Novel Piperazine Derivatives of Vindoline as Anticancer Agents

A series of novel vindoline-piperazine conjugates were synthesized by coupling 6 N-substituted piperazine pharmacophores at positions 10 and 17 of Vinca alkaloid monomer vindoline through different types of linkers. The in vitro antiproliferative activity of the 17 new conjugates was investigated on 60 human tumor cell lines (NCI60). Nine compounds presented significant antiproliferative effects. The most potent derivatives showed low micromolar growth inhibition (GI50) values against most of the cell lines. Among them, conjugates containing [4-(trifluoromethyl)benzyl]piperazine (23) and 1-bis(4-fluorophenyl)methyl piperazine (25) in position 17 of vindoline were outstanding. The first one was the most effective on the breast cancer MDA-MB-468 cell line (GI50 = 1.00 μM), while the second one was the most effective on the non-small cell lung cancer cell line HOP-92 (GI50 = 1.35 μM). The CellTiter-Glo Luminescent Cell Viability Assay was performed with conjugates 20, 23, and 25 on non-tumor Chinese hamster ovary (CHO) cells to determine the selectivity of the conjugates for cancer cells. These compounds exhibited promising selectivity with estimated half-maximal inhibitory concentration (IC50) values of 2.54 μM, 10.8 μM, and 6.64 μM, respectively. The obtained results may have an impact on the design of novel vindoline-based anticancer compounds.

An In Vitro Assessment Method for Chemotherapy-Induced Peripheral Neurotoxicity Caused by Anti-Cancer Drugs Based on Electrical Measurement of Impedance Value and Spontaneous Activity

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major adverse event of anti-cancer drugs, which still lack standardized measurement and treatment methods. In the present study, we attempted to evaluate neuronal dysfunctions in cultured rodent primary peripheral neurons using a microelectrode array system. After exposure to typical anti-cancer drugs (i.e., paclitaxel, vincristine, oxaliplatin, and bortezomib), we successfully detected neurotoxicity in dorsal root ganglia neurons by measuring electrical activities, including impedance value and spontaneous activity. The impedance value decreased significantly for all compounds, even at low concentrations, which indicated cell loss and/or neurite degeneration. The spontaneous activity was also suppressed after exposure, which suggested neurotoxicity again. However, an acute response was observed for paclitaxel and bortezomib before toxicity, which showed different mechanisms based on compounds. Therefore, MEA measurement of impedance value could provide a simple assessment method for CIPN, combined with neuronal morphological changes.