|
Adenoma
|
0.100 |
GeneticVariation
|
group |
BEFREE |
Hierarchical clustering isolated three relevant clusters: (i) cluster of microsatellite stable mucinous adenocarcinomas (54%) with KRAS mutation, and frequent MGMT changes, more frequently located in the left colon, often associated with contiguous precursor adenoma; (ii) cluster of BRAF-mutated mucinous adenocarcinomas (28%) with either microsatellite instability-high or microsatellite stable status, occurring in elderly female patients, nearly all located in the right colon, having the signature of serrated pathway of carcinomas; and (iii) a heterogeneous cluster of microsatellite instability-high mucinous carcinomas (18%), including inherited colorectal carcinomas, displaying a high-grade histological pattern.
|
28429715 |
2017 |
|
Adenoma
|
0.100 |
PosttranslationalModification
|
group |
BEFREE |
In conclusion, MGMT methylation is central to the development of cancer that involves a stepwise carcinogenesis of normal adenoma carcinoma cascade.
|
25596081 |
2015 |
|
Adenoma
|
0.100 |
PosttranslationalModification
|
group |
BEFREE |
MGMT methylation status was noted in 40% of cases (7/20 non-functioning adenomas and 5/10 functioning adenomas).
|
24690322 |
2014 |
|
Adenoma
|
0.100 |
PosttranslationalModification
|
group |
BEFREE |
Overall, 42% of the SS3 adenomas exhibited MGMT promoter methylation.
|
21311951 |
2011 |
|
Adenoma
|
0.100 |
GeneticVariation
|
group |
BEFREE |
KRAS codon 12/13 and 59/61 and BRAF V600E mutations, MSI, and MGMT and hMLH1 methylation and expression in 42 serrated adenocarcinomas and 17 serrated adenomas were compared with those in 59 non-serrated colorectal carcinomas (CRCs) and nine adenomas.
|
21457162 |
2011 |
|
Adenoma
|
0.100 |
Biomarker
|
group |
BEFREE |
The aim of this study was to investigate the methylation status of MutL homolog 1 (hMLH1), MutS homolog 2 (hMSH2), and O-6-methylguanine-DNA methyltransferase (MGMT) in a series of colorectal carcinomas that contain both adenomas and carcinomas.
|
21706233 |
2011 |
|
Adenoma
|
0.100 |
AlteredExpression
|
group |
BEFREE |
In 17 OTAs, only one adenoma showed low MGMT expression.
|
19589911 |
2009 |
|
Adenoma
|
0.100 |
Biomarker
|
group |
BEFREE |
The interactions between folate and MTHFR genotype were most pronounced for O(6)-MGMT: compared with CC homozygotes with low folate intake, the adjusted odds ratios (95% confidence interval) of having a methylated O(6)-MGMT promoter were 3.39 (0.82-13.93) for TT homozygotes with low folate intake and 0.37 (0.11-1.29) for TT homozygotes with high folate intake (P interaction = 0.02); the odds ratios for the occurrence of adenomas without methylation were 0.57 (0.16-2.11) for TT homozygotes with low folate intake and 3.37 (1.17-9.68) for TT homozygotes with high folate intake (P interaction = 0.03).
|
17301267 |
2007 |
|
Adenoma
|
0.100 |
AlteredExpression
|
group |
BEFREE |
To cast light on the contribution of methylation to genesis of ulcerative colitis (UC)-associated tumors, promoter methylation and expression of O6-methylguanine DNA methyltransferase (MGMT), hMLH1, p16INK4, and E-cadherin were examined in 14 low-grade dysplasias (LGDs), 15 high-grade dysplasias (HGDs), and 14 adenocarcinomas associated with UC and, for comparison, in 30 sporadic adenomas with LGD, 30 adenomas with HGD, and 60 adenocarcinomas, using methylation-specific polymerase chain reaction and immunohistochemical analysis.
