Linked Life Data

9309772

Source:http://linkedlifedata.com/resource/pubmed/id/9309772

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1998-1-16
pubmed:abstractText
Leishmania and other trypanosomatid protozoa require reduced pteridines (pterins and folates) for growth, suggesting that inhibition of these pathways could be targeted for effective chemotherapy. This goal has not yet been realized, indicating that pteridine metabolism may be unusual in this lower eukaryote. We have investigated this possibility using both wild type and laboratory-selected antifolate-resistant strains, and with defined genetic knockouts of several pteridine metabolic genes. In Leishmania, resistance to the antifolate methotrexate is mediated through several mechanisms singly or in combination, including alterations in transport leading to reduced drug influx, overproduction (R-region amplification) or point mutation of dihydrofolate reductase-thymidylate synthase (DHFR-TS), and amplification of a novel pteridine reductase (PTR1, encoded by the H-region). All of the proteins involved are potential targets for antifolate chemotherapy. Notably, parasites in which the gene encoding dihydrofolate reductase (DHFR) has been deleted (dhfr-ts- knockouts) do not survive in animal models, validating this enzyme as a target for effective chemotherapy. However, the properties of pteridine reductase 1 (PTR1) suggest a reason why antifolate chemotherapy has so far not been successful in trypanosomatids. PTR1, by its ability to provide reduced pterins and folates, has the potential to act as a by-pass and/or modulator of DHFR inhibition under physiological conditions. Moreover, PTR1 is less sensitive to many antifolates targeted primarily against DHFR. These findings suggest that successful antifolate chemotherapy in Leishmania will have to target simultaneously both DHFR and PTR1.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0031-1820
pubmed:author
pubmed:issnType
Print
pubmed:volume
114 Suppl
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
S101-10
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
New approaches to Leishmania chemotherapy: pteridine reductase 1 (PTR1) as a target and modulator of antifolate sensitivity.
pubmed:affiliation
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't