Expression of 6 MicroRNAs in Prostate Cancer and Its Significance

OBJECTIVE Numerous microRNAs (miRNAs) are deregulated in human cancers. The experimental evidence supports that miRNAs plays a role in the initiation and progression of human malignancies.The present study was undertaken to evaluate the differential expression of 6 miRNAs as biomarker for early detection of prostate cancer, and then to determine whether the expression profiling of these miRNAs could predict the prognosis of prostate cancer.METHODS The expression profilings of these 6 miRNAs were investigated using the method of locked nucleic acid (LNA)-modified oligonucleotide in situ hybridization (ISH). And the technology of tissue microarray (TMA) was employed using the formalin-fixed, paraffin-embedd (FFPE) specimens taken from 52 patients with prostate carcinoma (PCa) and 38 patients with benign prostatic hyperplasia (BPH).RESULTS The rates of positive expression for 6 miRNAs (miR-15b, miR-16, let-7g, miR- 96,miR-182 and miR-183) were 26.92%,15.38%o, 15.38%, 67.31%, 61.54% and 71.15% in the specimens of prostate cancer, and 57.89%, 76.32%, 68.42%, 44.74%, 31.58%,47.37% in the tissues of benign prostatic hyperplasia, respectively.The expressions of all 6 miRNAs between the prostate cancer and benign prostatic hyperplasia tissues were significantly different (P < 0.05). The positive rate of these 6 miRNAs was significantly related to the Gleason Grading of prostate cancer (P < 0.01). There was no significant correlation between the expression of these miRNAs and age and the concentration of serum PSA of the patient (P > 0.05). We also found that the expression of miR-15b, miR-96 and miR-182 correlated with clinical stages of tumor (P <0.05). The expression of miR-96 correlated with lobus prostatae of tumor invasion (P < 0.01), but the expressions of the remaining five miRNAs were not correlated with that (P > 0.05). In addition, the expression of miR-15b was negatively related to that of miR-96,miR-182 and miR-183, respectively (P < 0.01, r < 0.00).There was a positive correlation among the expressions of miR-96, miR-182 and miR-183 in prostate cancer (P < 0.01, r > 0.00). The expression of miR-16 was positively related to that of miR-let-7g (P < 0.01, r >0.00).CONCLUSION The results suggest that miRNA expression profiling could have relevance to the biological and clinical behavior of prostate cancer, and they might be important biomarkers for early detection and prognostic assessment of prostate cancer.