Reduced ER-mitochondria connectivity promotes neuroblastoma multidrug resistance

• Type of Material: Article
• Authors: Jorida Çoku, University of Pennsylvania; David M Booth, Thomas Jefferson Univ; Jan Skoda, Masaryk University; Madison C Pedrotty, Childrens Hospital of Philadelphia; Jennifer Vogel, University of Pennsylvania; Kangning Liu, Childrens Hospital of Philadelphia; Annette Vu, Childrens Hospital of Philadelphia; Erica L Carpenter, University of Pennsylvania; Jamie C Ye, Childrens Hospital of Philadelphia; Michelle A Chen, Childrens Hospital of Philadelphia; Peter Dunbar, Childrens Hospital of Philadelphia; Elizabeth Scadden, Childrens Hospital of Philadelphia; Taekyung D Yun, Columbia University; Eiko Nakamaru-Ogiso, Childrens Hospital of Philadelphia; Estela Area-Gomez, Columbia University; Yimei Li, University of Pennsylvania; Kelly Goldsmith, Emory University; Patrick C Reynolds, Texas Tech University; Gyorgy Hajnoczky, Thomas Jefferson University; Michael D Hogarty, Childrens Hospital of Philadelphia
• Language: English
• Date: 2022-02-25
• Publisher: WILEY
• Publication Version: Final Published Version
• Copyright Statement: © 2022 The Authors. Published under the terms of the CC BY NC ND 4.0 license
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.15252/embj.2021108272
• Title of Journal or Parent Work: EMBO JOURNAL
• Volume: 41
• Issue: 8
• Start Page: e108272
• End Page: e108272
• Grant/Funding Information: This study was supported by NIH CA198430, St. Baldrick’s Foundation, and CURE Childhood Cancer Foundation (to MDH); Alex’s Lemonade Stand Foundation (to EAG and MDH); NIH CA216254 (to GH); and the Czech Science Foundation (No. GJ20‐00987Y) to JS. The Metabolomics Workbench repository for archiving the lipidomic dataset is supported by NIH grant U2C‐DK119886.; This study is dedicated to the memory of our dear friend and co‐author Madison Pedrotty. We thank Renata Sano (Children’s Hospital of Philadelphia) for stimulating discussions related to this work; Ocean Malka, Rohan Vemu, and Kiera Patton for technical assistance; the Childhood Cancer Repository powered by Alex’s Lemonade Stand Foundation (www.cccells.org) for tumor models; Diego De Stefani for provision of the GCamp6f plasmid; John Maris for cancer gene sequencing data; and the children and families providing tumor samples for research via the Children’s Oncology Group (COG).
• Keywords: CELL-DEATH; inter-organelle contacts; BIM; sphingolipids; BAX; ceramides; ACTIVATION; ENDOPLASMIC-RETICULUM; Science & Technology; SENSITIVITY; Cell Biology; ALK INHIBITION; mitochondria-associated membranes; multidrug resistance; CALCIUM; Life Sciences & Biomedicine; APOPTOSIS; DRUG-RESISTANCE; Biochemistry & Molecular Biology
• Research Categories: Health Sciences, Oncology; Biology, Cell; Health Sciences, Pathology; Health Sciences, Medicine and Surgery

Abstract

Most cancer deaths result from progression of therapy resistant disease, yet our understanding of this phenotype is limited. Cancer therapies generate stress signals that act upon mitochondria to initiate apoptosis. Mitochondria isolated from neuroblastoma cells were exposed to tBid or Bim, death effectors activated by therapeutic stress. Multidrug-resistant tumor cells obtained from children at relapse had markedly attenuated Bak and Bax oligomerization and cytochrome c release (surrogates for apoptotic commitment) in comparison with patient-matched tumor cells obtained at diagnosis. Electron microscopy identified reduced ER–mitochondria-associated membranes (MAMs; ER–mitochondria contacts, ERMCs) in therapy-resistant cells, and genetically or biochemically reducing MAMs in therapy-sensitive tumors phenocopied resistance. MAMs serve as platforms to transfer Ca2+ and bioactive lipids to mitochondria. Reduced Ca2+ transfer was found in some but not all resistant cells, and inhibiting transfer did not attenuate apoptotic signaling. In contrast, reduced ceramide synthesis and transfer was common to resistant cells and its inhibition induced stress resistance. We identify ER–mitochondria-associated membranes as physiologic regulators of apoptosis via ceramide transfer and uncover a previously unrecognized mechanism for cancer multidrug resistance.