RESUMO
Exosomal microRNAs (miRNAs) from cancer cells play a key role in mediating the oral squamous cell carcinoma (OSCC) microenvironment. The objective of this study was to investigate how the long non-coding RNA (lncRNA) MEG3 affects OSCC angiogenesis through exosomal miR-421. Global miRNA microarray analysis and quantitative real-time PCR (qRT-PCR) were performed to determine the level of miRNAs in OSCC cell-derived exosomes. Cell migration, invasion, tube formation, immunohistochemistry, and hemoglobin concentrations were used to study the effects of exosomal miR-421 in angiogenesis. Western blotting was used to determine the expression level of HS2ST1 and VEGFR2-related downstream proteins. MiRNA array and qRT-PCR identified the upregulation of miR-421 in OSCC cell-derived exosomes. Furthermore, exosomal miR-421 can be taken up by human umbilical vein endothelial cells (HUVECs) and then target HS2ST1 through VEGF-mediated ERK and AKT phosphorylation, thereby promoting HUVEC migration, invasion, and tube formation. Additionally, forced expression of the lncRNA MEG3 in OSCC cells reduced exosomal miR-421 levels and then increased HS2ST1 expression, thereby reducing the VEGF/VEGFR2 pathway in HUVECs. Our results demonstrate a novel mechanism by which lncRNA MEG3 can act as a tumor suppressor and regulate endothelial angiogenesis through the exosomal miR-421/HS2ST1 axis, which provides a potential therapeutic strategy for OSCC angiogenesis.
Assuntos
Carcinoma de Células Escamosas , Movimento Celular , Exossomos , Regulação Neoplásica da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana , MicroRNAs , Neoplasias Bucais , Neovascularização Patológica , RNA Longo não Codificante , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Exossomos/metabolismo , Exossomos/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neoplasias Bucais/metabolismo , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Movimento Celular/genética , Linhagem Celular Tumoral , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , AngiogêneseRESUMO
We demonstrate the observation of gold-nanoparticle internalization in membranes of living cells by using noninterferometric widefield optical profilometry (NIWOP). The NIWOP technique can trace the height of an 80 nm gold particle on the membrane by calibrating the change of light intensity scattered from the particle along the optical axis. On the membrane, the depth resolution based on the scattering signal is similar to that based on the reflection signal, nearly 20 nm. Comparing the heights of the nanoparticle and the nearby cell membranes, we can identify the occurrence of particle internalization. Combining fluorescence microscopy with NIWOP, we also find actin aggregation around the site of the internalization process, which is an indication of endocytosis.