Chlorimipramine: A novel anticancer agent with a mitochondrial target

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Abstract

Mitochondria have been suggested to be a potential intracellular target for cancer chemotherapy. In this report, we demonstrate the ability of the tricyclic antidepressant chlorimipramine to kill human glioma cells in vitro by a molecular mechanism resulting in an increase in caspase 3 activity following inhibition of glioma oxygen consumption. Studies with isolated rat mitochondria showed that chlorimipramine specifically inhibited mitochondrial complex III activity, which causes decreased mitochondrial membrane potential as well as mitochondrial swelling and vacuolation. The use of chlorimipramine in human as an effective, non-toxic cancer therapeutic having a strong selectivity between cancer cells and normal cells on the basis of their mitochondrial function is discussed.

Section snippets

Materials and methods

Chemicals. All chemicals and other materials used were of the highest quality available and were from: The Sigma Chemical, Fancy Road Poole, UK; Nalgene, Nalge (Europe), Hereford, UK; Calbiochem, Beeston, Nottingham, UK; Fisher Scientific, Loughborough, UK or Molecular Probes, Invitrogen, Paisley, UK.

Glioma cell culture. Glioma cell lines used were derived from primary cultures of human biopsy material taken at craniotomy in the neurosurgical theatres of King’s College London and Atkinson

Chlorimipramine causes changes in glioma cell morphology

The microscopical examination of glioma and glial cells showed a time-dependent change in glioma cell morphology (rounding up of the cells) after 1 h exposure to CIMP, with many cells detaching from the tissue culture plate following 2 h exposure to CIMP (Fig. 1). Foetal astrocytes exposed to CIMP showed no changes in morphology and did not become detached from the tissue culture plate.

Chlorimipramine decreases glioma cell viability

The MTT assay demonstrated a concentration-dependent decrease in IPBB-98, IPDDC-98 and NP785-96 cell viability

Discussion

Approximately 95% of a cell’s oxygen utilisation is by the mitochondrial complex IV [27]. Thus, the decrease in oxygen uptake measured in glioma cells in the presence of CIMP suggests a blockade of mitochondrial electron transport. Using the specific mitochondrial enzyme assays on mitochondria isolated from brain, heart, liver, and kidney it is clear that CIMP inhibits both mitochondrial complex I and complex III activities. However, 1 μM antimycin a caused total inhibition of complex III

Acknowledgment

We thank the Samantha Dickson Research Trust (see http://www.sdrt.co.uk.) for financial support for the work described in this document and for the chlorimipramine clinical trial in human glioma.

References (46)

  • C.E. Cooper et al.

    Nitric oxide and peroxynitrite cause irreversible increases in the K(m) for oxygen of mitochondrial cytochrome oxidase: in vitro and in vivo studies

    Biochim. Biophys. Acta

    (2003)
  • F.L. Muller et al.

    Complex III Releases superoxide to both sides of the inner mitochondrial membrane

    J. Biol. Chem.

    (2004)
  • S. Orrenius

    Mitochondrial regulation of apoptotic cell death

    Toxicol. Lett.

    (2004)
  • M. Leist et al.

    The shape of cell death

    Biochem. Biophys. Res. Commun.

    (1997)
  • J.S. Kim et al.

    Mitochondrial permeability transition: a common pathway to necrosis and apoptosis

    Biochem. Biophys. Res. Commun.

    (2003)
  • J.W. Shay et al.

    Are mitochondrial DNA mutations involved in the carcinogenic process?

    Mutat. Res.

    (1987)
  • B. Zhivotovsky et al.

    Defects in the apoptotic machinery of cancer cells: role in drug resistance

    Semin. Cancer Biol.

    (2003)
  • M.R. Trimble

    Worldwide use of clomipramine

    J. Clin. Psychiatry

    (1990)
  • D. Wilkie

    Analysis of mitochondrial drug resistance in Saccharomyces cerevisiae

    Symp. Soc. Exp. Biol.

    (1970)
  • D. Wilkie et al.

    Effects of chlorimipramine on human cells in tissue culture

    Br. J. Exp. Pathol.

    (1970)
  • D. Wilkie

    The yeast cell in anti-mitochondrial activity of drugs

    Med. Biol. Illus.

    (1972)
  • C. Sauter

    Cytostatic activity of commonly used tricyclic antidepressants

    Oncology

    (1989)
  • H. Karlsson et al.

    Induction of apoptosis in proliferating lymphocytes by tricyclic antidepressants

    Apoptosis

    (1998)
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    1

    Present address: School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK.

    2

    Present address: MRC Applied Neuroscience Group, School of Biomedical Sciences, University of Nottingham, Nottingham NG7 2UH, UK.

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