2. Academic Validation
  3. BMPR2 inhibits activin and BMP signaling via wild-type ALK2

BMPR2 inhibits activin and BMP signaling via wild-type ALK2

  • J Cell Sci. 2018 Jun 11;131(11):jcs213512. doi: 10.1242/jcs.213512.
Oddrun Elise Olsen 1 2,  Meenu Sankar 3,  Samah Elsaadi 1,  Hanne Hella 1,  Glenn Buene 1,  Sagar Ramesh Darvekar 1,  Kristine Misund 1 2,  Takenobu Katagiri 4,  Petra Knaus 5,  Toril Holien 6 2
Affiliations

Affiliations

  • 1 Department of Clinical and Molecular Medicine, NTNU-Norwegian University of Science and Technology, 7491 Trondheim, Norway.
  • 2 Department of Hematology, St. Olav's University Hospital, 7030 Trondheim, Norway.
  • 3 School of Bioscience, University of Skövde, 541 28 Skövde, Sweden.
  • 4 Division of Pathophysiology, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama 350-1241, Japan.
  • 5 Institute for Chemistry and Biochemistry, Freie Universitaet Berlin, 14195 Berlin, Germany.
  • 6 Department of Clinical and Molecular Medicine, NTNU-Norwegian University of Science and Technology, 7491 Trondheim, Norway [email protected].
PMID: 29739878 DOI: 10.1242/jcs.213512
Abstract

TGF-β/BMP superfamily ligands require heteromeric complexes of type 1 and 2 receptors for ligand-dependent downstream signaling. Activin A, a TGF-β superfamily member, inhibits growth of multiple myeloma cells, but the mechanism for this is unknown. We therefore aimed to clarify how activins affect myeloma cell survival. Activin A activates the transcription factors SMAD2/3 through the ALK4 type 1 receptor, but may also activate SMAD1/5/8 through mutated variants of the type 1 receptor ALK2 (also known as ACVR1). We demonstrate that Activin A and B activate SMAD1/5/8 in myeloma cells through endogenous wild-type ALK2. Knockdown of the type 2 receptor BMPR2 strongly potentiated activin A- and activin B-induced activation of SMAD1/5/8 and subsequent cell death. Furthermore, activity of BMP6, BMP7 or BMP9, which may also signal via ALK2, was potentiated by knockdown of BMPR2. Similar results were seen in HepG2 liver carcinoma cells. We propose that BMPR2 inhibits ALK2-mediated signaling by preventing ALK2 from oligomerizing with the type 2 receptors ACVR2A and ACVR2B, which are necessary for activation of ALK2 by activins and several BMPs. In conclusion, BMPR2 could be explored as a possible target for therapy in patients with multiple myeloma.This article has an associated First Person interview with the first author of the paper.

Keywords

ACVR1; ACVR2A; ACVR2B; Activin; BMPR2; Bone morphogenetic protein.

Figures