Mutations in p53 cDNA sequence introduced by retroviral vector.
The high mutation rates of retroviruses are a potential problem with retroviral vectors. We studied the mutation rates and spectra of p53 sequences transduced with a retroviral vector in a cancer gene therapy model. When p53-deficient H358 non-small cell lung cancer cells were treated with a retroviral vector carrying normal p53 cDNA, most of transduced cells were killed by apoptosis. However, a small number of clones escaped p53-mediated apoptosis. We examined the p53 cDNA structure in these resistant clones. PCR-based analysis showed that 88/102 clones had detectable mutations in p53, including gross rearrangements, deletions/insertions, and base substitutions. To study the mutation rate of the p53 sequence in all transduced clones, the retroviral vector containing the non-functional p53 gene and the Neo-resistant marker gene was introduced into H358 cells. Only one of 95 isolated clones showed a base substitution. These results indicate that the mutation rate of p53 is not particularly high, but there is a significant risk that cancer cells will resist p53 gene therapy as a result of retroviral replication errors.
Su
Su
S
Department of Biochemistry and Molecular Biology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
Watanabe
Atsushi
A
Yamamoto
Motoko
M
Nakajima
Eiitsu
E
Miyake
Koichi
K
Shimada
Takashi
T
D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics; D045744:Cell Line, Tumor; D018076:DNA, Complementary / Q000235:genetics*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D009154:Mutation; D041681:NIH 3T3 Cells; D012190:Retroviridae / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000627:therapeutic use
D018076:DNA, Complementary; D016159:Tumor Suppressor Protein p53