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Connexin43 pseudogene is expressed in tumor cells and inhibits growth

Mustapha Kandouz1, Andrew Bier, George D Carystinos

  • 1Department of Oncology, Montréal Centre for Experimental Therapeutics in Cancer, Lady Davis Institute for Medical Research, McGill University, Montréal, Québec, Canada H3T 1E2.

Oncogene
|May 4, 2004
PubMed

Insights

The Connexin43 (Cx43) pseudogene (PsiCx43) is transcribed and translated into a protein in cancer cells, inhibiting their growth. This pseudogene does not affect gap junction communication, expanding the known functional pseudogenes.

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Genetics

Background:

  • Pseudogenes are DNA sequences typically considered nonfunctional.
  • Gap junctions, formed by connexins, facilitate intercellular communication and are often deregulated in cancer.
  • Connexin43 (Cx43) is the only connexin with a reported pseudogene, PsiCx43.

Purpose of the Study:

  • To investigate the functional potential of the Cx43 pseudogene (PsiCx43).
  • To determine if PsiCx43 is transcribed and translated in cancer cells.
  • To assess the functional significance of PsiCx43 in cancer cell behavior.

Main Methods:

  • Detection of PsiCx43 mRNA transcripts in cancer cell lines and normal mammary epithelial cells.
  • In vitro translation assay to assess PsiCx43 protein production.
  • Expression of a PsiCx43-green fluorescence protein fusion in MCF-7 cells.
  • MTT growth, colony formation, and scrape-loading assays to evaluate functional impact.

Main Results:

  • PsiCx43 mRNA transcripts were identified in cancer cell lines but not in normal cells.
  • The PsiCx43 coding plasmid was translated into a 43 kDa protein in vitro.
  • Expression of PsiCx43 led to significant growth inhibition in cancer cells.
  • PsiCx43 did not affect gap junctional intercellular communication.

Conclusions:

  • PsiCx43 is a functionally transcribed and translated pseudogene.
  • PsiCx43 exhibits growth inhibitory properties in cancer cells.
  • This finding expands the known repertoire of functional pseudogenes.

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