MiRNA 26a expression in a novel panel of African American prostate cancer cell lines.

INTRODUCTION African American men have disproportionately high incidence and mortality rates of prostate cancer when compared to other ethnic groups in the United States. The identification of molecular factors that contribute to this disparity could improve diagnosis and therapeutic intervention. Therefore, the purpose of this study was to determine the miRNA 26a expression profile in novel African American and Caucasian prostate cell lines at each clinical stage of prostate cancer progression. METHODS The miR-26a expression profile was investigated using novel African American and Caucasian prostate cell lines representing each pathological stage: non-malignant, malignant, and metastatic tumors. Relative miRNA expression was determined by qRT-PCR. RESULTS Our data showed a 2.25 fold increase for miR-26a in the non-malignant, a 13.3 fold increase in malignant and 2.38 fold increase in metastatic tumors, when comparing African American and Caucasian prostate cell lines of similar clinical stage and pathological grade. African American malignant prostate cancer cell lines showed the most significant fold difference in expression among all cell lines tested. Furthermore, there was a general increase in miR-26a expression toward the more aggressive cell lines in both African American and Caucasian prostate cell lines. CONCLUSION To date, we are unaware of any studies that compare the miRNA profile at different stages of prostate cancer among two racial groups. Although a gene target for miR-26a has not been identified, our data show a possible role for miRNA regulation of gene expression in prostate cancer progression. Furthermore, this study suggests that miRNAs could possibly contribute to the aggressiveness associated in African American patients with prostate cancer.