124-1 methylation in CLL.
METHODS: miR-34b/c, miR-34a and DAPK1 methylation was studied in 11 normal controls, 7 CLL cell lines, and 78 diagnostic CLL samples by methylation-specific polymerase chain reaction. MEC-1 cells were treated with 5-Aza-2'-deoxycytidine for reversal of methylation-associated miRNA silencing. Tumor suppressor properties of miR-34b were demonstrated by over-expression of precursor miR-34b in MEC-1 cells.
RESULTS: miR-34b/c promoter was unmethylated in normal controls, but completely methylated in 4 CLL cell lines. miR-34b/c expression was inversely correlated with miR-34b/c methylation. Different MSP statuses of miR-34b/c, including complete methylation and complete unmethylation, were verified by quantitative bisulfite pyrosequencing. 5-Aza-2'-deoxycytidine treatment resulted in promoter demethylation and miR-34b re-expression in MEC1 cells. Moreover, over-expression of miR-34b resulted in inhibition of cellular proliferation and increased cell death. In primary CLL samples, miR-34a, miR-34b/c and DAPK1 methylation was detected in 2.6%, 17.9% and 34.6% of patients at diagnosis respectively. Furthermore, 39.7%, 3.8% and 2.6% patients had methylation of one, two or all three genes respectively. Overall, 46.2% patients had methylation of at least one of these three genes. Besides, miR-34b/c methylation was associated with methylation of miR-34a (P = 0.03) and miR-203 (P = 0.012) in CLL.
CONCLUSIONS: Taken together, miR-34b/c is a tumor suppressor miRNA frequently methylated, and hence silenced in CLL. Together with DAPK1 methylation, miR-34b/c methylation is implicated in the disruption of the TP53-centered tumor suppressor network. Moreover, the association of miRNA methylation warrants further study.

Bodoor K, Haddad Y, Alkhateeb A, et al.
DNA hypermethylation of cell cycle (p15 and p16) and apoptotic (p14, p53, DAPK and TMS1) genes in peripheral blood of leukemia patients.
Asian Pac J Cancer Prev. 2014; 15(1):75-84 [PubMed] Related Publications
Aberrant DNA methylation of tumor suppressor genes has been reported in all major types of leukemia with potential involvement in the inactivation of regulatory cell cycle and apoptosis genes. However, most of the previous reports did not show the extent of concurrent methylation of multiple genes in the four leukemia types. Here, we analyzed six key genes (p14, p15, p16, p53, DAPK and TMS1) for DNA methylation using methylation specific PCR to analyze peripheral blood of 78 leukemia patients (24 CML, 25 CLL, 12 AML, and 17 ALL) and 24 healthy volunteers. In CML, methylation was detected for p15 (11%), p16 (9%), p53 (23%) and DAPK (23%), in CLL, p14 (25%), p15 (19%), p16 (12%), p53 (17%) and DAPK (36%), in AML, p14 (8%), p15 (45%), p53 (9%) and DAPK (17%) and in ALL, p15 (14%), p16 (8%), and p53 (8%). This study highlighted an essential role of DAPK methylation in chronic leukemia in contrast to p15 methylation in the acute cases, whereas TMS1 hypermethylation was absent in all cases. Furthermore, hypermethylation of multiple genes per patient was observed, with obvious selectiveness in the 9p21 chromosomal region genes (p14, p15 and p16). Interestingly, methylation of p15 increased the risk of methylation in p53, and vice versa, by five folds (p=0.03) indicating possible synergistic epigenetic disruption of different phases of the cell cycle or between the cell cycle and apoptosis. The investigation of multiple relationships between methylated genes might shed light on tumor specific inactivation of the cell cycle and apoptotic pathways.

