Sachiko Inubushi, Tomonari Kunihisa, Sachiko Mizumoto, Shotaro Inoue, Mayuko Miki, Atsushi Suetsugu, Hirokazu Tanino, Robert M Hoffman
{"title":"Methionine Restriction Increases Exosome Production and Secretion in Breast Cancer Cells.","authors":"Sachiko Inubushi, Tomonari Kunihisa, Sachiko Mizumoto, Shotaro Inoue, Mayuko Miki, Atsushi Suetsugu, Hirokazu Tanino, Robert M Hoffman","doi":"10.21873/cgp.20393","DOIUrl":null,"url":null,"abstract":"<p><strong>Background/aim: </strong>Methionine addiction is the elevated requirement for exogenous methionine for growth and survival of cancer cells, termed the Hoffman effect. Methionine-addicted cancer cells synthesize normal or excess amounts of methionine but still need an external source of methionine. Methionine restriction (MR) by either a methionine-free medium or in vivo by a low-methionine diet or by methioninase, selectively arrests cancer cells in the late S/G<sub>2</sub> cell cycle phase, but not normal cells. The present study focuses on the comparison of production and secretion of exosomes by cancer cells under MR and normal conditions.</p><p><strong>Materials and methods: </strong>MDA-MB-231 cells (triple-negative breast cancer), containing exosomes labeled with CD63-GFP (CD63-GFP exosomes), were visualized by fluorescence microscopy. MDA-MB-231 cells expressing exosome-specific CD63-GFP were cultured in methionine-containing (MET+) or in methionine-free (MET-) DMEM conditions. Exosomes were isolated from conditioned medium of cultured MDA-MD-231 cells by ultracentrifugation and characterized by nanoparticle tracking analysis (NTA) and Western blotting.</p><p><strong>Results: </strong>When MDA-MB-231-CD63-GFP cells were cultured under MR conditions, they arrested their growth and CD63-GFP-expressing exosomes were strongly increased in the cells. MR resulted in approximately a 2-fold increase in exosome production and secretion per cell, even though cell growth was arrested. Methionine restriction thus resulted in elevated exosome production and secretion per surviving cell.</p><p><strong>Conclusion: </strong>Exosome production and secretion in the cancer cells increased under MR, suggesting a relation between MR and exosome production and secretion.</p>","PeriodicalId":9516,"journal":{"name":"Cancer Genomics & Proteomics","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10464940/pdf/cgp-20-412.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cancer Genomics & Proteomics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.21873/cgp.20393","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GENETICS & HEREDITY","Score":null,"Total":0}
引用次数: 0
Abstract
Background/aim: Methionine addiction is the elevated requirement for exogenous methionine for growth and survival of cancer cells, termed the Hoffman effect. Methionine-addicted cancer cells synthesize normal or excess amounts of methionine but still need an external source of methionine. Methionine restriction (MR) by either a methionine-free medium or in vivo by a low-methionine diet or by methioninase, selectively arrests cancer cells in the late S/G2 cell cycle phase, but not normal cells. The present study focuses on the comparison of production and secretion of exosomes by cancer cells under MR and normal conditions.
Materials and methods: MDA-MB-231 cells (triple-negative breast cancer), containing exosomes labeled with CD63-GFP (CD63-GFP exosomes), were visualized by fluorescence microscopy. MDA-MB-231 cells expressing exosome-specific CD63-GFP were cultured in methionine-containing (MET+) or in methionine-free (MET-) DMEM conditions. Exosomes were isolated from conditioned medium of cultured MDA-MD-231 cells by ultracentrifugation and characterized by nanoparticle tracking analysis (NTA) and Western blotting.
Results: When MDA-MB-231-CD63-GFP cells were cultured under MR conditions, they arrested their growth and CD63-GFP-expressing exosomes were strongly increased in the cells. MR resulted in approximately a 2-fold increase in exosome production and secretion per cell, even though cell growth was arrested. Methionine restriction thus resulted in elevated exosome production and secretion per surviving cell.
Conclusion: Exosome production and secretion in the cancer cells increased under MR, suggesting a relation between MR and exosome production and secretion.
期刊介绍:
Cancer Genomics & Proteomics (CGP) is an international peer-reviewed journal designed to publish rapidly high quality articles and reviews on the application of genomic and proteomic technology to basic, experimental and clinical cancer research. In this site you may find information concerning the editorial board, editorial policy, issue contents, subscriptions, submission of manuscripts and advertising. The first issue of CGP circulated in January 2004.
Cancer Genomics & Proteomics is a journal of the International Institute of Anticancer Research. From January 2013 CGP is converted to an online-only open access journal.
Cancer Genomics & Proteomics supports (a) the aims and the research projects of the INTERNATIONAL INSTITUTE OF ANTICANCER RESEARCH and (b) the organization of the INTERNATIONAL CONFERENCES OF ANTICANCER RESEARCH.