Silencing of death receptor and caspase-8 expression in small cell lung carcinoma cell lines and tumors by DNA methylation

Cell Death Differ. 2003 Mar;10(3):356-64. doi: 10.1038/sj.cdd.4401157.


Small cell lung cancer cell lines were resistant to FasL and TRAIL-induced apoptosis, which could be explained by an absence of Fas and TRAIL-R1 mRNA expression and a deficiency of surface TRAIL-R2 protein. In addition, caspase-8 expression was absent, whereas FADD, FLIP and caspases-3, -7, -9 and -10 could be detected. Analysis of SCLC tumors revealed reduced levels of Fas, TRAIL-R1 and caspase-8 mRNA compared to non-small cell lung cancer (NSCLC) tumors. Methylation-specific PCR demonstrated methylation of CpG islands of the Fas, TRAIL-R1 and caspase-8 genes in SCLC cell lines and tumor samples, whereas NSCLC samples were not methylated. Cotreatment of SCLC cells with the demethylating agent 5'-aza-2-deoxycytidine and IFNgamma partially restored Fas, TRAIL-R1 and caspase-8 expression and increased sensitivity to FasL and TRAIL-induced death. These results suggest that SCLC cells are highly resistant to apoptosis mediated by death receptors and that this resistance can be reduced by a combination of demethylation and treatment with IFNgamma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Blotting, Western
  • Carcinoma, Small Cell / metabolism*
  • Caspase 8
  • Caspase 9
  • Caspases / biosynthesis
  • Caspases / metabolism
  • Caspases / physiology*
  • Cell Line
  • Cell Line, Tumor
  • CpG Islands
  • DNA Methylation*
  • DNA, Complementary / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Flow Cytometry
  • Humans
  • Immunoblotting
  • Interferon-gamma / metabolism
  • Lung Neoplasms / metabolism*
  • Polymerase Chain Reaction
  • RNA / metabolism
  • RNA, Messenger / metabolism
  • Receptors, TNF-Related Apoptosis-Inducing Ligand
  • Receptors, Tumor Necrosis Factor / biosynthesis*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors
  • fas Receptor / biosynthesis*


  • DNA, Complementary
  • RNA, Messenger
  • Receptors, TNF-Related Apoptosis-Inducing Ligand
  • Receptors, Tumor Necrosis Factor
  • TNFRSF10A protein, human
  • TNFRSF10B protein, human
  • fas Receptor
  • RNA
  • Interferon-gamma
  • CASP8 protein, human
  • CASP9 protein, human
  • Caspase 8
  • Caspase 9
  • Caspases