Real-time Quantitative Methylation-specific PCR Research Articles

Diagnostic value of neuronal pentraxin II methylation in patients with pancreatic cancer: Meta-analysis.

Pancreatic cancer (PC) is a devasting disease of which mortality almost parallels its incidence. PC tissue may express aberrantly methylated neuronal pentraxin II (NPTX2), but it is unclear what the consequences of this are. We systematically searched PubMed, Web of Science, the Chinese National Knowledge Infrastructure (CNKI), from inception to July 15, 2020, to identify if the detection of methylated NPTX2 have sufficient sensitivity and specificity to identify PC from other benign pancreatic diseases. Majority of the studies obtained samples from pancreatic juice by endoscopy or surgery and composed of population with chronic pancreatitis, benign cystic lesion, intraductal papillary mucinous neoplasm, and healthy controls. Our results demonstrated that the diagnostic value of methylated NPTX2 is of widely various sensitivity and specificity and it shown higher specificity in differentiate PC from benign diseases. The lab method of quantitative real-time methylation-specific PCR (QMSP) has higher specificity than real-time methylation-specific PCR (MSP) in detecting the indicator. NPTX2 methylation could serve as a promising molecular biomarker for pancreatic cancer diagnosis, for its high diagnostic value in differentiating pancreatic cancer from benign pancreatic disease with the lab method. The variable sensitivity of methylated NPTX2 was multifactorial, and it must be promoted before applied as screening test in clinical practice. Furthermore, experiments on methylated NPTX2 were needed to expanded for lower the heterogeneity.

Identification and validation of obesity-related gene LEP methylation as a prognostic indicator in patients with acute myeloid leukemia

BackgroundObesity confers enhanced risk for multiple diseases including cancer. The DNA methylation alterations in obesity-related genes have been implicated in several human solid tumors. However, the underlying role and clinical implication of DNA methylation of obesity-related genes in acute myeloid leukemia (AML) has yet to be elucidated.ResultsIn the discovery stage, we identified that DNA methylation-associated LEP expression was correlated with prognosis among obesity-related genes from the databases of The Cancer Genome Atlas. In the validation stage, we verified that LEP hypermethylation was a frequent event in AML by both targeted bisulfite sequencing and real-time quantitative methylation-specific PCR. Moreover, LEP hypermethylation, correlated with reduced LEP expression, was found to be associated with higher bone marrow blasts, lower platelets, and lower complete remission (CR) rate in AML. Importantly, survival analysis showed that LEP hypermethylation was significantly associated with shorter overall survival (OS) in AML. Moreover, multivariate analysis disclosed that LEP hypermethylation was an independent risk factor affecting CR and OS among non-M3 AML. By clinical and bioinformatics analysis, LEP may be also regulated by miR-517a/b expression in AML.ConclusionsOur findings indicated that the obesity-related gene LEP methylation is associated with LEP inactivation, and acts as an independent prognostic predictor in AML.

Genome-wide methylation sequencing identifies progression-related epigenetic drivers in myelodysplastic syndromes

The potential mechanism of myelodysplastic syndromes (MDS) progressing to acute myeloid leukemia (AML) remains poorly elucidated. It has been proved that epigenetic alterations play crucial roles in the pathogenesis of cancer progression including MDS. However, fewer studies explored the whole-genome methylation alterations during MDS progression. Reduced representation bisulfite sequencing was conducted in four paired MDS/secondary AML (MDS/sAML) patients and intended to explore the underlying methylation-associated epigenetic drivers in MDS progression. In four paired MDS/sAML patients, cases at sAML stage exhibited significantly increased methylation level as compared with the matched MDS stage. A total of 1090 differentially methylated fragments (DMFs) (441 hypermethylated and 649 hypomethylated) were identified involving in MDS pathogenesis, whereas 103 DMFs (96 hypermethylated and 7 hypomethylated) were involved in MDS progression. Targeted bisulfite sequencing further identified that aberrant GFRA1, IRX1, NPY, and ZNF300 methylation were frequent events in an additional group of de novo MDS and AML patients, of which only ZNF300 methylation was associated with ZNF300 expression. Subsequently, ZNF300 hypermethylation in larger cohorts of de novo MDS and AML patients was confirmed by real-time quantitative methylation-specific PCR. It was illustrated that ZNF300 methylation could act as a potential biomarker for the diagnosis and prognosis in MDS and AML patients. Functional experiments demonstrated the anti-proliferative and pro-apoptotic role of ZNF300 overexpression in MDS-derived AML cell-line SKM-1. Collectively, genome-wide DNA hypermethylation were frequent events during MDS progression. Among these changes, ZNF300 methylation, a regulator of ZNF300 expression, acted as an epigenetic driver in MDS progression. These findings provided a theoretical basis for the usage of demethylation drugs in MDS patients against disease progression.

