Bcl2L13 is a ceramide synthase inhibitor in glioblastoma

Proc Natl Acad Sci U S A. 2014 Apr 15;111(15):5682-7. doi: 10.1073/pnas.1316700111. Epub 2014 Mar 31.

Abstract

Therapy resistance is a major limitation to the successful treatment of cancer. Here, we identify Bcl2-like 13 (Bcl2L13), an atypical member of the Bcl-2 family, as a therapy susceptibility gene with elevated expression in solid and blood cancers, including glioblastoma (GBM). We demonstrate that mitochondria-associated Bcl2L13 inhibits apoptosis induced by a wide spectrum of chemo- and targeted therapies upstream of Bcl2-associated X protein activation and mitochondrial outer membrane permeabilization in vitro and promotes GBM tumor growth in vivo. Mechanistically, Bcl2L13 binds to proapoptotic ceramide synthases 2 (CerS2) and 6 (CerS6) via a unique C-terminal 250-aa sequence located between its Bcl-2 homology and membrane anchor domains and blocks homo- and heteromeric CerS2/6 complex formation and activity. Correspondingly, CerS2/6 activity and Bcl2L13 abundance are inversely correlated in GBM tumors. Thus, our genetic and functional studies identify Bcl2L13 as a regulator of therapy susceptibility and point to the Bcl2L13-CerS axis as a promising target to enhance responses of therapy-refractory cancers toward conventional and targeted regimens currently in clinical use.

Keywords: Bcl-2 protein family; intrinsic apoptosis signaling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Apoptosis / drug effects
  • Blotting, Western
  • Cloning, Molecular
  • Computational Biology
  • DNA Primers / genetics
  • Drug Resistance / genetics*
  • Gene Expression Regulation, Enzymologic / physiology*
  • Gene Library
  • Glioblastoma / drug therapy
  • Glioblastoma / enzymology*
  • Humans
  • Membrane Proteins / metabolism
  • Oxidoreductases / antagonists & inhibitors*
  • Polymerase Chain Reaction
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Saccharomyces cerevisiae
  • Sphingosine N-Acyltransferase / metabolism
  • Tumor Suppressor Proteins / metabolism
  • Two-Hybrid System Techniques

Substances

  • Antineoplastic Agents
  • BCL2L13 protein, human
  • DNA Primers
  • Membrane Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Tumor Suppressor Proteins
  • Oxidoreductases
  • dihydroceramide desaturase
  • CERS2 protein, human
  • CERS6 protein, human
  • Sphingosine N-Acyltransferase