Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Suppl
pubmed:dateCreated
1990-12-24
pubmed:abstractText
The effect of polyamine depletion on the survival response of human lung carcinoma cells (A-549) to acute heating at 45 degrees C and its effect on the induction and decay of thermotolerance were investigated in exponential and plateau-phase cells. A 48-h exposure to 1 mM alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, was used to deplete intracellular levels of putrescine and spermidine. Inhibition of polyamine synthesis had no effect on the survival of exponential cells to heating at 45 degrees C, but slightly enhanced the killing of slowly proliferating plateau-phase cells. While DFMO treatment did not inhibit the development of thermotolerance, it caused a reduction in the thermotolerance ratio of exponential cells from 2.6 to 1.80, and from 1.66 to 1.59 in plateau-phase cells. DFMO caused thermotolerance to decay more rapidly in polyamine-depleted cells as well. Flow cytometry demonstrated that DFMO did not alter the cell cycle distribution of plateau-phase cells (i.e., greater than 73% in G1/G0), but caused a block and time-dependent accumulation of exponential cells in G1/G0. The cytostatic properties of DFMO in exponential cells which favor its use with phase-specific agents, and its ability to alter the magnitude and decay of thermotolerance in human carcinoma cells suggest a potential role for this nontoxic agent in clinically oriented hyperthermia studies.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0033-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
S80-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Hyperthermia studies in polyamine-altered human lung carcinoma cells.
pubmed:affiliation
Center for Radiological Research, Columbia University College of Physicians & Surgeons, New York, New York 10032.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.