PPMP, a novel tubulin-depolymerizing agent against esophageal cancer in patient-derived tumor xenografts

Esophageal cancer is one of the least studied and deadliest cancers worldwide with a poor prognosis due to limited options for treatment. Chemotherapy agents such as the microtubule-targeting compounds are the mainstay of palliation for advanced esophageal cancer treatment. However, the toxicity and side effects of tubulin-binding agents (TBAs) have promoted the development of novel, more potent but less toxic TBAs. Herein, we identified 2-[4-(3,4-dimethoxyphenyl)-3-methyl-1H-pyrazol-5-yl]-5-[(2-methylprop-2-en-1-yl)oxy] phenol (PPMP) as a novel TBA for esophageal cancer treatment. PPMP markedly inhibited tubulin polymerization, and decreased viability and anchorage-independent growth of esophageal cancer cell lines, effects that were accompanied by G2/M arrest and apoptosis. Importantly, we produced patient-derived esophageal cancer xenografts to evaluate the therapeutic effect of PPMP in a setting that best mimics the clinical context in patients with esophageal cancer. Overall, we identified PPMP as a novel microtubule-destabilizing compound and as a new therapeutic agent against esophageal carcinoma.