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Wnt inhibitory factor-1 is silenced by promoter hypermethylation in human lung cancer

Julien Mazieres1, Biao He, Liang You

  • 1Thoracic Oncology Laboratory, Department of Surgery, Comprehensive Cancer Center, University of California-San Francisco, 1600 Divisadero Street, San Francisco, CA 94115, USA.

Cancer Research
|July 17, 2004
PubMed

Insights

Aberrant Wnt signaling drives lung cancer. Methylation silencing of Wnt Inhibitory Factor-1 (WIF-1) is a key mechanism, offering potential therapeutic targets for lung cancer treatment.

Area of Science:

  • Oncology
  • Molecular Biology
  • Epigenetics

Background:

  • Aberrant Wingless-type (Wnt) signaling pathway activation is implicated in various human cancers, including lung cancer.
  • Wnt Inhibitory Factor-1 (WIF-1) acts as a secreted antagonist, inhibiting Wnt signaling, and its down-regulation is observed in several cancers.

Purpose of the Study:

  • To investigate the mechanism of WIF-1 silencing in lung cancer.
  • To determine the role of WIF-1 promoter methylation in lung cancer pathogenesis.

Main Methods:

  • Identification of the human WIF-1 promoter.
  • Analysis of CpG island methylation status using methylation-specific PCR and bisulfite sequencing.
  • Assessment of WIF-1 expression in lung cancer cell lines and clinical samples.
  • Treatment with 5-aza-2'-deoxycytidine to evaluate WIF-1 expression restoration.

Main Results:

  • Frequent CpG island hypermethylation was observed in the functional WIF-1 promoter region of lung cancer cell lines.
  • WIF-1 promoter hypermethylation correlated with its transcriptional silencing.
  • WIF-1 expression was restored upon treatment with 5-aza-2'-deoxycytidine.
  • Down-regulation of WIF-1 was observed in 83% of fresh lung cancer specimens, correlating with promoter methylation.

Conclusions:

  • Methylation-mediated silencing of WIF-1 is a common mechanism contributing to aberrant Wnt signaling activation in lung cancer.
  • WIF-1 silencing represents a significant factor in lung cancer pathogenesis.
  • Targeting WIF-1 methylation could hold therapeutic potential for lung cancer.

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