Fluorescent laser scanning microscopy of F-actin disruption in human endometrial stromal cells expressing the SV40 large T antigen and the EJ ras oncogene.
To attempt to understand the effects of the SV40 large T antigen and an activated EJ ras oncogene on F-actin organization, we compared normal human endometrial stromal cells (HESC; proliferating, short life span) to cells transfected with the SV40 large T antigen either alone or in combination with the EJ ras oncogene. Normal HESC displayed numerous bundles of actin filaments (stress fibers) evenly distributed throughout the cell. In HESC transfected with a plasmid containing the gene for a temperature-sensitive SV40 large T antigen, stress fibers were disrupted and the remaining F-actin was also disrupted and clumped near the plasma membrane. Cells expressing both the SV40 large T antigen and the EJ ras oncogene sometimes appeared rounded, with stress fibers organized mainly near the cell periphery. Under restrictive temperature conditions for the function of the SV40 large T antigen, cells with or without the EJ ras oncogene reorganize actin stress fibers to resemble those of normal HESC. Therefore, the EJ ras oncogene alone does not disrupt F-actin organization. When operating in cooperation with the SV40 large T antigen, however, it leads to the reorganization of F-actin at the cell periphery and confers a rounded structure on the cells.
Carter
C A
CA
Department of Pathology, University of North Carolina, Chapel Hill.
Rinehart
C A
CA
Bagnell
C R
CR
Kaufman
D G
DG
D000199:Actins / Q000032:analysis* / Q000096:biosynthesis; D000952:Antigens, Polyomavirus Transforming / Q000096:biosynthesis*; D002471:Cell Transformation, Neoplastic / Q000648:ultrastructure*; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000648:ultrastructure*; D004717:Endometrium / Q000378:metabolism / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D007834:Lasers; D008856:Microscopy, Fluorescence; D009857:Oncogenes; D016283:Proto-Oncogene Proteins p21(ras) / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000096:biosynthesis; D014162:Transfection
D000199:Actins; D000952:Antigens, Polyomavirus Transforming; D011994:Recombinant Proteins; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)