Flow cytometric characterization of proliferation-associated nuclear antigen (p105) during the cell cycle in normal lymphocytes and promyelocytic leukemia cells (HL-60).
Bivariate flow cytometric analysis of p105 expression and DNA content was performed in human lymphocytes and promyelocytic leukemia cells (HL-60). We also employed a new method of detecting DNA strand breaks associated with apoptosis by labeling the 3'-OH termini in the breaks with biotinylated dUTP in a reaction employing exogenous terminal deoxynucleotidyl transferase (TdT). Phytohemagglutin-stimulated proliferating lymphocytes express p105 maximally after 48 hours, similar to HL-60 cells in exponential growth phase. Antigen expression in G1 was notably heterogeneous in G1 phase of both cell types and highest in M-phase cells treated for 6 hours with vinblastine. However, the p105-DNA ratio changed very little. Cycloheximide did not affect P105 expression. Methotrexate decreased p105 expression. Camptothecin and teniposide induced apoptosis, but apoptotic cells still expressed p105. Dual-parameter measurement also demonstrated that TdT-positive apoptotic cells expressed p105 at a higher level than apoptotic TdT negative cells. The data on drug treatment suggest that expression of p105 may be useful in monitoring chemotherapeutic effects but not as a marker of cell death from apoptosis.
Qiao
L
L
Department of Pathology, New York Medical College, Valhalla 10595, USA.
Gorczyca
W
W
Pizzolo
J G
JG
Melamed
M R
MR
Darzynkiewicz
Z
Z
D002166:Camptothecin / Q000494:pharmacology; D002453:Cell Cycle; D003513:Cycloheximide / Q000494:pharmacology; D004249:DNA Damage; D004273:DNA, Neoplasm / Q000235:genetics; D005434:Flow Cytometry; D018922:HL-60 Cells; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000378:metabolism*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D008727:Methotrexate / Q000494:pharmacology; D010835:Phytohemagglutinins / Q000494:pharmacology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D013713:Teniposide / Q000494:pharmacology; D014747:Vinblastine / Q000494:pharmacology
D004273:DNA, Neoplasm; D010835:Phytohemagglutinins; D018809:Proliferating Cell Nuclear Antigen; D014747:Vinblastine; D013713:Teniposide; D003513:Cycloheximide; D002166:Camptothecin; D008727:Methotrexate