Robust performance of a novel stool DNA test of methylated SDC2 for colorectal cancer detection: a multicenter clinical study

Background and AimsStool DNA testing is an emerging and attractive option for colorectal cancer (CRC) screening. We previously evaluated the feasibility of a stool DNA (sDNA) test of methylated SDC2 for CRC detection. The aim of this study was to assess its performance in a multicenter clinical trial setting.MethodsEach participant was required to undergo a sDNA test and a reference colonoscopy. The sDNA test consists of quantitative assessment of methylation status of SDC2 promoter. Results of real-time quantitative methylation-specific PCR were dichotomized as positive and negative, and the main evaluation indexes were sensitivity, specificity, and kappa value. All sDNA tests were performed and analyzed independently of colonoscopy.ResultsAmong the 1110 participants from three clinical sites analyzed, 359 and 38 were diagnosed, respectively, with CRC and advanced adenomas by colonoscopy. The sensitivity of the sDNA test was 301/359 (83.8%) for CRC, 16/38 (42.1%) for advanced adenomas, and 134/154 (87.0%) for early stage CRC (stage I–II). Detection rate did not vary significantly according to age, tumor location, differentiation, and TNM stage, except for gender. The follow-up testing of 40 postoperative patients with CRC returned negative results as their tumors had been surgically removed. The specificity of the sDNA test was 699/713 (98.0%), and unrelated cancers and diseases did not seem to interfere with the testing. The kappa value was 0.84, implying an excellent diagnostic consistency between the sDNA test and colonoscopy.ConclusionNoninvasive sDNA test using methylated SDC2 as the exclusive biomarker is a clinically viable and accurate CRC detection method.Chinese Clinical Trial RegistryChi-CTR-TRC-1900026409, retrospectively registered on October 8, 2019; http://www.chictr.org.cn/edit.aspx?pid=43888&htm=4.

Detection of Promoter DNA Methylation in Urine and Plasma Aids the Detection of Non-Small Cell Lung Cancer.

Low-dose CT screening can reduce lung cancer-related mortality. However, CT screening has an FDR of nearly 96%. We sought to assess whether urine samples can be a source for DNA methylation-based detection of non-small cell lung cancer (NSCLC). This nested case-control study of subjects with suspicious nodules on CT imaging obtained plasma and urine samples preoperatively. Cases (n = 74) had pathologic confirmation of NSCLC. Controls (n = 27) had a noncancer diagnosis. We detected promoter methylation in plasma and urine samples using methylation on beads and quantitative methylation-specific real-time PCR for cancer-specific genes (CDO1, TAC1, HOXA7, HOXA9, SOX17, and ZFP42). DNA methylation at cancer-specific loci was detected in both plasma and urine, and was more frequent in patients with cancer compared with controls for all six genes in plasma and in CDO1, TAC1, HOXA9, and SOX17 in urine. Univariate and multivariate logistic regression analysis showed that methylation detection in each one of six genes in plasma and CDO1, TAC1, HOXA9, and SOX17 in urine were significantly associated with the diagnosis of NSCLC, independent of age, race, and smoking pack-years. When methylation was detected for three or more genes in both plasma and urine, the sensitivity and specificity for lung cancer diagnosis were 73% and 92%, respectively. DNA methylation-based biomarkers in plasma and urine could be useful as an adjunct to CT screening to guide decision-making regarding further invasive procedures in patients with pulmonary nodules.

Peptidyl Arginine Deiminase Type 4 Gene Promoter Hypo-Methylation in Rheumatoid Arthritis.

