CpG Island Hypermethylation Status Research Articles

Epstein-Barr virus infection and gene promoter hypermethylation in rheumatoid arthritis patients with methotrexate-associated B cell lymphoproliferative disorders.

We analyzed CpG-island hypermethylation status in 12 genes of paraffin-embedded tissues from 38 rheumatoid arthritis (RA) patients with methotrexate (MTX)-associated large B cell lymphoproliferative disorder (BLPD), 11 RA patients with non-MTX-associated BLPD (non-MTX-BLPD), 22 controls with diffuse large B cell lymphoma (DLBCL), and 10 controls with Epstein-Barr virus (EBV)+ DLBCL. Among them, tumor cells from EBV+ MTX-BLPD patients and control EBV+ DLBCL patients had significantly lower median incidence of CpG island methylator phenotype (CIMP) than those from non-MTX-BLPD and control DLBCL groups (2.3 and 1.7 vs. 4.3 and 4.4; P<0.01 for each). In the MTX-BLPD group, EBV+ patients showed lower median CIMP than EBV- patients (2.3 vs. 3.2); they also had significantly lower hypermethylation incidence in four apoptosis-related genes, especially death-associated protein kinase (14 vs. 55%), higher incidence of massive tumor necrosis (86 vs. 27%), and lower BCL2 protein expression (19 vs. 86%) than did the control DLBCL group (P<0.01 for all). In all clinical stages, EBV+ MTX-BLPD patients had better prognoses than the EBV- MTX-BLPD (P=0.011), non-MTX-BLPD (P=0.002), and control DLBCL groups (P=0.015). MTX-BLPD patients without hypermethylated RAS-associated domain family-1A (RASSF1A) or O 6 -methyl guanine-DNA methyltransferase (MGMT) had significantly better prognosis than those with hypermethylation of those genes (P=0.033). We conclude that in RA patients with MTX-BLPD, EBV infection is associated with a lower incidence of CIMP, apoptosis-related gene hypermethylation, and BCL2 expression, which can induce tumor regression by MTX withdrawal and lead to better prognoses.

Site-specific methylation patterns of the GAL and GALR1/2 genes in head and neck cancer: Potential utility as biomarkers for prognosis.

The aim of this study was to evaluate the prognostic value of the promoter methylation status of galanin (GAL) and galanin receptor 1/2 (GALR1/2) by assessing their association with disease-free survival and known prognostic factors in head and neck cancer. We generated methylation profiles of GAL and GALR1/2 in tumor samples obtained from 202 patients with head and neck squamous cell carcinoma (HNSCC); these included 43 hypopharynx, 42 larynx, 59 oral cavity, and 58 oropharynx tumor samples. CpG island hypermethylation status of the three genes was analyzed using quantitative methylation-specific PCR (Q-MSP). In order to determine the prognostic value of the methylation status of these genes, the associations between methylation index and various clinical characteristics, especially tumor site, were assessed for tumors from patients with HNSCC. The methylation index was positively correlated with female gender (P = 0.008) and disease recurrence (P = 0.01) in oral cancer and human papillomavirus (HPV)-positive (P = 0.004) status and disease recurrence (P = 0.005) in oropharyngeal cancer. Among patients with oral and oropharyngeal cancer, promoter hypermethylation of GAL, GALR1, or GALR2 was statistically correlated with a decrease in disease-free survival (log-rank test, P = 0.036 and P = 0.042, respectively). Furthermore, methylation of GAL, GALR1, or GALR2 exhibited the highest association with poor survival (log-rank test, P = 0.018) in patients with HPV-negative oropharyngeal cancers. As such, GAL and GALR1/2 methylation status may serve as an important site-specific biomarker for prediction of clinical outcome in patients with HNSCC. © 2016 Wiley Periodicals, Inc.

