Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-3-22
pubmed:abstractText
Expression of iNOS in glioma and other tumors has been extensively documented but the effects of NO derived from iNOS on tumor-killing mechanisms of chemotherapy drugs remain to be fully defined. We note that increased NO synthesis by cytokine exposure or iNOS overexpression neutralized the cytotoxicity of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), but not cisplatin, in rat C6 glioma cells. Suppression of BCNU cytotoxicity associated with iNOS overexpression could be abolished by pharmacological inhibition of NOS or coexpression of an antisense RNA against iNOS. Both BCNU and CCNU are chloroethylnitrosoureas that kill tumor cells via carbamoylating and alkylating actions. Further studies using compounds that each carry these different activities indicate that iNOS neutralized carbamoylating, but not alkylating, action of chloroethylnitrosoureas. Temozolomide, a novel chemotherapy drug recently available for treating brain tumors, carries only alkylating, but not carbamoylating, action. Overexpression of iNOS in C6 cells failed to neutralize temozolomide cytotoxicity. Results from the present study demonstrate the ability of iNOS-derived NO to confer chemoresistance against the carbamoylating potential of chloroethylnitrosoureas in vitro. Further investigation is needed to test whether iNOS expression, frequently noted in malignant brain tumors, also enhances chemoresistance against chloroethylnitrosoureas in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
297
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
308-15
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Inducible nitric oxide synthase neutralizes carbamoylating potential of 1,3-bis(2-chloroethyl)-1-nitrosourea in c6 glioma cells.
pubmed:affiliation
Center for the Study of Nervous System Injury and Department of Neurology, Washington University School of Medicine, 660 South Euclid Ave., Campus Box 8111, St. Louis, MO 63110, USA. hsuc@neuro.wustl.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.