Filipa Vieira

MicroRNA-375 plays a dual role in prostate carcinogenesis

BackgroundProstate cancer (PCa), a highly incident and heterogeneous malignancy, mostly affects men from developed countries. Increased knowledge of the biological mechanisms underlying PCa onset and progression are critical for improved clinical management. MicroRNAs (miRNAs) deregulation is common in human cancers, and understanding how it impacts in PCa is of major importance. MiRNAs are mostly downregulated in cancer, although some are overexpressed, playing a critical role in tumor initiation and progression. We aimed to identify miRNAs overexpressed in PCa and subsequently determine its impact in tumorigenesis.ResultsMicroRNA expression profiling in primary PCa and morphological normal prostate (MNPT) tissues identified 17 miRNAs significantly overexpressed in PCa. Expression of three miRNAs, not previously associated with PCa, was subsequently assessed in large independent sets of primary tumors, in which miR-182 and miR-375 were validated, but not miR-32. Significantly higher expression levels of miR-375 were depicted in patients with higher Gleason score and more advanced pathological stage, as well as with regional lymph nodes metastases. Forced expression of miR-375 in PC-3 cells, which display the lowest miR-375 levels among PCa cell lines, increased apoptosis and reduced invasion ability and cell viability. Intriguingly, in 22Rv1 cells, which displayed the highest miR-375 expression, knockdown experiments also attenuated the malignant phenotype. Gene ontology analysis implicated miR-375 in several key pathways deregulated in PCa, including cell cycle and cell differentiation. Moreover, CCND2 was identified as putative miR-375 target in PCa, confirmed by luciferase assay.ConclusionsA dual role for miR-375 in prostate cancer progression is suggested, highlighting the importance of cellular context on microRNA targeting.

Deregulated expression of selected histone methylases and demethylases in prostate carcinoma.

Prostate cancer (PCa), a leading cause of cancer-related morbidity and mortality, arises through the acquisition of genetic and epigenetic alterations. Deregulation of histone methyltransferases (HMTs) or demethylases (HDMs) has been associated with PCa development and progression. However, the precise influence of altered HMTs or HDMs expression and respective histone marks in PCa onset and progression remains largely unknown. To clarify the role of HMTs and HDMs in prostate carcinogenesis, expression levels of 37 HMTs and 20 HDMs were assessed in normal prostate and PCa tissue samples by RT-qPCR. SMYD3, SUV39H2, PRMT6, KDM5A, and KDM6A were upregulated, whereas KMT2A-E (MLL1-5) and KDM4B were downregulated in PCa, compared with normal prostate tissues. Remarkably, PRMT6 was the histone modifier that best discriminated normal from tumorous tissue samples. Interestingly, EZH2 and SMYD3 expression levels significantly correlated with less differentiated and more aggressive tumors. Remarkably, SMYD3 expression levels were of independent prognostic value for the prediction of disease-specific survival of PCa patients with clinically localized disease submitted to radical prostatectomy. We concluded that expression profiling of HMTs and HDMs, especially SMYD3, might be of clinical usefulness for the assessment of PCa patients and assist in pre-therapeutic decision-making.

Enoxacin inhibits growth of prostate cancer cells and effectively restores microRNA processing

Prostate cancer (PCa) is one of the most incident malignancies worldwide. Although efficient therapy is available for early-stage PCa, treatment of advanced disease is mainly ineffective and remains a clinical challenge. microRNA (miRNA) dysregulation is associated with PCa development and progression. In fact, several studies have reported a widespread downregulation of miRNAs in PCa, which highlights the importance of studying compounds capable of restoring the global miRNA expression. The main aim of this study was to define the usefulness of enoxacin as an anti-tumoral agent in PCa, due to its ability to induce miRNA biogenesis in a TRBP-mediated manner. Using a panel of five PCa cell lines, we observed that all of them were wild type for the TARBP2 gene and expressed TRBP protein. Furthermore, primary prostate carcinomas displayed normal levels of TRBP protein. Remarkably, enoxacin was able to decrease cell viability, induce apoptosis, cause cell cycle arrest, and inhibit the invasiveness of cell lines. Enoxacin was also effective in restoring the global expression of miRNAs. This study is the first to show that PCa cells are highly responsive to the anti-tumoral effects of enoxacin. Therefore, enoxacin constitutes a promising therapeutic agent for PCa.

