Promoter Methylation In Human Cancers Research Articles

Protocadherin17 Promoter Methylation is a Potential Predictive Biomarker in Clear Cell Renal Cell Carcinoma.

BackgroundProtocadherin17 (PCDH17) is a tumor suppressor gene, and is frequently silenced by promoter methylation in human cancers, including clear cell renal cell carcinoma (ccRCC). However, the clinical significance of PCDH17 methylation in ccRCC remains largely unclear. The aim of the present study was to investigate the methylation status of PCDH17 in ccRCC and its potential relevance to clinicopathological parameters and prognosis.Material/MethodsMethylation-specific PCR was used to examine the methylation status of PCDH17 in 191 ccRCC tumors and matched paired adjacent noncancerous tissues. Subsequently, the associations between PCDH17 methylation and clinicopathological parameters and prognosis of patients with ccRCC were analyzed.ResultsPCDH17 methylation occurred in 66.5% of ccRCC tumors, but in only 12.1% of adjacent noncancerous tissues. PCDH17 methylation is significantly correlated with advanced stage, higher grade, and lymph node metastasis in ccRCC. Moreover, it is an independent prognostic factor for progression-free survival and overall survival of patients with ccRCC.ConclusionsPCDH17 methylation occurred more frequently and was associated with malignant clinicopathological characteristics and poor prognosis in ccRCC patients. Thus, PCDH17 methylation may be used as a novel biomarker to predict the prognosis of patients with ccRCC.

Abstract 383: Is loss of MGMT a therapeutic target in lung cancer

Abstract Background: MGMT is a DNA repair protein which removes alkylating DNA adducts from the O6 position of guanine. Expression of MGMT is often silenced by promoter methylation in human cancers. MGMT methylation is a predictive marker for prolonged survival in glioblastoma patients treated with an alkylating agent, temozolomide. As MGMT methylation has been found in lung cancers, there is an increasing interest on the clinical utility of temozomolide in the treatment of human cancers. However, it is essential to use appropriate quantitative or semi-quantitative method methods to definitively establish the methylation status of the tumour. Methods: We critically assessed MGMT methylation status in 6 lung cancer cell lines and 56 lung tumours using three different methodologies. We first assessed the MGMT methylation pattern using methylation sensitive - high resolution melting (MS-HRM). The methylation status at each CpG dinucleotide was assessed bisulfite pyrosequencing of methylated clones. The level of MGMT methylation was quantified using quantitative methylation specific PCR. Results: MGMT methylation was found in 3 lung cancer cell lines by MS-HRM. The melting profiles of all methylated samples were indicative of heterogeneous methylation pattern by melting curve analysis. To examine the methylation status at each CpG sites of individual template, two MGMT methylated lung cell lines (H1666 and H69) were further tested by limiting dilution analysis and bisulfite pyrosequencing. The number and site of methylated CpG dinucleotides greatly varied in each template, confirming the heterogeneous methylation pattern in both cell lines. In 56 lung tumours, heterogeneous MGMT methylation was detected in seven samples (13%) by MS-HRM. The level of MGMT methylation was then estimated. 17 lung tumours, including the 7 MS-HRM positives and 10 additional tumours, were positive. However, the methylated level in all of the methylated samples was low, ranging from below 1% (12 samples) and up to 12%. Conclusions: The level of MGMT promoter in lung cancer is difficult to estimate. Ideally clonal analysis should be used to estimate the proportion of methylated alleles. Alternatively, methylation profiling using MS-HRM followed by pyrosequencing can be used to identify tumours showing significant levels of methylation. If MGMT methylation is found only in a small proportion of tumour cells, it is unlikely to be a useful target for therapy. Overcalling of MGMT methylated tumours may provide the explanation for the lack of survival benefit with temozolomide treatment in MGMT-methylated lung cancer patients in a recent phase II clinical trial (NCT00423150). This indicates that incorporation of immunohistochemistry for the MGMT protein should also be part of the assessment of the MGMT status of lung cancer. Citation Format: Hongdo Do, Paul Mitchell, Alexander Dobrovic. Is loss of MGMT a therapeutic target in lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 383. doi:10.1158/1538-7445.AM2014-383

Clinical significance of protocadherin 8 (PCDH8) promoter methylation in non-muscle invasive bladder cancer

