MDM2SNP309 does not associate with elevated MDM2 protein expression or breast cancer risk

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• The MDM2 gene promoter contains SNP309 (T-G), a polymorphism potentially influencing MDM2 expression.
• In vitro studies suggested the GG genotype increases Sp1 binding, leading to higher MDM2 mRNA and protein levels.

Purpose of the Study:

• To investigate the association of MDM2 SNP309 polymorphism with cancer risk.
• To determine if SNP309 influences p53 and MDM2 protein expression in primary human tumors.

Main Methods:

• Genotyping of SNP309 using PCR-RFLP in cancer tissues (breast, endometrium, cervix, ovarian) and controls.
• Immunohistochemical analysis of p53 and MDM2 protein expression.
• Statistical correlation of SNP309 allele frequencies with protein levels and cancer incidence.

Main Results:

• No significant difference in G allele incidence was found between breast cancer patients and non-cancer controls.
• No statistically significant association was observed between G allele frequencies and p53 or MDM2 protein expression levels.

Conclusions:

• The MDM2 SNP309 polymorphism is not associated with cancer risk in the studied human cohorts.
• The G allele of SNP309 does not appear to be responsible for increased MDM2 or decreased p53 protein levels in primary breast tumors.