PUBLICATION

Discovery and characterization of Isofistularin-3, a marine brominated alkaloid, as a new DNA demethylating agent inducing cell cycle arrest and sensitization to TRAIL in cancer cells

Authors
Florean, C., Schnekenburger, M., Lee, J.Y., Kim, K.R., Mazumder, A., Song, S., Kim, J.M., Grandjenette, C., Kim, J.G., Yoon, A.Y., Dicato, M., Kim, K.W., Christov, C., Han, B.W., Proksch, P., Diederich, M.
ID
ZDB-PUB-160324-3
Date
2016
Source
Oncotarget   7(17): 24027-49 (Journal)
Registered Authors
Keywords
DNMT inhibitor, TSG hypermethylation, autophagy, cell cycle arrest, leukemia
MeSH Terms
  • Alkaloids/chemistry
  • Alkaloids/pharmacology*
  • Animals
  • Antineoplastic Agents, Alkylating/chemistry
  • Antineoplastic Agents, Alkylating/pharmacology
  • Apoptosis/drug effects
  • Biomarkers, Tumor
  • Cell Cycle Checkpoints/drug effects*
  • Cell Proliferation/drug effects
  • DNA Methylation/drug effects*
  • Drug Discovery
  • Drug Resistance, Neoplasm/drug effects*
  • Humans
  • Neoplasms/drug therapy*
  • Neoplasms/metabolism
  • Neoplasms/pathology
  • Porifera/chemistry
  • Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism
  • TNF-Related Apoptosis-Inducing Ligand/metabolism*
  • Tumor Cells, Cultured
  • Zebrafish/growth & development*
  • Zebrafish/metabolism
PubMed
27006469 Full text @ Oncotarget
Abstract
We characterized the brominated alkaloid Isofistularin-3 (Iso-3), from the marine sponge Aplysina aerophoba, as a new DNA methyltransferase (DNMT)1 inhibitor. Docking analysis confirmed our in vitro DNMT inhibition data and revealed binding of Iso-3 within the DNA binding site of DNMT1. Subsequent increased expression of tumor suppressor gene aryl hydrocarbon receptor (AHR) could be correlated to decreased methylation of CpG sites within the essential Sp1 regulatory region of its promoter. Iso-3 induced growth arrest of cancer cells in G0/G1 concomitant with increased p21 and p27 expression and reduced cyclin E1, PCNA and c-myc levels. Reduced proliferation was accompanied by morphological changes typical of autophagy revealed by fluorescent and transmission electron microscopy and validated by LC3I-II conversion. Furthermore, Iso-3 strongly synergized with tumor-necrosis-factor related apoptosis inducing ligand (TRAIL) in RAJI [combination index (CI) = 0.22] and U-937 cells (CI = 0.21) and increased TRAIL-induced apoptosis via a mechanism involving reduction of survivin expression but not of Bcl-2 family proteins nor X-linked inhibitor of apoptosis protein (XIAP). Iso-3 treatment decreased FLIPL expression and triggered activation of endoplasmatic reticulum (ER) stress with increased GRP78 expression, eventually inducing TRAIL receptor death receptor (DR)5 surface expression. Importantly, as a potential candidate for further anticancer drug development, Iso-3 reduced the viability, colony and in vivo tumor forming potential without affecting the viability of PBMCs from healthy donors or zebrafish development.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping