Linked Life Data

11225844

Source:http://linkedlifedata.com/resource/pubmed/id/11225844

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-2-27
pubmed:abstractText
Spontaneous and induced cancers are rare in non-isogeneic or inbred amphibians. Neoplastic cells become immortalized through loss of a normal capacity to die by apoptosis. Mature lymphocytes of mammals require activation and entry into the cell cycle in order to become susceptible to apoptosis. Whether Xenopus lymphocytes differ from mammalian lymphocytes in this regard is examined. In vitro exposure of PMA, or its analogue, MPMA, to adult splenocytes of Xenopus laevis was used to affect apoptosis. Flow cytometric analysis of FITC-Annexin V/propidium iodide (PI) fluorescence (apoptosis) and BrdU uptake (DNA synthesis) were assayed concurrently in the same lymphocyte population over time. Significant increases in apoptotic levels were induced throughout a 72 hour period in PMA-treated cells only. Lymphocytes were also separated by size for analysis. Several subpopulations of lymphocytes were identified, the most interesting of which was small and apoptotic within 4 hours, after PMA exposure. PMA-induced DNA synthesis did not become elevated until after 24 hours. "Direct" apoptosis, i.e. without cell cycle entry, was found only in these small, mature lymphocytes. Since small lymphocytes make up the vast majority of those being analyzed, "direct" apoptosis may be a determining mechanism in the resistance to neoplasia observed in Amphibia. Cells that die more readily are less likely to transform into neoplastic cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1360-8185
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
225-33
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Apoptosis and the cell cycle in Xenopus: PMA and MPMA exposure of splenocytes.
pubmed:affiliation
Department of Biology, Reed College, Portland, OR 97202, USA.
pubmed:publicationType
Journal Article