Kupčinskaitė-Noreikienė R, Skiecevičienė J, Jonaitis L, et al.
CpG island methylation of the MLH1, MGMT, DAPK, and CASP8 genes in cancerous and adjacent noncancerous stomach tissues.
Medicina (Kaunas). 2013; 49(8):361-6 [PubMed] Related Publications
BACKGROUND AND OBJECTIVE. Many factors are involved in the development of gastric adenocarcinoma. The CpG island methylation of apoptosis and mismatch repair genes by the loss of their function is important in gastric adenocarcinoma. The aim of this study was to determine the methylation frequency of MLH1, MGMT, CASP8, and DAPK in cancerous and adjacent noncancerous stomach tissues, to determine possible associations with the selected clinicopathological characteristics, and to identify possible correlation between the methylation of individual genes. MATERIAL AND METHODS. The methylation status of MLH1, MGMT, DAPK, and CASP8 was investigated in 69 patients with gastric adenocarcinoma by using methylation-specific polymerase chain reaction. The associations between patients' clinical characteristics and methylation status were assessed. RESULTS. The methylation frequency of the MLH1, DAPK, MGMT, and CASP8 gene promoters in cancerous and adjacent noncancerous tissues was 31.9% and 27.5%; 47.8% and 46.4%; 36.2% and 44.9%; and 5.8% and 5.8%, respectively, but the differences were not significant. There was no significant association between the methylation status of the mentioned genes and clinicopathological characteristics, such as age, sex, tumor type by the Lauren classification, degree of differentiation G, and TNM staging. An inverse correlation between the methylation of the DAPK and MLH1 gene promoters in cancerous and surrounding noncancerous tissues was found. CONCLUSIONS. The methylation of the MLH1, MGMT, DAPK, and CASP8 genes was found to occur both in cancerous and noncancerous stomach tissues. These findings provide additional insights into gene methylation patterns in gastric adenocarcinoma.

Vasiljević N, Scibior-Bentkowska D, Brentnall AR, et al.
Credentialing of DNA methylation assays for human genes as diagnostic biomarkers of cervical intraepithelial neoplasia in high-risk HPV positive women.
Gynecol Oncol. 2014; 132(3):709-14 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
OBJECTIVE: Testing for high risk human papillomavirus (HR-HPV) is increasing; however due to limitations in specificity there remains a need for better triage tests. Research efforts have focused recently on methylation of human genes which show promise as diagnostic classifiers.
METHODS: Methylation of 26 genes: APC, CADM1, CCND2, CDH13, CDKN2A, CTNNB1, DAPK1, DPYS, EDNRB, EPB41L3, ESR1, GSTP1, HIN1, JAM3, LMX1, MAL, MDR1, PAX1, PTGS2, RARB, RASSF1, SLIT2, SOX1, SPARC, TERT and TWIST1 was measured by pyrosequencing in cytology specimens from a pilot set of women with normal or cervical intraepithelial neoplasia grade 3 (CIN3) histology. Six genes were selected for testing in Predictors 1, a colposcopy referral study comprising 799 women. The three genes EPB41L3, DPYS and MAL were further tested in a second colposcopy referral study, Predictors 2, comprising 884 women.
RESULTS: The six genes selected from the pilot: EPB41L3, EDNRB, LMX1, DPYS, MAL and CADM1 showed significantly elevated methylation in CIN2 and CIN3 (CIN2/3) versus ≤CIN1 in Predictors 1 (p<0.01). Highest methylation was observed in cancer tissues. EPB41L3 methylation was the best single classifier of CIN2/3 in both HR-HPV positive (p<0.0001) and negative samples (p=0.02). Logistic regression modeling showed that other genes did not add significantly to EPB41L3 and in Predictors 2, its classifier value was validated with AUC 0.69 (95% CI 0.65-0.73).
CONCLUSION: Several methylated genes show promise for detecting CIN2/3 of which EPB41L3 seems the best. Methylated human gene biomarkers used in combination may be clinically useful for triage of women with HR-HPV infections.

