Olivia I Coleman1, Elena M Lobner1, Sandra Bierwirth1, Adam Sorbie1, Nadine Waldschmitt1, Eva Rath1, Emanuel Berger1, Ilias Lagkouvardos2, Thomas Clavel2, Kathleen D McCoy3, Achim Weber4, Mathias Heikenwalder5, Klaus-Peter Janssen6, Dirk Haller7. 1. Chair of Nutrition and Immunology, Technische Universität München, Freising, Germany. 2. ZIEL -Institute for Food & Health, Technische Universität München, Germany. 3. Department of Physiology and Pharmacology, University of Calgary, Canada. 4. Institute of Pathology, University Zurich and University Hospital Zurich, Zurich, Switzerland. 5. Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany. 6. Department of Surgery, Klinikum rechts der Isar, Technische Universität München, München, Germany. 7. Chair of Nutrition and Immunology, Technische Universität München, Freising, Germany; ZIEL -Institute for Food & Health, Technische Universität München, Germany. Electronic address: dirk.haller@tum.de.
Abstract
BACKGROUND & AIMS: Activating transcription factor 6 (ATF6) regulates endoplasmic reticulum stress. We studied whether ATF6 contributes to the development of colorectal cancer (CRC) using tissue from patients and transgenic mice. METHODS: We analyzed data from 541 patients with CRC in The Cancer Genome Atlas database for genetic variants and aberrant expression levels of unfolded protein response genes. Findings were validated in a cohort of 83 patients with CRC in Germany. We generated mice with intestinal epithelial cell-specific expression of the active form of Atf6 (nATF6IEC) from 2 alleles (homozygous), mice with expression of nATF6IEC from 1 allele (heterozygous), and nATF6IECfl/fl mice (controls). All nATF6IEC mice were housed under either specific-pathogen-free or germ-free conditions. Cecal microbiota from homozygous nATF6IEC mice or control mice was transferred into homozygous nATF6IEC mice or control mice. nATF6IEC mice were crossed with mice with disruptions in the myeloid differentiation primary response gene 88 and toll-like receptor adaptor molecule 1 gene (Myd88/Trif-knockout mice). Intestinal tissues were collected from mice and analyzed by histology, immunohistochemistry, immunoblots, gene expression profiling of unfolded protein response and inflammatory genes, array-based comparative genome hybridization, and 16S ribosomal RNA gene sequencing. RESULTS: Increased expression of ATF6 was associated with reduced disease-free survival times of patients with CRC. Homozygous nATF6IEC mice developed spontaneous colon adenomas at 12 weeks of age. Compared with controls, homozygous nATF6IEC mice had changes in the profile of their cecal microbiota, increased proliferation of intestinal epithelial cells, and loss of the mucus barrier-all preceding tumor formation. These mice had increased penetration of bacteria into the inner mucus layer and activation of signal transducer and activator of transcription 3, yet inflammation was not observed at the pretumor or tumor stages. Administration of antibiotics to homozygous nATF6IEC mice greatly reduced tumor incidence, and germ-free housing completely prevented tumorigenesis. Analysis of nATF6IEC MyD88/TRIF-knockout mice showed that tumor initiation and growth required MyD88/TRIF-dependent activation of signal transducer and activator of transcription 3. Transplantation of cecal microbiota from nATF6IEC mice and control mice, collected before tumor formation, caused tumor formation in ex-germ-free nATF6IEC mice. CONCLUSIONS: In patients with CRC, ATF6 was associated with reduced time of disease-free survival. In studies of nATF6IEC mice, we found sustained intestinal activation of ATF6 in the colon to promote dysbiosis and microbiota-dependent tumorigenesis.
BACKGROUND & AIMS:Activating transcription factor 6 (ATF6) regulates endoplasmic reticulum stress. We studied whether ATF6 contributes to the development of colorectal cancer (CRC) using tissue from patients and transgenic mice. METHODS: We analyzed data from 541 patients with CRC in The Cancer Genome Atlas database for genetic variants and aberrant expression levels of unfolded protein response genes. Findings were validated in a cohort of 83 patients with CRC in Germany. We generated mice with intestinal epithelial cell-specific expression of the active form of Atf6 (nATF6IEC) from 2 alleles (homozygous), mice with expression of nATF6IEC from 1 allele (heterozygous), and nATF6IECfl/fl mice (controls). All nATF6IEC mice were housed under either specific-pathogen-free or germ-free conditions. Cecal microbiota from homozygous nATF6IEC mice or control mice was transferred into homozygous nATF6IEC mice or control mice. nATF6IEC mice were crossed with mice with disruptions in the myeloid differentiation primary response gene 88 and toll-like receptor adaptor molecule 1 gene (Myd88/Trif-knockout mice). Intestinal tissues were collected from mice and analyzed by histology, immunohistochemistry, immunoblots, gene expression profiling of unfolded protein response and inflammatory genes, array-based comparative genome hybridization, and 16S ribosomal RNA gene sequencing. RESULTS: Increased expression of ATF6 was associated with reduced disease-free survival times of patients with CRC. Homozygous nATF6IEC mice developed spontaneous colon adenomas at 12 weeks of age. Compared with controls, homozygous nATF6IEC mice had changes in the profile of their cecal microbiota, increased proliferation of intestinal epithelial cells, and loss of the mucus barrier-all preceding tumor formation. These mice had increased penetration of bacteria into the inner mucus layer and activation of signal transducer and activator of transcription 3, yet inflammation was not observed at the pretumor or tumor stages. Administration of antibiotics to homozygous nATF6IEC mice greatly reduced tumor incidence, and germ-free housing completely prevented tumorigenesis. Analysis of nATF6IEC MyD88/TRIF-knockout mice showed that tumor initiation and growth required MyD88/TRIF-dependent activation of signal transducer and activator of transcription 3. Transplantation of cecal microbiota from nATF6IEC mice and control mice, collected before tumor formation, caused tumor formation in ex-germ-free nATF6IEC mice. CONCLUSIONS: In patients with CRC, ATF6 was associated with reduced time of disease-free survival. In studies of nATF6IEC mice, we found sustained intestinal activation of ATF6 in the colon to promote dysbiosis and microbiota-dependent tumorigenesis.
Authors: Stephanie T Stengel; Antonella Fazio; Simone Lipinski; Martin T Jahn; Konrad Aden; Go Ito; Felix Wottawa; Jan W P Kuiper; Olivia I Coleman; Florian Tran; Dora Bordoni; Joana P Bernardes; Marlene Jentzsch; Anne Luzius; Sandra Bierwirth; Berith Messner; Anna Henning; Lina Welz; Nassim Kakavand; Maren Falk-Paulsen; Simon Imm; Finn Hinrichsen; Matthias Zilbauer; Stefan Schreiber; Arthur Kaser; Richard Blumberg; Dirk Haller; Philip Rosenstiel Journal: Gastroenterology Date: 2020-07-13 Impact factor: 22.682
Authors: Juan F Burgueño; Julia Fritsch; Eddy E González; Kevin S Landau; Ana M Santander; Irina Fernández; Hajar Hazime; Julie M Davies; Rebeca Santaolalla; Matthew C Phillips; Sophia Diaz; Rishu Dheer; Nivis Brito; Judith Pignac-Kobinger; Ester Fernández; Gregory E Conner; Maria T Abreu Journal: Gastroenterology Date: 2020-10-24 Impact factor: 22.682