Prostate 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.

The infection by COVID-19 is a serious global public health problem. An efficient way to improve this disease's clinical management would be to characterize patients at higher risk of progressing to critically severe infection using prognostic biomarkers. The telomere length could be used for this purpose. Telomeres are responsible for controlling the number of maximum cell divisions. The telomere length is a biomarker of aging and several diseases. We aimed to compare leukocyte telomere length (LTL) between patients without COVID-19 and patients with different clinical severity of the infection. Were included 53 patients who underwent SARS-CoV-2 PCR divided in four groups. The first group was composed by patients with a negative diagnosis for COVID-19 (n = 12). The other three groups consisted of patients with a confirmed diagnosis of COVID-19 divided according to the severity of the disease: mild (n = 15), moderate (n = 17) and severe (n = 9). The LTL was determined by Q-PCR. The severe group had the shortest LTL, followed by the moderate group. The negative and mild groups showed no differences. There is an increase of patients with hypertension (p = 0.0099) and diabetes (p = 0.0067) in moderate and severe groups. Severe group was composed by older patients in comparison with the other three groups (p = 0.0083). Regarding sex, there was no significant difference between groups (p = 0.6279). In an ordinal regression model, only LTL and diabetes were significantly associated with disease severity. Shorter telomere length was significantly associated with the severity of COVID-19 infection, which can be useful as a biomarker or to better understand the SARS-CoV-2 pathophysiology.

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BackgroundClear cell renal cell carcinoma (ccRCC) is the third most common urological cancer in adults. Our aim is to evaluate genes and miRNAs expression profiles involved with angiogenesis and tumor characteristics in ccRCC.MethodsThe expression levels of miRNAs miR-99a, 99b, 100; 199a; 106a; 106b; 29a; 29b; 29c; 126; 200a, 200b and their respective target genes: mTOR, HIF1-α, VHL, PDGF, VEGF, VEGFR1 and VEGFR2 were analyzed using qRT-PCR in tumor tissue samples from 56 patients with ccRCC. Five samples of benign renal tissue were utilized as control. The expression levels of miRNAs and genes were related to tumor size, Fuhrman nuclear grade and microvascular invasion.ResultsmiR99a was overexpressed in most samples and its target gene mTOR was underexpressed, this also occurs for miRNAs 106a, 106b, and their target gene VHL. An increase in miR-200b was correlated with high-risk tumors (p = 0.01) while miR-126 overexpression was associated with Fuhrman’s low grade (p = 0.03).ConclusionsOur results show that in ccRCC there are changes in miRNAs expression affecting gene expression that could be important in determining the aggressiveness of this lethal neoplasia.