Cognitive processing of emotions in anorexia nervosa

OBJECTIVE This study attempts to explore the cognitive processing of emotions in anorexia nervosa (AN), based on the study of emotions felt and the assessment of meta-emotional abilities. METHOD Eighty patients with AN and a control group of 80 healthy female participants were screened for anxiety, depression and alexithymia and completed an experimental task designed to analyse the emotional experience and meta-emotional abilities. RESULTS Despite presenting higher levels of alexithymia, participants with AN demonstrated they were able to imagine emotions in hypothetical situations and to identify and label them. The group of patients with AN revealed feeling more intense and internally based negative emotions in comparison with the control group, but this emotional pattern tends to occur in situations associated with food and weight. CONCLUSIONS Findings on meta-emotional abilities suggested no global deficit in emotional processing, but rather, specific sensitivities pertaining to situations relevant to AN.

Expression of histone methyltransferases as novel biomarkers for renal cell tumor diagnosis and prognostication.

Renal cell tumors (RCTs) are the most lethal of the common urological cancers. The widespread use of imaging entailed an increased detection of small renal masses, emphasizing the need for accurate distinction between benign and malignant RCTs, which is critical for adequate therapeutic management. Histone methylation has been implicated in renal tumorigenesis, but its potential clinical value as RCT biomarker remains mostly unexplored. Hence, the main goal of this study was to identify differentially expressed histone methyltransferases (HMTs) and histone demethylases (HDMs) that might prove useful for RCT diagnosis and prognostication, emphasizing the discrimination between oncocytoma (a benign tumor) and renal cell carcinoma (RCC), especially the chromophobe subtype (chRCC). We found that the expression levels of 3 genes—SMYD2, SETD3, and NO66—was significantly altered in a set of RCTs, which was further validated in a large independent cohort. Higher expression levels were found in RCTs compared to normal renal tissues (RNTs) and in chRCCs comparatively to oncocytomas. SMYD2 and SETD3 mRNA levels correlated with protein expression assessed by immunohistochemistry. SMYD2 transcript levels discriminated RCTs from RNT, with 82.1% sensitivity and 100% specificity [area under curve (AUC) = 0.959], and distinguished chRCCs from oncocytomas, with 71.0% sensitivity and 73.3% specificity (AUC = 0.784). Low expression levels of SMYD2, SETD3, and NO66 were significantly associated with shorter disease-specific and disease-free survival, especially in patients with non-organ confined tumors. We conclude that expression of selected HMTs and HDMs might constitute novel biomarkers to assist in RCT diagnosis and assessment of tumor aggressiveness.

Histone methyltransferase PRMT6 plays an oncogenic role of in prostate cancer

Prostate cancer (PCa) is a major cause of morbidity and mortality. Until now the specific role of histone methyltransferases (HMTs) deregulated expression/activity in PCa is poorly understood. Herein we aimed to uncover the potential oncogenic role of PRMT6 in prostate carcinogenesis. PRMT6 overexpression was confirmed in PCa, at transcript and protein level. Stable PRMT6 knockdown in PC-3 cells attenuated malignant phenotype, increasing apoptosis and decreasing cell viability, migration and invasion. PRMT6 silencing was associated with decreased H3R2me2a levels and increased MLL and SMYD3 expression. PRMT6 silencing increased p21, p27 and CD44 and decreased MMP-9 expression and was associated with PI3K/AKT/mTOR downregulation and increased AR signaling pathway. In Sh-PRMT6 cells, AR restored expression might re-sensitized cells to androgen deprivation therapy, impacting in clinical management of castration-resistant PCa (CRPC). PRMT6 plays an oncogenic role in PCa and predicts for more clinically aggressive disease, constituting a potential target for patients with CRPC.

