关键词： pepsinogen C   gastric cancer   biological behavior   tumor metastasis   IQGAP1  

摘要： Simple Summary As the precursor of pepsin, Pepsinogen C (PGC) is the final product of the maturation and differentiation of gastric mucosa cells. The latest bioinformatics analysis found that PGC may play a little-known role in the carcinogenic process, but there is no relevant experimental evidence to prove the effect of PGC on the biological function of cancer cells. In our research, we found PGC may act as a tumor suppressor in the development and metastasis of gastric cancer. PGC can downregulate its interacting protein IQGAP1 and inhibit the Rho-GTPase pathway, thereby participating in the inhibition of gastric cancer cell migration and invasion. Thus, PGC has the potential to be a new therapeutic target for gastric *** Aim: This study systematically explored the biological effects and mechanisms of PGC on gastric cancer (GC) cells in vitro and in vivo. Method: The critical biological roles of PGC in GC were assessed via EdU staining, Hoechst staining, flow cytometry, mouse models, CCK-8, wound healing, transwell, and sphere-forming assays. The interaction study with IQ-domain GTPase-activating protein 1 (IQGAP1) was used by Liquid chromatography-mass spectrometry co-immunoprecipitation, immunofluorescence staining, CHX-chase assay, MG132 assay, and qRT-PCR. Results: PGC inhibited the proliferation, viability, epithelial-mesenchymal transition, migration, invasion, and stemness of GC cells and promoted GC cell differentiation. PGC suppressed subcutaneous tumor growth and peritoneal dissemination in vivo. The interaction study found PGC inhibits GC cell migration and invasion by downregulating IQGAP1 protein and IQGAP1-mediated Rho-GTPase signaling suppression. In addition, PGC disrupts the stability of the IQGAP1 protein, promoting its degradation and significantly shortening its half-life. Moreover, the expression levels of PGC and IQGAP1 in GC tissues were significantly negatively correlated. Conclusion: PGC may act as a tumor suppressor in the de

关键词： cancer metastasis   Rho GTPases   endothelial adhesion   β-integrin   signaling   shear stress   IQGAP1   NWASP   cell-cell adhesion  

摘要： Attachment of circulating tumor cells to the endothelial cells (ECs) lining blood vessels is a critical step in cancer metastatic colonization, which leads to metastatic outgrowth. Breast and prostate cancers are common malignancies in women and men, respectively. Here, we observe that 01-integrin is required for human prostate and breast cancer cell adhesion to ECs under shear -stress conditions in vitro and to lung blood vessel ECs in vivo. We identify IQGAP1 and neural Wiskott-Aldrich syndrome protein (NWASP) as regulators of 01-integrin transcription and protein expression in prostate and breast cancer cells. IQGAP1 and NWASP depletion in cancer cells decreases adhesion to ECs in vitro and retention in the lung vasculature and metastatic lung nodule formation in vivo. Mechanistically, NWASP and IQGAP1 act downstream of Cdc42 to increase 01-integrin expression both via extracellular signal -regulated kinase (ERK)/focal adhesion kinase signaling at the protein level and by myocardin-related transcription factor/ serum response factor (SRF) transcriptionally. Our results identify IQGAP1 and NWASP as potential therapeutic targets to reduce early metastatic dissemination.

关键词： IQGAP1   GBMLGG   nomogram   clinical prognosis  

摘要： Lower -grade gliomas (GBMLGG) are common, fatal, and difficult -to -treat cancers. The current treatment choices have impressive efficacy constraints. As a result, the development of effective treatments and the identification of new therapeutic targets are urgent requirements. Disulfide metabolism is the cause of the nonapoptotic programmed cell death known as disulfideptosis, which was only recently discovered. The mRNA expression data and related clinical information of GBMLGG patients downloaded from public databases were used in this study to investigate the prognostic significance of genes involved in disulfideptosis. In the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohort, our findings showed that many disulfidptosis-related genes were expressed differently in normal and GBMLGG tissues. It was discovered that IQ motif -containing GTPase-activating protein 1 (IQGAP1) is a key gene that influences the outcome of GBMLGG. Besides, a nomogram model was built to foresee the visualization of GBMLGG patients. In addition, in vivo and in vitro validation of IQGAP1's cancer -promoting function was done. In conclusion, we discovered a gene signature associated with disulfideptosis that can effectively predict OS in GBMLGG patients. As a result, treating disulfideptosis may be a viable alternative for GBMLGG patients.

