Role of reactive oxygen species in tumors based on the ‘seed and soil’ theory: A complex interaction

Tumor microenvironment (TME) can serve as the ‘soil’ for the growth and survival of tumor cells and function synergically with tumor cells to mediate tumor progression and therapeutic resistance. Reactive oxygen species (ROS) is somewhat of a double-edged sword for tumors. Accumulating evidence has reported that regulating ROS levels can serve an anti-tumor role in the TME, including the promotion of cancer cell apoptosis, inhibition of angiogenesis, preventing immune escape, manipulating tumor metabolic reorganization and improving drug resistance. In the present review, the potential role of ROS in anti-tumor therapy was summarized, including the possibility of directly or indirectly targeting the TME.