Linked Life Data

14713959

Source:http://linkedlifedata.com/resource/pubmed/id/14713959

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-3-19
pubmed:abstractText
Autophagy is originally named as a process of protein recycling. It begins with sequestering cytoplasmic organelles in a membrane vacuole called autophagosome. Autophagosomes then fuse with lysosomes, where the materials inside are degraded and recycled. To date, however, little is known about the role of autophagy in cancer therapy. In this study, we present that temozolomide (TMZ), a new alkylating agent, inhibited the viability of malignant glioma cells in a dose-dependent manner and induced G2/M arrest. At a clinically achievable dose (100 microM), TMZ induced autophagy, but not apoptosis in malignant glioma cells. After the treatment with TMZ, microtubule-associated protein light-chain 3 (LC3), a mammalian homologue of Apg8p/Aut7p essential for amino-acid starvation-induced autophagy in yeast, was recruited on autophagosome membranes. When autophagy was prevented at an early stage by 3-methyladenine, a phosphatidylinositol 3-phosphate kinase inhibitor, not only the characteristic pattern of LC3 localization, but also the antitumor effect of TMZ was suppressed. On the other hand, bafilomycin A1, a specific inhibitor of vacuolar type H(+)-ATPase, that prevents autophagy at a late stage by inhibiting fusion between autophagosomes and lysosomes, sensitized tumor cells to TMZ by inducing apoptosis through activation of caspase-3 with mitochondrial and lysosomal membrane permeabilization, while LC3 localization pattern stayed the same. These results indicate that TMZ induces autophagy in malignant glioma cells. Application of an autophagy inhibitor that works after the association of LC3 with autophagosome membrane, such as bafilomycin A1, is expected to enhance the cytotoxicity of TMZ for malignant gliomas.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1350-9047
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
448-57
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Role of autophagy in temozolomide-induced cytotoxicity for malignant glioma cells.
pubmed:affiliation
Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't