Polymorphisms in XPD and TP53 and mutation in human lung cancer

Area of Science:

• Oncology
• Genetics
• Molecular Biology

Background:

• Somatic mutation patterns in TP53 vary by cancer type and exposure, offering insights into disease origins.
• TP53 mutations are common in lung cancer, with G:C-->T:A mutations linked to smoking.
• Investigating genetic factors influencing lung cancer susceptibility is crucial for understanding carcinogenesis.

Purpose of the Study:

• To explore the influence of DNA repair and apoptosis gene polymorphisms on TP53 mutation spectra in lung cancer.
• To identify potential genetic mechanisms underlying lung cancer susceptibility differences.

Main Methods:

• Sequencing of the TP53 gene in a case-only study of 309 lung cancer patients (206 men, 103 women).
• Analysis of functional polymorphisms in XPD (rs1799793, rs1052559) and TP53 (rs1042522).
• Statistical analysis to assess associations and interactions between gene polymorphisms and TP53 mutation types.

Main Results:

• A TP53 mutation frequency of 25% was observed in exons 5-8.
• XPD polymorphisms (Asp312Asn, Lys751Gln) showed a modest association with G:C-->T:A TP53 mutations (OR 2.73).
• TP53 Arg72Pro polymorphism was associated with the presence of any TP53 mutation (OR 2.25) and G:C-->T:A mutations (OR 2.42).
• A significant interaction was found between XPD variant alleles and the TP53 Pro72 allele for TP53 mutations (P(int) = 0.027 for any mutation, P(int) = 0.041 for G:C-->T:A mutations).

Conclusions:

• TP53 mutation spectra in lung tumors are influenced by genetic factors, including XPD and TP53 polymorphisms.
• These genetic variations may contribute to differences in lung cancer susceptibility and the carcinogenic process.
• The observed interactions support biological roles of XPD and p53 in DNA repair and apoptosis.