Polymorphisms of DNA Repair and Xenobiotic Genes Predispose to CpG Island Methylation in Non‐Neoplastic Gastric Mucosa

Genetic factors, related to DNA repair or xenobiotic pathways might confer different degrees of susceptibility to gastric carcinogenesis. CpG island hyper methylation (CIHM) is a major event in gastric carcinogenesis. We evaluated the association between XRCC1, GSTP1, GSTT1 and GSTM1 polymorphisms with CIHM status in non-neoplastic gastric mucosa. XRCC1 Arg399Gln, and Arg194Trp, GSTP1 Ile104Val, and GSTT1, GSTM1 null polymorphisms were genotyped in 415 cancer free subjects, in relation to four candidate CpG (p14, p16, DAP-kinase and CDH1) loci, assessed by Methylation-Specific-Polymerase Chain Reaction (MSP). CIHM high was defined as two or more CpG islands methylated. Significant association between XRCC1 codon 399 Gln/Gln genotype and reduced susceptibility to CIHM of DAP-kinase (adjusted OR = 0.30, 95%CI = 0.13-0.71, p = .0055) and CIHM high (OR = 0.42, 95%CI = 0.19-0.97, p = .04). XRCC1 codon 399 Gin/Gln genotype also presented lower number of CIHM when compared with both Arg/Gln, and Arg/Arg + Arg/Gln genotypes (p = .02, .046, respectively) When subjects were divided according to age (>50 and <50), an association was found between GSTM1 null genotype and increased susceptibility to CIHM high in the 50 years and older generations (OR = 1.63, 95%CI = 1.01-2.62, p = .045). XRCC1 codon 399 Gln/Gln genotype is associated with reduced susceptibility to CIHM especially DAP-kinase. GSTM1 null genotype may increase the susceptibility to CIHM especially in older patients. Genetic factors, related to DNA repair or xenobiotic pathways may have a role in CIHM-related gastric carcinogenesis.

Effect of polymorphisms of IL‐1β and TNF‐α genes on CpG island hyper methylation (CIHM) in the nonneoplastic gastric mucosa

CpG island hyper methylation (CIHM) is one of the major events in gastric carcinogenesis. To evaluate the influence of host genetic factors in CIHM related carcinogenesis, we investigated the association between common polymorphisms in IL-1β and TNF-α genes, with CIHM status in the nonneoplastic gastric mucosa. Polymorphisms in the IL-1β gene (-31T>C and -511C>T) and the TNF-α gene (-857C>T) were genotyped in 385 cancer-free subjects. CIHM of four candidate genes: p16 (INK4a), p14 (ARF), E-cadherin (CDH1), and death-associated protein kinase (DAP-kinase), were determined by methylation-specific-polymerase chain reaction (MSP). CIHM high was defined as two or more CpG islands methylated. CIHM of all four genes and CIHM high were significantly associated with Helicobacter pylori infection status. In over all, significant marginal association was found between IL-1β-511 TT genotype and reduced susceptibility to CIHM of DAP-kinase (adjusted OR = 0.48, 95% CI = 0.29-0.78) and CIHM high (adjusted OR = 0.53, 95% CI = 0.32-0.86). This association was more enhanced in subjects 65 yr or younger age. We also found positive association between TNF-α-857T carrier and increased susceptibility to CIHM of CDH (adjusted OR = 1.78, 95% CI = 1.01-3.16), and CIHM high (adjusted OR = 1.86, 95% CI = 1.04-3.33) in the same generation. The mean number of CIHM was lower in subjects with IL-1β-511TT genotype, while the mean number was higher in subjects with TNF-α-857 T carrier especially in subjects 65 yr and younger patients. IL-1β-511 TT genotype is associated with reduced susceptibility to CIHM especially in younger generation. Furthermore, the TNF-α-857T carrier is associated with increased susceptibility of CIHM in the same generation.

Association between polymorphisms in the XRCC1 and GST genes, and CpG island methylation status in colonic mucosa in ulcerative colitis

