p53 mutants have selective dominant-negative effects on apoptosis but not growth arrest in human cancer cell lines - PubMed (original) (raw)

p53 mutants have selective dominant-negative effects on apoptosis but not growth arrest in human cancer cell lines

O N Aurelio et al. Mol Cell Biol. 2000 Feb.

Abstract

A bidirectional expression vector that allowed equal transcription of cloned wild-type and mutant p53 cDNAs from the same vector was developed. The vector was transfected into CaLu 6 lung carcinoma cells or Saos-2 osteosarcoma cells. All p53 mutants examined were recessive to wild-type p53 transactivation of p21(WAF1/CIP1) but dominant-negative for transactivation of Bax. An examination of effects on growth arrest and apoptotic pathways indicated that all mutants were recessive to wild type for growth arrest but only three of seven mutants were dominant negative for induction of apoptosis.

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Figures

FIG. 1

FIG. 1

Coexpression of wild-type and mutant p53 from the bidirectional expression vector, pBIRP. (A) Diagram of the bidirectional expression vector, pBIRP. Wild-type and/or mutant p53 cDNAs are cloned into the indicated restriction sites on the vector. P min, minimal promoter; TRE, tetracycline-responsive element; res, resistance; pA, poly(A); SV40, simian virus 40. (B) Representative Northern blot of CaLu 6 cells transiently transfected with the pBIRP vector (vec.) containing wild-type (wt) and/or mutant (mut.) p53 cDNA. (C) Western blot of lysates from cells transfected with bidirectional vectors bearing the indicated wild-type and mutant p53 cDNAs. Also indicated are the ratios of mutant to wild-type protein.

FIG. 2

FIG. 2

Effects of equal coexpression of wild-type and mutant p53 on transactivation of p53-responsive promoters. (A) p53 mutants are recessive to wild-type (wt) p53 for transactivation of p21WAF1/CIP1 promoter. (B) p53 mutants have a dominant-negative effect on Bax promoter transactivation.

FIG. 3

FIG. 3

Growth (colony) inhibition assays. Expression vectors expressing the indicated cDNAs were transfected into CaLu 6 cells and subjected to drug selection. Colonies were counted after 12 to 14 days selection. The results are the average of three separate experiments. (A) Most p53 mutants have lost the ability to inhibit cell growth. wt, wild type. (B) p53 mutants are recessive to wild-type p53 when coexpressed.

FIG. 4

FIG. 4

FACS analysis of dominant-negative effects on apoptosis. (A) Bar graph illustrating dominant-negative effects of only a fraction of the p53 mutants. wt, wild type. (B) Representative FACS profiles illustrating a dominant-negative (248w) and a recessive (175h) p53 mutant.

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References

    1. Attardi L D, Lowe S W, Brugarolas J, Jacks T. Transcriptional activation by p53, but not induction of the p21 gene, is essential for oncogene-mediated apoptosis. EMBO J. 1996;15:3693–3701. - PMC - PubMed
    1. Aurelio O N, Cajot J F, Hua M L, Khwaja Z, Stanbridge E J. Germ-line-derived hinge domain p53 mutants have lost apoptotic but not cell cycle arrest functions. Cancer Res. 1998;58:2190–2195. - PubMed
    1. Bader S A, Fasching C, Brodeur G M, Stanbridge E J. Dissociation of suppression of tumorigenicity and differentiation in vitro effected by transfer of single human chromosomes into human neuroblastoma cells. Cell Growth Differ. 1991;2:245–255. - PubMed
    1. Baron U, Freundlieb S, Gossen M, Bujard H. Co-regulation of two gene activities by tetracycline via a bidirectional promoter. Nucleic Acids Res. 1995;23:3605–3606. - PMC - PubMed
    1. Boukamp P, Peter W, Pascheberg U, Altmeier S, Fasching C, Stanbridge E J, Fusenig N E. Step-wise progression in human skin carcinogenesis in vitro involves mutational inactivation of p53, rasH oncogene activation and additional chromosome loss. Oncogene. 1995;11:961–969. - PubMed

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