RESUMO
The development of prophylactic agents against the SARS-CoV-2 virus is a public health priority in the search for new surrogate markers of active virus replication. Early detection markers are needed to follow disease progression and foresee patient negativization. Subgenomic RNA transcripts (with a focus on sgN) were evaluated in oro/nasopharyngeal swabs from COVID-19-affected patients with an analysis of 315 positive samples using qPCR technology. Cut-off Cq values for sgN (Cq < 33.15) and sgE (Cq < 34.06) showed correlations to high viral loads. The specific loss of sgN in home-isolated and hospitalized COVID-19-positive patients indicated negativization of patient condition, 3-7 days from the first swab, respectively. A new detection kit for sgN, gene E, gene ORF1ab, and gene RNAse P was developed recently. In addition, in vitro studies have shown that 2'-O-methyl antisense RNA (related to the sgN sequence) can impair SARS-CoV-2 N protein synthesis, viral replication, and syncytia formation in human cells (i.e., HEK-293T cells overexpressing ACE2) upon infection with VOC Alpha (B.1.1.7)-SARS-CoV-2 variant, defining the use that this procedure might have for future therapeutic actions against SARS-CoV-2.
Assuntos
COVID-19/virologia , Proteínas do Nucleocapsídeo de Coronavírus/genética , SARS-CoV-2/fisiologia , Replicação Viral/fisiologia , Proteínas do Nucleocapsídeo de Coronavírus/análise , Células Gigantes/efeitos dos fármacos , Células Gigantes/virologia , Células HEK293 , Humanos , Limite de Detecção , Nasofaringe/virologia , Fosfoproteínas/análise , Fosfoproteínas/genética , RNA Antissenso/farmacologia , RNA Viral , Ribonuclease P/genética , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , Sensibilidade e Especificidade , Isolamento Social , Carga Viral , Proteínas Viroporinas/genética , Replicação Viral/efeitos dos fármacosRESUMO
In non-small cell lung cancer (NSCLC), the epidermal growth factor receptor (EGFR) gene may undergo both mutations and copy number gains. EGFR mutant allele-specific imbalance (MASI) occurs when the ratio of mutant-to-wild-type alleles increases significantly. In this study, by using a previously validated microfluidic-chip-based technology, EGFR-MASI occurred in 25/67 mutant cases (37%), being more frequently associated with EGFR exon 19 deletions (p=0.033). In a subset of 49 treated patients, we assessed whether MASI is a modifier of anti-EGFR treatment benefit. The difference in progression-free survival and overall survival between EGFR-MASI-positive and EGFR-MASI-negative groups of patients did not show a statistical significance. In conclusion, EGFR-MASI is a significant event in NSCLC, specifically associated with EGFR exon 19 deletions. However, EGFR-MASI does not seem to play a role in predicting the response to first-generation EGFR small molecules inhibitors.
