Department of Medicine 1, University Hospital Erlangen-Nuremberg, Erlangen, Germany.
Institute for Surgical Research, Philipps-University Marburg, Marburg, Germany.
Gut. 2016 Jan;65(1):134-43. doi: 10.1136/gutjnl-2014-308286. Epub 2014 Dec 18.
Radiofrequency ablation (RFA), a palliative therapeutic option for solid hepatic tumours, stimulates localised and systemic antitumour cytotoxic T cells. We studied how far addition of CpG B oligonucleotides, toll like receptor (TLR) 9 agonists, would increase the antitumoural T cell response of RFA in the highly aggressive VX2 hepatoma.
Rabbits were randomised to receive RFA, CpG B, their combination or no therapy. The antitumour efficacy of RFA alone or in combination with CpG B was further tested by rechallenging a separate group with intravenously injected VX2 tumour cells after 120 days. Animals were assessed for survival, tumour size and spread, and tumour and immune related histological markers after 120 days. Peripheral blood mononuclear cells were tested for tumour-specific T cell activation and cytotoxicity. Immune modulatory cytokines tumour necrosis factor α, interleukin (IL)-2/IL-8/IL-10/IL-12 and interferon γ, and vascular endothelial growth factor were measured in serum.
Mean survival of untreated animals was 36 days, as compared with 97, 78 and 114 days for RFA, CpG and combination therapy, respectively. Compared with untreated controls, antitumour T cell stimulation/cytotoxicity increased 26/16-fold, 32/17-fold and 50/38-fold 2 weeks after RFA, CpG and combination treatments, respectively. The combination inhibited tumour spread to lungs and peritoneum significantly and prohibited new tumour growth in animals receiving a secondary systemic tumour cell injection. RFA alone induced a Th1 cytokine pattern, while IL-8 and IL-10 were only upregulated in CpG treated animals and controls.
The combination of TLR9 stimulation with RFA resulted in a potentiated antitumour T cell response and cytotoxicity in the VX2 tumour model. Only this combination prevented subsequent tumour spread and resulted in a significantly improved survival, justifying the need for further exploration of the combination of ablative therapies and TLR9 agonists in liver cancer.
射频消融（RFA）是一种针对实体肝肿瘤的姑息性治疗选择，可刺激局部和全身抗肿瘤细胞毒性 T 细胞。我们研究了添加 CpG B 寡核苷酸（TLR9 激动剂）在 VX2 肝癌中增加 RFA 的抗肿瘤 T 细胞反应的程度。
兔子被随机分为接受 RFA、CpG B、联合治疗或不治疗。RFA 单独或联合 CpG B 的抗肿瘤疗效通过在 120 天后用静脉注射 VX2 肿瘤细胞重新挑战另一个组进行进一步测试。120 天后，评估动物的存活、肿瘤大小和扩散情况以及肿瘤和免疫相关的组织学标志物。检测外周血单核细胞的肿瘤特异性 T 细胞激活和细胞毒性。测量血清中免疫调节细胞因子肿瘤坏死因子-α、白细胞介素（IL）-2/IL-8/IL-10/IL-12 和干扰素-γ以及血管内皮生长因子。
未治疗动物的平均存活时间为 36 天，而 RFA、CpG 和联合治疗组分别为 97、78 和 114 天。与未治疗对照组相比，RFA、CpG 和联合治疗后 2 周，抗肿瘤 T 细胞刺激/细胞毒性分别增加了 26/16 倍、32/17 倍和 50/38 倍。联合治疗显著抑制肿瘤向肺部和腹膜扩散，并防止接受二次全身肿瘤细胞注射的动物发生新的肿瘤生长。RFA 单独诱导 Th1 细胞因子模式，而 CpG 治疗的动物和对照组仅上调 IL-8 和 IL-10。
TLR9 刺激与 RFA 的联合应用在 VX2 肿瘤模型中产生了增强的抗肿瘤 T 细胞反应和细胞毒性。只有这种联合治疗才能防止随后的肿瘤扩散，并显著提高存活率，这证明需要进一步探索消融疗法和 TLR9 激动剂在肝癌中的联合应用。