Protein citrullination is carried out by peptidylarginine deiminase type 4 (PAD4) enzyme. As a consequence of this process, post-translationally modified proteins are formed that become antigens for anti-citrullinated protein antibodies (ACPA). The study aimed at identifying whether the PADI4 gene is subject to epigenetic regulation through methylation of its promoter region, whether the degree of methylation differs in healthy individuals vs. rheumatoid arthritis (RA) patients and changes in correlation with ACPA, anti-PAD4 and disease activity. A total of 125 RA patients and 30 healthy controls were enrolled. Quantitative real-time methylation-specific PCR was used to analyze the methylation status. ACPA and anti-PAD4 antibodies were determined in serum by enzyme-linked immunosorbent immunoassay. The differences were observed in the degree of PADI4 gene promoter methylation between RA patients and HC, along with an upward trend for the methylation in RA, which was inversely proportional to the disease activity. A weak or modest negative correlation between the degree of PADI4 gene methylation and anti-PAD4, disease activity score (DAS28) and ACPA level has been found. The elevated methylation is associated with lower disease activity, lower levels of ACPA and aPAD4. The methylation degree in this area is growing up during effective treatment and might play a role in the RA pathophysiology and therefore could be a future therapeutic target.

Hypermethylation of the miR-155 gene in the whole blood and decreased plasma level of miR-155 in rheumatoid arthritis.

ObjectivesmiR-155 plays a critical role in the inflammatory process and in diseases such as rheumatoid arthritis (RA). miR155 gene expression is regulated by its gene promoter region CpG island methylation. Previous studies have shown inconsistent changes in circulating levels of mir-155 in RA patients. The aims of our study were to evaluate miR-155 levels in plasma, to investigate its gene methylation level, and to correlate these levels with RA disease activity.MethodsOne hundred and twenty-five patients with RA, and 30 age and sex-matched healthy controls (HC) were enrolled. Whole blood and plasma samples were collected and stored at -80°C until analysis. DAS28 score at the time of the blood draw was used to assess RA disease activity. The methylation status of miR-155 host gene was determined in whole blood by quantitative real-time methylation-specific PCR (qPCR). miR-155 expression levels were evaluated by quantitative reverse transcription PCR.ResultsWe found significantly lower circulating miR155 levels in RA patients compared to HC. Interestingly, the miR-155 gene methylation level was significantly higher in RA patients than in HC. miR-155 levels did not correlate with ACPA or RF positivity or disease activity.ConclusionsWe show here higher miR-155 methylation in whole blood and lower plasma miR155 expression in RA patients in comparison to HC. The evaluation of miR-155 host gene methylation status or miR155 plasma level might be a potentially useful marker in RA determination.

Methylation analysis of NPTX2 and SH2D5 genes in chronic migraine: A case–control study

Background: Methylation of two CpG sites related to neuronal pentraxin II protein (NPTX2) and SH2 domain containing 5 protein (SH2D5), corresponding to two neuroplasticity genes, has been associated to headache chronification. We aimed to investigate the epigenetic modification of these two genes in chronic migraine (CM). Methods: We conducted a case–control study in which the DNA of 305 age- and sex-matched subjects classified according to the International Classification of Headache Disorders version beta (ICHD-III β) in CM (109), episodic migraine (EM; n = 98), and healthy controls (HC; 98) was analyzed. Real-time quantitative methylation-specific PCR was performed using specific methylation primers for two representative CpG sites within these genes. Results: We found no significant differences in methylation level between CM, EM, and HC in the first exon of the NPTX2 gene nor in the 5′ upstream region of the SH2D5 gene. Methylation level in the first exon of the NPTX2 showed a low correlation with age ( r = 0.266; p < 0.005). Conclusion: We did not find methylation level differences in analyzed regions related to NPTX2 and SH2D5 in our CM sample. Despite the potential relevance of neuroplasticity genes in headache chronification, we conclude that CM is a more heterogeneous clinical diagnosis than desired and that an epigenetic marker remains elusive.

