Objective To identify genetic regulators of ionizing radiation(IR)sensitivity through clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)genome-wide screening.Methods A specialized single guide RNA(sgRNA)library was developed targeting 987 stress-response regulatory genes identified through Kyoto Encyclopedia of Genes and Genomes(KEGG),Reactome and gene ontology(GO)databases,followed by construction of sgRNA plasmids and packaging into a lentiviral library.Using colon adenocarcinoma Caco-2 cells as a model system,the Cas9-stable transgenic line was established via lentiviral transduction and antibiotic selection.Library-transduced cells underwent puromycin selection,followed by γ-irradiation(dose optimized via preliminary experiments).Post-irradiation phenotypic selection was conducted after 14 days,with subsequent next-generation sequencing of surviving cell populations to identify enriched/depleted sgRNAs.Candidate genes were functionally validated through orthogonal assays:cell counting kit-8(CCK-8)proliferation analysis,clonogenic survival assays and flow cytometric quantification of reactive oxygen species(ROS)and apoptotic markers.Results The optimized screening platform identified 281 radiation response genes(165 radiosensitive and 116 radioprotective candidates).Functional validation revealed Bcl2-associated athanogene 3(BAG3)knockdown significantly enhanced radioresistance.Proliferation was increased 1.2-1.5 fold,clonogenic survival improved 1.5-2.0 fold,and ROS was reduced by 13％-25％coupled with 32％-73％apoptosis attenuation compared to control groups.Conclusion The integrated CRISPR/Cas9 screening platform effectively identifies novel radiation response regulators,as evidenced by the discovery of BAG3 as a critical radiosensitivity determinant.This high-throughput functional genomics approach provides a robust methodology for systematically mapping molecular determinants of cellular radiation response,with potential applications in both mechanistic studies and therapeutic target discovery.

Objective To investigate the effect of erythroid differentiation associated gene(EDAG)on hematopoietic stem/progenitor cells(HSPCs)under chronic inflammation.Methods In this study,EDAG-/-and wild type(WT)mice were divided into the experiment group and control group.An infectious chronic inflammation model was established via multiple intraperitoneal injections of Listeria monocytogenes(LM),while a sterile chronic inflammation model was generated via multiple intraperitoneal injections of polyinosinic-polycytidylic acid[Poly(I∶C)].The effect of EDAG on HSPCs was explored under chronic inflammation conditions.Results In the LM repeated infection model,EDAG deletion led to a decrease in HSPCs and long-term hematopoietic stem cells(LT-HSCs)in mice as well as a significant bias towards myeloid differentiation in peripheral blood.Similarly,EDAG knockout also resulted in reduced numbers of HSPCs and decreased colony-forming ability in aseptic chronic inflammation models.Conclusion EDAG deficiency accelerates HSPC depletion in young mice under chronic inflammation,indicating strong protection of EDAG against HSPC damage induced by chronic inflammation.