Department of Surgery, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Ismaninger Str. 22, 81675, Munich, Germany.
Key laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Hepatic, Biliary & Pancreatic Surgery, Peking University School of Oncology, Beijing Cancer Hospital & Institute, Beijing, 100710, China.
J Exp Clin Cancer Res. 2020 Dec 24;39(1):289. doi: 10.1186/s13046-020-01796-4.
Nerve-cancer interactions are increasingly recognized to be of paramount importance for the emergence and progression of pancreatic cancer (PCa). Here, we investigated the role of indirect cholinergic activation on PCa progression through inhibition of acetylcholinesterase (AChE) via clinically available AChE-inhibitors, i.e. physostigmine and pyridostigmine.
We applied immunohistochemistry, immunoblotting, MTT-viability, invasion, flow-cytometric-cell-cycle-assays, phospho-kinase arrays, multiplex ELISA and xenografted mice to assess the impact of AChE inhibition on PCa cell growth and invasiveness, and tumor-associated inflammation. Survival analyses were performed in a novel genetically-induced, surgically-resectable mouse model of PCa under adjuvant treatment with gemcitabine+/-physostigmine/pyridostigmine (n = 30 mice). Human PCa specimens (n = 39) were analyzed for the impact of cancer AChE expression on tumor stage and survival.
We discovered a strong expression of AChE in cancer cells of human PCa specimens. Inhibition of this cancer-cell-intrinsic AChE via pyridostigmine and physostigmine, or administration of acetylcholine (ACh), diminished PCa cell viability and invasion in vitro and in vivo via suppression of pERK signaling, and reduced tumor-associated macrophage (TAM) infiltration and serum pro-inflammatory cytokine levels. In the novel genetically-induced, surgically-resectable PCa mouse model, adjuvant co-therapy with AChE blockers had no impact on survival. Accordingly, survival of resected PCa patients did not differ based on tumor AChE expression levels. Patients with higher-stage PCa also exhibited loss of the ACh-synthesizing enzyme, choline-acetyltransferase (ChAT), in their nerves.
For future clinical trials of PCa, direct cholinergic stimulation of the muscarinic signaling, rather than indirect activation via AChE blockade, may be a more effective strategy.
神经-癌症相互作用对于胰腺癌（PCa）的发生和发展至关重要。在这里，我们通过临床可用的乙酰胆碱酯酶抑制剂（例如毒扁豆碱和吡斯的明）抑制乙酰胆碱酯酶来研究间接胆碱能激活对 PCa 进展的作用。
我们应用免疫组织化学、免疫印迹、MTT 活力测定、侵袭、流式细胞术细胞周期分析、磷酸激酶阵列、多重 ELISA 和异种移植小鼠来评估 AChE 抑制对 PCa 细胞生长和侵袭以及肿瘤相关炎症的影响。在新型基因诱导的、可手术切除的 PCa 小鼠模型中，在吉西他滨+/-毒扁豆碱/吡斯的明辅助治疗下进行生存分析（n=30 只小鼠）。分析了 39 例人 PCa 标本中癌症 AChE 表达对肿瘤分期和生存的影响。
我们发现人 PCa 标本中癌细胞强烈表达 AChE。通过吡斯的明和毒扁豆碱抑制这种癌细胞内源性 AChE，或给予乙酰胆碱（ACh），可通过抑制 pERK 信号通路来减少体外和体内的 PCa 细胞活力和侵袭，并减少肿瘤相关巨噬细胞（TAM）浸润和血清促炎细胞因子水平。在新型基因诱导的、可手术切除的 PCa 小鼠模型中，AChE 阻滞剂的辅助联合治疗对生存没有影响。因此，根据肿瘤 AChE 表达水平，切除的 PCa 患者的生存没有差异。高分期 PCa 患者的神经中也失去了胆碱乙酰转移酶（ChAT），这是合成 ACh 的酶。
对于 PCa 的未来临床试验，直接通过毒蕈碱样受体刺激胆碱能信号，而不是通过 AChE 阻断间接激活，可能是一种更有效的策略。
