CircRRAS2 promotes myogenic differentiation of bovine MuSCs and is a novel regulatory molecule of muscle development.

The proliferation and myogenic differentiation of muscle stem cells (MuSCs) are important factors affecting muscle development and beef quality. There is increasing evidence that circRNAs can regulate myogenesis. We found a novel circRNA, named circRRAS2 that is significantly upregulated in the differentiation phase of bovine MuSCs. Here, we aimed to determine its roles in the proliferation and myogenic differentiation of these cells. The results showed that circRRAS2 was expressed in several bovine tissues. CircRRAS2 inhibited MuSCs proliferation and promoted myoblast differentiation. In addition, chromatin isolation by using RNA purification and mass spectrometry in differentiated muscle cells identified 52 RNA-binding proteins that could potentially bind to circRRAS2, in order to regulate their differentiation. The results suggest that circRRAS2 could be a specific regulator of myogenesis in bovine muscle.HighlightsCircRRAS2 expression is higher in DM cells than in GM cells.CircRRAS2 could significantly inhibit the proliferation and apoptosis of bovine MuSCs.CircRRAS2 promotes the differentiation of bovine MuSCs into myotubes.CircRRAS2 may exert regulatory effects through multiple RNA binding proteins.

CircUBE2Q2 promotes differentiation of cattle muscle stem cells and is a potential regulatory molecule of skeletal muscle development.

BACKGROUND: The growth and development of muscle stem cells (MuSCs) are significant events known to affect muscle plasticity, disease, meat production, and meat quality, which involves the types and functions of mRNA and non-coding RNA. Here, MuSCs were cultured from Guangxi fetal cattle. RNA sequencing was used to analyze the RNA expression of mRNA and non-coding RNAs during the cell proliferation and differentiation phases. RESULTS: Two thousand one hundred forty-eight mRNAs and 888 non-coding RNAs were differentially expressed between cell proliferation and differentiation phases, including 113 miRNAs, 662 lncRNAs, and 113 circRNAs. RT-qPCR verified the differential expression levels of mRNAs and non-coding RNAs, and the differentially expressed circUBE2Q2 was subsequently characterized. Expression profile analysis revealed that circUBE2Q2 was abundant in muscle tissues and intramuscular fat. The expression of cricUBE2Q2 was also significantly upregulated during MuSCs myogenic differentiation and SVFs adipogenic differentiation and decreased with age in cattle muscle tissue. Finally, the molecular mechanism of circUBE2Q2 regulating MuSCs function that affects skeletal muscle development was investigated. The results showed that circUBE2Q2 could serve as a sponge for miR-133a, significantly promoting differentiation and apoptosis of cultured MuSCs, and inhibiting proliferation of MuSCs. CONCLUSIONS: CircUBE2Q2 is associated with muscle growth and development and induces MuSCs myogenic differentiation through sponging miR-133a. This study will provide new clues for the mechanisms by which mRNAs and non-coding RNAs regulate skeletal muscle growth and development, affecting muscle quality and diseases.

MicroRNA-107: a novel promoter of tumor progression that targets the CPEB3/EGFR axis in human hepatocellular carcinoma.

MicroRNAs (miRNAs) are dysregulated in many types of malignancies, including human hepatocellular carcinoma (HCC). MiR-107 has been implicated in several types of cancer regulation; however, relatively little is known about miR-107 in human HCC. In the present study, we showed that the overexpression of miR-107 accelerates the tumor progression of HCC in vitro and in vivo through its new target gene, CPEB3. Furthermore, our results demonstrated that CPEB3 is a newly discovered tumor suppressor that acts via the EGFR pathway. Therefore, our study demonstrates that the newly discovered miR-107/CPEB3/EGFR axis plays an important role in HCC progression and might represent a new potential therapeutic target for HCC treatment.