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Tong D, Ortega J, Kim C, Huang J, Gu L, Li GM. Arsenic Inhibits DNA Mismatch Repair by Promoting EGFR Expression and PCNA Phosphorylation. J Biol Chem 2015; 290:14536-41. [PMID: 25907674 DOI: 10.1074/jbc.m115.641399] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Indexed: 01/04/2023] Open
Abstract
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 ability to stimulate 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.
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Affiliation(s)
- Dan Tong
- From the College of Life Sciences, Wuhan University, Wuhan, China 430072, Department of Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40536, and Tsinghua University School of Medicine, Beijing, China 100084
| | - Janice Ortega
- Department of Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40536, and
| | - Christine Kim
- Department of Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40536, and
| | - Jian Huang
- From the College of Life Sciences, Wuhan University, Wuhan, China 430072
| | - Liya Gu
- Department of Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40536, and
| | - Guo-Min Li
- From the College of Life Sciences, Wuhan University, Wuhan, China 430072, Department of Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40536, and Tsinghua University School of Medicine, Beijing, China 100084
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