BMP3 suppresses colon tumorigenesis via ActRIIB/SMAD2-dependent and TAK1/JNK signaling pathways

BackgroundBMP3 gene is often found hypermethylated and hence inactivated in several types of cancers including colorectal cancer (CRC), indicating that it has a suppressor role in carcinogenesis. Though BMP3 is a reliable biomarker for screening CRC, the molecular mechanism of BMP3 in carcinogenesis remains largely unknown.MethodsThe expression level of BMP3 was examined by immunohistochemistry staining and western blot. Methylation-specific PCR (MSP) and real-time quantitative MSP were used to test the hypermethylation status of BMP3 gene. Analyses of BMP3 function in colon cancer cell proliferation, migration, invasion, and apoptosis were performed using HCT116 and KM12 cells. BMP3 was further knocked down or overexpressed in CRC cells, and the effects on cell growth of xenograft tumors in nude mice were assessed. Co-immunoprecipitation and immunofluorescence staining were used to analyze the association between BMP3 and BMPR2 or BMP3 and ActRIIB. Microarray analysis was performed to identify most differentially expressed genes and pathways regulated by BMP3. The BMP3-regulated SMAD2-dependent signaling pathway and TAK1/JNK signal axes were further investigated by quantitative PCR and western blot.ResultsBMP3 gene was hypermethylated and its expression was downregulated in both CRC tissues and cell lines. Expressing exogenous BMP3 in HCT116 inhibited cell growth, migration, and invasion and increased rate of apoptosis both in vitro and in vivo. However, shRNA-mediated attenuation of endogenous BMP3 in KM12 reversed such inhibitory and apoptotic effects. Furthermore, BMP3 could bind to ActRIIB, an activin type II receptor at the cellular membrane, thereby activating SMAD2-dependent pathway and TAK1/JNK signal axes to regulate downstream targets including caspase-7, p21, and SMAD4 that play crucial roles in cell cycle control and apoptosis.ConclusionsOur study reveals a previously unknown mechanism of BMP3 tumor suppression in CRC and provides a rationale for future investigation of BMP3 as a potential target for the development of novel therapeutic agents to fight CRC.

SOX30 methylation correlates with disease progression in patients with chronic myeloid leukemia.

BackgroundOur previous study has reported that aberrant SOX30 methylation was associated with poor prognosis in AML, and it correlated with disease progression in MDS. Herein, we further determined SOX30 methylation and its clinical significance in the other myeloid malignance – chronic myeloid leukemia (CML).MethodsSOX30 methylation was examined by real-time quantitative methylation-specific PCR and bisulfite sequencing PCR, whereas SOX30 expression was detected by real-time quantitative PCR.ResultsSOX30 methylation was identified in 11% (10/95) CML patients. SOX30 methylation was associated with lower hemoglobin and platelets (P=0.006 and 0.032, respectively). Importantly, significant differences were observed in the distributions of clinical stages and cytogenetics (P=0.006 and 0.002, respectively). The frequency of SOX30 methylation in chronic phase (CP) stage occurred with lowest frequency (4/74, 5%), higher in accelerated phase (AP) stage (1/7, 14%), and the highest in blast crisis (BC) stage (12/31, 39%). In addition, SOX30 methylated patients tended to have a higher level of BCR-ABL transcript than SOX30 non-methylated patients (P=0.063). In two paired CML patients, SOX30 methylation showed lower density in CP stage (19% and 17%, respectively), and was significantly increased in BC stage (89% and 69%, respectively) during disease progression. Additionally, SOX30 methylated CML patients presented a lower SOX30 transcript level than SOX30 non-methylated CML patients (P=0.046).ConclusionOur study revealed that SOX30 methylation correlated with disease progression in chronic myeloid leukemia.

