CircFOXN2 alleviates glucocorticoid- and tacrolimus-induced dyslipidemia by reducing FASN mRNA stability by binding to PTBP1 during liver transplantation.

We aimed to examine impacts and functional mechanism of circular RNA forkhead box N2 (FOXN2) in tacrolimus (TAC)- and dexamethasone (Dex)-induced lipid metabolism disorders. RNA level and protein contents in TAC, Dex, or combined TAC- plus Dex-treated patients and Huh-7 cells were measured utilizing quantitative real-time (qRT)-PCR and western blotting assays measured the formation of lipid droplet. Total cholesterol (TC) and triglyceride (TG) levels were determined using corresponding commercial kits and Oil red O staining. RNA immunoprecipitation and RNA pull-down verified the binding relationship among circFOXN2, polypyrimidine tract binding protein 1 (PTBP1) and fatty acid synthase (FASN). Male C57BL/6 mice were used to establish a dyslipidemia mouse model to validate the discoveries at the cellular level. Dex treatment significantly promoted TAC-mediated increase of TC and TG in serum samples and Huh-7 cells. Moreover, circFOXN2 was reduced but FASN was elevated in TAC-treated Huh-7 cells, and these expression trends were markedly enhanced by Dex cotreatment. Overexpression of circFOXN2 could reverse the accumulation of TC and TG and the upregulation of FASN and sterol regulatory element binding transcription factor 2 (SREBP2) mediated by Dex and TAC cotreatment. Mechanistically, circFOXN2 reduced FASN mRNA stability by recruiting PTBP1. The protective roles of circFOXN2 overexpression on lipid metabolism disorders were weakened by FASN overexpression. In vivo finding also disclosed that circFOXN2 greatly alleviated the dysregulation of lipid metabolism triggered by TAC plus Dex. CircFOXN2 alleviated the dysregulation of lipid metabolism induced by the combination of TAC and Dex by modulating the PTBP1/FASN axis.NEW & NOTEWORTHY Collectively, our experiments revealed for the first time that circFOXN2 alleviated the Dex- and TAC-induced dysregulation of lipid metabolism by regulating the PTBP1/FASN axis. These findings suggested that circFOXN2 and FASN might be candidate targets for the treatment of Dex- and TAC-induced metabolic disorders.

miR­92a represses the viability and migration of nerve cells in Hirschsprung's disease by regulating the KLF4/PI3K/AKT pathway.

Hirschsprung's disease (HSCR) is an intestinal disease caused by defects in neural crest cell migration, proliferation, differentiation, and survival. Many reports have proposed that miRNA dysregulation is related to the occurrence of HSCR. However, the roles and mechanisms of miRNAs have not been thoroughly studied. The levels of miR­92a and KLF4 were examined using qRT­PCR and immunohistochemistry, respectively. Cell viability, migration and apoptosis were evaluated by MTT, Transwell and flow cytometry assays, respectively. A dual­luciferase reporter assay was employed to verify the binding relationship between miR­92a and KLF4. Levels of PI3K/AKT signals were further determined by western blot assay. Herein, elevated expression of miR­92a and reduced expression of KLF4 were found in HSCR tissues, and their expression patterns were negatively correlated. Overexpression of miR­92a inhibited cell viability and migration but enhanced cell apoptosis. However, overexpression of KLF4 had the opposite effects. Mechanistically, KLF4 was a target of miR­92a and it negatively affected biological functions by activating PI3K/AKT signaling. These results proved that miR­92a inhibited the proliferation and metastasis of nerve cells by regulating the KLF4/PI3K/AKT axis.

lncRNA TUG1 regulates angiogenesis via the miR­204­5p/JAK2/STAT3 axis in hepatoblastoma.

Hepatoblastoma is the most common malignant hepatic tumour type with hypervascularity in early childhood. In recent decades, emerging evidence has proven that long non­coding RNAs (lncRNAs) serve an important oncogenic role in the pathogenesis of hepatoblastoma. However, the underlying mechanism of lncRNA taurine upregulated 1 (TUG1) in the angiogenesis of hepatoblastoma remains unknown. The expression patterns of TUG1 and microRNA (miR)­204­5p were detected in hepatoblastoma tissues and cell lines via reverse transcription­quantitative PCR and were analysed using a Pearson's correlation test. A tube formation assay was performed using human umbilical vein endothelial cells to assess the vasculogenic activity of treated HuH­6 cells. ELISA was used to detect the level of the secretory proangiogenic factor VEGFA in the culture media of HuH­6 cells. A dual luciferase reporter assay was performed to validate the binding relationships of TUG1/miR­204­5p and miR­204­5p/Janus kinase 2 (JAK2). Moreover, western blotting was conducted to measure the protein expression levels of VEGFA, phosphorylated (p)­JAK2, JAK2, p­STAT3 and STAT3. It was identified that TUG1 was upregulated, while miR­204­5p was downregulated in hepatoblastoma tissues and cells. TUG1 knockdown inhibited angiogenesis induced by hepatoblastoma cells. Furthermore, miR­204­5p was identified as a target of TUG1. The results demonstrated that TUG1 attenuated the inhibitory effect of miR­204­5p on the JAK2/STAT3 pathway and promoted angiogenesis in hepatoblastoma cells. In summary, TUG1 was upregulated in hepatoblastoma and suppressed miR­204­5p, thereby activating the downstream signalling pathway of JAK2/STAT3 to facilitate angiogenesis. The present findings will provide novel targets for the treatment of hepatoblastoma.

Long Non-Coding RNA CRNDE Regulates Angiogenesis in Hepatoblastoma by Targeting the MiR-203/VEGFA Axis.

OBJECTIVE: MiR-203 has been shown to participate in multiple malignancies, but the role of miR-203 in hepatoblastoma (HB) remains unclear. The aim of our study was to investigate the effects of miR-203 in HB. METHODS: A total of 15 pairs of HB tissues and para-tumour normal tissues were collected for the experiments. RT-qPCR and Western blotting were performed to detect the expression of CRNDE, miR-203, and VEGFA at the mRNA and/or protein levels, respectively. A dual luciferase assay verified the target relationship between miR-203 and the 3'UTR of VEGFA as well as miR-203 and CRNDE. In addition, MTT, wound healing, and tube formation assays were performed to assess the effects of miR-203, VEGFA, and CRNDE on cell proliferation, migration, and angiogenesis, respectively. RESULTS: Our data revealed that miR-203 expression was decreased in HB tissues, while long non-coding RNA (lncRNA) CRNDE expression was increased. The dysregulation of miR-203 and CRNDE was closely related to tumour size and stage. Moreover, overexpression of miR-203 inhibited angiogenesis. A dual luciferase assay verified that VEGFA is a direct target of miR-203 and that CRNDE binds to miR-203. Furthermore, our results showed that miR-203 suppressed cell viability, migration, and angiogenesis by regulating VEGFA expression. Additionally, it was confirmed that CRNDE promoted angiogenesis by negatively regulating miR-203 expression. CONCLUSION: lncRNA CRNDE targets the miR-203/VEGFA axis and promotes angiogenesis in HB. These results provide insight into the underlying mechanisms of HB and indicate that CRNDE and miR-203 might be potential targets for HB therapy.