miRNAs detection for non-small cell lung cancer diagnosis

• Autor(a) principal: Teixeira, Bernardo Ferreira Pires
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/11653
• topic: Cancro do Pulmão de Não-Pequenas Células; Células Mononucleares do Sangue Perifério; Deteção In Situ; Diagnóstico; Micrornas; Sondas Moleculares; Domínio/Área Científica::Engenharia e Tecnologia::Biotecnologia

Lung cancer is one of the most severe and prevalent cancers worldwide. Last year, it was responsible for around two million new cases, and represented the leading cancer regarding mortality. Lung cancer subtype non-small cell lung cancer (NSCLC) constitutes the majority of total lung cancer cases, getting generally diagnosed in advanced stages. Current NSCLC diagnosis approaches lack of sensitivity and specificity. Moreover, most accurate NSCLC diagnosis comprises risky patient-invasive procedures like biopsies. The forward-looking demand for new innovative NSCLC diagnosis approaches that could reinforce ongoing procedures is crucial for an even more precise NSCLC staging and early diagnosis. Recently, new molecular biomarkers are emerging as potential non-invasive diagnostic agents for early-stage NSCLC screening, including multiple miRNAs that display an unusual expression profile in NSCLC. Furthermore, plasma and peripheral blood mononuclear cells (PBMCs) miRNA profile could relate to NSCLC diagnosis. Molecular beacons (MBs) are oligonucleotide probes with a stem-loop structural configuration capable of detect specific nucleic acid sequences throughout fluorescence. The following work studied the development of an in situ MB-based strategy for miRNA detection in NSCLC biological samples. Initially, plasma and PBMCs were isolated from whole blood samples from NSCLC and healthy individuals. miRNA expression profile was screened in PBMCs by RT-qPCR analysis, and further MBs were designed targeting selected miRNAs. Obtained results revealed an upregulated expression of miR-21-3p, miR-21-5p, miR-155-3p and miR-3662 in NSCLC PBMCs, whereas levels of miR-92b-5p, miR-150-3p, miR-155-5p and miR-181a-5p were reduced. Therefore, an in situ method involving miR-21 detection in PBMCs via MBs was shaped and optimized. Accomplished results demonstrated the developed MB approach potential towards miR-21 detection in PBMCs for NSCLC diagnosis.