Expression of Toll-like receptor 8 in diffuse large B-cell lymphoma and its clinical significance / 白血病·淋巴瘤

ABSTRACT

Objective:To investigate the expression of Toll-like receptor 8 (TLR8) in diffuse large B-cell lymphoma (DLBCL) and its correlation with clinicopathological characteristics and prognosis of patients.Methods:The data in the Oncomine database was used to analyze the difference of TLR8 mRNA expression between DLBCL tumor tissues and normal lymphocytes, and the result was verified in two independent subsets GSE 25638 and GSE 32018 of the NCBI-GEO database. The OSDLBCL online survival analysis tool was used to analyze the correlation of TLR8 mRNA relative expression level with overall survival (OS) and progression-free survival (PFS) of DLBCL patients. Gene ontology bioprocess (GO_BP) enrichment analysis was performed by using GSEA software. The correlation of TLR8 mRNA expression with tumor immune cell infiltration degree and immune checkpoint-related molecule expression was analyzed by TIMER online tool website. A total of 53 DLBCL patients who underwent lymph node biopsy in Yancheng No. 1 People's Hospital from June 2020 to June 2021 were selected. Immunohistochemistry was used to detect the expression of TLR8 protein, and its relationship with the clinicopathological characteristics of patients was analyzed.Results:The analysis result of data from Oncomine and GEO databases showed that the relative expression levels of TLR8 mRNA in tumor tissues of patients with DLBCL or activated B cell-like DLCBL were higher than those in normal lymphocytes (all P < 0.001). The results of OSDLBCL online survival analysis indicated that the OS ( P = 0.020) and PFS ( P = 0.004) in DLBCL patients with high TLR8 mRNA expression were worse than those in patients with low TLR8 mRNA expression. The level of TLR8 was related to the abnormal function of immune response, cytokine metabolism and DNA damage monitoring; the result of TIMER online analysis showed that the expression level of TLR8 mRNA was positively related to the degree of neutrophil infiltration ( r = 0.78, P < 0.001) and the expression of immunosuppressive molecules [HAVCR2 ( r = 0.85, P < 0.001), LAG3 ( r = 0.63, P < 0.001), CD274 ( r = 0.77, P < 0.001), TIGIT ( r = 0.32, P = 0.037), and C10ORF54 ( r = 0.34, P = 0.029)]. Among 53 DLBCL patients, 29 patients (54.7%) had low expression of TLR8 protein and 24 patients (45.3%) had high expression of TLR8 protein. There were statistical differences in the expressions of TLR8 protein in DLBCL patients with different serum lactate dehydrogenase and β 2-microglobulin levels (both P < 0.05). Conclusions:TLR8 is highly expressed in DLBCL patients, and TLR8 may be a prognostic marker of DLBCL.