腺苷通过调节肿瘤微环境中T细胞和自然杀伤(NK)细胞的功能来促进抗肿瘤免疫反应;然而,腺苷受体在口腔鳞状细胞癌(OSCC)进展中的作用及其对免疫检查点治疗的影响尚不清楚.在这项研究中,我们获取了2014年2月至2016年12月在山东大学齐鲁医院收治的80例OSCC患者的肿瘤组织.此后,我们使用免疫组织化学染色检测了腺苷2b受体(A2BR)和程序性死亡配体1(PD-L1)的表达,并分析了它们在肿瘤组织不同区域的表达之间的相关性。如肿瘤巢,边界,和副肿瘤基质。为了确定A2BR在PD-L1表达中的作用,CAL-27(OSCC细胞系)用BAY60-6583(A2BR激动剂)处理,采用Westernblot和流式细胞术检测PD-L1的表达。此外,CAL-27用核转录因子-κB(NF-κB)抑制剂处理,PDTC,确定A2BR是否通过NF-κB信号通路调节PD-L1表达。此外,进行了transwell分析以验证A2BR和PD-L1对NK细胞募集的影响.我们的研究结果表明A2BR和PD-L1在OSCC中共表达。此外,用BAY60-6583处理可诱导CAL-27细胞中PD-L1的表达,在用PDTC预处理的细胞中部分减少,提示A2BR激动剂通过NF-κB信号通路诱导PD-L1表达。此外,OSCC中A2BR的高表达与NK细胞的低浸润有关。此外,我们的结果表明,用MRS-1706(A2BR反向激动剂)和/或CD274(PD-L1中和抗体)治疗可促进NK细胞募集和对OSCC细胞的细胞毒性.总之,我们的研究结果强调了A2BR和PD-L1共同抑制通过调节NK细胞募集和细胞毒性治疗OSCC的协同作用.
Adenosine promotes anti-tumor immune responses by modulating the functions of T-cells and natural killer (NK) cells in the tumor microenvironment; however, the role of adenosine receptors in the progression of oral squamous cell carcinoma (OSCC) and its effects on immune checkpoint therapy remain unclear. In this study, we obtained the tumor tissues from 80 OSCC patients admitted at the Shandong University Qilu Hospital between February 2014 and December 2016. Thereafter, we detected the expression of adenosine 2b receptor (A2BR) and programmed death-ligand 1 (PD-L1) using immunohistochemical staining and analyzed the association between their expression in different regions of the tumor tissues, such as tumor nest, border, and paracancer stroma. To determine the role of A2BR in PD-L1 expression, CAL-27 (an OSCC cell line) was treated with BAY60-6583 (an A2BR agonist), and PD-L1 expression was determined using western blot and flow cytometry. Furthermore, CAL-27 was treated with a nuclear transcription factor-kappa B (NF-κ B) inhibitor, PDTC, to determine whether A2BR regulates PD-L1 expression via the NF-κ B signaling pathway. Additionally, a transwell assay was performed to verify the effect of A2BR and PD-L1 on NK cell recruitment. The results of our study demonstrated that A2BR and PD-L1 are co-expressed in OSCC. Moreover, treatment with BAY60-6583 induced PD-L1 expression in the CAL-27 cells, which was partially reduced in cells pretreated with PDTC, suggesting that A2BR agonists induce PD-L1 expression via the induction of the NF-κ B signaling pathway. Furthermore, high A2BR expression in OSCC was associated with lower infiltration of NK cells. Additionally, our results demonstrated that treatment with MRS-1706 (an A2BR inverse agonist) and/or CD274 (a PD-L1-neutralizing antibody) promoted NK cell recruitment and cytotoxicity against OSCC cells. Altogether, our findings highlight the synergistic effect of co-inhibition of A2BR and PD-L1 in the treatment of OSCC via the modulation of NK cell recruitment and cytotoxicity.