Prevalência da alexitimia na anorexia nervosa e sua associação com variáveis clínicas e sociodemográficas

objective: To analyze the prevalence of alexithymia in anorexia nervosa and its relationship with clinical and sociodemographic variables, such as, body mass index, anorexia nervosa duration, age, years of education and socioeconomic status. Methods: Two groups of female participants, between the ages of 13 and 34 years, were recruited. One group was composed of 80 participants with anorexia nervosa (AN Group) and the other consisted of 80 healthy participants (Control Group). The Portuguese version of the Toronto Alexithymia Scale – 20 items – was applied to both groups. results: The prevalence of alexithymia in the AN Group was 62.5% and 12.5% in the Control Group. The mean values of alexithymia (total score and factors) did

High immunoexpression of Ki67, EZH2, and SMYD3 in diagnostic prostate biopsies independently predicts outcome in patients with prostate cancer

INTRODUCTION Overtreatment is a major concern in patients with prostate cancer (PCa). Prognostic biomarkers discriminating indolent from aggressive disease in prostate biopsy are urgently needed. We aimed to evaluate the prognostic value of Ki67, EZH2, LSD1, and SMYD3 immunoexpression in diagnostic biopsies from a cohort of PCa patients with long term follow-up. MATERIALS AND METHODS A series of 189 consecutive prostate biopsies diagnosed with PCa (1997-2001) in a cancer center was included in the study, with follow-up last updated in November 2016. Biopsies were reviewed and graded according to 2016 WHO criteria. Immunohistochemistry was performed in the most representative block. Nuclear staining was assessed using digital image analysis. Study outcomes included disease-specific, disease-free, and progression-free survival. Statistical analysis was tabulated using SPSS version 22.0. Survival curves and hazard ratios (HRs) were estimated using Kaplan-Meyer and Cox-regression models, respectively. Statistical significance was set at P<0.05. RESULTS The proportion of patients who completed the study was 177/189 (94%). In univariable analysis, high Ki67, EZH2, and SMYD3 immunoexpression associated with significantly worse disease-specific survival (HR = 1.86, 95% CI: 1.05-3.29; HR = 1.87, 95% CI: 1.10-3.27; HR = 2.68, 95% CI: 1.02-7.92). In multivariable analysis, the 3 biomarkers displayed significantly worse DSS adjusted for CAPRA score (HR = 1.78, 95% CI: 1.01-3.16; HR = 1.93, 95% CI: 1.12-3.32; HR = 2.71, 95% CI: 1.04-7.10). Among patients with low/intermediate risk CAPRA score, high Ki67 immunoexpression identified those more prone to experience disease recurrence (HR = 9.20, 95% CI: 1.27-66.44) and progression (HR = 2.97, 95% CI: 1.05-8.43). CONCLUSIONS High Ki67, EZH2, and SMYD3 immunoexpression, adjusted for standard clinicopathological parameters, independently predicts outcome in patients with PCa, at diagnosis. This might assist in discriminating indolent from aggressive PCa, improving treatment selection.

Phenotypic impact of deregulated expression of class I histone deacetylases in urothelial cell carcinoma of the bladder

Deregulated expression of histone deacetylases (HDACs) has been implicated in tumorigenesis. Herein, we investigated class I HDACs expression in bladder urothelial cell carcinoma (BUCC), its prognostic value and biological significance. Significantly increased transcript levels of all HDACs were found in BUCC compared to 20 normal mucosas, and these were higher in lower grade and stage tumors. Increased HDAC3 levels were associated with improved patient survival. SiRNA experiments showed decrease cell viability and motility, and increased apoptosis. We concluded that class I HDACs play an important role in bladder carcinogenesis through deregulation of proliferation, migration and apoptosis, constituting putative therapeutic targets.

Histone posttranslational modifications and chromatin remodelers in prostate cancer

Prostate cancer (PCa) is one of the most incident and prevalent cancers in men worldwide and a leading cause of cancer-related morbidity and mortality. Epigenetics plays an important role in prostate carcinogenesis, namely abnormal expression of histone modifier enzymes and related chromatin modifications. Notwithstanding, the limited knowledge of the specific role of deregulated activity/expression of histone modifiers and respective histone modifications hinders their use in clinical management, particularly for PCa detection and prognostication. Due to the limitations in the analysis of global patterns of histone modifications, few studies reported on the biomarker potential of these epigenetic marks. Importantly, the reversible nature of histone modifications makes them a promising therapeutic option for this malignancy. Indeed, over the past years, molecules with inhibitory activity upon the epigenetic machinery have been developed and are currently under evaluation in clinical trials to test their effectiveness.