The ERCC1 N118N polymorphism does not change cellular ERCC1 protein expression or platinum sensitivity

Area of Science:

• Genetics
• Molecular Biology
• Pharmacology

Background:

• Genetic polymorphisms in ERCC1 (Excision Repair Cross-Complementation group 1) are investigated for their role in platinum-based chemotherapy sensitivity.
• The ERCC1 N118N polymorphism (rs11615) is widely studied, yet its functional impact remains unclear.

Purpose of the Study:

• To investigate the functional impact of the ERCC1 N118N polymorphism on ERCC1 gene expression and platinum sensitivity.
• To determine if reduced codon usage frequency of AAT, containing the variant allele, affects ERCC1 function.

Main Methods:

• ERCC1 cDNA clones with either the C (wild-type) or T (variant) allele were introduced into an ERCC1-deficient cell line (UV20).
• Assays were performed to evaluate the effects of both alleles on ERCC1 transcription, translation, and platinum sensitivity.

Main Results:

• Both ERCC1 mRNA and protein levels increased after cisplatin treatment, with no significant difference between the C and T alleles.
• Cells complemented with ERCC1 showed significantly higher survival rates after platinum exposure compared to the parental cell line.
• No significant differences in platinum sensitivity were observed between cells transfected with the wild-type or polymorphic ERCC1 allele.

Conclusions:

• The ERCC1 N118N polymorphism itself does not appear to be directly responsible for altered ERCC1 expression or function.
• The observed effects of this polymorphism on platinum sensitivity may be due to linkage with other causative genetic variants or haplotypes.