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Teotónio Fernandes, Mónica Alexandra

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  • NF-kappa B-dependent RANKL expression in a mouse model of immature T-cell leukemia
    Publication . Fernandes, Mónica T; Caroco, Lara S.; Pacheco-Leyva, Ivette; R. dos Santos, Nuno
    Activation of the receptor activator of nuclear factor-kappa B (RANK) by its ligand (RANKL) is involved in both solid and hematological malignancies, including multiple myeloma, acute myeloid leukemia and B-cell leukemia. Although RANKL expression has been described in normal T cells, a potential role in T-cell leukemia remains undefined. Here, we used a model of immature T-cell leukemia/lymphoma, the TEL-JAK2 transgenic mice, to assess RANKL expression in leukemic cells and its regulatory mechanisms. We found that Rankl mRNA was significantly overexpressed in leukemic T cells when compared to wild-type thymocytes, their nonmalignant counterparts. Moreover, Rankl mRNA and RANKL surface expression in leukemic cells was induced by T-cell receptor (TCR) signaling activation, dependently on the NFKB signaling pathway. These results indicate that TCR-activated leukemic T cells express high levels of RANKL and are potential inducers of RANK signaling in microenvironmental cells. (C) 2019 Elsevier Inc. All rights reserved.
  • Post-transcriptional silencing of Bos taurus prion family genes and its impact on granulosa cell steroidogenesis
    Publication . Pimenta, Jorge M.B.G.A.; Pires, Virgínia M.R.; Nolasco, Sofia; Castelo-Branco, Pedro; Marques, Carla C.; Apolónio, Joana; Azevedo, Rita; Fernandes, Mónica T.; Lopes-da-Costa, Luís; Prates, José; Pereira, Rosa M.L.N.
    Prion proteins constitute a major public health concern, which has partly overshadowed their physiological roles in several scenarios. Indeed, these proteins were implicated in male fertility but their role in female fertility is relatively less explored. This study was designed to evaluate the role of SPRN and PRNP prion family genes in bovine follicular steroidogenesis pathways. Post-transcriptional SPRN and PRNP silencing with siRNAs was established in bovine granulosa cell (GC) in vitro culture, and gene expression and progesterone and estradiol concentrations were evaluated. SPRN knockdown, led to a down regulation of CYP11A1 mRNA levels (2.1-fold), and PRNP knockdown led to an upregulation of SPRN mRNA levels (2.3-fold). CYP19A1 expression and estradiol synthesis was not detected in any experimental group. Finally, SPRN knockdown led to a mild reduction in progesterone production in GCs and this was the only experimental group that did not exhibit an increment in progesterone levels after 48 h of culture. As a conclusion, it was possible to detect the expression of the SPRN gene in bovine GCs, a potential interaction between SPRN and PRNP regulation, and the impact of SPRN expression on CYP11A1 and progesterone levels. These findings bring new insights into the role of these genes in ovarian steroidogenesis and female reproductive physiology. (c) 2022 Elsevier Inc. All rights reserved.
  • Tribbles gene expression profiles in colorectal cancer
    Publication . Fernandes, Mónica T.; Yassuda, Victor; Bragança, José; Link, Wolfgang; Ferreira, Bibiana; De Sousa-Coelho, Ana Luísa
    Colorectal cancer (CRC) is the third most common cancer and the second leading cause of death due to cancer in the world. Therefore, the identification of novel druggable targets is urgently needed. Tribbles proteins belong to a pseudokinase family, previously recognized in CRC as oncogenes and potential therapeutic targets. Here, we analyzed the expression of TRIB1, TRIB2, and TRIB3 simultaneously in 33 data sets from CRC based on available GEO profiles. We show that all three Tribbles genes are overrepresented in CRC cell lines and primary tumors, though depending on specific features of the CRC samples. Higher expression of TRIB2 in the tumor microenvironment and TRIB3 overexpression in an early stage of CRC development, unveil a potential and unexplored role for these proteins in the context of CRC. Differential Tribbles expression was also explored in diverse cellular experimental conditions where either genetic or pharmacological approaches were used, providing novel hints for future research. This comprehensive bioinformatic analysis provides new insights into Tribbles gene expression and transcript regulation in CRC.
