Suppression of dual-specificity phosphatase-2 by hypoxia increases chemoresistance and malignancy in human cancer cells

Shih Chieh Lin, Chun Wei Chien, Jenq Chang Lee, Yi Chun Yeh, Keng Fu Hsu, Yen Yu Lai, Shao Chieh Lin, Shaw Jenq Tsai

Research output: Contribution to journalArticlepeer-review

58 Citations (Scopus)

Abstract

Hypoxia inducible factor-1 (HIF-1) is the master transcriptional regulator of the cellular response to altered oxygen levels. HIF-1α protein is elevated in most solid tumors and contributes to poor disease outcome by promoting tumor progression, metastasis, and resistance to chemotherapy. To date, the relationship between HIF-1 and these processes, particularly chemoresistance, has remained largely unexplored. Here, we show that expression of the MAPK-specific phosphatase dual-specificity phosphatase-2 (DUSP2) is markedly reduced or completely absent in many human cancers and that its level of expression inversely correlates with that of HIF-1α and with cancer malignancy. Analysis of human cancer cell lines indicated that HIF-1α inhibited DUSP2 transcription, which resulted in prolonged phosphorylation of ERK and, hence, increased chemoresistance. Knockdown of DUSP2 increased drug resistance under normoxia, while forced expression of DUSP2 abolished hypoxia-induced chemoresistance. Further, reexpression of DUSP2 during cancer progression caused tumor regression and markedly increased drug sensitivity in mice xenografted with human tumor cell lines. Furthermore, a variety of genes involved in drug response, angiogenesis, cell survival, and apoptosis were found to be downregulated by DUSP2. Our results demonstrate that DUSP2 is a key downstream regulator of HIF-1-mediated tumor progression and chemoresistance. DUSP2 therefore may represent a novel drug target of particular relevance in tumors resistant to conventional chemotherapy.

Original languageEnglish
Pages (from-to)1905-1916
Number of pages12
JournalJournal of Clinical Investigation
Volume121
Issue number5
DOIs
Publication statusPublished - 2011 May 2

All Science Journal Classification (ASJC) codes

  • Medicine(all)

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