RESUMO
BACKGROUND: MiR-21-5p is a highly expressed microRNA that plays an important role in various cancer-promoting processes, including anchorage-independent growth, invasion, migration metastasis, and drug resistance in lung cancer. Studies indicate that miR-21-5p may contribute to these processes by promoting epithelial-mesenchymal transition (EMT). Ras homolog gene family member B (RhoB), a gene downregulated by miR-21-5p, has also been linked to EMT in lung cancer. However, the role of the miR-21-5p/RhoB axis in EMT regulation in lung adenocarcinoma remains unclear. In this study, we aimed to investigate the regulatory role of the miR-21-5p/RhoB axis in EMT and related in vitro functional characteristics such as migration, invasion, cisplatin resistance, and the formation of tumor spheroids. METHODS AND RESULTS: A549 cells were transfected with the miR-21-5p inhibitor, RhoB siRNA, and their corresponding negative controls. Wound healing, transwell invasion, Methyl thiazole tetrazolium (MTT), and sphere formation assays were also performed to evaluate the migration, invasion, cisplatin resistance, and anchorage-independent growth of A549 cells. RT-qPCR was used to determine the mRNA expression levels of EMT markers. MiR-21-5p knockdown inhibited migration, invasion, cisplatin resistance, and sphere formation while upregulating E-cadherin and downregulating Slug. Furthermore, RhoB silencing restored EMT and related in vitro functional characteristics in A549 cells. CONCLUSIONS: Knockdown of miR-21-5p inhibits EMT and related in vitro functional characteristics by upregulating RhoB, suggesting that miR-21-5p may promote EMT through downregulation of RhoB.
Assuntos
Adenocarcinoma de Pulmão , Movimento Celular , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares , MicroRNAs , Proteína rhoB de Ligação ao GTP , Humanos , Transição Epitelial-Mesenquimal/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Proteína rhoB de Ligação ao GTP/genética , Proteína rhoB de Ligação ao GTP/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Movimento Celular/genética , Células A549 , Resistencia a Medicamentos Antineoplásicos/genética , Cisplatino/farmacologia , Regulação para Cima/genética , Proliferação de Células/genética , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Invasividade Neoplásica/genética , Caderinas/genética , Caderinas/metabolismoRESUMO
Cancer is one of the most actively researched diseases having a high mortality rate when not detected at an early stage. Thus, rapid, simultaneous, and sensitive quantification of cancer biomarkers plays an important role in early diagnosis, with patient impact to disability adjusted life years. Herein, a diatomite-based SERS flexible platform for the rapid and sensitive detection of circulating cancer-specific protein biomarkers in serum is presented. In this approach, diatomite/AgNPs strips with maximum SERS activity prepared using the layer-by-layer (LbL) technique were modified with specific antibodies, and specific antigens (HER2, CA15-3, PSA, and MUC4) were captured and detected. By using Raman probes specific to the captured antigens in serum, a SERS limit of detection (LOD) of 0.1 ng/mL was measured (calculated LOD < 0.1 ng/mL). This value is lower than the cutoff amount of cancer antigens in the person's blood. The specificity for the antigens of each antibody was calculated to be higher than 95%. As a result, an immunosensor for rapid detection of cancer biomarkers in serum with good specificity, high sensitivity, good reproducibility, and low cost has been demonstrated. Overall, we show that the prepared diatomite-based SERS substrate with a high surface-to-volume ratio is a useable platform for immunoassay tests.