Abstract
Reactive nitrogen species (RNS) play a pivotal role in tumorigenesis through complex regulatory networks within the tumor microenvironment (TME). This review summarizes recent advances in understanding RNS-mediated mechanisms, focusing on core components and their concentration-dependent bidirectional effects on tumor cell proliferation, apoptosis, invasion, and metabolism. It explores RNS sources in the TME, including autonomous synthesis by tumor cells and secretion by immune cells (e.g., TAMs, TANs), and their modulation of key signaling pathways (e.g., PI3 K/Akt, NF-κB, HIF-1α). Additionally, the review discusses RNS-mediated regulation of immune responses and angiogenesis, highlighting their dual roles in promoting tumor progression and enabling immune evasion. Finally, it outlines potential clinical applications, such as RNS-targeted diagnostic probes and therapeutic strategies (e.g., iNOS inhibitors, NO donors), providing a foundation for precision oncology.