GABRP regulates chemokine signalling, macrophage recruitment and tumour progression in pancreatic cancer through tuning KCNN4-mediated Ca2+ signalling in a GABA-independent manner
GABRP regulates chemokine signalling, macrophage recruitment and tumour progression in pancreatic cancer through tuning KCNN4-mediated Ca2+ signalling in a GABA-independent manner
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GABRP 通过以不依赖 GABA 的方式调节 KCNN4 介导的 Ca2 信号传导来调节胰腺癌中的趋化因子信号传导、巨噬细胞募集和肿瘤进展
DOI：
10.1136/gutjnl-2018-317479
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发表时间：
2019-11-01
期刊：
影响因子：
24.5
通讯作者：
Zhang, Zhi-Gang
中科院分区：
文献类型：
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作者：
Jiang, Shu-Heng;Zhu, Li-Li;Zhang, Zhi-Gang
背景和目的胰腺导管腺癌（PDAC）是世界范围内癌症相关死亡的主要原因。神经递质启动信号通路与肿瘤的发生和发展密切相关。在这里，我们研究了神经递质受体失调是否在胰腺肿瘤发生过程中起作用。方法利用肿瘤基因组图谱和基因表达综合数据库鉴定差异表达的神经递质受体。采用免疫组织化学和western blot方法研究γ -氨基丁酸A型受体pi亚基（GABRP）在人和小鼠PDAC组织和细胞中的表达规律。通过皮下移植模型和肺转移模型检测GABRP对PDAC的体内影响。采用生物信息学分析、transwell实验和原位异种移植模型验证GABRP对PDAC巨噬细胞的体内外作用。采用ELISA、共免疫沉淀、近端结扎、电生理、启动子荧光素酶活性和实时荧光定量PCR等方法分析其分子机制。结果GABRP在PDAC组织中表达显著升高，与预后不良相关，促进肿瘤生长和转移。GABRP在PDAC中与巨噬细胞浸润相关，巨噬细胞的药理学缺失在很大程度上取消了GABRP在PDAC中的致癌功能。机制上，GABRP与KCNN4相互作用诱导Ca2+进入，激活核因子κB信号，最终通过诱导CXCL5和CCL20表达促进巨噬细胞浸润。结论过表达GABRP在PDAC中表现出不依赖于神经递质的免疫调节作用。靶向GABRP或其相互作用伙伴KCNN4可能是治疗PDAC的有效策略。
Background and aims Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related death worldwide. Neurotransmitter-initiated signalling pathway is profoundly implicated in tumour initiation and progression. Here, we investigated whether dysregulated neurotransmitter receptors play a role during pancreatic tumourigenesis. Methods The Cancer Genome Atlas and Gene Expression Omnibus datasets were used to identify differentially expressed neurotransmitter receptors. The expression pattern of gamma-aminobutyric acid type A receptor pi subunit (GABRP) in human and mouse PDAC tissues and cells was studied by immunohistochemistry and western blot analysis. The in vivo implications of GABRP in PDAC were tested by subcutaneous xenograft model and lung metastasis model. Bioinformatics analysis, transwell experiment and orthotopic xenograft model were used to identify the in vitro and in vivo effects of GABRP on macrophages in PDAC. ELISA, co-immunoprecipitation, proximity ligation assay, electrophysiology, promoter luciferase activity and quantitative real-time PCR analyses were used to identify molecular mechanism. Results GABRP expression was remarkably increased in PDAC tissues and associated with poor prognosis, contributed to tumour growth and metastasis. GABRP was correlated with macrophage infiltration in PDAC and pharmacological deletion of macrophages largely abrogated the oncogenic functions of GABRP in PDAC. Mechanistically, GABRP interacted with KCNN4 to induce Ca2+ entry, which leads to activation of nuclear factor κB signalling and ultimately facilitates macrophage infiltration by inducing CXCL5 and CCL20 expression. Conclusions Overexpressed GABRP exhibits an immunomodulatory role in PDAC in a neurotransmitter-independent manner. Targeting GABRP or its interaction partner KCNN4 may be an effective therapeutic strategy for PDAC.