Frontiers in Immunology (Sep 2022)

Dysbiosis of human tumor microbiome and aberrant residence of Actinomyces in tumor-associated fibroblasts in young-onset colorectal cancer

  • Zhuoqing Xu,
  • Zhuoqing Xu,
  • Zhuoqing Xu,
  • Zeping Lv,
  • Zeping Lv,
  • Zeping Lv,
  • Fangqian Chen,
  • Fangqian Chen,
  • Fangqian Chen,
  • Yuchen Zhang,
  • Yuchen Zhang,
  • Yuchen Zhang,
  • Zifeng Xu,
  • Zifeng Xu,
  • Zifeng Xu,
  • Jianting Huo,
  • Jianting Huo,
  • Jianting Huo,
  • Wangyi Liu,
  • Wangyi Liu,
  • Suyue Yu,
  • Suyue Yu,
  • Suyue Yu,
  • Abudumaimaitijiang Tuersun,
  • Abudumaimaitijiang Tuersun,
  • Abudumaimaitijiang Tuersun,
  • Jingkun Zhao,
  • Jingkun Zhao,
  • Yaping Zong,
  • Yaping Zong,
  • Xiaonan Shen,
  • Wenqing Feng,
  • Wenqing Feng,
  • Wenqing Feng,
  • Aiguo Lu,
  • Aiguo Lu

DOI
https://doi.org/10.3389/fimmu.2022.1008975
Journal volume & issue
Vol. 13

Abstract

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Colorectal cancer (CRC) is the third most common form of cancer, and the incidence of sporadic young-onset colorectal cancer (yCRC) has been increasing. Microbiota residing in the tumor microenvironment are emerging tumor components. The colonic microbiome differs between patients with CRC and healthy controls; however, few studies have investigated the role of the tumor microbiota in disease diagnosis and tumorigenesis of yCRC. We performed 16S rRNA sequencing analysis to identify the microbiome in CRC and found that tumor microbial diversity decreased in yCRC. Proteobacteria and Firmicutes were the most abundant phyla in all CRC samples, and Actinomyces and Schaalia cardiffensis were the key microbiota in the yCRC group. Correlation analysis revealed that Actinomyces co-occurred with various pro-tumor microbial taxa, including Bacteroidia, Gammaproteobacteria, and Pseudomonas. An independent cohort was used to validate the results. The Actinomyces in CRC was co-localized with cancer-associated fibroblasts and activated the TLR2/NF-κB pathway and reduces CD8+ T lymphocyte infiltration in CRC microenvironment. This study suggests that tumoral microbiota plays an important role in promoting tumorigenesis and therefore has potential as a promising non-invasive tool and intervention target for anti-tumor therapy.

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