BackgroundPCDH8 is a novel tumor suppressor gene, and frequently inactivated by promoter methylation in human cancers. However, there is little information regarding PCDH8 methylation in non-muscle invasive bladder cancer (NMIBC). The aim of this study was to investigate the methylation status of PCDH8 in NMIBC and its clinical significance.MethodsThe methylation status of PCDH8 in 233 NMIBC tissues and 43 normal bladder epithelial tissues was examined by methylation-specific PCR (MSP), and then analyzed the correlations between PCDH8 methylation and clinicopatholocial features. Subsequently, Kaplan-Meier survival analysis and Multivariate Cox proportional hazard model analysis was used to investigate the correlation between PCDH8 methylation and prognosis of patients with NMIBC.ResultsPCDH8 methylation occurred frequently in NMIBC tissues than those in normal bladder epithelial tissues. In addition, PCDH8 methylation significantly correlated with advanced stage, high grade, larger tumor size, tumor recurrence and progression in NMIBC. Kaplan-Meier survival analysis revealed that patients with PCDH8 methylated have shorter recurrence-free survival, progression-free survival and five-year overall survival than patients with PCDH8 unmethylated. Multivariate analysis suggested that PCDH8 methylation was an independent prognostic biomarker for recurrence-free survival, progression-free survival and five-year overall survival simultaneously.ConclusionsPCDH8 methylation may be associated with tumor progression and poor prognosis in NMIBC and may be used as a potential biomarker to predict the prognosis of patients with NMIBC.

Aberrant methylation of CDH13 is a potential biomarker for predicting the recurrence and progression of non muscle invasive bladder cancer.

BackgroundCDH13 is a novel tumor suppressor gene often inactivated by aberrant promoter methylation in human cancers. Previous studies have shown that CDH13 methylation correlated with advanced disease and poor prognosis in non-muscle invasive bladder cancer (NMIBC). The aim of the current study was to investigate the correlations between CDH13 methylation and disease recurrence as well as progression of NMIBC.Material/MethodsThe methylation status of CDH13 in 178 NMIBC samples and 38 normal bladder epithelial tissues was examined by methylation-specific PCR (MSP), and then correlated with clinicopathological features.ResultsWe found that CDH13 methylation occurs frequently in NMIBC, and significantly correlates with high grade, advanced stage, larger tumor size, and tumor recurrence and progression. Moreover, patients with methylated CDH13 exhibited significantly shorter recurrence-free survival (P<0.0001) and progression-free survival (P=0.0060) than patients with unmethylated CDH13. In addition, a multivariate Cox proportional hazard model analysis suggests that CDH13 methylation is an independent predictor for the recurrence (P=0.0043) and progression (P=0.0016) of NMIBC after initial transurethral resection.ConclusionsOur findings demonstrate that CDH13 methylation is a frequent event in NMIBC, and is associated with unfavorable tumor features. It should be used as an independent predictor for the recurrence and progression of NMIBC, and may be useful for the design of individualized therapeutic modalities.

Clinical significance of protocadherin 8 (PCDH8) promoter methylation in non-muscle invasive bladder cancer

BackgroundPCDH8 is a novel tumor suppressor gene, and frequently inactivated by promoter methylation in human cancers. However, there is little information regarding PCDH8 methylation in non-muscle invasive bladder cancer (NMIBC). The aim of this study was to investigate the methylation status of PCDH8 in NMIBC and its clinical significance.MethodsThe methylation status of PCDH8 in 233 NMIBC tissues and 43 normal bladder epithelial tissues was examined by methylation-specific PCR (MSP), and then analyzed the correlations between PCDH8 methylation and clinicopatholocial features. Subsequently, Kaplan-Meier survival analysis and Multivariate Cox proportional hazard model analysis was used to investigate the correlation between PCDH8 methylation and prognosis of patients with NMIBC.ResultsPCDH8 methylation occurred frequently in NMIBC tissues than those in normal bladder epithelial tissues. In addition, PCDH8 methylation significantly correlated with advanced stage, high grade, larger tumor size, tumor recurrence and progression in NMIBC. Kaplan-Meier survival analysis revealed that patients with PCDH8 methylated have shorter recurrence-free survival, progression-free survival and five-year overall survival than patients with PCDH8 unmethylated. Multivariate analysis suggested that PCDH8 methylation was an independent prognostic biomarker for recurrence-free survival, progression-free survival and five-year overall survival simultaneously.ConclusionsPCDH8 methylation may be associated with tumor progression and poor prognosis in NMIBC and may be used as a potential biomarker to predict the prognosis of patients with NMIBC.

