The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system discovered using bacteria has been repurposed for genome editing in human cells. Transient expression of the editor proteins (e.g. Cas9 protein) is desirable to reduce the risk of mutagenesis from off-target activity. Using the specific interaction between bacteriophage RNA-binding proteins and their RNA aptamers, we developed a system able to package up to 100 copies of Staphylococcus aureus Cas9 ( SaCas9 ) mRNA in each l enti v irus- l ike bionano p article (LVLP). The SaCas9 LVLPs mediated transient SaCas9 expression and achieved highly efficient genome editing in the presence of guide RNA. Lower off-target rates occurred in cells transduced with LVLPs containing SaCas9 mRNA, compared with cells transduced with adeno-associated virus or lentivirus expressing SaCas9 . Our LVLP system may be useful for efficiently delivering Cas9 mRNA to cell lines and primary cells for in vitro and in vivo gene editing applications.

Background: miR-26b-5p is reported to be involved in the progression of multiple cancers, but its function and mechanism in human papillary thyroid cancer (PTC) remain unknown. We aimed to uncover the function and mechanism of miR-26b-5p in PTC. Methods: We performed qRT-PCR to detect the differences in miR-26b-5p expression between normal tissue and PTC. In vitro, we established cell lines stably overexpressing miR-26b-5p and investigated the function and underlying mechanism of miR-26b-5p in PTC. Results: miR-26b-5p was downregulated in PTC compared with normal tissue. miR-26b-5p was correlated with the clinical stage. miR-26b-5p inhibited the proliferation, invasion and migration of PTC cell lines. We next detected EMT and proliferation markers. miR-26b-5p was shown to exert its function in a β-catenin-dependent manner. Conclusion: Taken together, our results showed that miR-26b-5p inhibits proliferation, migration, invasion and EMT by degrading β-catenin.

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Background This study utilized CRISPR/Cas9 gene editing technology to construct a Mex3c gene-deficient mouse model, and studied C-FOS expression in hypothalamic nuclei. Material/Methods Thirty Mex3c −/+ mice, 30 mice in the normal group, and 30 Mex3c −/+ mice were randomly divided into control, leptin, and ghrelin groups according to different intraperitoneal injections. HE and Nissl staining were performed to observe the morphology of hypothalamic nerve cells. The C-FOS expression in hypothalamic nuclei of each group was analyzed by immunohistochemical techniques. HE staining was used to observe neural tube morphology, and LFB staining was used to observe nerve myelin sheath morphology. TEM was used to observe neuronal ultrastructure and immunohistochemical techniques were utilized to analyze nestin expression. Results C-FOS expression was lower in the normal control group than in the leptin and ghrelin groups. The Mex3c control group and the leptin group had higher C-FOS expression than the ghrelin group. In neural tube studies, no significant differences were found in the neural tube pathological sections of E14.5-day embryos in each group. Nestin results demonstrated lower expression in the normal group and there was little difference between the HD and Mex3c groups. Conclusions Mex3c appears to participate in the regulation of energy metabolism by inducing C-FOS expression in the hypothalamus. The neural tubes of the offspring of Mex3c −/+ mice had defects during development.