On the absence of mutations in nucleotide excision repair genes in sporadic solid tumors.
In general, stochastic tumors show genomic instability associated with the proliferation of DNA point mutations, that is, a mutator phenotype. This feature cannot be explained by a dysfunctional mismatch repair alone, and indicates that nucleotide excision repair (NER) and/or base excision repair should be suppressed. However, mutations in NER genes are not causally implicated in the oncogenesis of sporadic solid tumors, according to the Cancer Gene Census at http://www.sanger.ac.uk/genetics/CGP/Census/. This brings up an apparent paradox: how to explain the recurrent non-existence in NER genes of somatic mutations causally related to cancer? In a recent study, we have shown that the origin of point mutations in cancer cell genomes can be explained by a structurally conserved NER with a functional disorder generated from its entanglement with a disabled apoptosis gene network. In the present study, we further characterize NER gene network properties and show that it has a highly connected architecture. This feature suggests that the absence of mutations in NER genes in sporadic solid tumors is a result of their participation in many essential cellular functions.
Mombach
J C M
JC
Centro de Ciências Rurais, UNIPAMPA, São Gabriel, Brasil.
Castro
M A A
MA
Moreira
J C F
JC
de Almeida
R M C
RM
D017209:Apoptosis / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D053263:Gene Regulatory Networks; D042822:Genomic Instability; D006801:Humans; D009369:Neoplasms / Q000235:genetics*; D017354:Point Mutation