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Prostate cancer is the second leading cause of cancer deaths in men in the United States and often metastasizes to bone. Androgen-independent prostate cancer is highly resistant to the current standard of care and presents a challenge to quality of life. We have discovered a novel in vitro protocol that facilitates the solubilization of the lipophilic molecule Coenzyme Q10 (Q10). Q10 is naturally resident in mitochondria and has been described as a potent antioxidant and crucial in the production of ATP. We previously demonstrated a pharmacologic dose of Q10 (50μM) selectively induces apoptosis in human melanoma, while being supportive to normal keratinocytes and fibroblasts in vitro. In the present study, we tested the effect of Q10 on an androgen-independent prostate cancer model, PC3 and osteosarcoma 143b cells using proliferation assays. In addition, the effect of Q10 on mitochondrial polarity was investigated using JC-1 stain in the presence of Q10. At 200 μM Q10, results show a reduction of 69.57% ± 7.56 and 74.51% ± 4.51 in PC-3 and 143b cells, respectively. Moreover, uptake and aggregation level of JC-1 in PC-3 mitochondria analyzed by flow cytometry revealed a significant increase in green fluorescence in Q10 treated cells, indicating mitochondrial depolarization, a hallmark of apoptosis. Taken together, the data suggest that Coenzyme Q10 is a viable anti-tumor agent with minimal normal tissue toxicity and may be useful in controlling disease progression of prostate cancer.

[Proc Amer Assoc Cancer Res, Volume 46, 2005]