Alterations of DNA content in human endometrial stromal cells transfected with a temperature-sensitive SV40: tetraploidization and physiological consequences.
The normal genomic stability of human cells is reversed during neoplastic transformation. The SV40 large T antigen alters the DNA content in human endometrial stromal cells in a manner that relates to neoplastic progression. Human endometrial stromal cells were transfected with a plasmid containing the A209 temperature-sensitive mutant of SV40 (tsSV40), which is also defective in the viral origin of replication. Ninety-seven clonal transfectants from seven different primary cell strains were isolated. Initial analysis revealed that 20% of the clonal populations (19/97) had an apparent diploid DNA content, 35% (34/97) had an apparent tetraploid DNA content, and the remainder were mixed populations of diploid and tetraploid cells. No aneuploid populations were observed. Diploid tsSV40 transformed cells always give rise to a population of cells with a tetraploid DNA content when continuously cultured at the permissive temperature. The doubling of DNA content can be vastly accelerated by the sudden reintroduction of large T antigen activity following a shift from non-permissive to permissive temperature. Tetraploid tsSV40 transfected cells have a lower capacity for anchorage-independent growth and earlier entry into 'crisis' than diploid cells. These results indicate that during the pre-crisis, extended lifespan phase of growth, the SV40 large T antigen causes a doubling of DNA content. This apparent doubling of DNA content does not confer growth advantage during the extended lifespan that precedes 'crisis'.
Rinehart
C A
CA
Department of Pathology, University of North Carolina, Chapel Hill 27599-7525.
Mayben
J P
JP
Butler
T D
TD
Haskill
J S
JS
Kaufman
D G
DG
D000952:Antigens, Polyomavirus Transforming / Q000502:physiology; D002455:Cell Division; D002472:Cell Transformation, Viral; D004247:DNA / Q000032:analysis*; D004717:Endometrium / Q000737:chemistry*; D005260:Female; D006801:Humans; D011123:Polyploidy; D013539:Simian virus 40 / Q000235:genetics*; D013696:Temperature; D014162:Transfection
D000952:Antigens, Polyomavirus Transforming; D004247:DNA