From RNAi to single-cell CRISPR: Evolving functional screening in aging and cancer

Abstract

Aging and cancer reflect distinct but interconnected manifestations of cellular stress responses shaped by context-specific molecular and environmental factors. Senescence initially restrains malignancy through stable cell-cycle arrest and immune clearance, yet persistence of senescent cells and the senescence-associated secretory phenotype (SASP) paradoxically drives tumor progression, therapeutic resistance, and immune evasion via chronic inflammation and metabolic reprogramming. Functional genomic screening has evolved from bulk RNA interference to precision clustered regularly interspaced short palindromic repeats (CRISPR) modalities, including knockout, interference, activation, and base editing, and onward to single-cell and in vivo platforms. These technological advances have transformed our capacity to dissect cellular state transitions and network dependencies with unprecedented resolution. Here, we trace this technological evolution and synthesize its impact on aging and cancer research, with emphasis on chromatin regulation, metabolic rewiring, the SASP, nucleocytoplasmic transport, therapeutic response, and the tumor microenvironment. We emphasize that the current evidence derives predominantly from preclinical functional screens and computational predictions. We propose shifting from gene-centric discovery toward context-dependent network analysis. Integrating precise editing, in vivo screening, single-cell multi-omics, and emerging artificial intelligence (AI)-assisted design may provide information and a design basis for future combined strategies that simultaneously target vulnerabilities in senescent cells and malignant populations.