e14668 Background: Esophageal squamous cell carcinoma (ESCC) is one of the most common digestive malignant tumor in China. Recent studies have shown that Fusobacterium nucleatum ( F. nucleatum) promotes ESCC progression through various mechanisms. One of them is about changing the tumor micro- environment through cytokine–cytokine receptor interaction. Methods: From January 2022 to June 2023, a total of 34 patients with ESCC from 4th Hospital of Hebei Medical University thoracic surgery were enrolled. All of the patients did not apply any neoadjuvant therapy before and received radical resection. Real-time reverse transcriptase - PCR (RT-PCR) were performed to examine the expressions of F. nucleatum in tumor tissues and para-tumor tissue. According to the CT values of the RT-PCR results, the level of the F. nucleatum infection could be separated in two groups - positive group and negative group. Immunohistochemistry (IHC) staining were used to examine the expressions of chemokine CCL20 in both groups. Immunofluorescence (IF) was characterised homing receptors CCR6 on CD206 + macrophages. In addition, transwell assay was carried on to quantify macrophages migration ability towards chemokines CCL20 in vitro. Results: F. nucleatum DNA positivity was significantly associated with higher expression of chemokine CCL20 and accumulation of CD68 + CD206 + macrophages. F. nucleatum DNA positivity was also significantly correlated with worse histopathological grading. Otherwise, there were no significant correlation between F. nucleatum infection and gender, age, tobacco or alcohol use, T or N grade, TNM stage, tumor locations, blood vessel or nerve invasion and tumor size. IHC showed that the expression of CCL20 were higher in F. nucleatum DNA positive tumor tissue. After coculture with F. nucleatum and KYSE30 cell lines in vitro, the CCL20 production by KYSE30 cells were accelerated. In addition, immunofluorescence showed that CCL20 could recruit M2-like macrophages into the tumor environment by bonding CCR6 existed on the cell surface. Furthermore, the migration ability of macrophages was distinctly elevated by CCL20 result from F. nucleatum infection. Conclusions: F. nucleatum promotes esophageal squamous cell carcinoma progression via CCL20/CCR6-mediated migration of M2-like macrophages to the tumor micro- environment and deteriorates the suppression of the local immune micro- environment within the tumor. Such bacteria may be a biomarker to predict the efficacy of immunotherapy in ESCC. Table: see text
Su et al. (2024) studied this question.