Arsenic inhibits DNA mismatch repair by promoting EGFR expression and PCNA phosphorylation

Dan Tong, Janice Ortega, Christine Kim, Jian Huang, Liya Gu, Guo Min Li

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


Both genotoxic and non-genotoxic chemicals can act as carcinogens. However, while genotoxic compounds lead directly to mutations that promote unregulated cell growth, the mechanism by which non-genotoxic carcinogens lead to cellular transformation is poorly understood. Using a model non-genotoxic carcinogen, arsenic, we show here that exposure to arsenic inhibits mismatch repair (MMR) in human cells, possibly through its abilitytostimulate epidermal growth factor receptor (EGFR)-dependent tyrosine phosphorylation of proliferating cellular nuclear antigen (PCNA). HeLa cells exposed to exogenous arsenic demonstrate a dose- and time-dependent increase in the levels of EGFR and tyrosine 211-phosphorylated PCNA. Cell extracts derived from arsenic-treated HeLa cells are defective in MMR, and unphosphorylated recombinant PCNA restores normal MMR activity to these extracts. These results suggest a model in which arsenic induces expression of EGFR, which in turn phosphorylates PCNA, and phosphorylated PCNA then inhibits MMR, leading to increased susceptibility to carcinogenesis. This study suggests a putative novel mechanism of action for arsenic and other non-genotoxic carcinogens.

Original languageEnglish (US)
Pages (from-to)14536-14541
Number of pages6
JournalJournal of Biological Chemistry
Issue number23
StatePublished - Jun 5 2015

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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