Clinical Study of SCIN Expression and Dromoter Methylation in Patients with Chronic Myeloid Leukemia

To investigate the clinical significance of SCIN gene expression and promoter methylation in patients with chronic myeloid leukemia (CML). Real-time quantitative PCR was used to detect the expression level of SCIN in mononucleatr cells of bone marrow samples from 64 CML patients and 37 controls. The methylation levels of SCIN promoter in 65 patients with CML and 29 controls were detected by real-time quantitative methylation-specific PCR and bisulfite sequencing PCR. The expression level of SCIN in CML patients was significantly down-regulated (P＜0.05), compared with the control group. The down-regulation rate of SCIN expression in CML patients at chronic phase, accelerated phase and blast crisis was 61%, 67% and 75%, respectively. Spearman correlation analysis showed that the expression level of SCIN negatively correlated with the transcript level of BCR-ABL1 (R=-0.315, P＜0.05). However, there was no significant difference in clinical parameters such as sex, age, white blood cell count, hemoglobin level, platelet count, chromosome, CML staging and BCL-ABL1 transcript level between low and high SCIN expression groups of CML patients (P＞0.05). No significant difference in methylation of SCIN promoter between CML patients and controls, and no correlation between SCIN expression and promoter methylation were observed (P＞0.05). The SCIN expression is down-regulated in CML patients, which may relate with the pathogenesis that is, BCR-ABL1 fusion gene induces CML tumorigenesis. The down-regulation of SCIN expression may relate with the progression of CML.

Early detection of colorectal cancer based on presence of methylated syndecan-2 (SDC2) in stool DNA

BackgroundColorectal cancer (CRC) screening can effectively reduce disease-related mortality by detecting CRC at earlier stages. We have previously demonstrated that the presence of SDC2 methylation in stool DNA is significantly associated with the occurrence of CRC regardless of clinical stage. The aim of this study was to evaluate the clinical performance of stool DNA-based SDC2 methylation test for CRC.MethodsAberrant SDC2 methylation in stool-derived DNA was measured by linear target enrichment (LTE)-quantitative methylation-specific real-time PCR (qMSP). Duplicate reactions of meSDC2 LTE-qMSP test were performed for stool samples obtained from CRC patients representing all stages (0–IV) and asymptomatic individuals who were subsequently underwent colonoscopy examination. To determine the diagnostic value of test in CRC and control groups, sensitivity and specificity were evaluated by receiver operating characteristic curve analysis.ResultsOf 585 subjects who could be evaluated, 245 had CRC, 44 had various sizes of adenomatous polyps, and 245 had negative colonoscopy results. Stool DNA-based meSDC2 LTE-qMSP showed an overall sensitivity of 90.2% with AUC of 0.902 in detecting CRC (0–IV) not associated with tumor stage, location, sex, or age (P > 0.05), with a specificity of 90.2%. Sensitivity for detecting early stages (0-II) was 89.1% (114/128). This test also detected 66.7% (2/3) and 24.4% (10/41) of advanced and non-advanced adenomas, respectively.ConclusionsResults of this study validated the capability of stool DNA based-SDC2 methylation test by LTE-qMSP for early detection of CRC patient with high specificity.Trial registrationClinicalTrials.gov, NCT03146520, Registered 10 May 2017, Retrospectively registered; however, control arm was prospectively registered.

Methylomic Analysis of Ovarian Cancers Identifies Tumor-Specific Alterations Readily Detectable in Early Precursor Lesions.

High-grade serous ovarian carcinoma (HGSOC) typically remains undiagnosed until advanced stages when peritoneal dissemination has already occurred. Here, we sought to identify HGSOC-specific alterations in DNA methylation and assess their potential to provide sensitive and specific detection of HGSOC at its earliest stages. MethylationEPIC genome-wide methylation analysis was performed on a discovery cohort comprising 23 HGSOC, 37 non-HGSOC malignant, and 36 histologically unremarkable gynecologic tissue samples. The resulting data were processed using selective bioinformatic criteria to identify regions of high-confidence HGSOC-specific differential methylation. Quantitative methylation-specific real-time PCR (qMSP) assays were then developed for 8 of the top-performing regions and analytically validated in a cohort of 90 tissue samples. Lastly, qMSP assays were used to assess and compare methylation in 30 laser-capture microdissected (LCM) fallopian tube epithelia samples obtained from cancer-free and serous tubal intraepithelial carcinoma (STIC) positive women. Bioinformatic selection identified 91 regions of robust, HGSOC-specific hypermethylation, 23 of which exhibited an area under the receiver-operator curve (AUC) value ≥ 0.9 in the discovery cohort. Seven of 8 top-performing regions demonstrated AUC values between 0.838 and 0.968 when analytically validated by qMSP in a 90-patient cohort. A panel of the 3 top-performing genes (c17orf64, IRX2, and TUBB6) was able to perfectly discriminate HGSOC (AUC 1.0). Hypermethylation within these loci was found exclusively in LCM fallopian tube epithelia from women with STIC lesions, but not in cancer-free fallopian tubes. A panel of methylation biomarkers can be used to accurately identify HGSOC, even at precursor stages of the disease.

