RESUMO
BACKGROUND: The imbalance between the action of the tissue inhibitors of matrix metalloproteinases (TIMPs) and the matrix metalloproteinases (MMPs) is one component of metastasis physiology. TIMP-1 overrides MMP-9 activity in cancer and might be regulated by miR-618. The aims of this study were to clarify whether TIMP-1 expression is modified by miR-618 and to clarify the effect of miR-618 expression on the invasion of prostate cancer cells. We also studied miR-618 expression in surgical specimens of patients with localized prostate cancer submitted to open radical prostatectomy. METHODS: After transfection of miR-618 or its antagonist in DU145 cells, qRT-PCR for TIMP-1/MMP-9 and both ELISA and zymography for MMP-9 were performed. Total miRNA was extracted from surgical specimens of PCa, and miR-618 expression was examined for correlations with Gleason score, pathological status and biochemical recurrence. RESULTS: DU145 cells transfected with miR-618 had a 76% reduction in TIMP-1 expression relative to control cells (p = 0.003). miR-618 inhibition reduced MMP-9 expression by 31% (p = 0.032) and MMP-9 absorbance evaluated with ELISA assay (p = 0.06).Zymography suggested higher MMP-9 activity in DU145 cells transfected with miR-618 than those transfected with miR-618 inhibitor, but the difference was not significant (p = 0.55). However, miR-618 expression was lower in surgical specimens of patients with Gleason score > 7 (p = 0.08) and more advanced disease (p = 0.07). CONCLUSIONS: In vitro, miR-618 overexpression decreases TIMP-1 and miR-618 inhibition decreases MMP-9, suggesting that miR-618 might be an oncomiR. However, the analysis of clinical samples of localized prostate cancer revealed an inconsistent pattern, as increased miR-618 expression was associated with lower Gleason score and pathological status. Further studies are needed to address whether miR-618 is a context-dependent miRNA.
Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/biossíntese , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/metabolismo , Inibidor Tecidual de Metaloproteinase-1/biossíntese , Linhagem Celular Tumoral , Estudos de Coortes , Humanos , Masculino , MicroRNAs/genética , Neoplasias da Próstata/genética , Inibidor Tecidual de Metaloproteinase-1/genéticaRESUMO
BACKGROUND: Ureteropelvic junction obstruction (UPJO) diagnosed prenatally occurs in 1:150 - 1:1200 pregnancies. Although many studies investigating the molecular changes of this obstructed segment have been performed, the underlying mechanisms are still unclear. The role of extracellular matrix (ECM) components remains controversial, and the investigations in the field of ECM changes, might help the better understanding of the pathogenesis of this common condition. The aim of the present study was to investigate for the first time in the literature whether MMP9 and its specific inhibitors, TIMP1 and RECK, are expressed in a reproducible, specific pattern in UPJ. METHODS: UPJO specimens were obtained from 16 children at the time of dismembered pyeloplasty due to intrinsic UPJ stenosis. Expression levels of the three genes (MMP9, TIMP1 and RECK) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Then correlated the expression levels of the genes according to grade study population that was divided in 2 categories according to Society of Fetal Urology classification, grade 3 (moderate) and 4 (severe). For DTPA we subdivided the childrens in 2 groups, obstructive (T 1/2 more than 20 min) and partial obstructive (T 1/2 between 10 and 20 min) and success in a surgery was defined as decrease in T 1/2 to less than 20 min, absence of symptoms, improving renal function and decreasing dilatation on successive exams. RESULTS: MMP9 was underexpressed and TIMP1 and RECK were overexpressed in children with obstructive DTPA but the differences were not statistically significant. Overexpression of MMP9 was higher among patients with severe grade of UPJ compared to those with moderate grade. Surprisingly expression levels of MMP-9 was three times higher in children who were successfully treated by surgery (n = 10) (p = 0.072), so those who were followed for at least 1 year after surgery and remained with improvement in renal function and decreasing dilation on intravenous urogram and TIMP-1 was underexpressed in 100 % of this cases (p = 0.00). CONCLUSIONS: We showed an increase in expression of MMP9 and a decrease in expression of TIMP1 in children who improving renal function and decreasing dilation after surgery. We believe that the higher expression of MMP9 in these cases can reflect an increase in degradation and remodeling process that could be used as a marker for surgical outcome.