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- Dysregulated gene expression in colorectal cancer upon exposure to bisphenol A alternatives - a new approachPublication . Lacerda, Rafaela; Ventura, Célia; Louro, Henriqueta; Silva, Maria João; Romão, LuísaBisphenol A (BPA) has been widely used in plastics and resins since the 1950s, making it a common part of everyday products like food containers and bottle linings. Alternative substances are increasingly replacing BPA, but they are raising health and environmental concerns. Some mimic BPA’s endocrine-disrupting effects, while others affect different biological pathways. Substitutions in bisphenols can alter their biological properties, including nuclear receptor activation. Some BPA alternatives, like BPS, BPF and BPZ, may also pose cancer risks by activating oestrogen receptors, potentially even more than BPA itself. They may also contribute to colorectal cancer (CRC). Research suggests that BPA and its substitutes can influence cancer progression by altering cellular pathways, promoting metastasis and affecting gene expression. One of the key steps in gene expression regulation is translation initiation, whose canonical pathway is globally impaired under stress conditions, like exposure to BPA alternatives. Thus, we will subject NCM460 (normal intestinal mucosa) and HCT116 (colorectal carcinoma) cells to BPS, BPF and BPZ exposure and identify the transcripts actively being translated in such conditions, using ribosome profiling. We will analyse data with the R package anota2seq and evaluate the positively identified targets (compared to total RNA sequencing) for the existence of alternative mechanisms of translation initiation regulating their expression. The accurate characterisation of such mechanisms will be crucial for designing antisense RNA oligomers (ASOs) for potential therapeutic approaches. We will evaluate the cytotoxic effects of BPS, BPF and BPZ in the presence or absence of the selected alternatively translated transcripts (functional or targeted with the designed ASOs). Cytotoxic effects will be assessed through in vitro assays, analysing metabolic activity, membrane integrity, and cell proliferation. Thus, our research explores protein synthesis dysregulation to reduce CRC risks from BPS, BPF and BPZ exposure — an emerging public health issue.
- Atypical MEGDHEL Syndrome: A Milder Phenotype With Hepatic Presentation and Failure to Thrive Associated With a Homozygous Nonsense Variant of SERAC1Publication . Marchante Pita, Rita; Amaral, Raquel; Vilarinho, Laura; Diogo, Luísa; Gonçalves, Isabel; Nobre, SusanaMEGDHEL syndrome, caused by a gene defect, is clinically defined as the association of 3-MGA-uria (MEG), deafness (D), hepatopathy (H), encephalopathy (E), and Leigh-like features (L). Clinical presentation typically begins in the neonatal period, with neurological symptoms becoming more evident by 2 years of age. Severe liver involvement has also been reported. We report the case of a 3-year-old boy with increased transaminases and failure to thrive of unknown cause. He was born prematurely at 35 weeks and needed neonatal intensive care support for 24 h due to transient tachypnea. At 18 months, laboratory investigations for failure to thrive revealed elevated transaminases without cholestasis, which persisted on subsequent evaluations. Abdominal wall collateral veins were found during physical examination, and the liver ultrasound revealed steatosis, prompting the decision to proceed with a liver biopsy. Common causes of chronic liver disease were ruled out. Following liver biopsy, performed under general anesthesia, he had an episode of unexplained decompensation (metabolic acidosis, hyperlactatemia, and 3-methylglutaconic aciduria). The aciduria persisted upon subsequent evaluation. Liver histology showed macro/microvesicular steatosis (25%), portal tract inflammation, and mild fibrosis. Cardiac evaluation, along with brain magnetic resonance imaging and spectroscopy, was normal. Further investigations revealed decreased hepatic activity of respiratory mitochondrial chain complexes and marginal mtDNA depletion (28.1%). Analysis of the gene showed homozygosity for p.Y259* (c.777T>G, exon 9). This case report raises awareness for an atypical presentation of MEGDHEL syndrome associated with a homozygous nonsense variant of SERAC1 clinically characterized by mild hypertransaminasemia, failure to thrive, no neurological involvement, and starting in early childhood rather than infancy.
- Alimentação e Saúde: Mitos, Realidades e Boas PráticasPublication . Albuquerque, T.G.Focado em desmistificar mitos sobre nutrição e promover hábitos saudáveis baseados em evidências científicas.