Cho Y, Turner ND, Davidson LA, et al.
Colon cancer cell apoptosis is induced by combined exposure to the n-3 fatty acid docosahexaenoic acid and butyrate through promoter methylation.
Exp Biol Med (Maywood). 2014; 239(3):302-10 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
DNA methylation and histone acetylation contribute to the transcriptional regulation of genes involved in apoptosis. We have demonstrated that docosahexaenoic acid (DHA, 22:6 n-3) and butyrate enhance colonocyte apoptosis. To determine if DHA and/or butyrate elevate apoptosis through epigenetic mechanisms thereby restoring the transcription of apoptosis-related genes, we examined global methylation; gene-specific promoter methylation of 24 apoptosis-related genes; transcription levels of Cideb, Dapk1, and Tnfrsf25; and global histone acetylation in the HCT-116 colon cancer cell line. Cells were treated with combinations of (50 µM) DHA or linoleic acid (18:2 n-6), (5 mM) butyrate or an inhibitor of DNA methyltransferases, and 5-aza-2'-deoxycytidine (5-Aza-dC, 2 µM). Among highly methylated genes, the combination of DHA and butyrate significantly reduced methylation of the proapoptotic Bcl2l11, Cideb, Dapk1, Ltbr, and Tnfrsf25 genes compared to untreated control cells. DHA treatment reduced the methylation of Cideb, Dapk1, and Tnfrsf25. These data suggest that the induction of apoptosis by DHA and butyrate is mediated, in part, through changes in the methylation state of apoptosis-related genes.

Li Y, Geng P, Jiang W, et al.
Enhancement of radiosensitivity by 5-Aza-CdR through activation of G2/M checkpoint response and apoptosis in osteosarcoma cells.
Tumour Biol. 2014; 35(5):4831-9 [PubMed] Related Publications
Radiation resistance is a major problem preventing successful treatment. Therefore, identifying sensitizers is vitally important for radiotherapy success. Epigenetic events such as DNA methylation have been proposed to mediate the sensitivity of tumor therapy. In this study, we investigated the influence of demethylating agent 5-Aza-2'-deoxycytidine (5-Aza-CdR) on the radiosensitivity of human osteosarcoma cell lines. 5-Aza-CdR was capable of sensitizing three osteosarcoma cells to irradiation in a time-dependent manner, with the maximum effect attained by 48 h. Pretreatment with 5-Aza-CdR synchronized cells in G2/M phase of the cell cycle and enhanced irradiation-induced apoptosis compared with irradiation alone in SaOS2, HOS, and U2OS cells. Moreover, 5-Aza-CdR restored mRNA expressions of 14-3-3σ, CHK2, and DAPK-1 in the three cells, accompanied with demethylation of their promoters. These findings demonstrate that demethylation with 5-Aza-CdR increases radiosensitivity in some osteosarcoma cells through arresting cells at G2/M phase and increasing apoptosis, which is partly mediated by upregulation of 14-3-3σ, CHK2, and DAPK-1 genes, suggesting that 5-Aza-CdR may be a potential radiosensitizer to improve the therapy effect in osteosarcoma.

López F, Sampedro T, Llorente JL, et al.
Utility of MS-MLPA in DNA methylation profiling in primary laryngeal squamous cell carcinoma.
Oral Oncol. 2014; 50(4):291-7 [PubMed] Related Publications
OBJECTIVES: Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay is a method that has rarely been exploited in DNA methylation profiling of laryngeal squamous cell carcinoma (LSCC).
MATERIAL AND METHODS: Methylation of the gene was investigated by MS-MLPA in a well-characterized series of 53 LSCC and 30 samples of healthy mucosa. Aberrant promoter hypermethylation was confirmed using bisulfite pyrosequencing, and methylation-specific.
RESULTS: Promoter hypermethylation was observed in 36 of the 53 patients (68%). CDKN2B (28%), APC (17%), RARβ (15%), DAPK1 (11%) and CHFR (11%) were most frequently hypermethylated. Aberrant methylation of CHFR was mainly a late-stage event. Methylation-specific polymerase chain reaction and bisulfite pyrosequencing confirmed aberrant methylation for CDKN2B, APC and DAPK1.
CONCLUSION: Promoter methylation profiling of LSCC using MS-MLPA identified CDKN2B, DAPK1, RARβ, APC, and CHFR as frequent epigenetic events. The clinical implications of these genes as biomarkers are highly relevant as attractive targets for cancer therapy, given the reversible nature of epigenetic gene silencing.

