Background

The mouse double minute 2 (MDM2) is a negative regulator of the p53 tumor suppressor protein. Overexpression of MDM2 is associated with poor survival and is a useful predictive factor for poor prognosis in various cancers in human. Studies revealed a genetic polymorphism located in intron 1 of the MDM2 gene, MDM2-SNP309, (a change from T to G) is main functional polymorphism and important to develop tumors. However, inconsistent associations between the MDM2-SNP309 and the risk or early onset age of human different cancers have been reported worldwide. These conflicting results may have depended on different patient subgroups and ethnicities studies. We studied the association of the MDM2-SNP309 

polymorphism andbladder cancer in Mongolian patients for the first time.

Objective

To investigate association between MDM2-SNP309 and the risk bladder cancer or early onset age of the cancer in Mongolian patients.

Materials and Methods

We genotyped MDM2-SNP309 in 44 patients with bladder cancer and 44 age and gender matched healthy controls among Mongolian people.Genomic DNA was extracted from whole blood samples by the standard method of Qiagen mini blood DNA extraction kit (Qiagen Inc., Valencia, CA) and PCR amplification was performed using 100 ng genomic DNA template according to manufacturer’s protocol (Invitrogen, Carlsbad, CA). MDM2 SNP309 genotyping was carried out by restriction fragment length polymorphism assay. 

Results

The allele frequencies of MDM2 SNP309 in the 44 bladder cancer patients were wild-type (T/T) 27.3%, homozygous (G/G) 34.1% and heterozygous (T/G) 38.6% whereas in the control cases were wild-type (T/T) 29.5%, homozygous (G/G) 20.5% and heterozygous (T/G) 50.0%. The proportion of homozygous (G/G) genotype was higher for bladder cancer cases than for healthy controls. Compared to the low-risk (wild type) genotype, an increased risk association with bladder cancer was shown for the GG genotype (OR=2.0, 95% CI=1.03-1.84). There is also a significant difference in median age onset of bladder cancer between GG low and high risk genotypes T/T and T/G (p=0,003)( p=0.0001), respectively (Figure2).

Conclusion

The current sample data suggests that MDM2 SNP309 GG genotype may be associated with the risk of bladder cancer as well as an earlier age onset in Mongolian patients with bladder cancer.

Key words: bladder cancer, MDM2 SNP309, polymorphism

Pp. 4-8, Tables 3, Figures 2, References 15

Судлаачдын бусад өгүүлэл

Сүүлд хийгдсэн