Abstract
Prostate cancer is the most frequent malignancy affecting men worldwide. Due to the low sensitivity and specificity of the prostate-specific antigen test and the digital rectal exam as screening modalities, several alternatives are being studied. This study aimed to evaluate the application of MMP-9 and its regulators (TIMP-1, RECK, and miR-338-3p) as diagnostic and prognostic indicators of prostate cancer. A total of 134 randomly selected patients under investigation for prostate cancer submitted to a transrectal ultrasound-guided prostate biopsy were enrolled in the study; of these, 61 were positive for the disease (cases), and 73 were negative (control group). The tissue samples were further analyzed by gene and miR-338-3p expression analysis using qRT-PCR (one randomly selected fragment of each patient). Approximately 58% of the patients with prostate cancer presented MMP9 upregulation, while 73%, 65%, and 69% downregulated IMP-1, RECK, and miR-338-3p, respectively. MiR-338-3p was expressed at lower levels in patients with PSA concentrations exceeding 20 ng/mL (p=0.045) and abnormal DRE (p=0.006), while the RECK was more expressed in patients with abnormal DRE (p=0.01). We found that most patients with prostate cancer overexpressed MMP-9; on the other hand, most of them underexpressed TIMP-1, RECK, and miR-338-3p. MiR-338-3p presented as a possible predictor of poor prognosis. Further studies are warranted to evaluate these biomarkers as prognosis factors better.