Publication detail

Vacuolar-ATPase-mediated intracellular sequestration of ellipticine contributes to drug resistance in neuroblastoma cells

HRABĚTA, J. GROH, T. POLJAKOVÁ, J. KHALIL, M. ADAM, V. KÍZEK, R. UHLÍK, J. DOKTOROVÁ, H. ČERNÁ, T. FREI, E. STIBOROVÁ, M. ECKSCHLAGER, T.

Original Title

Vacuolar-ATPase-mediated intracellular sequestration of ellipticine contributes to drug resistance in neuroblastoma cells

Type

journal article in Web of Science

Language

English

Original Abstract

Neuroblastoma is the most common cancer in infants and the fourth most common cancer in children. Aggressive cell growth and chemoresistance are notorious obstacles in neuroblastoma therapy. Exposure to the anticancer drug ellipticine inhibits efficiently growth of neuroblastoma cells and induces apoptosis in these cells. However, ellipticine induced resistance in these cells. The upregulation of a vacuolar (V)-ATPase gene is one of the factors associated with resistance development. In accordance with this finding, we found that levels of V-ATPase protein expression are higher in the ellipticine-resistant UKF-NB-4(ELLI) line than in the parental ellipticine-sensitive UKF-NB-4 cell line. Treatment of ellipticine-sensitive UKF-NB-4 and ellipticine-resistant UKF-NB-4(ELLI) cells with ellipticine-induced cytoplasmic vacuolization and ellipticine is concentrated in these vacuoles. Confocal microscopy and staining of the cells with a lysosomal marker suggested these vacuoles as lysosomes. Transmission electron microscopy and no effect of an autophagy inhibitor wortmannin ruled out autophagy. Pretreatment with a V-ATPase inhibitor bafilomycin A and/or the lysosomotropic drug chloroquine prior to ellipticine enhanced the ellipticine-mediated apoptosis and decreased ellipticine-resistance in UKF-NB-4(ELLI) cells. Moreover, pretreatment with these inhibitors increased formation of ellipticine-derived DNA adducts, one of the most important DNA-damaging mechanisms responsible for ellipticine cytotoxicity. In conclusion, resistance to ellipticine in the tested neuroblastoma cells is associated with V-ATPase-mediated vacuolar trapping of this drug, which may be decreased by bafilomycin A and/or chloroquine.

Keywords

neuroblastoma; resistance to ellipticine; vacuolation; drug sequestration; vacuolar ATPase

Authors

HRABĚTA, J.; GROH, T.; POLJAKOVÁ, J.; KHALIL, M.; ADAM, V.; KÍZEK, R.; UHLÍK, J.; DOKTOROVÁ, H.; ČERNÁ, T.; FREI, E.; STIBOROVÁ, M.; ECKSCHLAGER, T.

RIV year

2015

Released

1. 9. 2015

ISBN

1019-6439

Periodical

INTERNATIONAL JOURNAL OF ONCOLOGY

Year of study

47

Number

3

State

Hellenic Republic

Pages from

971

Pages to

980

Pages count

10

BibTex

@article{BUT123332,
  author="Jan {Hraběta} and Eva {Frei} and Marie {Stiborová} and Tomáš {Eckschlager} and Tomáš {Groh} and René {Kizek} and Jitka {Poljaková} and Mohamed Ashraf {Khalil} and Vojtěch {Adam} and Jiří {Uhlík} and Helena {Doktorová} and Tereza {Černá}",
  title="Vacuolar-ATPase-mediated intracellular sequestration of ellipticine contributes to drug resistance in neuroblastoma cells",
  journal="INTERNATIONAL JOURNAL OF ONCOLOGY",
  year="2015",
  volume="47",
  number="3",
  pages="971--980",
  doi="10.3892/ijo.2015.3066",
  issn="1019-6439"
}