The Relationship Between the Expression of circFAT1 and Immune Cell in Patients with Non-Small Cell Lung Cancer

OBJECTIVE: To analyze the correlation between the expression of circFAT1 in serum and immune cells in patients with non-small cell lung cancer (NSCLC). METHODS: A total of 96 patients with NSCLC admitted to our hospital from November 2019 to November 2022 were regarded as the study subjects. In the meantime, 96 volunteers who had physical examination in our hospital were regarded as the control group. The expression level of circFAT1 in serum was detected by real-time fluorescence quantitative PCR. NSCLC cancer tissue (NSCLC group) and paracancerous tissue (tissue ≥ 2cm away from the focus) (paracancerous group) were collected during the operation, the expression of CD4+, CD8+ and Foxp3+ in tissues was determined by immunohistochemistry; the expression level of circFAT1 mRNA in NSCLC tissue was analyzed using the Ualcan database. Spearman correlation was applied to analyze the correlation between the expression of circFAT1 and immune cells (CD4+, Foxp3+, CD8+). RESULTS: The level of circFAT1 in NSCLC tissue was higher than that in normal tissue (P < 0.05). Compared with the control group, the expression level of circFAT1 in serum of NSCLC group was obviously higher (P < 0.05). The expression level of circFAT1 was related to lymph node metastasis, TNM stage and differentiation (P < 0.05). Compared with the paracancerous group, the positive expression rate of CD8+ in NSCLC group was obviously lower, and the positive expression rates of CD4+ and Foxp3+ were obviously higher (P < 0.05). The expression of CD4+, Foxp3+ and CD8+ in NSCLC patients’ cancer tissue was related to lymph node metastasis, TNM stage and differentiation degree (P < 0.05). Spearman correlation analysis showed that circFAT1 was positively correlated with the expression of CD4+ and Foxp3+ and negatively correlated with the expression of CD8+ (P < 0.05). CONCLUSION: CircFAT1 is highly expressed in the serum of NSCLC patients and is closely related to immune cells.