Wild-type human p53 and a temperature-sensitive mutant induce Fas/APO-1 expression.
Fas/APO-1 is a cell surface protein known to trigger apoptosis upon specific antibody engagement. Because wild-type p53 can activate transcription as well as induce apoptosis, we queried whether p53 might upregulate Fas/APO-1. To explore this possibility, we examined human p53-null (H358 non-small-cell lung adenocarcinoma and K562 erythroleukemia) and wild-type p53-containing (H460 non-small-cell lung adenocarcinoma) cell lines. When H358 or H460 cells were transduced with a replication-deficient adenovirus expression construct containing the human wild-type p53 gene but not with vector alone, a marked upregulation (approximately a three-to fourfold increase) of cell surface Fas/APO-1 was observed by flow cytometry. Similarly, K562, cells stably transfected with a plasmid vector containing the temperature-sensitive human p53 mutant Ala-143 demonstrated a four- to sixfold upregulation of Fas/APO-1 by flow-cytometric analysis at the permissive temperature of 32.5 degrees C. Temperature-sensitive upregulation of Fas/APO-1 in K562 Ala-143 cells was verified by immunoprecipitation and demonstrated to result from enhanced mRNA production by nuclear run-on and Northern (RNA) analyses. Stably transfected K562 cells expressing temperature-insensitive, transcriptionally inactive p53 mutants (His-175, Trp-248, His-273, or Gly-281) failed to upregulate Fas/APO-1 at either 32.5 degrees or 37.5 degrees C. The temperature-sensitive transcription of Fas/APO-1 occurred in the presence of cycloheximide, indicating that de novo protein synthesis was not required and suggested a direct involvement of p53. Collectively, these observations argue that Fas/APO-1 is a target gene for transcriptional activation by p53.
Owen-Schaub
L B
LB
Department of Immunology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Zhang
W
W
Cusack
J C
JC
Angelo
L S
LS
Santee
S M
SM
Fujiwara
T
T
Roth
J A
JA
Deisseroth
A B
AB
Zhang
W W
WW
Kruzel
E
E
D000230:Adenocarcinoma / Q000378:metabolism; D000954:Antigens, Surface / Q000096:biosynthesis*; D017209:Apoptosis; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism; D009154:Mutation; D012333:RNA, Messenger / Q000032:analysis; D013696:Temperature; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D015854:Up-Regulation; D019014:fas Receptor
D000954:Antigens, Surface; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D019014:fas Receptor