|
17276933 |
2007 |
|
Adenoma
|
0.100 |
PosttranslationalModification
|
group |
BEFREE |
We found MLH1 and p14(ARF) are methylated in 53 and 60% of the Lynch syndrome adenomas and in 4 and 20% of sporadic adenomas, whereas CDKN2A/p16 and MGMT are methylated in 6 and 14% of the Lynch syndrome adenomas versus 50 and 64% of sporadic adenomas.
|
17278092 |
2007 |
|
Adenoma
|
0.100 |
AlteredExpression
|
group |
BEFREE |
Methylations of MGMT, CDKN2A (p16) and MLH1 were detected in 28, 33 and 9% of the 101 flat-type adenomas, respectively.
|
17143260 |
2007 |
|
Adenoma
|
0.100 |
AlteredExpression
|
group |
BEFREE |
Aberrant expression of p53 was uncommon overall, but occurred more frequently in MPs and SAs (12%) than adenomas (1%) (P < 0.04) and there was concordant loss of expression of MGMT.
|
16879389 |
2006 |
|
Adenoma
|
0.100 |
Biomarker
|
group |
BEFREE |
Utilizing real-time PCR (MethyLight), we quantified DNA methylation in five CIMP-specific gene promoters [CACNA1G (calcium channel, voltage-dependent, T type alpha-1G subunit), CDKN2A (p16/INK4A), CRABP1 (cellular retinoic acid binding protein-1), MLH1 and NEUROG1 (neurogenin 1)] and MGMT in six synchronous carcinoma pairs (12 carcinomas) and eight synchronous carcinoma and adenoma pairs (16 tumors).
|
16699497 |
2006 |
|
Adenoma
|
0.100 |
GeneticVariation
|
group |
BEFREE |
DNA methylation was tested at Methylated IN Tumor (MINT) loci (1,2,12,31) and the CpG promoter region of genes MLH1, HPP1, MGMT, p14ARF and p16INK4a in FAP-associated adenomas (33) from 5 patients with a known APC mutation (Group 1, FAP), adenomas (29) from 4 Multiple Adenoma patients (Group 2 Multiple), adenomas (14) from 3 patients with sporadic colorectal cancers showing high microsatellite instability (Group 3, MSI-H) and adenomas (16) from 7 patients, with sporadic colorectal cancers showing microsatellite stable or low level instability (Group 4, MSS/MSI-L).
|
16152625 |
2006 |
|
Adenoma
|
0.100 |
AlteredExpression
|
group |
BEFREE |
Loss of MGMT expression was found in 22.2% (6 of 27) of adenomas and 45.2% (28 of 62) of carcinomas.
|
15800999 |
2005 |
|
Adenoma
|
0.100 |
GeneticVariation
|
group |
BEFREE |
Mixed polyps, particularly those with carcinoma, showed loss of hMLH1 (33%), MGMT (37%), and even hMSH2 (11%) with significantly higher frequency compared to hyperplastic polyps, conventional adenomas, and serrated adenomas.
|
15712188 |
2005 |
|
Adenoma
|
0.100 |
AlteredExpression
|
group |
BEFREE |
Among FAP patients, four of 33 cancers and six of 93 adenomas showed loss of MGMT protein expression.
|
12720298 |
2003 |
|
Adenoma
|
0.100 |
PosttranslationalModification
|
group |
BEFREE |
K-ras mutations in serrated adenomas may be unaffected by the epigenetic silencing of O6-methylguanine-DNA methyltransferase by promoter hypermethylation.
|
12626907 |
2003 |
|
Adenoma
|
0.100 |
PosttranslationalModification
|
group |
BEFREE |
Promoter hypermethylation of MGMT was detected in one well-differentiated adenocarcinoma (16.7%) of 6 cancer samples and not detected in any of adenomas and dysplasias.
|
12920593 |
2003 |
|
Adenoma
|
0.100 |
PosttranslationalModification
|
group |
BEFREE |
In addition, MGMT loss associated with hypermethylation was observed in the small adenomas, including those that do not yet contain K-ras mutations.
|
10811111 |
2000 |