关键词： 动脉粥样硬化   内皮细胞   细胞凋亡  

摘要： 背景：　　动脉粥样硬化（Atherosclerosis,AS）是一种慢性炎症性疾病，其导致的心脑血管疾病是人类健康所面对的最大威胁之一。正常血管内皮细胞可以调节血管张力、预防血栓形成和调节炎症，在维持血管稳态和抑制动脉粥样硬化方面具有重要作用，而脂质沉积诱导的内皮细胞损伤可以促进AS形成。目前，越来越多的证据表明，内皮细胞凋亡是动脉粥样硬化的始动因素。　　IQ结构域GTP酶激活蛋白1（IQmotifcontainingGTPaseactivatingproteins1,IQGAP1）是多种信号通路的重要调节因子，可以调控细胞生长、发育以及死亡，参与动脉粥样硬化的发生发展。另有研究表明IQGAP1可能调节Hippo信号通路的关键蛋白YAP（Yes-associatedprotein）从而影响细胞凋亡。所以本课题研究了IQGAP1在内皮细胞凋亡和动脉粥样硬化中的作用，并初步探索其作用机制。　　目的：　　研究IQGAP1对动脉粥样硬化中血管内皮细胞凋亡和YAP的调控作用。　　研究方法：　　1.通过高脂饮食建立小鼠动脉粥样硬化模型，应用WesternBlot方法鉴定IQGAP1以及凋亡相关蛋白在动脉粥样硬化小鼠模型中表达水平。　　2.体外构建棕榈酸（Palmiticacid,PA）诱导人脐静脉内皮细胞（HumanUmbilicalVeinEndothelialCells,HUVEC）凋亡模型，在凋亡模型中使用Jetprime转染小干扰RNA（SmallinterferingRNA,siRNA）敲低或者pcDNA3.1-3xFlag-IQGAP1过表达细胞内IQGAP1水平，采用流式细胞术（FlowCytometry,FCM）观察细胞凋亡并采用WB检测细胞凋亡蛋白改变水平。探索脂质沉积诱导的内皮细胞凋亡与IQGAP1的关系。　　3.在HUVEC中敲低或者过表达IQGAP1，使用WB及免疫荧光观察YAP蛋白水平的变化。　　4.在HUVEC中使用siRNA同时敲低IQGAP1和YAP，采用流式细胞术观察细胞凋亡并采用WB检测细胞凋亡蛋白改变水平。　　5.通过AAV-siRNA在动脉粥样硬化模型小鼠中实现敲低IQGAP1，进一步探索IQGAP1在动脉粥样硬化模型鼠血管内皮凋亡中发挥的作用。　　结果：　　1.通过高脂饮食建立小鼠动脉粥样硬化模型，WB检测到高脂饮食小鼠主动脉中IQGAP1，Caspase-3，BAX（Bcl-2-associatedXprotein）高于对照组，BCL-2低于对照组。TUNEL染色结果表明高脂饮食小鼠主动脉凋亡细胞高于对照组。　　2.在PA诱导的HUVEC凋亡模型中，敲低IQGAP1之后，Caspase-3和BAX水平降低，BCL-2（B-celllymphoma-2）升高;反之上调。流式细胞术表明，敲低IQGAP1后，细胞凋亡水平有所降低;反之升高。EdU染色结果表明，敲低IQGAP1后，细胞增殖水平有所升高;反之降低。　　3.在HUVEC细胞中敲低IQGAP1后，免疫荧光及WB结果表明YAP蛋白表达量有所升高;反之，过表达IQGAP1后，YAP蛋白表达量降低。　　4.在HUVEC细胞中敲低IQGAP1后，流式细胞术表明细胞凋亡水平降低，但将IQGAP1及YAP同时敲低后，细胞凋亡水平相较于单独敲低IQGAP1升高。敲低YAP逆转了敲低IQGAP1带来的抗凋亡作用。　　5.在高脂饮食小鼠体内注射AAV-si-IQGAP1后，主动脉表达IGQAP1降低，动脉粥样硬化斑块大小降低，细胞凋亡水平降低，且YAP升高。　　结论：　　1.动脉粥样硬化斑块中凋亡水平高于正常组，IQGAP1在动脉粥样硬化斑块中表达明显增高。　　2.使用siRNA敲低IQGAP1可以抑制PA诱导的细胞凋亡，并促进细胞增殖。反之过表达IQGAP1会诱导细胞发生凋亡，抑制细胞增殖。　　***的表达水平与IQGAP1呈负相关，敲低IQGAP1会增加YAP的表达量，而过表达IQGAP1会降低YAP的表达量。　　4.使用siRNA敲低YAP后，可以促进细胞发生凋亡，抑制细胞增殖。　　5.在小鼠高脂饮食模型中使用AAV-si-RNA，验证了敲低IQGAP1可以降低小鼠主动脉粥样硬化斑块和细胞凋亡水平，敲低IQGAP1后YAP表达水平升高。

