NAYARA IZABEL VIANA MOURA
Projetos de Pesquisa
Unidades Organizacionais
LIM/55 - Laboratório de Urologia, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Treating metastatic prostate cancer with microRNA-145(2018) ISCAIFE, Alexandre; REIS, Sabrina Thalita; MORAIS, Denis Reis; VIANA, Nayara Izabel; SILVA, Iran Amorim da; PIMENTA, Ruan; BORDINI, Andre; DIP, Nelson; SROUGI, Miguel; LEITE, Katia Ramos MoreiraProstate cancer (PCa) is an incurable disease at the metastatic stage. Although there are different options for treatment, the results are limited. MicroRNAs (miRNAs) are a group of small, noncoding, regulatory RNAs with important roles in regulating gene expression. miR-145 is reported to be a key tumor suppressor miRNA (tsmiR) that controls important oncogenes, such as MYC and RAS. In this study, in vitro studies were performed to show the control of MYC and RAS by miR-145. Flow cytometry was used to analyze cell proliferation and apoptosis. The efficacy of miR-145 in treating metastatic PCa was tested in nude mice using a model of bone metastasis promoted by intraventricular injection of PC-3MLuc-C6 cells. Tumor growth was evaluated by an in vivo bioluminescence system. After the full establishment of metastases on day 21, six animals were treated with three intravenous doses of miR-145 (on days 21, 24 and 27), and six were injected with scramble miRNA as controls. Compared to the controls, tumor growth was significantly reduced in animals receiving miR-145, most importantly on day 7 after the third and last dose of miRNA. After discontinuing the treatment, tumor growth resumed, becoming similar to the group of non-treated animals. A decrease in MYC and RAS expression was observed in all cell lines after treatment with miR-145, although statistical significance was achieved only in experiments with LNCaP and PC3 cell lines, with a decrease in 56% (p = 0.012) and 31% (p = 0.013) of RAS expression, respectively. Our results suggest that miR-145 is a potential molecule to be tested for treatment of metastatic, castration-resistant PCa.
- miR-29b enhances prostate cancer cell invasion independently of MMP-2 expression(2018) IVANOVIC, Renato F.; VIANA, Nayara I.; MORAIS, Denis R.; SILVA, Iran A.; LEITE, Katia R.; PONTES-JUNIOR, Jose; INOUE, Gustavo; NAHAS, William C.; SROUGI, Miguel; REIS, Sabrina T.Background: The ability to metastasize is one of the most important characteristics of neoplastic cells. An imbalance between the action of some matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs drives the invasion process. Some studies have suggested that MMP-2 is involved in metastasis, while other studies have reported that collagen production by cancer cells might also contribute to motility. However, decreased expression of microRNA-29b (miR-29b), which may control MMP-2 and collagen gene expression, has been shown in prostate cancer (PCa). The objectives of the present study were to clarify whether MMP-2 as well as collagens I and III (encoded by COL1A1 and COL3A1, respectively) are controlled by miR-29b and to determine whether metastasis is altered by this relationship. Methods: PCa DU145 and PC-3 cells were transfected with 100 mu L of OPTI-MEM I containing 100 nmol of miR-29b (or its inhibitor) along with 1.5 mu L of lipofectamine. Positive and negative controls were prepared using the same protocol. MMP-2, COL1A1 and COL3A1 messenger RNA (mRNA) levels were evaluated via real-time polymerase chain reaction (qRT-PCR). For qRT-PCR, 6 x 10(4) cells were used. Invasion studies were conducted with Matrigel assays, which simulate invasion of the extracellular matrix by neoplastic cells. After transfection of 3 x 10(4) cells, invasion was allowed to proceed for 48 h. Invasive cells were counted under an optical microscope. Each experiment was performed in triplicate. Results: MMP-2 mRNA was not expressed in DU145 cells after transfection with miR-29b. After transfection of cells with the miR-29b inhibitor, COL1A1 (p = 0.02) and COL3A1 (p = 0.06) mRNA expression was increased in DU145 cells, and a large number of transfected DU145 and PC3 cells invaded the Matrigel membrane. Conclusions: In vitro studies showed that reducing the amount of miR-29b may lead to higher PCa cell invasion via a process that is independent of MMP-2. Collagen expression, controlled by miR-29b, may facilitate this motility process. Thus, the present study suggests that collagen production plays an active role in metastasis control and restoration of miR-29b levels may decrease metastasis. Altogether, these findings support further exploration of drug therapy targeting this aspect of the metastasis circuit.
- miR-618: possible control over TIMP-1 and its expression in localized prostate cancer(2018) IVANOVIC, Renato F.; VIANA, Nayara I.; MORAIS, Denis R.; MOURA, Caio; SILVA, Iran A.; LEITE, Katia R.; PONTES-JUNIOR, Jose; NAHAS, William C.; SROUGI, Miguel; REIS, Sabrina T.BackgroundThe 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.MethodsAfter 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.ResultsDU145 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).ConclusionsIn 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.