Core Viewpoint - Cellular senescence is a stable state of growth arrest closely related to age-related diseases and cancer development, characterized by an intrinsic anti-apoptotic ability and a unique secretory phenotype known as the senescence-associated secretory phenotype (SASP) [1][2]. Group 1 - Senescent tumor cells release mitochondrial DNA (mtDNA), which enhances immunosuppression mediated by polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) through the cGAS-STING pathway [3][9]. - The release of mtDNA from senescent cells can exacerbate inflammation associated with tissue damage or disease progression, indicating a potential mechanism linking cellular senescence to age-related diseases and cancer [2][6]. - The study highlights that targeting the release of mtDNA could reprogram the immunosuppressive tumor microenvironment, thereby improving cancer treatment outcomes for patients undergoing chemotherapy [9][10]. Group 2 - The research team found that both naturally senescent primary cells and tumor cells undergoing senescence due to treatment actively release mtDNA into the extracellular environment [5][7]. - Extracellular mtDNA is encapsulated in extracellular vesicles and selectively transferred to PMN-MDSC, enhancing their immunosuppressive activity through the cGAS-STING-NF-κB signaling pathway [5][10]. - Pharmacological inhibition of voltage-dependent anion channels (VDAC) can reduce extracellular mtDNA levels and reverse PMN-MDSC-driven immunosuppression, improving chemotherapy efficacy in prostate cancer mouse models [6][10].