SPLUNC1 regulates LPS-induced progression of nasopharyngeal carcinoma and proliferation of myeloid-derived suppressor cells

• DOI: 10.1007/s12032-022-01816-7
• Publication Date: 2022-09-29T20:03:15Z
• Authors: Ling Tang; Ling Peng; Huai Liu; Tengfei Xiao; Wangning Gu; Hongmin Yang; Hui Wang; Pan Chen
• Keywords: Lipopolysaccharides; 0303 health sciences; Nasopharyngeal Carcinoma; Interleukin-6; Tumor Necrosis Factor-alpha; Myeloid-Derived Suppressor Cells; Nasopharyngeal Neoplasms; Phosphoproteins; B7-H1 Antigen; 03 medical and health sciences; Tumor Microenvironment; Humans; Cell Proliferation; Glycoproteins

Abstract Background: Nasopharyngeal carcinoma (NPC) is one of the aggressive malignant tumors with high mortality, and the proliferation of myeloid-derived suppressor cells (MDSCs) could promote the metastasis of NPC through inhibiting the function of T cells. Meanwhile, SPLUNC1 was known to inhibit the malignant behavior of NPC cells, while the detailed function of SPLUNC1 in LPS-modified immune microenvironment of NPC remains unclear.Methods: To assess the impact of SPLUNC1 in immune microenvironment during the progression of NPC, NPC cells were exposed to LPS and then co-cultured with MDSCs for 48 h. RT-qPCR and western blot were performed to evaluate the mRNA and protein levels, respectively. The levels of cytokines were tested by ELISA. Meanwhile, the expression of CD33+ was tested by flow cytometry. Results: The expressions of CXCL-2 and CXCR-2 in NPC cells were higher, compared with those in NP69 cells. In contrast, SPLUNC1 level in NPC cells was much lower than that in NP69 cells. SPLUNC1 level was negatively correlated with CXCL-2 and CXCR-2. Overexpression of SPLUNC1 reversed LPS-induced inflammatory responses and proliferation in NPC cells. In addition, SPLUNC1 upregulation could reverse LPS-induced proliferation of MDSCs in tumor microenvironment. Meanwhile, SPLUNC1 overexpression could regulate CXCL-2/CXCR-2 axis. Conclusion: SPLUNC1 regulates LPS-induced progression of nasopharyngeal carcinoma and proliferation of MDSCs. Thus, our study might provide a theoretical basis for discovering new strategies against NPC.