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Wednesday, 29 July 2015

The germacranolide sesquiterpene lactone neurolenin B of the medicinal plant Neurolaena lobata (L.) R.Br. ex Cass inhibits NPM/ALK-driven cell expansion and NF-κB-driven tumour intravasation

Volume 22, Issue 9, 15 August 2015, Pages 862–874

Abstract

Background

The t(2;5)(p23;q35) chromosomal translocation results in the expression of the fusion protein NPM/ALK that when expressed in T-lymphocytes gives rise to anaplastic large cell lymphomas (ALCL). In search of new therapy options the dichloromethane extract of the ethnomedicinal plant Neurolaena lobata (L.) R.Br. ex Cass was shown to inhibit NPM/ALK expression.

Purpose

Therefore, we analysed whether the active principles that were recently isolated and found to inhibit inflammatory responses specifically inhibit growth of NPM/ALK+ ALCL, leukaemia and breast cancer cells, but not of normal cells, and the intravasation through the lymphendothelial barrier.

Methods

ALCL, leukaemia and breast cancer cells, and normal peripheral blood mononuclear cells (PBMCs) were treated with isolated sesquiterpene lactones and analysed for cell cycle progression, proliferation, mitochondrial activity, apoptosis, protein and mRNA expression, NF-κB and cytochrome P450 activity, 12(S)-HETE production and lymphendothelial intravasation.

Results

In vitro treatment of ALCL by neurolenin B suppressed NPM/ALK, JunB and PDGF-Rβ expression, inhibited the growth of ALCL cells late in M phase, and induced apoptosis via caspase 3 without compromising mitochondrial activity (as a measure of general exogenic toxicity). Moreover, neurolenin B attenuated tumour spheroid intravasation probably through inhibition of NF-κB and CYP1A1.

Conclusion

Neurolenin B specifically decreased pro-carcinogenic NPM/ALK expression in ALK+ ALCL cells and, via the inhibition of NF-kB signalling, attenuated tumour intra/extravasation into the lymphatics. Hence, neurolenin B may open new options to treat ALCL and to manage early metastatic processes to which no other therapies exist.

Graphical abstract

Image for unlabelled figure

Keywords

  • Neurolenins;
  • NPM/ALK;
  • ALCL;
  • Intravasation;
  • 3D-compound testing;
  • Toxicity

Abbreviations

  • ALCL, anaplastic large cell lymphoma;
  • ALOX, lipoxygenase A;
  • CCID, circular chemorepellent induced defect;
  • CYP, cytochrome P450;
  • DME, dichloro methane extract;
  • EROD, ethoxyresorufin-O-deethylase;
  • HO/PI, Hoechst 33258/propidium iodide;
  • LEC, lymph endothelial cell;
  • MYPT1, myosin phosphatase 1 target subunit 1;
  • NF-κB, nuclear factor kappa B;
  • NPM/ALK, nucleophosmin/anaplastic lymphoma kinase, the t(2;5)(p23;q35) chromosomal translocation;
  • PARP, poly ADP-ribose polymerase;
  • PBMC, peripheral blood mononuclear cell;
  • PDGF-Rβ, platelet derived growth factor receptor;
  • p21, tumour suppressor protein 21;
  • 3D, 3-dimensional;
  • 12(S)-HETE, 12(S) hydroxyeicosatetraenoic acid

Corresponding author. Tel.: +43 1 40160 56507; fax: +43 1 40160 956501.
1
Equal contribution.
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