Chemical reverse transformation of CHO-K1 cells induces changes in expression of a candidate tumour suppressor and of a gene not previously characterised as transformation related

Eur J Cell Biol. 1999 Aug;78(8):561-6. doi: 10.1016/s0171-9335(99)80021-1.


Chemical reverse transformation of CHO-K1 and other cells is a well-established phenomenon, in which oncogenically transformed cells re-acquire fibroblastoid morphology, contact inhibition and anchorage-dependent growth, in response to cyclic AMP and other agents. A limited number of changes in gene transcription and enzyme activity have been demonstrated to coincide with these morphological and physiological changes. We have used a partial differential display to identify four genes that are transcriptionally modulated in reverse transformation. One of these, encoding ribosomal protein S18, is transcriptionally suppressed, probably as a result of the detransforming process. Three others are transcriptionally activated. One has homology to NADH-ubiquinone oxidoreductase chain 4 protein, and is also probably changed as a result of the detransforming process. Another is homologous to a human sequence which encodes a 27 kDa protein, p27(BBP/eIF6), that is involved in the biogenesis of 60S ribosomal subunit, and in cell lines of epithelial origin binds to beta integrin. This has not previously been described as transformation-related, and could have a causative role in reverse transformation. The third has homology, with transcriptional or processing variations, to a human genomic sequence, a positional candidate for a tumour suppressor gene, encoding the Krit1 protein which interacts with the Ras-family GTPase Krev-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Northern
  • CHO Cells / metabolism
  • Chromosomes, Human, Pair 7
  • Cricetinae
  • DNA, Complementary / analysis
  • Expressed Sequence Tags
  • Gene Expression Regulation
  • Genes, Tumor Suppressor / genetics*
  • Humans
  • Models, Genetic
  • Molecular Sequence Data
  • RNA / analysis
  • Sequence Homology, Amino Acid
  • Transformation, Genetic*


  • DNA, Complementary
  • RNA

Associated data

  • GENBANK/AA023763