Characterization of phenothiazine-induced apoptosis in neuroblastoma and glioma cell lines: clinical relevance and possible application for brain-derived tumors

J Mol Neurosci. 2004;22(3):189-98. doi: 10.1385/JMN:22:3:189.

Abstract

In this study we aimed to (1). screen phenothiazines for cytotoxic activity in glioma, neuroblastoma, and primary mouse brain tissue; and (2). determine the mechanism of the cytotoxic effect (apoptosis, necrosis) and the roles of calmodulin inhibition and sigma receptor modulation. Rat glioma (C6) and human neuroblastoma (SHSY-5Y) cell lines were treated with different phenothiazines. All agents induced a dose-dependent decrease in viability and proliferation, with the highest activity elicited by thioridazine. Sensitivity to thioridazine of glioma and neuroblastoma cells was significantly higher (p < 0.05) than that of primary mouse brain culture (IC50 11.2 and 15.1 microM vs 41.3 microM, respectively). The N-mustard fluphenazine induced significantly lower cytotoxicity in glioma cells, compared to fluphenazine. The sigma receptor selective ligand (+)-SK&F10047 increased viability slightly while combined with fluphenazine; SK&F10047 did not alter fluphenazine activity. Flow cytometry of propidium iodide (PI)-stained glioma cells treated with thioridazine, fluphenazine, or perphenazine (6-50 microM) resulted in a concentration-dependent increase of fragmented DNA up to 94% vs 3% in controls by all agents. Thioridazine (12.5 microM)-treated glioma cells costained with PI and Hoechst 33342 revealed a red fluorescence of fragmented nuclei in treated cells and a blue fluorescence of intact control nuclei. After 4-h exposure to thioridazine (25 and 50 microM), a 25- to 30-fold increase in caspase-3 activity in neuroblastoma cells was noted. Overall, the marked apoptotic effect of phenothiazines in brain-derived cancer cells, and the low sensitivity of primary brain tissue suggest the potential use of selected agents as therapeutic modalities in brain cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / therapeutic use
  • Antineoplastic Agents / toxicity*
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • Brain Neoplasms / drug therapy*
  • Calmodulin / drug effects
  • Calmodulin / metabolism
  • Caspase 3
  • Caspases / drug effects
  • Caspases / metabolism
  • Cell Division / drug effects
  • Cell Division / physiology
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • DNA Fragmentation / drug effects
  • DNA Fragmentation / physiology
  • Dose-Response Relationship, Drug
  • Fluphenazine / toxicity
  • Glioma / drug therapy*
  • Humans
  • Mice
  • Mice, Inbred ICR
  • Neuroblastoma / drug therapy*
  • Phenazocine / analogs & derivatives*
  • Phenazocine / pharmacology
  • Phenothiazines / therapeutic use
  • Phenothiazines / toxicity*
  • Rats
  • Receptors, sigma / drug effects
  • Receptors, sigma / metabolism
  • Thioridazine / toxicity
  • Up-Regulation / drug effects
  • Up-Regulation / physiology

Substances

  • Antineoplastic Agents
  • Calmodulin
  • Phenothiazines
  • Receptors, sigma
  • SK&F 10047
  • CASP3 protein, human
  • Casp3 protein, mouse
  • Casp3 protein, rat
  • Caspase 3
  • Caspases
  • phenothiazine
  • Phenazocine
  • Thioridazine
  • Fluphenazine