A serine 37 mutation associated with two missense mutations at highly conserved regions of p53 affect pro-apoptotic genes expression in a T-lymphoblastoid drug resistant cell line

Caterina Cinti, Pier Paolo Claudio, Antonio De Luca, Monica Cuccurese, Candace M. Howard, Maurizio D'esposito, Marco G. Paggi, Dario La Sala, Livio Azzoni, Thanos D. Halazonetis, Antonio Giordano, Nadir Mario Maraldi

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Abstract

The p53 protein accumulates rapidly through post-transcriptional mechanisms following cellular exposure to DNA damaging agents and is also activated as a transcription factor leading to growth arrest or apoptosis. Phosphorylation of p53 occurs after DNA damage thereby modulating its activity and impeding the interaction of p53 with its negative regulator oncogene Mdm2. The serines 15 and 37 present in the amino terminal region of p53 are phosphorylated by the DNA-dependent protein kinase (DNA-PK) in response to DNA damage. In order to verify if specific p53 mutations occur in the multi-drug resistance phenotype, we analysed the p53 gene in two T-lymphoblastoid cell lines, CCRF-CEM and its multi-drug-resistant clone CCRF-CEM VLB100, selected for resistance to vinblastine sulfate and cross-resistant to other cytotoxic drugs. Both cell lines showed two heterozygous mutations in the DNA binding domain at codons 175 and 248. The multi-drug resistant cell line, CCRF-CEM VLB100, showed an additional mutation that involves the serine 37 whose phosphorylation is important to modulate the protein activity in response to DNA damage. The effects of these mutations on p53 transactivation capacity were evaluated. The activity of p53 on pro-apoptotic genes expression in response to DNA damage induced by (-irradiation, was affected in the vinblastine (VLB) resistant cell line but not in CCRF-CEM sensitive cell line resulting in a much reduced apoptotic cell death of the multi-drug resistant cells.

Original languageEnglish
Pages (from-to)5098-5105
Number of pages8
JournalOncogene
Volume19
Issue number44
Publication statusPublished - Oct 19 2000

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Keywords

  • Apoptotic genes
  • Drug resistance
  • P53 mutations
  • T-lymphoblastoid cells

ASJC Scopus subject areas

  • Molecular Biology
  • Cancer Research
  • Genetics

Cite this

Cinti, C., Claudio, P. P., De Luca, A., Cuccurese, M., Howard, C. M., D'esposito, M., Paggi, M. G., La Sala, D., Azzoni, L., Halazonetis, T. D., Giordano, A., & Maraldi, N. M. (2000). A serine 37 mutation associated with two missense mutations at highly conserved regions of p53 affect pro-apoptotic genes expression in a T-lymphoblastoid drug resistant cell line. Oncogene, 19(44), 5098-5105.