BackgroundPrognosis of prostate cancer (PCa) is based mainly in histological aspects together with PSA serum levels that not always reflect the real aggressive potential of the neoplasia. The micro RNA (miRNA) mir-21 has been shown to regulate invasiveness in cancer through translational repression of the Metaloproteinase (MMP) inhibitor RECK. Our aim is to investigate the levels of expression of RECK and miR-21 in PCa comparing with classical prognostic factors and disease outcome and also test if RECK is a target of miR-21 in in vitro study using PCa cell line.Materials and methodsTo determine if RECK is a target of miR-21 in prostate cancer we performed an in vitro assay with PCa cell line DU-145 transfected with pre-miR-21 and anti-miR-21. To determine miR-21 and RECK expression levels in PCa samples we performed quantitative real-time polymerase chain reaction (qRT-PCR).ResultsThe in vitro assays showed a decrease in expression levels of RECK after transfection with pre-miR-21, and an increase of MMP9 that is regulated by RECK compared to PCa cells treated with anti-miR-21. We defined three profiles to compare the prognostic factors. The first was characterized by miR-21 and RECK underexpression (N = 25) the second was characterized by miR-21 overexpression and RECK underexpression (N = 12), and the third was characterized by miR-21 underexpression and RECK overexpression (N = 16). From men who presented the second profile (miR-21 overexpression and RECK underexpression) 91.7% were staged pT3. For the other two groups 48.0%, and 46.7% of patients were staged pT3 (p = 0.025).ConclusionsOur results demonstrate RECK as a target of miR-21. We believe that miR-21 may be important in PCa progression through its regulation of RECK, a known regulator of tumor cell invasion.

Baccharis dracunculifolia DC. (Asteraceae), popularly known as 'alecrim do campo', is a native plant from Brazil used in folk medicine as febrifuge, anti-inflammatory, antiseptic, and to treat skin sores. Also, B. dracunculifolia is the most important plant source of the Brazilian green propolis, which is recognized for its antiseptic and antiprotozoal activities. This study aimed at investigating the in vitro antiprotozoal, schistosomicidal, and antimicrobial activities of the essential oil from the leaves of B. dracunculifolia. The essential oil was obtained by hydrodistillation and analyzed by GC and GC/MS, which allowed the identification of 14 compounds, mainly oxygenated sesquiterpenes, such as (E)-nerolidol (33.51%) and spathulenol (16.24%). The essential oil showed activity against promastigote forms of Leishmania donovani, with IC(50) values of 42 microg/ml. The essential oil displayed high activity in the schistosomicidal assay, since all pairs of Schistosoma mansoni adult worms were dead after incubation with the essential oil (10, 50, and 100 microg/ml). B. dracunculifolia essential oil was neither cytotoxic against Vero cells, nor active in the antimicrobial and antiplasmodial assays.

The search for biomarkers to characterize prostate cancer aggressiveness has been the objective for the majority of researchers involved with the most prevalent tumor in men. MiRNAs are important for the control of many cellular functions and their deregulation is involved with tumor development and progression. To find miRNAs differentially expressed in prostate cancer and their relation to prognostic factors and biochemical recurrence we studied 53 surgical specimens from men who underwent radical prostatectomy, through a microarray analysis using the microarray platform (GeneChip® miRNA Array -Affymetrix) with more than 46,000 probes and 847 mature human miRNAs and transcripts. We defined different as an expression level greater or less than 1.1 with p<0.05. The validation study using qRT-PCR had confirmed miR21 as overexpressed in tumor that have recurred with a risk of 2.5. Transfection of miR-21 using lipid based assay in DU145 cell line, showed decrease in expression of RECK resulting in increase in expression of MMP9. Invasion assay with Matrigel showed increase in tumor cell invasion after miR-21 transfection. We conclude that miR-21 overexpression is related to increased biochemical recurrence after surgical treatment of prostate cancer. And the negative control of RECK results in overexpression of MMP9 promotes increasing tumor cell invasion supporting miR-21 as an oncomiR related to aggressiveness in prostate cancer.

OBJECTIVE:MicroRNAs are noncoding RNA molecules involved in the development and progression of tumors. We have found that miRNA-100 is underexpressed in metastatic prostate cancer compared to localized disease. Conversely higher levels of miR-100 are related to biochemical recurrence after surgery. This suggests that miR-100 may be a context-dependent miRNA, acting as oncogene or tumor suppressor miRNA. Our aim is to demonstrate the role of miR-100 in the control of predicted target genes in prostate cancer cell lines.METHODS:Cell lines DU145 and PC3 were transfected with miR-100, antimiR-100 and after 24 h and 48 h of exposure, qRT-PCR and western blot were performed for mTOR, FGFR3, THAP2, SMARCA5 and BAZ2A.RESULTS:There was reduction in mTOR (p = 0.025), THAP2 (p = 0.038), SMARCA5 (p = 0.001) and BAZ2A (p = 0.006) mRNA expression in DU145 cells after exposure to miR-100. In PC3 cells, mTOR expression was decreased by miR-100 (p = 0.01). There was a reduction in the expression levels of proteins encoded by studied genes, ranging from 34% to 69%.CONCLUSIONS:We demonstrate that miR-100 is a context-dependent miRNA controlling BAZ2, mTOR, FGFR3, SMARCA5 and THAP2 that might be involved in PC progression. The elucidation of the roles of miRNAs in tumors is important because they can be used as therapeutic targets in the future.