Therapeutic Potential of CAPE in Targeting Hallmarks of Cancer in TPC‐1 Thyroid Cancer Cells Through Modulation of Mitochondrial Membrane Potential

The objective of this study was to examine the chemotherapeutic effect of CAPE, via the mitochondrial membrane potential (MMP, Δψm) pathway in TPC-1 human papillary thyroid cancer cells. The cytotoxic effect of CAPE was evaluated using MTT and crystal violet assays, while its apoptotic activity was measured using Bax, Bcl-2, Caspase-3,-8,-9 and Apaf-1 assays. Effects on mitochondria were performed by analyzing JC-1 fluorescent probe-MMP, ROMO1 and mitochondrial ATP-synthase. The analysis of ROS and 8-OHdG was undertaken to assess the degree of oxidative stress and DNA damage, while LDH analysis was used as a marker of both cytotoxicity and cellular membrane damage. To determine antimetastatic activity, cell migration and colony formation assays were performed. Finally, Giemsa staining was chosen for cytomorphological analysis. CAPE treatment in TPC-1 cells was selected as the effective dose (IC₅₀: 25 µM/48 h) for further experiments, and it was found that this reduced Bcl-2 levels and increased the activation of key components Bax, Caspase-3,-8,-9 and Apaf-1, indicating that CAPE-induced cell death was apoptosis-dependent. The study revealed that CAPE induced mitochondrial depolarization, leading to a substantial decrease in mitochondrial ATP-synthase, along with a notable increase in intracellular ROS, ROMO1 levels, and 8-OHdG DNA damage and extracellular LDH. Furthermore, CAPE exhibited a significant inhibitory effect on cell migration and colony formation, accompanied by cytomorphological changes. In conclusion, this study demonstrates that CAPE, which shows bioactivity by modulating MMP, can target several hallmarks of cancer in TPC-1 cells and therefore has an important potential for future in vivo research.