Selective Induction of Cellular Toxicity and Anti-tumor Efficacy by N-Methylpiperazinyl Diarylidenylpiperidone and its Pro-nitroxide Conjugate through ROS-mediated Mitochondrial Dysfunction and G2/M Cell-cycle Arrest in Human Pancreatic Cancer.

: Pancreatic adenocarcinoma is an aggressive cancer with poor clinical prognosis and limited therapeutic options. There is a significant lack of effective, safe, and targeted therapies for successful treatment of pancreatic cancer. In this report, we describe the anticancer efficacy of two novel compounds, N-methylpiperazinyl diarylidenylpiperidone (L-2663) and its pro-nitroxide conjugate (HO-4589) evaluated on human pancreatic adenocarcinoma (AsPC-1) cell line and xenograft tumor in mice. Using flow cytometry, we determined the effect of the L-2663 and HO-4589 drugs in inducing mitochondrial toxicity, triggering cell-cycle arrest, and apoptosis. EPR spectroscopy was used to quantify cellular uptake, metabolic conversion and stability of HO-4589 in cells and in vivo monitoring of tumor oxygenation as a function of growth. The results established different antiproliferative efficacy of the L-2663 and HO-4589 compounds, with a targeted action on cancer cells while being less toxic to noncancerous cells. The study may have important implications in the future designs of safe and effective chemotherapeutic agents for the treatment of pancreatic cancer.