Research Article Cancer Prevention Research Nucleatum Subspecies Animalis Influences Proinflammatory Cytokine Expression and Monocyte Activation in Human Colorectal Tumors Xiangcang Ye1, Rui Wang1, Rajat Bhattacharya1, Delphine R. Boulbes1, Fan Fan1, Ling Xia1, Harish Adoni1, Nadim J. Ajami2, Matthew C. Wong2, Daniel P. Smith2, Joseph F. Petrosino2, Susan Venable3, Wei Qiao4, Veera Baladandayuthapani4, Dipen Maru5, and Lee M. Ellis1,6

Abstract

Chronic infection and associated inflammation have using immunoassays and found that expression of the long been suspected to promote human carcinogenesis. cytokines IL17A and TNFa was markedly increased but Recently, certain gut , including some in the Fuso- IL21 decreased in the colorectal tumors. Furthermore, the bacterium genus, have been implicated in playing a role in chemokine (C-C motif) ligand 20 was differentially human colorectal cancer development. However, the Fuso- expressed in colorectal tumors at all stages. In in vitro co- bacterium species and subspecies involved and their onco- culture assays, F. nucleatum ssp. animalis induced CCL20 genic mechanisms remain to be determined. We sought to protein expression in colorectal cancer cells and monocytes. identify the specific Fusobacterium spp. and ssp. in clinical It also stimulated the monocyte/macrophage activation and colorectal cancer specimens by targeted sequencing of migration. Our observations suggested that infection with Fusobacterium 16S ribosomal RNA gene. Five Fusobacterium F. nucleatum ssp. animalis in colorectal tissue could induce spp. were identified in clinical colorectal cancer specimens. inflammatory response and promote colorectal cancer Additional analyses confirmed that Fusobacterium nuclea- development. Further studies are warranted to determine tum ssp. animalis was the most prevalent F. nucleatum if F. nucleatum ssp. animalis could be a novel target for subspecies in human colorectal cancers. We also assessed colorectal cancer prevention and treatment. Cancer Prev Res; inflammatory cytokines in colorectal cancer specimens 10(7); 398–409. 2017 AACR.

Introduction 1Department of Surgical Oncology, The University of Texas MD Ander- son Cancer Center, Houston, Texas. 2Alkek Center for Metagenomics The gastrointestinal tract has a high density of commensal and Microbiome Research, Department of Molecular Virology and microbes that are not only important to digestive physiol- Microbiology, Baylor College of Medicine, Houston, Texas. 3Texas ogy but also critical to immune system development and Children's Microbiome Center, Department of Pathology and Immu- function. However, an altered intestinal microbiota is 4 nology, Baylor College of Medicine, Houston, Texas. Department of believed to be a potential risk factor for colorectal carcino- Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas. 5Department of Pathology, The University of Texas genesis (1, 2). Early studies linked certain enteric bacterial fl MD Anderson Cancer Center, Houston, Texas. 6Department of Molec- infections with in ammatory bowel disease and colorectal ular and Cellular Oncology, The University of Texas MD Anderson cancer, particularly pathogenic bacterial species such as Cancer Center, Houston, Texas. Streptococcus gallolyticus (3), Enterococcus faecalis (4), adherent Note: Supplementary data for this article are available at Cancer Escherichia coli (5), and enterotoxigenic Bacteroides fragilis Prevention Research Online (http://cancerprevres.aacrjournals.org/). (6). However, the role of these species as causal factors for Corresponding Authors: L.M. Ellis, The University of Texas MD colorectal carcinogenesis remains to be determined. Anderson Cancer Center, 1400 Pressler St., Unit 1484, Houston, Recent discoveries using next-generation sequencing and TX 77030. Phone: 713-792-6926; Fax: 713-792-4689; E-mail: functional studies established an association between