关键词： IQGAP1   氧化应激   mtDNA   焦亡   动脉粥样硬化  

摘要： 研究背景 动脉粥样硬化（Atheroscleros,AS）是一种慢性炎症性疾病,简单来说一般包括三个病理过程—脂质沉积、炎症浸润、泡沫细胞形成最终导致血管内径变窄,是世界上最常见的引起死亡的原因之一。AS的形成与内皮细胞,单核细胞,巨噬细胞以及平滑肌细胞的功能有着密切关系,在形成早期,血液和动脉内膜之间内皮单层发生改变,这是AS的起始部位;且内皮细胞易受高脂血症、氧化应激、趋化因子、DNA异位等损伤模式分子的影响引起炎症反应,这进一步导致内环境的紊乱促进了内皮细胞功能活化。然而,目前药物治疗AS仍然具有一定的局限性。越来越多的研究表明抑制内皮细胞焦亡可能成为治疗AS的一种新思路,但其具体发生机制仍不清楚。焦亡是一种不同于细胞凋亡和坏死的程序性细胞死亡过程,与炎症小体的形成密切相关并伴随着促炎因子的大量释放。IQGAP蛋白家族存在于许多生物体中,已在人类中鉴定出三种IQGAP1、IQGAP2和IQGAP3,其中IQGAP1在组织中广泛表达,是最具特征的IQGAP蛋白质,在真核生物中具有进化保守性,有助于形成调节细胞骨架动力学、细胞内信号传导和细胞间相互作用的复合物;同时,在调节细胞粘附、信号传导和迁移中起重要作用。随着研究的逐渐深入,日益增多的证据表明IQGAP1作用于心肌细胞影响心脏重塑,心室壁变薄和收缩力下降;同时对血管生成过程中内皮细胞的增殖和迁移有着重要作用,这与线粒体活性氧（mt ROS）的产生有关。重要的是,随着mt ROS在细胞内累积可能会导致线粒体损伤进而发生Caspase-1-NLRP3经典途径焦亡。新的发现表明线粒体损伤导致线粒体DNA（mtDNA）泄露到细胞质,激活细胞质中DNA感受器cGAS-STING,并触发分子链反应以诱导I型干扰素（IFN-I）,启动和维持炎症反应。在心血管领域中发现mtDNA激活的cGAS-STING信号在心肌细胞焦亡中同样被广泛关注,但在AS中未有确切报道。我们的探索性研究IQGAP1是否通过调节线粒体功能导致mtDNA泄露激活cGAS-STING信号通路诱导内皮细胞焦亡以及特异性小分子抑制剂RU.521和C-176的治疗作用,以期对AS的发生机制和治疗提供了一个新的视野。 研究目的 1.研究动脉粥样硬化模型中IQGAP1,cGAS,STING对内皮细胞焦亡的影响。 2.阐明IQGAP1对动脉粥样硬化进程中活性氧ROS影响及其部分调控机制。 3.检测线粒体损伤后细胞质中ds DNA泄露并进行定量和组织定位分析。 4.明确IQGAP1在线粒体损伤过程中调节mtDNA释放激活DNA感受器cGAS-STING信号通路。 5.小分子抑制剂RU.521和C-176通过特异性阻断cGAS和STING信号通路,从而抑制IQGAP1促进的动脉粥样硬化,探索可能存在的的药物靶点。 研究方法 1.购买40只ApoE-/-C57BL/J和40只Ldlr-/-C57BL/J,两种小鼠各随机分为四组正常饮食组（Cont）,高脂饮食组（HFD）,高脂饮食+AAV-Sh RNA-IQGAP1（AAV-Si-IQGAP1）组,高脂饮食+AAV-Sh RNA-NC（AAV-NC）组。在适应一周后注射腺病毒及其对照,两种小鼠分别使用相对应的高脂饲料连续喂养12周,每间隔两周记录小鼠体重。使用HE,油红切片,油红大体染色对主动脉组织进行病理检测并检测血清生化指标LDL,TC,TG,HDL。使用IHC、IF和Westernblot观察焦亡相关分子NLRP3,GSDMD-N,Caspase-1和cGAS,STING信号通路蛋白表达,qRT-PCR观察炎症因子IL-1β,IL-18和DNA感受器cGAS,STING以及抗氧化应激GPX-1,SOD-1 m RNA的表达情况。 2.在小鼠组织中通过线粒体追踪标记Mito-Tracker与ds DNA抗体进行双重定位染色,观察mtDNA的释放情况的定性分析。同时,对小鼠主动脉组织进行利用mtDNA提取试剂盒进行q-PCR定量分析。利用TUNEL染色观察主动脉组织内皮细胞焦亡情况,通过透射电镜观察线粒体损伤。 3.在体外通过棕榈酸（PA,0.3mmol/L）刺激人脐静脉内皮细胞（HUVECs）模拟内皮细胞损伤模型。通过Mito SOX染色,DCFH-DA流式细胞术检测PA诱导HUVECs细胞中活性氧（ROS）的产生。通过Western blot观察PA诱导的HUVECs中焦亡相关蛋白NLRP3,GSDMD-N,Caspase-1,IL-1β,IL-18的表达情况,扫描电镜观察焦亡细胞膜“打孔”现象。 4.在体外分别构建IQGAP1的过表达质粒和阴性对照（pc DNA3.1-3x Flag-IQGAP1,pc DNA3.1-3x Flag-NC）,小干扰RN

