AUTHOR=Zhang Ning , Liu Yiwen , Yuan Xiang , Liang Mengxia , Wang Xiaopeng , Wang Min , Kong Jinyu , Yang Hong , Zhou Fuyou 

TITLE=Clinical Significance of Fusobacterium nucleatum Infection and Regulatory T Cell Enrichment in Esophageal Squamous Cell Carcinoma

JOURNAL=Pathology and Oncology Research

VOLUME=Volume 27 - 2021

YEAR=2021

URL=https://www.por-journal.com/journals/pathology-and-oncology-research/articles/10.3389/pore.2021.1609846

DOI=10.3389/pore.2021.1609846

ISSN=1532-2807

ABSTRACT=A variety of pathogenic microorganisms can promote the occurrence and development of tumors through long-term colonization in the body. Studies have shown that Fusobacterium nucleatum (F. nucleatum) is abundant in esophageal precancerous lesions, and F. nucleatum is closely related to the malignant progression of esophageal squamous cell carcinoma(ESCC). The invasion of exogenous microorganisms can reshape the immune microenvironment, make the body immune incapacitated, and assist tumor cells in immune escape. Studies have shown that a variety of pathogenic microorganisms can induce the recruitment of regulatory T cells(Tregs), to make tumor cells escape immune surveillance and provide favorable conditions for their own long-term colonization. Tregs is the main obstacle of tumor immunotherapy, and has a significant positive correlation with the occurrence and development of many kinds of tumors. Because F. nucleatum can instantly enter the cells and colonize for a long time, we speculate that F. nucleatum may induce immune escape from tumor cells by recruiting Tregs, and promote the malignant progression of ESCC. In this study, we investigated the correlation between F. nucleatum infection and Tregs infiltration in ESCC and found that the colonization rate of F. nucleatum in ESCC was significantly consistent with its high expression. Therefore, we propose that chronic infection of, F. nucleatum may induce recruitment of Tregs enrichment. Then, we analyzed the correlation between the positive group of Tregs recruited by F. nucleatum and clinicopathological features and survival prognosis of patients.It was found that the positive group of Tregs recruited by F. nucleatum was closely related to sex, smoking, drinking, degree of differentiation, depth of invasion, lymph node metastasis and clinical stage. At the same time, the survival rate and median survival time were significantly shortened in the positive group.Therefore, we put forward the view that long-term smoking and drinking will cause a bad oral and esophageal environment, and the risk of F. nucleatum infection will be significantly increased. After F. nucleatum infection and colonization, a large number of Tregs may be recruited to infiltrate, weaken the anti-tumor immune response, and promote the malignant progression of ESCC.