Inflammatory IFIT3 renders chemotherapy resistance by regulating post-translational modification of VDAC2 in pancreatic cancer
Inflammatory IFIT3 renders chemotherapy resistance by regulating post-translational modification of VDAC2 in pancreatic cancer
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DOI：
10.7150/thno.43093
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发表时间：
2020-01-01
期刊：
影响因子：
12.4
通讯作者：
Bruns, Christiane J.
中科院分区：
文献类型：
--
作者：
Wang, Zhefang;Qin, Jie;Bruns, Christiane J.
胰腺导管腺癌（PDAC）是世界范围内最致命的癌症之一，有效的治疗仍然是一个挑战。IFIT3是一种干扰素刺激基因，具有抗病毒和促炎功能。我们之前的研究表明，在接受化疗的PDAC患者中，IFIT3的高表达与生存率低相关，这表明IFIT3与PDAC化疗耐药之间存在联系。然而，IFIT3在PDAC化疗耐药中的确切作用和分子机制尚不清楚。方法：下载一组转录组数据集并分析IFIT3在PDAC中的特征。采用高转移性PDAC细胞系L3.6pl和患者源性原代细胞TBO368，建立IFIT3敲低和相应的敲入细胞进行体外研究。通过化疗诱导的细胞凋亡、ROS产生、共聚焦免疫荧光、亚细胞分离、染色质免疫沉淀、共免疫沉淀和质谱分析，进一步探讨IFIT3在PDAC化疗耐药中的生物学作用。结果：基于PDAC转录组数据，我们发现IFIT3的表达与PDAC的鳞状分子亚型以及炎症反应和凋亡途径的增加有关。我们进一步确定了IFIT3在化疗期间线粒体相关凋亡的调控中的关键作用。IFIT3的敲低降低了PDAC细胞对吉西他滨、紫杉醇和FOLFIRINOX方案治疗的化疗耐药性，独立于个别化疗方案。IFIT3过表达可促进耐药。共免疫沉淀鉴定了IFIT3与线粒体通道蛋白VDAC2之间的直接相互作用，VDAC2是线粒体相关凋亡的重要调节因子。随后发现，IFIT3通过稳定VDAC2与O-GlcNAc转移酶的相互作用，调控VDAC2的翻译后修饰- o - glcn酰化。增加的o - glcn酰化VDAC2保护PDAC细胞免受化疗诱导的凋亡。结论：这些结果有效地证明了IFIT3表达影响PDAC化疗耐药的核心机制。靶向IFIT3/VDAC2可能代表了一种使侵袭性胰腺癌对传统化疗方案敏感的新策略。
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide and effective therapy remains a challenge. IFIT3 is an interferon-stimulated gene with antiviral and pro-inflammatory functions. Our previous work has shown that high expression of IFIT3 is correlated with poor survival in PDAC patients who receive chemotherapy suggesting a link between IFIT3 and chemotherapy resistance in PDAC. However, the exact role and molecular mechanism of IFIT3 in chemotherapy resistance in PDAC has been unclear.Methods: A group of transcriptome datasets were downloaded and analyzed for the characterization of IFIT3 in PDAC. Highly metastatic PDAC cell line L3.6pl and patient-derived primary cell TBO368 were used and IFIT3 knockdown and the corresponding knockin cells were established for in vitro studies. Chemotherapy-induced apoptosis, ROS production, confocal immunofluorescence, subcellular fractionation, chromatin-immunoprecipitation, co-immunoprecipitation and mass spectrometry analysis were determined to further explore the biological role of IFIT3 in chemotherapy resistance of PDAC.Results: Based on PDAC transcriptome data, we show that IFIT3 expression is associated with the squamous molecular subtype of PDAC and an increase in inflammatory response and apoptosis pathways. We further identify a crucial role for IFIT3 in the regulation of mitochondria-associated apoptosis during chemotherapy. Knockdown of IFIT3 attenuates the chemotherapy resistance of PDAC cells to gemcitabine, paclitaxel, and FOLFIRINOX regimen treatments, independent of individual chemotherapy regimens. While IFIT3 overexpression was found to promote drug resistance. Co-immunoprecipitation identified a direct interaction between IFIT3 and the mitochondrial channel protein VDAC2, an important regulator of mitochondria-associated apoptosis. It was subsequently found that IFIT3 regulates the post-translational modification-O-GlcNAcylation of VDAC2 by stabilizing the interaction of VDAC2 with O-GlcNAc transferase. Increased O-GlcNAcylation of VDAC2 protected PDAC cells from chemotherapy induced apoptosis.Conclusions: These results effectively demonstrate a central mechanism by which IFIT3 expression can affect chemotherapy resistance in PDAC. Targeting IFIT3/VDAC2 may represent a novel strategy to sensitize aggressive forms of pancreatic cancer to conventional chemotherapy regimens.