SOX7 methylation is an independent prognostic factor in myelodysplastic syndromes

ObjectiveSOX7 downregulation caused by its promoter methylation was associated with poor survival in several types of human solid tumors. However, the pattern of SOX7 methylation and its clinical significance are less studied in hematological malignancies. Herein, we evaluated the methylation pattern of SOX7 in myelodysplastic syndrome (MDS) and determined its clinical implication in patients with MDS. MethodsSOX7 methylation was determined by real-time quantitative methylation-specific PCR (RQ-MSP) in 99 MDS patients. Bisulfite sequencing PCR was applied to confirm the results of RQ-MSP. ResultsSOX7 methylation was detected in 55.6% of 99 patients but not in healthy donors. No correlation was found between SOX7 methylation and clinical parameters including patient age, gender, white blood cell count, hemoglobin, and platelet count. However, patients with SOX7 methylation harbored more U2AF1 mutation than patients without SOX7 methylation (P = 0.015). Kaplan-Meier curves indicated that the patients with SOX7 methylation presented reduced overall survival (OS) (P = 0.034). Furthermore, subgroup analysis indicated that SOX7 methylation was associated with poor OS in male patients (P = 0.034) and in patients older than 60 years (P = 0.019). According to the multivariate analysis, SOX7 methylation remained as an independent prognosis factor in MDS patients both as dichotomous (HR = 2.14, P = 0.041) and as continuous (HR = 1.55, P = 0.042) variable. Importantly, SOX7 methylation was significantly increased during progression from MDS to secondary acute myeloid leukemia (sAML). ConclusionsOur findings demonstrated that SOX7 methylation conferred adverse prognosis in MDS patients and was associated with leukemia progression.

Abstract 3308: Urine epigenetic biomarkers for NSCLC diagnosis

Abstract Purpose: The National Lung Cancer Screening Trial showed mortality reduction on patients with NSCLC by the use of Low-dose CT screening. The study exhibits an unreasonably high false positive rate of 96.6%, which can to lead to significant morbidity and mortality from unnecessary tests. This study aim to determine if methylated promoter regions of a panel of genes that are correlated with Non-Small Cell Lung Cancer can be detected in urine from patients with lung cancer versus those without. Materials and Methods: We conducted a prospective case-control study recruiting subjects from the Lung Cancer Spore Trial. Urine and pre-operative CT scans were obtained from all patients. We processed the urine using the Methylation on Beads assay to isolate and bisulfite treat circulating DNA and then employed Quantitative Methylation Specific Real-Time PCR to detect promoter methylation status of the genes: CDO1, TAC1, HOXA7, HOXA9, SOX17 and ZFP42. Sensitivity, specificity, PPV and NPV values were calculated for each gene methylation status. Results: 34 patients were studied, including 23 patients with NSCLC and 11 patients with benign non-cancerous lesions. The sensitivity, specificity, PPV and NPV values for lung cancer detection in urine are shown in Table 1. Sensitivities ranged 43-96%, Specificities 64-91%, PPV 71-100% and NPV 40-67%. Promoter methylation of the gene panel CDO1, TAC1, HOXA7, HOXA9, SOX17 and ZPF42 has a 78% sensitivity, 91% specificity, 95% PPV and 67% NPV for lung cancer detection. Conclusion: Our study suggests that urine can provide a highly sensitive and specific non-invasive route for lung cancer detection. These results are very promising and could potentially reduce unnecessary morbidity and mortality in people undergoing screening for NSCLC by use of a non-invasive method that could be more accessible on primary care centers. However, further studies and validation with larger sample sizes and different populations are necessary before its application to clinical practice. Patients with positive gene methylation from urine samples and its accuracy for NSCLC detection.Cancer (n=23)Cancer (n=23)Control (n=11)Control (n=11)nSensitivitynSpecificityPPVNPVCDO114611919353TAC11565010010058SOX1716704648050HOXA711483737940HOXA910431919143ZPF4222969187167Panel of genes18781919567 Citation Format: Lane Lerner, Lily Zheng, Anastasia Kottorou, Chen Chen, Tomoaki Ito, Kristen Rodgers, Beverly Lee, Robert Winn, Enrico Benedetti, Tza- Huei Wang, Malcolm V. Brock, James G. Herman, Alicia Hulbert. Urine epigenetic biomarkers for NSCLC diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3308.

