학술논문

NF1 deficiency drives metabolic reprogramming in ER+ breast cancer.
Document Type
Academic Journal
Author
House RRJ; Department of Cell Biology, Van Andel Research Institute, Grand Rapids, MI, USA.; Tovar EA; Department of Cell Biology, Van Andel Research Institute, Grand Rapids, MI, USA.; Redlon LN; Department of Cell Biology, Van Andel Research Institute, Grand Rapids, MI, USA.; Essenburg CJ; Department of Cell Biology, Van Andel Research Institute, Grand Rapids, MI, USA.; Dischinger PS; Department of Cell Biology, Van Andel Research Institute, Grand Rapids, MI, USA.; Ellis AE; Mass Spectrometry Core, Van Andel Research Institute, Grand Rapids, MI, USA.; Beddows I; Department of Epigenetics, Van Andel Research Institute, Grand Rapids, MI, USA.; Sheldon RD; Mass Spectrometry Core, Van Andel Research Institute, Grand Rapids, MI, USA.; Lien EC; Department of Metabolism and Nutritional Programming, Van Andel Research Institute, Grand Rapids, MI, USA.; Graveel CR; Department of Cell Biology, Van Andel Research Institute, Grand Rapids, MI, USA.; Steensma MR; Department of Cell Biology, Van Andel Research Institute, Grand Rapids, MI, USA; Helen DeVos Children's Hospital, Spectrum Health System, Grand Rapids, MI, USA; Michigan State University College of Human Medicine, Grand Rapids, MI, USA. Electronic address: Matt.Steensma@vai.org.
Source
Publisher: Elsevier GmbH Country of Publication: Germany NLM ID: 101605730 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 2212-8778 (Electronic) Linking ISSN: 22128778 NLM ISO Abbreviation: Mol Metab Subsets: MEDLINE
Subject
Language
English
Abstract
Objective: NF1 is a tumor suppressor gene and its protein product, neurofibromin, is a negative regulator of the RAS pathway. NF1 is one of the top driver mutations in sporadic breast cancer such that 27 % of breast cancers exhibit damaging NF1 alterations. NF1 loss-of-function is a frequent event in the genomic evolution of estrogen receptor (ER)+ breast cancer metastasis and endocrine resistance. Individuals with Neurofibromatosis type 1 (NF) - a disorder caused by germline NF1 mutations - have an increased risk of dying from breast cancer [1-4]. NF-related breast cancers are associated with decreased overall survival compared to sporadic breast cancer. Despite numerous studies interrogating the role of RAS mutations in tumor metabolism, no study has comprehensively profiled the NF1-deficient breast cancer metabolome to define patterns of energetic and metabolic reprogramming. The goals of this investigation were (1) to define the role of NF1 deficiency in estrogen receptor-positive (ER+) breast cancer metabolic reprogramming and (2) to identify potential targeted pathway and metabolic inhibitor combination therapies for NF1-deficient ER + breast cancer.
Methods: We employed two ER+ NF1-deficient breast cancer models: (1) an NF1-deficient MCF7 breast cancer cell line to model sporadic breast cancer, and (2) three distinct, Nf1-deficient rat models to model NF-related breast cancer [1]. IncuCyte proliferation analysis was used to measure the effect of NF1 deficiency on cell proliferation and drug response. Protein quantity was assessed by Western Blot analysis. We then used RNAseq to investigate the transcriptional effect of NF1 deficiency on global and metabolism-related transcription. We measured cellular energetics using Agilent Seahorse XF-96 Glyco Stress Test and Mito Stress Test assays. We performed stable isotope labeling and measured [U- 13 C]-glucose and [U- 13 C]-glutamine metabolite incorporation and measured total metabolite pools using mass spectrometry. Lastly, we used a Bliss synergy model to investigate NF1-driven changes in targeted and metabolic inhibitor synergy.
Results: Our results revealed that NF1 deficiency enhanced cell proliferation, altered neurofibromin expression, and increased RAS and PI3K/AKT pathway signaling while constraining oxidative ATP production and restricting energetic flexibility. Neurofibromin deficiency also increased glutamine influx into TCA intermediates and dramatically increased lipid pools, especially triglycerides (TG). Lastly, NF1 deficiency alters the synergy between metabolic inhibitors and traditional targeted inhibitors. This includes increased synergy with inhibitors targeting glycolysis, glutamine metabolism, mitochondrial fatty acid transport, and TG synthesis.
Conclusions: NF1 deficiency drives metabolic reprogramming in ER+ breast cancer. This reprogramming is characterized by oxidative ATP constraints, glutamine TCA influx, and lipid pool expansion, and these metabolic changes introduce novel metabolic-to-targeted inhibitor synergies.
Competing Interests: Declaration of competing interest None.
(Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)