CpG island hypermethylation (CIHM) is frequently observed in the colonic mucosa in ulcerative colitis (UC) and is deeply involved in UC-associated colorectal carcinogenesis. We evaluated the influence of common polymorphisms related to DNA repair or xenobiotic pathway (XRCC1, GSTP1, GSTT1, and GSTM1) on the individual susceptibility to CIHM status in the non-neoplastic rectal mucosa in UC patients. XRCC1 Arg399Gln and Arg194Trp, GSTP1 Ile104Val, and GSTT1, GSTM1 null polymorphisms were genotyped in 84 UC patients without neoplastic lesions, in relation to CIHM in the rectal mucosa of three candidate CpG loci (p14, p16, and CDH1) assessed by methylation-specific polymerase chain reaction. XRCC1 codon 399 Arg/Gln genotype (odds ratio (OR) = 0.31, 95%CI = 0.12-0.81, p = 0.017) and 399 Gln carrier (GlnGln+Arg/Gln: OR = 0.30, 95%CI = 0.12-0.76, p = 0.01) were significantly associated with reduced susceptibility to CIHM of the CDH1 promoter. GSTP1 Val carrier (Ile Val+Val/Val) also held a significantly lower susceptibility to CIHM of the p16 promoter (OR = 0.26, 95%CI = 0.08-0.86, p = 0.028). In contrast, GSTT1 present genotype (OR = 3.16, 95%CI = 1.27-7.89, p = 0.01) was significantly associated with increased susceptibility to CIHM of the same gene. XRCC1 codon 399 Gln/Gln genotype was significantly associated with lower mean number of CIHM when compared to the Arg/Arg genotype (1.53 ± 1.01 vs. 0.63 ± 1.06, p = 0.024). In addition, the GSTP1 Ile/Val carrier (Ile/Val+Val/Val) was also significantly associated with lower mean number of CIHM (1.43 ± 1.03 vs. 0.84 ± 1.07, p = 0.03). XRCC1 Arg399Gln and GSTP1 Ile104Val polymorphisms may influence the CIHM status in the rectal mucosa of UC patients and may be substantially involved in UC-associated carcinogenesis.

Mixed-type gastric cancer and its association with high-frequency CpG island hypermethylation

Gastric carcinoma (GC) is one of the human cancers in which promoter CpG island hypermethylation is frequently found. We used the MethyLight assay to evaluate the methylation status of 16 CpG island loci that are hypermethylated in GC. We analyzed the relationship between CpG island hypermethylation of these 16 genes and the clinicopathological features in 191 advanced GCs. A significant difference was observed between the number of methylated genes in Epstein-Barr virus (EBV)-negative and microsatellite instability (MSI)-negative GCs of different histological types (Lauren classification; P < 0.01). We found that mixed-type (MT) carcinomas, which have both diffuse-type (DT) and intestinal-type (IT) components, had more methylated genes (10.6) than either DT carcinomas (7.6 methylated genes) or IT carcinomas (6.7 methylated genes) (P < 0.001). This trend was also observed when EBV-positive or MSI-positive GCs were excluded from the analysis (9.2, 6.9, and 4.8; P < 0.001). When the IT and DT components were dissected from MT carcinomas and the methylation of these 16 genes was evaluated, both components had a number of methylated genes similar to MT carcinomas, (10.2 and 9.7, respectively), which was significantly higher than was found in IT and DT carcinomas (P < 0.05). These findings indicate that MT carcinoma is distinct from IT and DT carcinomas in its enhanced CpG island hypermethylation status and implicate the enhanced promoter CpG island hypermethylation in the histogenesis of MT carcinoma.

Association between IL-17A, -17F and MIF polymorphisms predispose to CpG island hyper-methylation in gastric cancer

CpG island hyper-methylation (CIHM) is one of the major events in the gastric carcinogenesis. IL-17A, -17F and MIF have a crucial role in the gastric inflammation and carcinogenesis. Recently, we showed that the genetic polymorphisms of MIF-794-CATT repeat are associated with CIHM status in the non-neoplastic gastric mucosa. Consequently, the CIHM status in the gastric cancer tissue, in relation to IL-17A (-197G>A), -17F (7488T>C), and MIF (-173G>C and -794 tetranucleotide repeats) polymorphisms was investigated. Gastric cancer tissues were obtained from 102 patients. CIHM of p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific polymerase chain reaction (MSP). CIHM high was defined as three or all CpG islands methylated. We employed the PCR-SSCP (multiplex PCR for IL-17A and -17F) method to detect the gene polymorphisms. We did not find significant association between CIHM status and IL-17F (7488T>C) and MIF (-173G>C) polymorphisms. However, concerning the IL-17A (-197G>A) polymorphism, we found that IL-17A G carrier (GG+GA) held a significantly higher risk of CIHM of p16 (OR=11.22, 95% CI=1.38-91.17, p=0.024) and CIHM high (OR=3.51, 95% CI=1.15-10.68, p=0.027). An association was also found between the 7-CATT repeat carrier (5/7 + 6/7 + 7/7) of the MIF polymorphism (-794-CATT) and reduced risk of CIHM of CDH1 (OR=0.36, 95% CI=0.14-0.92, p=0.032). No association was found between CHIM status and homozygote genotypes of each repeat (-794-CATT 5/5, 6/6, and 7/7). The present results provided evidence that the genetic polymorphisms of IL-17A, and MIF-794-CATT repeat are associated with CIHM status in the gastric cancer. Genetic polymorphisms of IL-17A, and MIF-794-CATT repeat may be involved in methylation-related carcinogenesis in the stomach.

