Phenotypic discovery of a pyrimidine derivative with dual anti-prostate cancer and cardioprotective potential via ROS modulation.

Cardiotoxicity remains a major limitation of current anticancer therapies, highlighting the need for agents that combine antitumor efficacy with intrinsic cardiac safety. Phenotypic screening of a pyrimidine-based compound library identified compound 9v as a potent anti-prostate cancer candidate with dual biological functions. Compound 9v inhibited PC-3 cell proliferation with an IC₅₀ of 3.96 ± 0.18 μM, outperforming 5-fluorouracil, and markedly suppressed colony formation and migration while inducing apoptosis. Mechanistic studies showed that 9v activated the mitochondrial apoptotic pathway by increasing Bax, cleaved caspase-9, and cleaved caspase-3 levels while reducing Bcl-2 expression. Remarkably, 9v exerted bidirectional regulation of ROS homeostasis, promoting ROS accumulation in PC-3 cells but suppressing oxidative stress in H9C2 cardiomyocytes under H₂O₂ challenge. In addition, 9v exhibited weak cytotoxicity toward normal prostate stromal cells, no obvious acute toxicity in mice, and no detectable cardiotoxicity in vitro. Moreover, it exhibited protective effects against oxidative injury in cardiomyocytes, as demonstrated by increased cell viability and decreased LDH and cTnT release. Taken together, these results identify 9v as a promising lead compound with both anti-prostate cancer activity and cardioprotective potential in an in vitro oxidative stress model, providing a basis for the development of multifunctional anticancer agents with improved cardiovascular safety.