The genesis and progression of cancer is a stepwise process by which critical genes are altered because of mutations, epigenetic modifications and gene copy number changes. This alterations result in the activation of growth promoting genes (oncogenes) and inactivation of growth suppressor genes (tumor suppressor genes, TSGs). Nonsense mutations are mutations that lead to premature termination codon, which results in a truncated and often non-functional protein product. It is estimated that one third of the mutations associated with
human disease are nonsense mutations. Nonsense transcripts are removed from the cell by a post-transcriptional quality control mechanism called nonsense mediated decay (NMD). Recently gene identification by NMD pathway inhibition (GINI) was developed by combining NMD pathway inhibition with microarray experiments to identify genes that carry nonsense mutations.
We have applied GINI to identify new TSGs that carry nonsense mutations, which are involved in colorectal cancer (CRC). We used human 30k oligonucleotide microarray to compare mRNA level of CRC cell lines (RKO,HT29,Colo205), before and after pharmacologically inhibiting NMD pathway. We have identified a list of genes that are potential NMD targets, and therefore possible new TSGs.
Validate the candidate TSGs, by sequence and expression analysis (RT-PCR) on cell lines and on a panel of primary tumours.
For more information please contact dr. R.J.A. Fijneman