Identification of target actin content and polymerization status as a mechanism of tumor resistance after cytolytic T lymphocyte pressure

Proc Natl Acad Sci U S A. 2006 Jan 31;103(5):1428-33. doi: 10.1073/pnas.0510454103. Epub 2006 Jan 23.


To investigate tumor resistance to T cell lysis, a resistant variant was selected after specific cytolytic T lymphocytes (CTL) selection pressure. Although the resistant variant triggered perforin and granzyme B transcription in specific CTLs, as well as their degranulation, it exhibited a dramatic resistance to cytotoxic T cell killing. It also displayed strong morphological changes with alterations of the actin cytoskeleton. Electron microscopy analysis revealed a loosen interaction between CTLs and the resistant variant despite the formation of apparently normal conjugates. Transcriptional profiling identified a gene expression signature that distinguished sensitive from resistant tumor targets. More notably, we found that actin-related genes ephrin-A1 and scinderin were overexpressed in resistant target. Silencing of these genes using RNA interference resulted in a restoration of normal cell morphology and a significant attenuation of variant resistance to CTL killing. Our present study shows that a shift in cytoskeletal organization can be used, by tumor cells, as a strategy to promote their resistance after CTL selection pressure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / chemistry
  • Actins / metabolism*
  • Cell Line, Tumor
  • Ephrin-A1 / chemistry
  • Gelsolin / metabolism
  • Gene Silencing
  • Genetic Variation
  • Humans
  • Immunoprecipitation
  • Microscopy, Confocal
  • Microscopy, Electron
  • Neoplasms / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Phenotype
  • Polymers / chemistry*
  • Pressure
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • T-Lymphocytes, Cytotoxic / immunology*
  • T-Lymphocytes, Cytotoxic / metabolism
  • Time Factors
  • Transcription, Genetic


  • Actins
  • Ephrin-A1
  • Gelsolin
  • Polymers
  • scinderin