Background: Hepatocellular carcinoma (HCC) is characterized by a poor prognosis and accounts for the fourth common cause of cancer-related deaths. Recently, pyroptosis has been revealed to be involved in the progression of multiple cancers. However, the role of pyroptosis in the HCC prognosis remains elusive.Methods: The clinical information and RNA-seq data of the HCC patients were collected from the TCGA-LIHC datasets, and the differential pyroptosis-related genes (PRG) were firstly explored. The univariate Cox regression and consensus clustering were applied to recognize the HCC subtypes. The prognostic PRGs were then submitted to the LASSO regression analysis to build a prognostic model in the TCGA training cohort. We further evaluated the predictive model in the TCGA test cohort and ICGC validation cohort (LIRI-JP). The accuracy of prediction was validated using the Kaplan—Meier (K-M) and receiver operating characteristic (ROC) analyses. The single-sample gene set enrichment analysis (ssGSEA) was used to determine the differential immune cell infiltrations and related pathways. Finally, the expression of the prognostic genes was validated by qRT-PCR in vivo and in vitro.Results: We identified a total of 26 differential PRGs, among which three PRGs comprising GSDME, GPX4, and SCAF11 were subsequently chosen for constructing a prognostic model. This model significantly distinguished the HCC patients with different survival years in the TCGA training, test, and ICGC validation cohorts. The risk score of this model was confirmed as an independent prognostic factor. A nomogram was generated indicating the survival years for each HCC patient. The ssGSEA demonstrated several tumor-infiltrating immune cells to be remarkably associated with the risk scores. The qRT-PCR results also showed the apparent dysregulation of PRGs in HCC. Finally, the drug sensitivity was analyzed, indicating that Lenvatinib might impact the progression of HCC via targeting GSDME, which was also validated in human Huh7 cells.Conclusion: The PRG signature comprised of GSDME, GPX4, and SCAF11 can serve as an independent prognostic factor for HCC patients, which would provide further evidence for more clinical and functional studies.

The dynamic three-dimensional structures of chromatin and extrachromosomal DNA molecules regulate fundamental cellular processes and beyond. However, the visualization of specific DNA sequences in live cells, especially nonrepetitive sequences accounting for most of the genome, is still vastly challenging. Here, we introduce a robust CRISPR -mediated f luorescence i n s itu h ybridization amplifi er (CRISPR FISHer) system, which exploits engineered sgRNA and protein trimerization domain-mediated, phase separation-based exponential assembly of fluorescent proteins in the CRISPR-targeting locus, conferring enhancements in both local brightness and signal-to-background ratio and thus achieving single sgRNA-directed visualization of native nonrepetitive DNA loci in live cells. In one application, by labeling and tracking the broken ends of chromosomal fragments, CRISPR FISHer enables real-time visualization of the entire process of chromosome breakage, separation, and subsequent intra- or inter-chromosomal ends rejoining in a single live cell. Furthermore, CRISPR FISHer allows the movement of small extrachromosomal circular DNAs (eccDNAs) and invading DNAs to be recorded, revealing substantial differences in dynamic behaviors between chromosomal and extrachromosomal loci. With the potential to track any specified self or non-self DNA sequences, CRISPR FISHer dramatically broadens the scope of live-cell imaging in biological events and for biomedical diagnoses.

Editorial: Genome editing applications of CRISPR/Cas9 in metabolic diseases, hormonal system and cancer research

Discovering mechanisms of regeneration holds great promise for advancing regenerative medicine. Non-histone modifications by epigenetic factors participate in important biological processes. Through in vivo CRISPR screening combined with partial hepatectomy (PHx-CRISPR), we identified the histone H3K9 methyltransferase SETDB1 as an enhancer of regeneration. Loss of SETDB1 delays regeneration, and overexpressing SETDB1 accelerates liver regeneration across various liver injury models. SETDB1 promotes liver regeneration by positively regulating the expression of granulocyte colony-stimulating factor (CSF3) in hepatocytes. SETDB1 facilitates the expression of CSF3 in hepatocytes by methylating and activating AKT, establishing CSF3 as a critical downstream effector in the SETDB1-AKT liver regeneration pathway. Notably, increasing SETDB1 levels in humanized mouse liver suppresses drug-induced liver damage. Our findings reveal an unexpected role for non-histone modification by SETDB1 in regulating cytokine signaling during liver regeneration and offer insights into targeted therapies for regenerative medicine and tissue repair.