The role of ATP-binding cassette transporter genes in the progression of prostate cancer.

BACKGROUND: Prostate cancer (PCa) is the most commonly diagnosed neoplasm and the second leading cause of cancer-related death among men in developed countries. There is no clear evidence showing the success of current screening tests in reducing mortality of PCa. In this study, we aimed to profile expressions of nine ABC transporters, ABCA5, ABCB1, ABCB6, ABCC1, ABCC2, ABCC3, ABCC5, ABCC10, and ABCF2, in recurrent, non-recurrent PCa and normal prostate tissues.

METHODS: A total of 77 (39 recurrent, 38 non-recurrent) radical prostatectomy and 20 normal prostate samples, obtained from Baylor College of Medicine Prostate Cancer program, were included into the study and divided into two independent groups as test and validation sample sets. Differential expression of selected ABC transporters was assessed using quantitative real-time PCR (qRT-PCR). Pearson's correlation test, receiver operating characteristics (ROC) analysis and Kaplan-Meier test were used for statistical analysis.

RESULTS: QRT-PCR results demonstrated the elevated expression of ABCA5, ABCB1, ABCB6, ABCC1, and ABCC2 as well as reduced expression of ABCC3 in PCa samples compared to normal prostate tissues. In addition, we found deregulation of ABCB1, ABCB6, ABCC3, and ABCC10 in recurrent PCa samples and validated differential expression of ABCB6, ABCC3, and ABCC10 in recurrent PCa compared to non-recurrent PCa. Pearson's correlation, ROC and Kaplan-Meier analysis revealed the power of these three ABC transporters for estimating prognosis of PCa.

CONCLUSIONS: We demonstrated differential expression of ABC transporters both in tumor versus normal and recurrent versus non-recurrent comparisons. Our data suggest ABCB6, ABCC3, and ABCC10 as valuable predictors of PCa progression.