CRISPR in the Tumor Microenvironment: From Diagnostic Profiling to Precision Therapy

The tumor microenvironment (TME) is a dynamic and heterogeneous ecosystem that shapes tumor initiation, progression, immune evasion, and therapeutic resistance. Its cellular and molecular composition evolves throughout disease progression. The CRISPR–Cas gene-editing system has emerged as a transformative platform for decoding TME biology and enabling innovative diagnostic and therapeutic strategies. In this review, we outline the fundamental principles of CRISPR–Cas technologies and summarize their applications in functional genetic screening, interrogation of cell–cell interactions, and dissection of dynamic signaling networks within the TME. We highlight advances in CRISPR-based diagnostic platforms that allow highly sensitive and specific detection of cancer-associated signals across in vitro systems, patient-derived organoids, and ex vivo tumor samples. Furthermore, we discuss emerging CRISPR-enabled therapeutic approaches targeting the TME, including genetic modulation of tumor cells, reprogramming of immune and stromal compartments, and disruption of tumor vasculature and metabolic niches to enhance antitumor efficacy. Particular emphasis is placed on delivery strategies that achieve cell-type specificity and spatial precision. Finally, we examine key challenges that limit clinical translation, such as off-target editing, immunogenicity, and the inherent plasticity and heterogeneity of the TME, and discuss future directions to improve safety, robustness, and therapeutic durability. Collectively, this review provides a comprehensive framework for leveraging CRISPR–Cas technologies to advance TME-focused cancer diagnostics and therapeutics.