In summary, it can be concluded that with the selective MDM2-p53 interaction inhibitor RITA, in combination with cisplatin causes a high induction of both p53 and MDM2, a massive induction of apoptosis, and a strong reduction in cell survival in colon and Prostate cancer cell lines due to the release on caspase-3 resulting in apoptosis through internal pathway of apoptosis. This evidence concerns the gene CASP3 and prostate carcinoma.