On the absence of mutations in nucleotide excision repair genes in sporadic solid tumors

Area of Science:

• Genomics
• Cancer Biology
• Molecular Oncology

Background:

• Stochastic tumors exhibit genomic instability and a mutator phenotype, characterized by increased DNA point mutations.
• This instability cannot be solely attributed to mismatch repair dysfunction, suggesting a role for nucleotide excision repair (NER) or base excision repair suppression.
• However, somatic mutations in NER genes are rarely found in sporadic solid tumors, creating a paradox in understanding cancer development.

Purpose of the Study:

• To investigate the reasons behind the absence of cancer-associated somatic mutations in NER genes.
• To further characterize the network properties of NER.

Main Methods:

• Analysis of NER gene network architecture.
• Investigating the entanglement of NER with apoptosis gene networks.

Main Results:

• The study previously demonstrated that point mutations in cancer genomes arise from a structurally conserved NER with functional disorder due to its entanglement with a disabled apoptosis network.
• The current study reveals that the NER gene network possesses a highly connected architecture.
• This intricate network structure is proposed as the reason for the lack of mutations in NER genes within sporadic solid tumors.

Conclusions:

• The absence of mutations in NER genes in sporadic solid tumors is explained by their extensive involvement in numerous essential cellular functions.
• The highly connected nature of the NER network contributes to its resilience and the observed lack of somatic mutations in cancer.