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Retinoblastoma protein-initiated cellular growth arrest overcomes the ability of cotransfected wild-type p53 to induce apoptosis.
- Source :
-
British Journal of Cancer . 10/15/2000, Vol. 83 Issue 8, p1039-1046. 8p. - Publication Year :
- 2000
-
Abstract
- The retinoblastoma gene, RB, participates in the regulation of the G1/S-phase transition and in p53-mediated apoptosis. We have previously reported that stably transfected RB functions as a growth and tumour suppressor in HTB9 human bladder carcinoma cells, which carry a mutation of the p53 gene at codon 280 and lack RB expression. To elucidate the potential role of RB in the regulation of p53-mediated apoptosis, we transfected a wt p53 expression plasmid under the control of the human cytomegalovirus promoter into parental and RB-transfected HTB9 cells. The p53(+)/RB(-)cells were susceptible to apoptosis under various experimental conditions: 1) incubation in serum-free culture for 72 h, 2) short-term (6 h) or long-term (48 h) exposure to etoposide, and 3) culturing in soft agar. In contrast, p53(+)/RB(+)cells were significantly resistant to apoptosis under similar conditions and exhibited efficient growth arrest, as measured by laser scanning cytometry. Tumorigenicity in nude mice of parental HTB9 cells was lost by exogenous expression of wt p53. Likewise, none of mice injected subcutaneously with either p53(-)/RB(+)or p53(+)/RB(+)cells developed tumours, indicating that RB allows suppression of tumorigenesis, regardless of p53 status. These results suggest that the growth-inhibitory function of RB may overcome the ability of wt p53 to induce apoptosis. [ABSTRACT FROM AUTHOR]
- Subjects :
- *RETINOBLASTOMA
*P53 antioncogene
*GENE transfection
*APOPTOSIS
*CELL cycle
*PROTEIN metabolism
*ANIMAL experimentation
*COMPARATIVE studies
*ETOPOSIDE
*GENETIC techniques
*RESEARCH methodology
*MEDICAL cooperation
*MICE
*ONCOGENES
*POLYMERASE chain reaction
*PROTEINS
*RECOMBINANT proteins
*RESEARCH
*RESEARCH funding
*EVALUATION research
*REVERSE transcriptase polymerase chain reaction
*CANCER cell culture
BLADDER tumors
Subjects
Details
- Language :
- English
- ISSN :
- 00070920
- Volume :
- 83
- Issue :
- 8
- Database :
- Academic Search Index
- Journal :
- British Journal of Cancer
- Publication Type :
- Academic Journal
- Accession number :
- 11343488
- Full Text :
- https://doi.org/10.1054/bjoc.2000.1411