Evidence for the development of p53 mutations after cytotoxic therapy in a neuroblastoma cell line

• Published in: Cancer research (Chicago, Ill.) Vol. 61; no. 1; pp. 8 - 13
• Main Authors: TWEDDLE, Deborah A, MALCOLM, Archie J, BOWN, Nick, PEARSON, Andrew D. J, LUNEC, John
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 2001
• Subjects: Antineoplastic agents; Biological and medical sciences; chromosome 17; Cyclin-Dependent Kinase Inhibitor p21; Cyclins - biosynthesis; Cyclins - genetics; DNA Damage; DNA, Neoplasm - drug effects; DNA, Neoplasm - radiation effects; General aspects; Genes, p53 - drug effects; Genes, p53 - physiology; Genes, p53 - radiation effects; Humans; Karyotyping; Medical sciences; Mutation, Missense; Neuroblastoma - genetics; Neuroblastoma - pathology; Neuroblastoma - therapy; Nuclear Proteins; Pharmacology. Drug treatments; Proto-Oncogene Proteins - biosynthesis; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins c-mdm2; Radiation therapy and radiosensitizing agent; Treatment with physical agents; Treatment. General aspects; Tumor Cells, Cultured - drug effects; Tumor Cells, Cultured - radiation effects; Tumor Suppressor Protein p53 - biosynthesis; Tumor Suppressor Protein p53 - physiology; Tumors; Antineoplastic agent; Human; Nervous system diseases; Relapse; Malignant tumor; Neuroblastoma; Radiotherapy; Doxorubicin; In vitro; Vincristine; Resistance; Alkaloid; Cyclophosphamide; Gamma irradiation; Oxazaphosphinane derivatives; TP53 Gene; Chromosome E17; Nitrogen mustard; Genetics; Anthracyclins; Mutation; Autonomic neuropathy; Mechanism of action; Tumor suppressor gene
• ISSN: 0008-5472; 1538-7445

p53 mutations are rare in neuroblastomas at diagnosis perhaps accounting for their initial response to therapy, but advanced neuroblastoma frequently relapses, and it is possible that p53 mutations develop later. Two neuroblastoma cell lines derived from the same patient before [SKNBE(1n)] and after [SKNBE(2c)] cytotoxic therapy were analyzed for the presence of chromosome 17 and p53 genes by fluorescent in situ hybridization, p53 mutations by DNA sequencing, and p53 function after irradiation by studying the transcription of p53-regulated genes, cell cycle arrest, and induction of apoptosis. The SKNBE(1n) cell line was wild-type for p53, had two p53 genes, two copies of chromosome arm 17p and showed functional p53 after irradiation. The SKNBE(2c) cell line derived from the same patient 5 months later at relapse had loss of an entire chromosome 17, resulting in hemizygosity for the p53 locus on 17p and a missense p53 mutation in exon 5, and p53 was not functional after irradiation. The appearance of a p53 mutation in a cell line derived from a relapsed neuroblastoma suggests that this may be a mechanism of resistance to therapy. If p53 mutations develop frequently in relapsed neuroblastoma, cytotoxic agents more sensitive to mutant p53 might be more effective at relapse.