Ubiquitously observed low oxygen-level, hypoxia, insolid tumors induces resistance to radiation therapy (RT), because the efficacy of the ionization radiation on deactivating tumor cells is highly dependent on the oxygen level in tumor tissues. Tumor oxygenation can mitigate this resistance, thus improving the effectiveness of RT. Recently, enzymes such as catalase and peroxidase that decompose the high concentration of hydrogen peroxide in tumors to generate oxygen were demonstrated promising in overcoming the hypoxia-induced resistance in solid tumors; however, these proteinaceous enzymes are chemically unstable, costly, and have short shelf-lives. In this project, we will test the feasibility of using a peroxidase-like DNAzyme, instead of the proteinaceous enzyme. The DNAzyme is made from guanine-rich oligoDNA sequences that bind hemin, the same cofactor as in the proteinaceous enzymes, and thus exhibit similar enzymatic activity; however, the DNAzyme is more stable, easier to synthesize, and more cost-effective than peroxidase. We will test the effectiveness of DNAzymes that are encapsulated within liposome nanoparticles for sensitizing RT in a prostate cancer cell model, in contrast to various controls. The new knowledge developed in this project will benefit both the researchers for further tests and the patients in the future.