Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Determining Mitochondrial and Cytotoxicity in DU-145, PC-3, MCF7, and MDA-MB-231 after Melatonin Exposure using Alamar Blue and Biolog Systems

E-cadherin plays an essential role in cell-cell connections. Loss of these connections is an important step in the transition of normal cells into cancer cells. The epithelial-mesenchymal transition (EMT) is the transition from a normal cell phenotype to metastatic cells that can grow without restrictions and invade other tissues. Loss of E-cadherin expression is a marker for EMT. Melatonin has been shown to increase E-cadherin expression in MCF7 breast cancer cells. In this experiment DU-145, PC-3 (prostate cancer cell lines), MCF7, and MDA-MB-231 (breast cancer cell lines) were exposed to melatonin (0 through 300 µM) and cytotoxicity was measured at 24, 48, and 96 hours using the Alamar Blue system. Results were compared with earlier cytotoxicity data generated by the MTT assay. In addition, PC3 and MDA-MB-231 cell lines were exposed to melatonin and doxorubicin to test mitochondrial damage to determine if melatonin supports mitochondrial function in doxorubicin induced cell death using the Biolog system. Results showed that melatonin in concentrations lower than 300 µM are not toxic to cells in all 4 cell lines. Previous experiments have shown that melatonin does not damage mitochondrial function. Experiments with doxorubicin are still on going. The presence of apoptosis was determined by using Saguaro ChromaLIVE Dye after doxorubicin exposure.