  • Human stem cells for cardiac disease modeling and preclinical and clinical applications—are we on the road to success?
    Publication . Correia, Cátia; Ferreira, Anita; Fernandes, Mónica T.; Silva, Bárbara M.; Esteves, Filipa; Leitao, Helena; Bragança, José; Calado, Sofia
    Cardiovascular diseases (CVDs) are pointed out by the World Health Organization (WHO) as the leading cause of death, contributing to a significant and growing global health and economic burden. Despite advancements in clinical approaches, there is a critical need for innovative cardiovascular treatments to improve patient outcomes. Therapies based on adult stem cells (ASCs) and embryonic stem cells (ESCs) have emerged as promising strategies to regenerate damaged cardiac tissue and restore cardiac function. Moreover, the generation of human induced pluripotent stem cells (iPSCs) from somatic cells has opened new avenues for disease modeling, drug discovery, and regenerative medicine applications, with fewer ethical concerns than those associated with ESCs. Herein, we provide a state-of-the-art review on the application of human pluripotent stem cells in CVD research and clinics. We describe the types and sources of stem cells that have been tested in preclinical and clinical trials for the treatment of CVDs as well as the applications of pluripotent stem-cell-derived in vitro systems to mimic disease phenotypes. How human stem-cell-based in vitro systems can overcome the limitations of current toxicological studies is also discussed. Finally, the current state of clinical trials involving stem-cell-based approaches to treat CVDs are presented, and the strengths and weaknesses are critically discussed to assess whether researchers and clinicians are getting closer to success.
  • Charting the path: navigating embryonic development to potentially safeguard against congenital heart defects
    Publication . Bragança, José; Pinto, Rute L.; Silva, Barbara S.; Marques, Nuno; Leitao, Helena; Fernandes, Mónica T.
    Congenital heart diseases (CHDs) are structural or functional defects present at birth due to improper heart development. Current therapeutic approaches to treating severe CHDs are primarily palliative surgical interventions during the peri- or prenatal stages, when the heart has fully developed from faulty embryogenesis. However, earlier interventions during embryonic development have the potential for better outcomes, as demonstrated by fetal cardiac interventions performed in utero, which have shown improved neonatal and prenatal survival rates, as well as reduced lifelong morbidity. Extensive research on heart development has identified key steps, cellular players, and the intricate network of signaling pathways and transcription factors governing cardiogenesis. Additionally, some reports have indicated that certain adverse genetic and environmental conditions leading to heart malformations and embryonic death may be amendable through the activation of alternative mechanisms. This review first highlights key molecular and cellular processes involved in heart development. Subsequently, it explores the potential for future therapeutic strategies, targeting early embryonic stages, to prevent CHDs, through the delivery of biomolecules or exosomes to compensate for faulty cardiogenic mechanisms. Implementing such non-surgical interventions during early gestation may offer a prophylactic approach toward reducing the occurrence and severity of CHDs.
