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@#BACKGROUND: Exosomes and exosomal microRNAs have been implicated in tumor occurrence and metastasis. Our previous study showed that microRNA-761 (miR-761) is overexpressed in hepatocellular carcinoma (HCC) tissues and that its inhibition affects mitochondrial function and inhibits HCC metastasis. The mechanism by which exosomal miR-761 modulates the tumor microenvironment has not been elucidated. METHODS: Exosomal miR-761 was detected in six cell lines. Cell counting kit-8 (CCK-8) and transwell migration assays were performed to determine the function of exosomal miR-761 in HCC cells. The luciferase reporter assay was used to analyze miR-761 target genes in normal fibroblasts (NFs). The inhibitors AZD1480 and C188-9 were employed to determine the role of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway in the transformation of cancer-associated fibroblasts (CAFs). RESULTS: In this study, we characterized the mechanism by which miR-761 reprogrammed the tumor microenvironment. We found that HCC-derived exosomal miR-761 was taken up by NFs. Moreover, HCC exosomes affected the tumor microenvironment by activating NFs via suppressor of cytokine signaling 2 (SOCS2) and the JAK2/STAT3 signaling pathway. CONCLUSIONS: These results demonstrated that exosomal miR-761 modulated the tumor microenvironment via SOCS2/JAK2/STAT3 pathway-dependent activation of CAFs. Our findings may inspire new strategies for HCC prevention and therapy.
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Objective To investigate the effect of long non-coding RNA (IncRNA) nuclear-enriched abundant transcript 1 (NEATl) on hypoxia-reoxygenation (H/R) glial astrocyte injury, and to explore whether the mechanism was related to the regulation of micro RNA (miR)-761. Methods Rat cortical astrocytes were cultured to construct a H/R injury model. Astrocytes were divided into control group, model group, model+ small interfering RNA negative control (si-NC) group, model+ si-NEATl group, model+ miR-NC group, model + miR-761 group, model + si-NEATl + anti-miR-NC group, model+si-NEATl+anti-miR-761 group. Expression of NEATl and miR-761 were detected by Real-time PCR. The experiment was repeated 3 times. The content of malonaldefryde (MDA), and the activity of superoxide dismutase (SOD) and catalase (CAT) were detected by kits. Dual luciferase reporter experiment and Real-time PCR were used to analyze the targeting relationship between NEATl and miR-761. The experiment was repeated 3 times. Results Compared with the control group, the cell apoptosis rate and MDA content of the model group increased significantly, SOD and CAT activities decreased significantly, NEATl expression increased significantly, and miR-761 expression decreased significantly (P< 0. 05). Compared with the model+si-NC group, the apoptosis rate and MDA content of the model+si-NEATl group reduced significantly, and SOD and CAT activities increased significantly (P < 0 . 0 5) . Compared with the model + miR-NC group, the apoptosis rate and MDA content of the model + miR-761 group reduced significantly, and SOD and CAT activities increased significantly (P < 0 . 0 5) . MiR-761 was the target gene of N E A T l, and NEATl negatively regulated miR-761 expression. Compared with the model+si-NEATl+anti-miR-NC group, the apoptosis rate and MDA content of the model+siNEAT1+anti-miR-761 group increased significantly, and SOD and CAT activities decreased significantly (P < 0 . 0 5) . Conclusion Interference with NEATl expression can protect astrocytes from H / R injury by up-regulating miR-761.