Association of the ABCG2 C421A polymorphism with prostate cancer risk and survival
Version of Record online: 15 AUG 2008
© 2008 BJU INTERNATIONAL. NO CLAIM TO ORIGINAL US GOVERNMENT WORKS
Volume 102, Issue 11, pages 1694–1699, December 2008
How to Cite
Gardner, E. R., Ahlers, C. M., Shukla, S., Sissung, T. M., Ockers, S. B., Price, D. K., Hamada, A., Robey, R. W., Steinberg, S. M., Ambudkar, S. V., Dahut, W. L. and Figg, W. D. (2008), Association of the ABCG2 C421A polymorphism with prostate cancer risk and survival. BJU International, 102: 1694–1699. doi: 10.1111/j.1464-410X.2008.07913.x
- Issue online: 21 NOV 2008
- Version of Record online: 15 AUG 2008
- Accepted for publication 28 April 2008
- prostate cancer;
To determine if the C421A single nucleotide polymorphism (SNP) in the ATP-binding cassette transporter ABCG2 increases prostate cancer risk or affects survival.
PATIENTS, SUBJECTS AND METHODS
Numerous studies have suggested that dietary, hormonal and environmental factors all play a role in the initiation in prostate cancer; among these, the carcinogenic heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a known substrate of the ABCG2. A SNP of ABCG2, C421A, resulting in a glutamine to lysine change at amino acid 141, has been shown to result in decreased function of the protein. Due to the expression of ABCG2 in the prostate, together with the purported role of dietary carcinogens and steroids in the development and progression of prostate cancer, 311 individuals were genotyped for the ABCG2 C421A SNP, 170 patients with androgen-independent prostate cancer (AIPC) and 141 ‘healthy’ controls. We also evaluated the effect of this SNP on the intracellular accumulation of PhIP and testosterone in vitro.
There were no significant differences in the prevalence of prostate cancer based on ABCG2 genetic variation in this population. However, survival was significantly longer for individuals with wild-type ABCG2, as compared with those hetero- or homozygous for the C421A SNP (7.4 years vs 5.3 years, P = 0.044). Intracellular accumulation of PhIP was 80% higher in HEK293 cells transfected with Q141K ABCG2 than in wild-type cells, confirming that this SNP decreases transport of PhIP. In contrast, testosterone was not transported by either wild-type or variant transfected cells, nor did it act as in inhibitor of ABCG2 in subsequent transport assays.
Increased exposure to PhIP may decrease survival, but the ABCG2 C421A polymorphism does not appear to increase the risk of prostate cancer.