Promoter methylation of H-cadherin is a potential biomarker in patients with bladder transitional cell carcinoma

H-cadherin, functions as a tumor suppressor, is frequently silenced by promoter methylation in human cancers. The aim of this study was to evaluate the feasibility of using H-cadherin methylation in tumor tissues as a potential biomarker in patients with bladder transitional cell carcinoma (TCC). We examined the methylation status of H-cadherin in 133 primary bladder TCC samples and 43 normal bladder epithelial tissues using methylation-specific polymerase chain reaction (MSP) and then analyzed the associations between H-cadherin methylation and clinicopathologic features as well as patients' outcome. H-cadherin methylation was detected in 47 (35.3%) bladder TCC samples, but not found in controls (P = 0.0000). Moreover, H-cadherin methylation was significantly associated with advanced stage (P = 0.0006), high grade (P = 0.0165), larger tumor size (P = 0.0225), tumor recurrence (P = 0.0106), and poor prognosis (P = 0.0000). In addition, multivariate analysis indicated that H-cadherin methylation is independently associated with poor outcome and had a relative risk of death of 3.832 (P = 0.0071, 95% confidence interval: 1.443-10.176). The results suggest that H-cadherin methylation may be used as a potential biomarker for the malignancy of bladder TCC and as an independent prognostic biomarker in patients with bladder TCC.

Clinical Significance ofCDH13Promoter Methylation in Serum Samples from Patients with Bladder Transitional Cell Carcinoma

H-cadherin (CDH13; also known as T-cadherin), which functions as a tumour suppressor, is frequently silenced by promoter methylation in human cancers including bladder transitional cell carcinoma (TCC). This study investigated the clinical significance of methylation of the CDH13 gene promoter in serum from patients with bladder TCC. Methylation status of CDH13 in serum samples from 127 patients with primary bladder TCC and 41 healthy volunteers (controls) was examined by methylation-specific polymerase chain reaction. CDH13 methylation was found in 39 patients with bladder TCC (30.7%) but in no controls. CDH13 methylation was significantly associated with advanced tumour stage, high-grade tumour, large tumour size, tumour recurrence and poor prognosis. The results suggested that CDH13 methylation in serum may be a potential predictive biomarker for malignancy in bladder TCC, and an independent pretherapeutic predictor of outcome. Demonstration of CDH13 methylation in serum may facilitate in the prediction of which patients require more aggressive additional post-operative systemic therapy.

RASSF1A gene promoter methylation in esophageal cancer specimens

SUMMARY. RASSF1A is frequently inactivated by promoter methylation in human cancers. To understand the involvement of the RASSF1A gene in esophageal squamous cell cancer (ESCC), we investigated the methylation of the RASSF1A gene in primary ESCC to define the frequency of this epigenetic aberration and its clinicopathological significance. Methylation-specific polymerase chain reaction (MSP) was used to detect RASSF1A gene methylation in DNA from 55 cases of ESCC. Methylation of the RASSF1A gene was found in 13 of 55 (24%) cases of primary ESCC. No association was found between the promoter methylation of the RASSF1A gene in primary ESCC and age, gender, localization, invasion depth, or tumor stage. Association was found with tumor differentiation. There was no correlation with its prognosis. In conclusion, it was suggested that an inactivation of the RASSF1A gene due to promoter methylation was associated with de-differentiation of the tumor in ESCC.

High frequency of DAP-kinase gene promoter methylation in colorectal cancer specimens and its identification in serum

Death-associated protein (DAP)-kinase is frequently inactivated by promoter methylation in human cancers. To understand the involvement of the DAP-kinase gene in colorectal cancer (CRC), we investigated the methylation of the DAP-kinasegene in primary CRC to define the frequency of this epigenetic aberration and the clinicopathological significance. For this reason, methylation-specific polymerase chain reaction (MSP) was used to detect DAP-kinase gene methylation in DNA from 122 cases of CRC and 18 paired serum samples. Methylation of the DAP-kinase gene was found in 67 of 122 (55%) cases of primary CRC. Study of the serum DNA from 14 patients exhibiting methylated DAP-kinase gene revealed aberrant methylation in three patients (21%). False positives were not obtained in any of the patients who did not exhibit methylation. No association was found between the promoter methylation of the DAP-kinase gene in primary CRC and gender, localization, tumor differentiation, invasion depth, regional lymph node involvement, or tumor stage. In conclusion, methylation of the DAP-kinase gene is common in CRC. The detection of the methylation of the DAP-kinase gene has a potential clinical application as a diagnostic tumor marker for CRC.