P53 Arg72Pro and MDM2 309 SNPs in hereditary retinoblastoma

The tumor suppressor p53 and its negative regulator MDM2 have crucial roles in a variety of cellular functions such as the control of the cell cycle, senescence, genome stability and apoptosis, and are frequently deregulated in carcinogenesis. Previous studies have highlighted the contribution of the common functional polymorphisms p53 p.Arg72Pro and MDM2 309SNP to the risk of both common cancers and Li-Fraumeni syndrome. Their possible role in retinoblastoma has recently been addressed by Castéra et al, who however only studied the MDM2 309SNP. Here, for the first time, we analyzed both single nucleotide polymorphisms (SNPs) in a case-control study of 111 Italian hereditary retinoblastoma patients. We found a significant association of the p53 Pro/Pro genotype with the disease (odds ratio=3.58, P=0.002). The MDM2 309SNP showed a weak negative association of allele G that deserves further investigation. These findings further support the hypothesis that genetic variability of the p53 pathway contributes to the individual susceptibility to retinoblastoma, as shown for Li-Fraumeni syndrome and a variety of non-hereditary cancers.