Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-3-10
pubmed:abstractText
The O(6)-methylguanine-methyltransferase (MGMT) promoter methylation status is a predictive parameter for the response of malignant gliomas to alkylating agents such as temozolomide. First clinical reports on treating brain metastases with temozolomide describe varying effects. This may be due to the fact that MGMT promoter methylation of brain metastases has not yet been explored in depth. Therefore, we assessed MGMT promoter methylation of various brain metastases including those derived from lung (n = 91), breast (n = 72) kidney (n = 49) and from malignant melanomas (n = 113) by methylation-specific polymerase chain reaction (MS-PCR) and MGMT immunoreactivity. Fifty-nine of 199 brain metastases (29.6%) revealed a methylated MGMT promoter. The methylation rate was the highest in brain metastases derived from lung carcinomas (46.5%) followed by those from breast carcinoma (28.8%), malignant melanoma (24.7%) and from renal carcinoma (20%). A significant correlation of homogeneous MGMT-immunoreactivity (>95% MGMT positive tumor cells) and an unmethylated MGMT promoter was found. Promoter methylation was detected in 26 of 61 (43%) tumors lacking MGMT immunoreactivity, in 17 of 63 (27%) metastases with heterogeneous MGMT expression, but only in 5 of 54 brain metastases (9%) showing a homogeneous MGMT immunoreactivity. Our results demonstrate that a significant number of brain metastases reveal a methylated MGMT-promoter. Based on an obvious correlation between homogeneous MGMT immunoreactivity and unmethylated MGMT promoter, we hypothesize that immunohistochemistry for MGMT may be a helpful diagnostic tool to identify those tumors that probably will not benefit from the use of alkylating agents. The discrepancy between promoter methylation and a lack of MGMT immunoreactivity argues for assessing MGMT promoter methylation both by immunohistochemical as well as by molecular approaches for diagnostic purposes.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-10233835, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-10404096, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-10866320, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-11070098, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-11085511, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-11350911, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-12172983, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-12202665, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-12739231, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-14654977, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-15297393, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-15450401, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-15629610, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-15662974, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-15758010, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-16033832, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-16215811, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-16237290, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-16556052, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-16849758, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-16949297, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-17234766, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-17410359, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-17442986, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-17442989, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-17523078, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-17597110, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-17691113, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-18711169, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-1875945, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-7000780, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-7785768, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-8062258, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-8573590, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-8632775, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-8968045, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-9662379, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-9779706, http://linkedlifedata.com/resource/pubmed/commentcorrection/19274096-9850030
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1932-6203
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
e4775
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Homogeneous MGMT immunoreactivity correlates with an unmethylated MGMT promoter status in brain metastases of various solid tumors.
pubmed:affiliation
Department of Pathology, Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't