  • Cdkn2a inactivation promotes malignant transformation of mouse immature thymocytes before the β-selection checkpoint
    Publication . Catarino, Telmo A.; Pacheco-Leyva, Ivette; Kindi, Faiza Al; Ghezzo, Marinella N.; Fernandes, Mónica T.; Costa, Telma; Rodrigues Dos Santos, Nuno
    CDKN2A deletion is the most frequent genetic alteration in T-cell acute lymphoblastic leukemia (T-ALL), occurring across all molecular and immunophenotypic subtypes. CDKN2A encodes two functionally unrelated tumor suppressor proteins, ARF and INK4a, which are critical regulators of cell cycle and proliferation. Arf has been reported to suppress T-ALL development in post−b-selection thymocytes, but whether CDKN2A acts as a tumor suppressor gene in immature, pre−b-selection thymocytes remains to be elucidated. Resorting to a Rag2-deficient model of T-ALL, driven by the ETV6:: JAK2 fusion, we report that Cdkn2a haploinsufficiency at early stages of T-cell development facilitates leukemia development
  • CITED2 and the modulation of the hypoxic response in cancer
    Publication . Fernandes, Mónica T; Calado, Sofia; Mendes-Silva, Leonardo; Bragança, José
    CITED2 (CBP/p300-interacting transactivator with Glu/Asp-rich C-terminal domain, 2) is a ubiquitously expressed protein exhibiting a high affinity for the CH1 domain of the transcriptional co-activators CBP/p300, for which it competes with hypoxia-inducible factors (HIFs). CITED2 is particularly efficient in the inhibition of HIF-1α-dependent transcription in different contexts, ranging from organ development and metabolic homeostasis to tissue regeneration and immunity, being also potentially involved in various other physiological processes. In addition, CITED2 plays an important role in inhibiting HIF in some diseases, including kidney and heart diseases and type 2-diabetes. In the particular case of cancer, CITED2 either functions by promoting or suppressing cancer development depending on the context and type of tumors. For instance, CITED2 overexpression promotes breast and prostate cancers, as well as acute myeloid leukemia, while its expression is downregulated to sustain colorectal cancer and hepatocellular carcinoma. In addition, the role of CITED2 in the maintenance of cancer stem cells reveals its potential as a target in non-small cell lung carcinoma and acute myeloid leukemia, for example. But besides the wide body of evidence linking both CITED2 and HIF signaling to carcinogenesis, little data is available regarding CITED2 role as a negative regulator of HIF-1α specifically in cancer. Therefore, comprehensive studies exploring further the interactions of these two important mediators in cancer-specific models are sorely needed and this can potentially lead to the development of novel targeted therapies.
  • Identification of novel DNA methylation prognostic biomarkers for AML with normal cytogenetics
    Publication . Cardoso, Cândida; Pestana, Daniel; Gokuladhas, Sreemol; Marreiros, Ana; Justin M. O'Sullivan; Binnie, Alexandra; Teotónio Fernandes, Mónica Alexandra; Castelo-Branco, Pedro
    PURPOSE AML is a hematologic cancer that is clinically heterogeneous, with a wide range of clinical outcomes. DNA methylation changes are a hallmark of AML but are not routinely used as a criterion for risk stratification. The aim of this study was to explore DNA methylation markers that could risk stratify patients with cytogenetically normal AML (CN-AML), currently classified as intermediate-risk.MATERIALS AND METHODSDNA methylation profiles in whole blood samples from 77 patients with CN-AML in The Cancer Genome Atlas (LAML cohort) were analyzed. Individual 5'-cytosine-phosphate-guanine-3' (CpG) sites were assessed for their ability to predict overall survival. The output was validated using DNA methylation profiles from bone marrow samples of 79 patients with CN-AML in a separate data set from the Gene Expression Omnibus.RESULTSIn the training set, using DNA methylation data derived from the 450K array, we identified 2,549 CpG sites that could potentially distinguish patients with CN-AML with an adverse prognosis (intermediate-poor) from those with a more favorable prognosis (intermediate-favorable) independent of age. Of these, 25 CpGs showed consistent prognostic potential across both the 450K and 27K array platforms. In a separate validation data set, nine of these 25 CpGs exhibited statistically significant differences in 2-year survival. These nine validated CpGs formed the basis for a combined prognostic biomarker panel, which includes an 8-CpG Somatic Panel and the methylation status of cg23947872. This panel displayed strong predictive ability for 2-year survival, 2-year progression-free survival, and complete remission in the validation cohort.CONCLUSIONThis study highlights DNA methylation profiling as a promising approach to enhance risk stratification in patients with CN-AML, potentially offering a pathway to more personalized treatment strategies.