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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2011-3-18
pubmed:abstractText
8-oxoguanine is a major base lesion in DNA or in nucleotides caused by oxidative stress, and is highly mutagenic because it can pair with adenine as well as cytosine. Adenine DNA glycosylase, encoded by the human mutY homolog gene, MUTYH, excises adenine in the nascent strand when inserted opposite 8-oxoguanine in template DNA, and thus suppresses mutagenesis caused by 8-oxoguanine that has accumulated in DNA due to oxidative stress. Several germ-line mutations in MUTYH are predisposed to MUTYH-associated polyposis, an autosomal recessive disorder characterized by multiple colorectal adenomas and carcinomas. Loss of function of MUTYH leads to an accumulation of somatic mutations in APC and KRAS genes, resulting in the development of adenomas/carcinomas. We recently demonstrated that accumulation of 8-oxoguanine in nuclear and mitochondrial DNA triggers two distinct cell death pathways that are independent of each other. Both pathways are initiated by the accumulation of MUTYH-generated single-strand breaks (SSBs) in nuclear or mitochondrial DNA. Our findings indicate that MUTYH-induced cell death due to oxidative stress results in an efficient elimination of mutagenic cells that have accumulated high levels of 8-oxoguanine in their DNAs. It is most likely that loss of function of MUTYH in stem or progenitor cells in the intestinal epithelium of MUTYH-associated polyposis patients results in escape from programmed cell death; however, accumulated 8-oxoguanine causes various mutations in APC or KRAS genes in these proliferative cells, thereby promoting tumorigenesis. We thus propose that MUTYH suppresses tumorigenesis under conditions of oxidative stress by inducing cell death and by suppressing mutagenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1349-7006
pubmed:author
pubmed:copyrightInfo
© 2011 Japanese Cancer Association.
pubmed:issnType
Electronic
pubmed:volume
102
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
677-82
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
DNA glycosylase encoded by MUTYH functions as a molecular switch for programmed cell death under oxidative stress to suppress tumorigenesis.
pubmed:affiliation
Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't