Antitumor activity of bax and p53 naked gene transfer in lung cancer: in vitro and in vivo analysis.
In vitro and in vivo data have demonstrated that virus-mediated p53 gene transfer can induce active cell death and lung tumor regression. In contrast, the therapeutic potential of bax, another apoptosis-inducing gene, has not been described. We compared p53 and bax cytotoxic effects by transient transfection of an average of 25 +/- 5% of the H-322 and H-358 bronchioloalveolar carcinoma cell lines in vitro. Under these conditions, bax expression killed 70 to 90% of the transfected cells whereas p53 killed only 40% of them. The killing activity of both genes involved apoptosis, as shown by TUNEL staining. Surprisingly, BrdU incorporation indicated that the cells that did resist Bax toxicity were blocked in the pre-S phase of the cell cycle, a result expected for p53 only. In vivo, repeated injections of naked DNA encoding Bax or p53 inhibited the growth of 4-mm preestablished H-322 tumors in nude mice. Growth retardation only, and not inhibition, was observed in H-358, a poorly transfectable and rapidly growing tumor. These results indicate that Bax and p53 share a similar, strong antitumor activity in vivo, even if the former is a more potent inducer of apoptosis in vitro.
Lung Cancer Research Group, Institut Albert Bonniot, Faculté de Médecine, Université Joseph Fourier, Grenoble, France.
J L
JL
Coll
A
A
Negoescu
N
N
Louis
L
L
Sachs
C
C
Tenaud
V
V
Girardot
B
B
Demeinex
E
E
Brambilla
C
C
Brambilla
M
M
Favrot
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002470:Cell Survival / Q000235:genetics; D004247:DNA / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D018014:Gene Transfer Techniques; D017930:Genes, Reporter / Q000235:genetics; D016158:Genes, p53 / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008081:Liposomes / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics*; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000235:genetics / Q000628:therapy; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D014162:Transfection / Q000235:genetics; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein
C494827:Bax protein, mouse; D008081:Liposomes; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D004247:DNA