Ratovitski EA
Phospho-ΔNp63α/microRNA network modulates epigenetic regulatory enzymes in squamous cell carcinomas.
Cell Cycle. 2014; 13(5):749-61 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
The tumor protein (TP) p63/microRNAs functional network may play a key role in supporting the response of squamous cell carcinomas (SCC) to chemotherapy. We show that the cisplatin exposure of SCC-11 cells led to upregulation of miR-297, miR-92b-3p, and miR-485-5p through a phosphorylated ΔNp63α-dependent mechanism that subsequently modulated the expression of the protein targets implicated in DNA methylation (DNMT3A), histone deacetylation (HDAC9), and demethylation (KDM4C). Further studies showed that mimics for miR-297, miR-92b-3p, or miR-485-5p, along with siRNA against and inhibitors of DNMT3A, HDAC9, and KDM4C modulated the expression of DAPK1, SMARCA2, and MDM2 genes assessed by the quantitative PCR, promoter luciferase reporter, and chromatin immunoprecipitation assays. Finally, the above-mentioned treatments affecting epigenetic enzymes also modulated the response of SCC cells to chemotherapeutic drugs, rendering the resistant SCC cells more sensitive to cisplatin exposure, thereby providing the groundwork for novel chemotherapeutic venues in treating patients with SCC.

Pease M, Ling C, Mack WJ, et al.
The role of epigenetic modification in tumorigenesis and progression of pituitary adenomas: a systematic review of the literature.
PLoS One. 2013; 8(12):e82619 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND: Pituitary adenomas (PAs) are commonly occurring neoplasms with diverse endocrine and neurological effects. Although somatic gene mutations are uncommon in sporadic PAs, recent studies lend support to epigenetic modification as a potential cause of tumorigenesis and tumor progression.
METHODS: A systematic literature review of the PubMed and Google Scholar databases was conducted to identify abstracts (n=1,082) pertaining to key targets and mechanisms implicated in epigenetic dysregulation of PAs published between 1993-2013. Data regarding histopathological subtype, target genes, mode of epigenetic modification, and clinical correlation were recorded and analyzed.
RESULTS: Of the 47 that studies met inclusion criteria and focused on epigenomic assessment of PAs, only 2 were genome-scale analyses. Current evidence supports epigenetic alteration in at least 24 PA genes, which were categorized into four groups based on function and epigenetic alteration: 1) Sixteen tumor suppressor genes silenced via DNA methylation; 2) Two oncogenes overexpressed via histone acetylation and hypomethylation; 3) Three imprinted genes with selective allelic silencing; and 4) One epigenome writer inducing abnormal genome-scale activity and 5) Two transcription regulators indirectly modifying the genome. Of these, 5 genes (CDKN2A, GADD45y, FGFR2, caspase-8, and PTAG) showed particular susceptibility to epigenetic modification, with abnormal DNA methylation in >50% of PA samples. Several genes displayed correlations between epigenetic modification and clinically relevant parameters, including invasiveness (CDKN2A; DAPK; Rb1), sex (MAGE-A3), tumor size (GNAS1), and histopathological subtype (CDKN2A; MEG3; p27; RASSF1A; Rb1).
CONCLUSIONS: Epigenetic modification of selected PA genes may play a key role in tumorigenesis and progression, which may translate into important diagnostic and therapeutic applications.

Rettori MM, de Carvalho AC, Longo AL, et al.
TIMP3 and CCNA1 hypermethylation in HNSCC is associated with an increased incidence of second primary tumors.
J Transl Med. 2013; 11:316 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND: Hypermethylation in the promoter regions is associated with the suppression of gene expression and has been considered a potential molecular marker for several tumor types, including head and neck squamous cell carcinomas (HNSCC).
METHODS: To evaluate the gene hypermethylation profile as a prognostic marker, this retrospective study used a QMSP approach to determine the methylation status of 19 genes in 70 HNSCC patients.
RESULTS: The methylation profile analysis of primary HNSCC revealed that genes CCNA1, DAPK, MGMT, TIMP3 and SFRP1 were frequently hypermethylated, with high specificity and sensitivity. TIMP3 and CCNA1 hypermethylation was significantly associated with lower rates of second primary tumor-free survival (p = 0.007 and p = 0.001; log-rank test, respectively).
CONCLUSION: This study, for the first time, presents CCNA1 and TIMP3 hypermethylation as a helpful tool to identify HNSCC subjects at risk of developing second primary carcinomas.

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