Clonal expansion of p53 mutant cells in leukemia progression in vitro

Using the polymerase chain reaction followed by single-strand conformation polymorphism (PCR-SSCP) analysis and direct nucleotide sequence determination, the p53 gene was analyzed in six fresh leukemia samples from which cell lines with p53 mutations were established. Mutations of the p53 gene which were identical to those in the cell lines were observed in three of the fresh samples. In the other three samples, p53 gene mutations were not detected by the conventional PCR-SSCP method. However, when analyzed using allele-specific gene amplification, less than 10% of the leukemic cell population of the three samples, which were below the detection threshold of PCR-SSCP, were shown to have p53 gene mutations