Single‐cell RNA sequencing has emerged as a powerful tool for resolving cellular states associated with normal and maligned developmental processes. Here, we used scRNA‐seq to examine the cell cycle states of expanding human neural stem cells (hNSCs). From these data, we constructed a cell cycle classifier that identifies traditional cell cycle phases and a putative quiescent‐like state in neuroepithelial‐derived cell types during mammalian neurogenesis and in gliomas. The Neural G0 markers are enriched with quiescent NSC genes and other neurodevelopmental markers found in non‐dividing neural progenitors. Putative glioblastoma stem‐like cells were significantly enriched in the Neural G0 cell population. Neural G0 cell populations and gene expression are significantly associated with less aggressive tumors and extended patient survival for gliomas. Genetic screens to identify modulators of Neural G0 revealed that knockout of genes associated with the Hippo/Yap and p53 pathways diminished Neural G0 in vitro, resulting in faster G1 transit, down‐regulation of quiescence‐associated markers, and loss of Neural G0 gene expression. Thus, Neural G0 represents a dynamic quiescent‐like state found in neuroepithelial‐derived cells and gliomas.
Background: CRISPR-Cas9-based technologies have revolutionized experimental manipulation of mammalian genomes. None-the-less, limitations of the delivery and efficacy of these technologies restrict their application in primary cells. Aims: To create an optimized protocol for penetrant, reproducible, and fast targeted genome editing in cell cultures derived from primary cells, using patient-derived glioblastoma stem-like cells (GSCs) and human neural stem/progenitor cells (NSCs) for proof-of-concept experiments. Methods and results: We employed transient nucleofection of Cas9:sgRNA ribonucleoprotein complexes composed of chemically synthesized 2 0-O-methyl 3 0 phosphorothioatemodified sgRNAs and purified Cas9 protein. Insertion-deletion mutation (indel) frequency and size distribution were measured via computational deconvolution of Sanger sequencing trace data. We found that this optimized technique routinely allows for >90% indel formation in only 3 days, without the need to create clonal lines for simple loss-of-function experiments. Using Western blotting, we observed near-total protein loss of target genes in cell pools. Additionally, we found that this approach allows for the creation of targeted genomic deletions. Furthermore, by using RNA-seq in edited NSCs to assess gene expression changes resulting from knockout of tumor suppressors commonly altered in glioblastoma, we also demonstrated the utility of this method for quickly creating a series of gene knockouts that allow for the study of oncogenic activities. Conclusion: Our data suggest that this relatively simple method can be used for highly efficient and fast gene knockout, as well as for targeted genomic deletions, even in hyperdiploid cells (such as GSCs). This represents an extremely useful tool for the cancer research community when wishing to inactivate not only coding genes, but also non-coding RNAs, UTRs, enhancers, and promoters. This method can be readily applied to diverse cell types by varying the nucleofection conditions.
Perinatal loss, including fetal and infant death, is a devastating experience for parents, resulting in long-term adverse physical and psychosocial outcomes. However, little is known about what services might best support grieving parents. We aimed to understand the role of professional bereavement photography in assisting the grieving process of parents who have lost a fetus or infant, by examining the perspectives of bereaved parents, professional photographers, and health care professionals. Twenty semistructured interviews were conducted, and interview transcripts were analyzed using modified grounded theory. Twenty-three individuals participated, including 6 bereaved parents, 8 photographers, and 9 health care professionals. Analyses generated 5 major themes describing ways in which the photographs were valuable to parents: validation of the experience, permission to share, creation of a permanent and tangible legacy, creation of positive memories, and moving forward after the loss. Hospitals should consider incorporation of professional bereavement photography services into palliative care and bereavement programs.
CRISPR‐Cas9‐based technologies have revolutionized experimental manipulation of mammalian genomes. However, limitations regarding the delivery and efficacy of these technologies restrict their application in primary cells. This article describes a protocol for penetrant, reproducible, and fast CRISPR‐Cas9 genome editing in cell cultures derived from primary cells. The protocol employs transient nucleofection of ribonucleoprotein complexes composed of chemically synthesized 2′‐O‐methyl‐3′phosphorothioate‐modified single guide RNAs (sgRNAs) and purified Cas9 protein. It can be used both for targeted insertion‐deletion mutation (indel) formation at up to >90% efficiency (via use of a single sgRNA) and for targeted deletion of genomic regions (via combined use of multiple sgRNAs). This article provides examples of the nucleofection buffer and programs that are optimal for patient‐derived glioblastoma (GBM) stem‐like cells (GSCs) and human neural stem/progenitor cells (NSCs), but the protocol can be readily applied to other primary cell cultures by modifying the nucleofection conditions. In summary, this is a relatively simple method that can be used for highly efficient and fast gene knockout, as well as for targeted genomic deletions, even in hyperdiploid cells such as many cancer stem‐like cells. © 2020 Wiley Periodicals LLC Basic Protocol: Cas9:sgRNA ribonucleoprotein nucleofection for insertion‐deletion (indel) mutation and genomic deletion generation in primary cell cultures
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