Loss of TP53-DNA interaction induced by p.C135R in lung cancer

Marcela Aranda, Fernando Gonzalez-Nilo, Gonzalo Riadi, Victor Díaz, José Perez, Ghyslaine Martel, Pierre Hainaut, Adriana Mimbacas

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The p53 tumor suppressor gene (TP53 ; OMIM: 191170) plays an important role in tumorigenesis in lung epithelial cells. TP53 encodes a sequence-specific DNA-binding protein that regulates transcription of several genes in response to DNA damage promoting cell cycle arrest, DNA repair or apoptosis. A mutation does not necessarily alter the protein function and since not all altered tumor protein p53 (TP53) conformations lead to the same biological properties, we studied Cys135Arg TP53 gene mutation in squamous cell type of non-small cell lung cancers (NSCLCs), by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing. Cys135Arg TP53 mutation, rare in databases (11/23544 in R11, IARC TP53 database), was detected. We chose p.C135R in order to examine DNA-TP53 interaction. A comparison with the wild-type after 1 nano-second molecular dynamic simulation analysis revealed a significant structural change (over 4Å displacement) in the contact loop Lys-Ser-Val which lies upstream and next to the mutated site in the TP53, that sterically prevents its DNA-binding activity. Additionally, the mutation produced a change in the electrostatic potential surface of the protein in the same loop where the structural modification took place. To demonstrate the degree of loss of function, functional assays in yeast and bacteria with oligonucleotides for competitive electrophoretic mobility shift assays (EMSAs) were done proving that this mutation decreases TP53 ability to bind DNA of the TP53 response element from the human p21 gene. These results demonstrate that the amino acid change C135R in the human TP53 generates the loss of TP53 DNA-binding activity directly affecting its role as a transcription factor and suggests that this observation can explain part of the phenotype described in patients affected by this type of tumor.

Original languageEnglish
Pages (from-to)1213-1217
Number of pages5
JournalOncology Reports
Volume18
Issue number5
DOIs
Publication statusPublished - Nov 2007

Keywords

  • EMSA
  • Modeling
  • Molecular dynamics
  • Mutations
  • Non-small cell lung carcinoma
  • Polymerase chain reaction-single-strand conformation polymorphism
  • Protein/DNA
  • Sequencing
  • Simulation
  • Sterical effect
  • TP53
  • Tumor suppressor gene

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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