Percorrer por autor "Loureiro, Susana Sofia Macêdo"
A mostrar 1 - 1 de 1
Resultados por página
Opções de ordenação
- Non-invasive screening strategies for colorectal cancer: Protocol optimization and RNA biomarker identificationPublication . Loureiro, Susana Sofia Macêdo; Lima, Luís; Santos, MarleneColorectal cancer (CRC) continues to have high incidence and mortality and benefits from non-invasive screening strategies that detect precursor lesions early and increase adherence. Circulating biomarkers and fecal transcriptomic profiles are promising approaches, but they require clinical validation and robust laboratory protocols. (i) Evaluate selected plasma microRNAs as potential biomarkers for detecting lesions across the neoplastic development of CRC; (ii) optimize a workflow for detecting human fecal RNA, comparing critical processing steps and cDNA synthesis conditions to improve performance and reproducibility in RT-qPCR. Case-control study with four clinical groups (no lesion, low-grade dysplasia, high-grade dysplasia/advanced lesions, and CRC). Four plasma microRNAs were quantified by RT-qPCR. In parallel, different conditions in the fecal RNA extraction process and the influence of different reverse transcriptases and primer types were tested to optimize the detection of human mRNA. Plasma microRNAs showed consistent expression disturbances across groups, with better performance when combined in panels, suggesting discriminatory value. In fecal RNA, debris removal and optimized centrifugation parameters increased extraction yield and enhanced the capacity to detect human mRNA. Kit- and primer-dependent differences were observed in cDNA synthesis, with appropriate selection of these elements improving the efficiency and reproducibility of RT-qPCR. The results support the potential of plasma microRNA panels as a complement to current screening methods and establish an optimized protocol for fecal RNA, creating a technical foundation for multicenter validation and multi-matrix integration in CRC screening.