Association between common genetic variants in pre-microRNAs and the clinicopathological characteristics and survival of gastric cancer patients

Common single-nucleotide polymorphisms (SNPs) in microRNAs (miRNAs) have been shown to be associated with susceptibility to several types of human cancer. We evaluated the association between three SNPs (rs11614913, rs2910164 and rs3746444) in pre-miRNAs (miR-196a2, miR-146a and miR-499) and various clinicopathological characteristics, including CpG island hypermethylation (CIHM) status and overall survival in gastric cancer (GC) patients. rs11614913 (T>C), rs2910164 (C>G) and rs3746444 (A>G) SNPs were genotyped in 127 GC patients. CIHM of p14, p16, DAP-kinase and CDH1 genes was determined by methylation-specific polymerase chain reaction in the cancer tissues. A significant marginal association was found between the rs11614913 CC genotype and polypoid or elevated type morphology in early-stage GC (OR=6.29, 95% CI 1.18-33.47, p=0.03). The rs2910164 CC and CG genotypes were associated with increased susceptibility to CIHM of DAP-kinase (CC+CG, OR=5.48, 95% CI 1.30-23.10, p=0.02; CC, OR=6.93, 95% CI 1.37-35.02, p=0.02; CG, OR=4.24, 95% CI 0.87-20.78, p=0.07). The 11614913 TT and TC genotypes were associated with a higher number of CIHM (no. of CIHM 0-1 vs. 2-4; TT+TC, OR=3.67, 95% CI 0.98-13.72, p=0.05; TC, OR=4.08, 95% CI 1.04-15.97, p=0.04). When the subjects were divided according to age group, the combined rs11614913 TT+TC genotype tended to be associated with worse overall survival than the CC genotype in patients younger than 65 years of age (p=0.05). The combined rs2910164 CG+GG genotype also tended to be associated with worse overall survival than the CC genotype in the same age group (p=0.09). It appears that rs11614913 and rs2910164 SNPs in pre-miRNAs (miR-196a2 and miR-146a) affect the clinicopathological characteristics of GC, including its morphological appearance, CIHM status and overall survival.

Frequency ofP16INK4aandP14ARFGenes Methylation and Its Impact on Bladder Cancer Cases in North Indian Population

Introduction:Amongst the genitourinary cancers, carcinoma of the urinary bladder is one of the leading causes of death in India. Hypermethylation of the CpG islands of gene promoter is one of the earliest and most frequent epigenetic alterations leading to cancer as well as in its development. Several studies have suggested that tumour suppressor genes play a key role in the development of cancer. Methylation in theCDKN2Ahas been associated with various malignant diseases, but information with respect to urinary bladder cancer is lacking in north Indian population.Materials and methods:We analyzed the methylation ofP16INK4aandP14ARFin 80 tissues and matched blood samples of patients suffering from bladder cancer and 80 blood samples of cancer-free individuals by MS-PCR.Results:In tissue and matched blood samples of bladder cancer patients, the incidence ofP14ARFhypermethylation significantly increased (OR = 0.31, 95%CI = 0.12–0.8,P= 0.01) and (OR = 0.0, 95%CI=0.0–0.62,P= 0.006) respectively with an increase in age. Clinicopathological analysis revealed that P14ARF hypermethylation in tissue and blood samples was significantly associated with invasive stage (≥ T2) (OR = 0.21, 95%CI = 0.08–0.51,P= 0.0002) and (OR = 0.09, 95%CI = 0.03–0.37,P= 0.00001) respectively. Muscle invasive tumour stage (≥T2) showed significant association with increased risk of P16INK4α promoter hypermethylation in tissue and blood samples of patients (OR = 0.38, 95%CI = 0.17–0.82,P= 0.01) and (OR = 0.13, 95%CI = 0.05–0.36,P= 0.00005) respectively.Conclusion:These results suggest that the CpG island hypermethylation status of the defined panel of genes may be a useful biomarker in patients suffering from bladder cancer.