Methylation-associated DOK1 and DOK2 down-regulation: Potential biomarkers for predicting adverse prognosis in acute myeloid leukemia.

DOK-1 and DOK-2 (DOK1/2) are closely related members of downstream of tyrosine kinase (DOK) family genes, which are found to be frequently rearranged in several hematopoietic cancers. However, the clinical implications of DOK1/2 in acute myeloid leukemia (AML) remain largely unknown. To investigate the clinical significance, real-time quantitative PCR (RQ-PCR) was carried out to detect DOK1/2 expressions in 125 de novo AML patients and 28 healthy controls. Real-time quantitative methylation-specific PCR (RQ-MSP) and bisulfite sequencing PCR (BSP) were applied to detect DOK1/2 methylation level and density. DOK1/2 expressions were significantly down-regulated in AML patients. The promoters of DOK1/2 were highly hypermethylated and negatively correlated with DOK1/2 expressions in AML patients. In addition, we also confirmed that DOK1/2 expressions could be restored by DOK1/2 demethylation using 5-aza-2'-deoxycytidine in leukemia cell line THP-1. Survival analyses showed that low-expressed DOK1/2 were associated with markedly shorter overall survival and leukemia free survival in both whole-cohort AML and non-M3 AML patients. Multivariate analyses further revealed that DOK1/2 were act as independent prognostic factors in AML patients. These findings indicate that decreased DOK1/2 expressions associated with their promoter hypermethylations predict adverse prognosis in AML.

Demethylation of GFRA4 Promotes Cell Proliferation and Invasion in Hirschsprung Disease.

Hirschsprung disease (HSCR) is congenital intestinal aganglionosis attributed to a failure to migrate and survive of neural crest-derived cells. Glial cell-derived neurotrophic factor alpha 4 (GFRA4) is expressed in the derivatives of the neural crest in the enteric nervous system, but whether it is related with HSCR still remains unclear. This study was designed to investigate its role and epigenetic mechanisms in HSCR in vitro. The expression of GFRA4 mRNA in HSCR tissues was determined using quantitative real-time PCR analysis. In this study, we found that GFRA4 expression was significantly reduced in HSCR tissues and cells through GFRA4 methylation by quantitative real-time PCR analysis, methylation-specific PCR, and bisulfite sequencing PCR. DNA methyltransferase inhibitor, 5-AzaC, concomitantly upregulated the protein levels of GFRA4, as well as DNA methyltransferase1 (DNMT1) and DNMT2 in SH-5YSY cells. Moreover, we found upregulated GFRA4 significantly promoted cell proliferation, cell cycle progression and invasion, but inhibited apoptosis in SH-5YSY cells, whereas GFRA4 knockdown caused the opposite effects in SH-5YSY cells by CCK-8, 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, and Transwell assays. In conclusion, our results support that aberrant CpG hypermethylation at least partly accounts for GFRA4 silencing in HSCR, which impairs its protective role in enteric nervous system.

Decreased SCIN expression, associated with promoter methylation, is a valuable predictor for prognosis in acute myeloid leukemia.

