Tissue-Associated Bacterial Alterations in Rectal Carcinoma Patients Revealed by 16S rRNA Community Profiling

Tissue-Associated Bacterial Alterations in Rectal Carcinoma Patients Revealed by 16S rRNA Community Profiling

Author Thomas, Andrew M. Google Scholar
Jesus, Eliane C. Google Scholar
Lopes, Ademar Google Scholar
Aguiar, Samuel, Jr. Google Scholar
Begnami, Maria D. Google Scholar
Rocha, Rafael Malagoli Autor UNIFESP Google Scholar
Carpinetti, Paola Avelar Google Scholar
Camargo, Anamaria A. Google Scholar
Hoffmann, Christian Google Scholar
Freitas, Helano C. Google Scholar
Silva, Israel T. Google Scholar
Nunes, Diana N. Google Scholar
Setubal, Joao C. Google Scholar
Dias-Neto, Emmanuel Google Scholar
Abstract Sporadic and inflammatory forms of colorectal cancer (CRC) account for more than 80% of cases. Recent publications have shown mechanistic evidence for the involvement of gut bacteria in the development of both CRC-forms. Whereas, colon and rectal cancer have been routinely studied together as CRC, increasing evidence show these to be distinct diseases. Also, the common use of fecal samples to study microbial communities may reflect disease state but possibly not the tumor microenvironment. We performed this study to evaluate differences in bacterial communities found in tissue samples of 18 rectal-cancer subjects when compared to 18 non-cancer controls. Samples were collected during exploratory colonoscopy (non-cancer group) or during surgery for tumor excision (rectal-cancer group). High throughput 16S rRNA amplicon sequencing of the V4V5 region was conducted on the Ion PGM platform, reads were filtered using Qiime and clustered using UPARSE. We observed significant increases in species richness and diversity in rectal cancer samples, evidenced by the total number of OTUs and the Shannon and Simpson indexes. Enterotyping analysis divided our cohort into two groups, with the majority of rectal cancer samples clustering into one enterotype, characterized by a greater abundance of Bacteroides and Dorea. At the phylum level, rectal-cancer samples had increased abundance of candidate phylum OD1 (also known as Parcubacteria) whilst non-cancer samples had increased abundance of Planctomycetes. At the genera level, rectal-cancer samples had higher abundances of Bacteroides, Phascolarctobacterium, Parabacteroides, Desulfovibrio, and Odoribacter whereas non-cancer samples had higher abundances of Pseudomonas, Escherichia, Acinetobacter, Lactobacillus, and Bacillus. Two Bacteroides fragilis OTUs were more abundant among rectal-cancer patients seen through 16S rRNA amplicon sequencing, whose presence was confirmed by immunohistochemistry and enrichment verified by digital droplet PCR. Our findings point to increased bacterial richness and diversity in rectal cancer, along with several differences in microbial community composition. Our work is the first to present evidence for a possible role of bacteria such as B. fragilis and the phylum Parcubacteria in rectal cancer, emphasizing the need to study tissue-associated bacteria and specific regions of the gastrointestinal tract in order to better understand the possible links between the microbiota and rectal cancer.
Keywords mucosa-associated microbiota
rectal cancer
16S rRNA gene sequencing
Bacteroides fragilis
Bacterial diversity and community composition
xmlui.dri2xhtml.METS-1.0.item-coverage Lausanne
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Programa Nacional de Apoio à Atenção Oncológica (Pronon)
Associacao Beneficiente Alzira Denise Hertzog Silva (ABADHS)
Grant number FAPESP: 2015/01507-7
FAPESP: 2013/07914-8
CAPES: 88887.062078/2014-00
CAPES: 3385/2013
PRONON: 25000.055.167/2015-23
Date 2016
Published in Frontiers In Cellular And Infection Microbiology. Lausanne, v. 6, p. -, 2016.
ISSN 2235-2988 (Sherpa/Romeo, impact factor)
Publisher Frontiers Media Sa
Extent -
Origin http://dx.doi.org/10.3389/fcimb.2016.00179
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000389614300001
URI https://repositorio.unifesp.br/handle/11600/56556

Show full item record


Name: WOS000389614300001.pdf
Size: 2.677Mb
Format: PDF
Open file

This item appears in the following Collection(s)




My Account