Frequency of P16INK4a and P14ARF genes methylation and its impact on bladder cancer cases in north Indian population.

Introduction: Amongst the genitourinary cancers, carcinoma of the urinary bladder is one of the leading causes of death in India. Hypermethylation of the CpG islands of gene promoter is one of the earliest and most frequent epigenetic alterations leading to cancer as well as in its development. Several studies have suggested that tumour suppressor genes play a key role in the development of cancer. Methylation in the CDKN2A has been associated with various malignant diseases, but information with respect to urinary bladder cancer is lacking in north Indian population. Materials and methods: We analyzed the methylation of P16INK4a and P14ARF in 80 tissues and matched blood samples of patients suffering from bladder cancer and 80 blood samples of cancer-free individuals by MS-PCR. Results: In tissue and matched blood samples of bladder cancer patients, the incidence of P14ARF hypermethylation significantly increased (OR = 0.31, 95%CI = 0.12–0.8, P = 0.01) and (OR = 0.0, 95%CI=0.0–0.62, P = 0.006) respectively with an increase in age. Clinicopathological analysis revealed that P14ARF hypermethylation in tissue and blood samples was significantly associated with invasive stage (≥ T2) (OR = 0.21, 95%CI = 0.08–0.51, P = 0.0002) and (OR = 0.09, 95%CI = 0.03–0.37, P = 0.00001) respectively. Muscle invasive tumour stage (≥T2) showed significant association with increased risk of P16INK4α promoter hypermethylation in tissue and blood samples of patients (OR = 0.38, 95%CI = 0.17–0.82, P = 0.01) and (OR = 0.13, 95%CI = 0.05–0.36, P = 0.00005) respectively. Conclusion: These results suggest that the CpG island hypermethylation status of the defined panel of genes may be a useful biomarker in patients suffering from bladder cancer.

Effect of polymorphisms of IL-17A, -17F and MIF genes on CpG island hyper-methylation (CIHM) in the human gastric mucosa

CpG island hyper-methylation (CIHM) is one of the major events in the gastric carcinogenesis and also occurs in non-neoplastic gastric mucosa. IL-17A, -17F and MIF have a crucial role in the gastric inflammation and carcinogenesis. The CIHM status in the non-cancerous gastric mucosa, in relation to IL-17A (-197G>A, rs2275913), -17F (7488T>C, rs763780) and MIF (-173G>C and -794 tetranucleotide repeats) polymorphisms was investigated. Gastric mucosa samples were obtained from 121 cancer free subjects. CIHM of p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific polymerase chain reaction (MSP). CIHM high was defined as three or all CpG islands methylated. We employed the PCR-SSCP (multiplex PCR for IL-17A and -17F) method to detect the gene polymorphisms. No association were found between CIHM status and L-17A (-197G>A), IL-17F (7488T>C) and MIF (-173G>C) polymorphisms. MIF 5-CATT repeat carrier (5/5+5/6+5/7) held a significantly higher risk of CIHM of DAP-kinase (OR=2.33, 95% CI=1.07-5.09, p=0.03) and CIHM high (OR=3.63, 95% CI=1.31-10.08, p=0.01). Weak association was also found between the same genotype and increased risk of CIHM of p16 (OR=2.45, 95% CI=0.90-6.68, p=0.08) and CDH1 (OR=2.23, 95% CI=0.94-5.32, p=0.07). 6-CATT repeat carrier (5/6+6/6+6/7) was significantly associated with reduced risk of CIHM of p16 (OR=0.31, 95% CI=0.11-0.90, p=0.03), CDH1 (OR=0.40, 95% CI=0.17-0.98, p=0.045), DAP-kinase (OR=0.37, 95% CI=0.17-0.83, p=0.02) and CIHM high (OR=0.25, 95% CI=0.09-0.74, p=0.01). -7-CATT repeat carrier (6/7+7/7) was weakly associated with reduced risk of CIHM of p16 (OR=0.34, 95% CI=0.10-1.13, p=0.08), DAP-kinase (OR=0.43, 95% CI=0.17-1.06, p=0.07) and CIHM high (OR=0.38, 95%CI=0.12-1.20, p=0.098). The present results provided the first evidence that the genetic polymorphisms MIF polymorphism is associated with CIHM status in the human gastric mucosa. Genetic polymorphisms of MIF-794-CATT repeat may be involved in methylation related carcinogenesis in the stomach.