The present study was aimed to investigate SCIN expression as well as promoter methylation and further explore their clinical relevance in acute myeloid leukemia (AML) patients. Real-time quantitative PCR was carried out to detect the expression level of SCIN in 119 AML patients and 37 healthy controls. Real-time quantitative methylation-specific PCR and bisulfite sequencing PCR were carried out to detect SCIN promoter methylation levels in 103 AML patients and 29 controls. As compared with controls, the level of SCIN transcript was significantly down-regulated in AML patients (P = 0.001), and the level of methylated SCIN promoter was significantly higher in AML patients (P = 0.001). Moreover, the level of promoter methylation was weakly negatively correlated with SCIN expression in AML patients (R = -0.265, P = 0.027). Demethylation of SCIN promoter by 5-aza-2'-deoxycytidine could restore its expression in leukemic cell line THP1. The age of SCINlow patients was significantly higher and C/EBPA mutation was significantly less than SCINhigh patients (P = 0.039 and 0.038, respectively). Moreover, the rate of complete remission (CR) of SCINlow patients was significantly lower than SCINhigh patients (P = 0.009). Kaplan-Meier analysis showed that low SCIN expression was associated with shorter overall survival (P = 0.036). Cox regression analysis demonstrated low SCIN expression was an independent poor prognostic factor (P = 0.047). Furthermore, SCIN expression was restored in those patients who achieved CR after induction therapy (P = 0.003). These findings indicate that decreased SCIN expression associated with its promoter methylation is a valuable biomarker for predicting adverse prognosis in AML patients.

A novel DNA methylation panel accurately detects colorectal cancer independently of molecular pathway

BackgroundColorectal cancer (CRC) is one of the most incident cancers, associated with significant morbidity and mortality, and usually classified into three main molecular pathways: chromosomal instability, microsatellite instability (MSI) and CpG island methylator phenotype (CIMP). Currently, available screening methods are either costly or of limited specificity, impairing global implementation. More cost-effective strategies, including DNA methylation-based tests, might prove advantageous. Although some are already available, its performance is suboptimal, entailing the need for better candidate biomarkers. Herein, we tested whether combined use of APC, IGF2, MGMT, RASSF1A, and SEPT9 promoter methylation might accurately detect CRC irrespective of molecular subtype.MethodsSelected genes were validated using formalin-fixed paraffin-embedded tissues from 214 CRC and 50 non-malignant colorectal mucosae (CRN). Promoter methylation levels were assessed using real-time quantitative methylation-specific PCR. MSI and CIMP status were determined. Molecular data were correlated with standard clinicopathological features. Diagnostic and prognostic performances were evaluated by receiver operator characteristics curve and survival analyses, respectively.ResultsExcept for IGF2, promoter methylation levels were significantly higher in CRC compared to CRN. A three-gene panel (MGMT, RASSF1A, SEPT9) identified malignancy with 96.6% sensitivity, 74.0% specificity and 91.5 positive predictive value (area under the curve: 0.97), independently of tumor location, stage, and molecular pathway.ConclusionsCombined promoter methylation analysis of MGMT/RASSF1A/SEPT9 displays a better performance than currently available epigenetic-based biomarkers for CRC, providing the basis for the development of a non-invasive assay to detect CRC irrespective of the molecular pathway.

Cadmium down-regulates apolipoprotein E (ApoE) expression during malignant transformation of rat liver cells: direct evidence for DNA hypermethylation in the promoter region of ApoE.

There is adequate evidence for the carcinogenicity of cadmium (Cd). However, a significant unaddressed question remains as to how this metal actually causes malignant transformation (tumor initiation). Since it has been shown that Cd only has the weak direct interaction potential with DNA, the metal is recognized as an indirect genotoxicant and mutagen. Currently, Cd-mediated "epigenetic" modifications, such as changes in DNA methylation resulting in alteration in target gene expression, coupled with cancer progression, are the focus of mechanistic research. We have reported that the apolipoprotein E (ApoE) gene, a suppressor of cell invasion, is an early Cd target, and is involved in the malignant transformation of TRL 1215 rodent liver cells. Cd exposure suppresses ApoE expression which can be re-activated with 5-aza-2'-deoxycytidine, a DNA demethylating agent. In the present study, we sought direct evidence of Cd-induced DNA hypermethylation of the ApoE promoter region by performing bisulfite sequencing and real-time quantitative methylation-specific PCR. Our data clearly suggest that Cd can down-regulate the expression of ApoE via introduction of excess DNA methylation in the promoter region of ApoE during malignant transformation of TRL 1215 cells.