CpG Island Hypermethylation of Tumor‐Suppressor Genes in H. pylori‐Infected Non‐Neoplastic Gastric Mucosa Is Linked with Gastric Cancer Risk

Gastric carcinogenesis involves CpG island hypermethylation (CIHM) of tumor-suppressor genes. Although the CIHM of these genes occurs in non-neoplastic gastric cells, it is unclear whether this epigenetic alteration is linked with aging and/or gastric cancer risk. We investigated this linkage in noncancerous gastric mucosa infected with H. pylori. Noncancerous corpus mucosa was endoscopically obtained from H. pylori-positive gastric cancer patients (n = 34), and age-matched H. pylori-positive noncancerous controls (n = 68). Genomic DNA retrieved from the mucosa was subjected to methylation-specific polymerase chain reaction for p16, Ecad, and DAPK genes. Linkage between CIHM and clinicopathologic factors was evaluated. CIHM rates of DAPK, Ecad, and p16 promoters were significantly higher in noncancerous gastric mucosa of gastric cancer patients (91, 88, and 68%, respectively) than in noncancerous controls (71, 53, and 25%, respectively). Multivariate regression analysis showed a significant linkage between CIHM in noncancerous mucosa and coexistence of gastric cancer. Significant linkage between polymorphoneutrophil infiltration and CIHM was observed except for CIHM of p16. No linkage was observed between CIHM and other parameters, including age. High CIHM status (all three tested genes methylated) was associated with an increased risk of gastric cancer, with an odds ratio of 9.8 (95% confidence interval, 3.8-25.3). In a subset of the H. pylori-infected population, CIHM of tumor-suppressor genes in noncancerous gastric mucosa is linked with the risk of gastric cancer and polymorphoneutrophil infiltration, but not aging. CIHM is a potential marker of gastric cancer risk.

CpG Island Hypermethylation Profile in the Serum of Men With Clinically Localized and Hormone Refractory Metastatic Prostate Cancer

We have noted that hypermethylation at GSTP1 in the preoperative serum of men with localized prostate cancer predicts early prostate specific antigen failure following surgical treatment. In this study we investigated the hypermethylation profile of several genes in the serum of men with localized and hormone refractory prostate cancer. We assayed the serum of 192 men with clinically localized prostate cancer and 18 with hormone refractory metastatic disease. A total of 35 serum samples from patients with negative prostate biopsy served as a negative control. CpG Island hypermethylation status of certain genes was assessed, including MDR1, EDNRB, CD44, NEP, PTGS2, RASSF1A, RAR-beta and ESR1. The results of hypermethylation at GSTP1 were included from a previous study. CpG island hypermethylation at MDR1 was positive in 38.2% of cases without PSA recurrence and in 16.1% of those with biochemical recurrence after radical prostatectomy. DNA hypermethylation at the remaining 7 gene loci was not detected in the serum of patients with localized prostate cancer. In serum from metastatic prostate cancer cases CpG island hypermethylation was detected at MDR1 in 15 (83.3%), EDNRB in 9 (50%), RAR-beta in 7 (38.9%), GTSP1 in 5 (27.8%) and NEP or RASSF1A in 3 (16.7%). CpG island hypermethylation at CD44, PTGS2 or ESR was not detected in any samples. All histologically normal cases were negative for CpG island hypermethylation. DNA hypermethylation at MDR1 was detected in cases of localized prostate cancer. CpG island hypermethylation at several gene loci was detected in men with advanced disease. No single gene was consistently observed to be hypermethylated in men with hormone refractory disease. These results suggest that the CpG island hypermethylation status of a defined panel of genes may be a useful biomarker in men with hormone refractory prostate cancer.