关键词： Hepatocellular carcinoma   PD-L1   M2 macrophages   CD8(+)T cells   Immune escape   MISP   IQGAP1   STAT3  

摘要： Background: Hepatocellular carcinoma (HCC) is a prevailing cancer affecting human health. M2 macrophages are essential in mediating immune responses in tumors. This study investigated the action of M2 macrophages in immune escape of HCC. Methods: Mitotic spindle positioning (MISP), IQ motif containing GTPase activating protein 1 (IQGAP1) and programmed cell death-1 (PD-L1) levels in primary HCC/tumor-adjacent tissues were determined by Western blot, followed by correlation analysis. M2 macrophage and CD3(+)CD8(+)T cell percentages were estimated by flow cytometry. Hep3B and HepG2 cells were treated with M2 macrophage conditioned medium (M2-CM) and M2 macrophage-derived extracellular vesicles (M2-EVs) and/or co-cultured with CD8(+)T cells, followed by assessment of cell viability and apoptosis. TNF- alpha and INF-gamma levels were measured by ELISA. MISP and IQGAP1 over-expression plasmids were transfected into HCC cells to explore their role in immune escape. The interactions among MISP, IQGAP1, STAT3, and PD-L1 were analyzed by co-immunoprecipitation. The mechanism of M2-EVs in HCC immune escape was verified in nude mice. Results: MISP/IQGAP1/PD-L1 were upregulated in HCC tissues. MISP negatively-correlated with IQGAP1/PD-L1 and IQGAP1 positively-correlated with PD-L1. M2 macrophages were reduced but CD8(+)T cells were increased in HCC tissues with high MISP expression. M2-CM or M2-EVs inhibited the killing ability of CD8(+)T cells, increased HCC cell viability, impeded HCC cell apoptosis, induced CD8(+)T cell apoptosis, downregulated TNF- alpha and INF-gamma, and upregulated PD-L1. M2-EVs facilitated HCC cell immune escape by potentiating IQGAP1 nuclear trans-location and activating STAT3 phosphorylation through MISP downregulation. In vivo experiments further verified the action of M2-EVs through MISP. Conclusion: M2-EVs promote HCC cell immune escape by upregulating PD-L1 through the MISP/IQGAP1/STAT3 axis.

关键词： ITGB4   TNFAIP2   IQGAP1   RAC1   drug resistance   triple-negative breast cancer   Human  

摘要： Anti-tumor drug resistance is a challenge for human triple-negative breast cancer (TNBC) treatment. Our previous work demonstrated that TNFAIP2 activates RAC1 to promote TNBC cell proliferation and migration. However, the mechanism by which TNFAIP2 activates RAC1 is unknown. In this study, we found that TNFAIP2 interacts with IQGAP1 and Integrin beta 4. Integrin beta 4 activates RAC1 through TNFAIP2 and IQGAP1 and confers DNA damage-related drug resistance in TNBC. These results indicate that the Integrin beta 4/TNFAIP2/IQGAP1/RAC1 axis provides potential therapeutic targets to overcome DNA damage-related drug resistance in TNBC.

关键词： Atherosclerosis   IQGAP1   Oxidative stress   MtDNA sensors   Pyroptosis  

摘要： Atherosclerosis (AS) is the most common cardiovascular disease and has limited therapeutic options. IQ motifcontaining GTPase-activating protein 1 (IQGAP1) is an important scaffolding protein regulating mitochondrial function influencing endothelial cell activity. Evidence suggests that mitochondrial damage can lead to leakage of mtDNA into the cytoplasm to activate the DNA sensor cGAS-STING to mediate pyroptosis. However, whether IQGAP1 induces NLRP3-mediated endothelial cell pyroptosis by regulating mitochondrial function and activating the DNA sensor cGAS-STING, and its underlying mechanisms remain unclear. In vivo, ApoE-/- C57BL/J and Ldlr-/- C57BL/J mice were pre-injected with adeno-associated virus (AAV) by the tail vein to specifically silence IQGAP1 expression and were fed a high-fat diet (HFD) for 12 weeks. IQGAP1 knockdown reduced mtDNA release and decreased the expression of DNA receptors and pyroptosis-related molecules as determined by immunohistochemistry and immunofluorescence. In vitro, palmitic acid (0.3 mmol/L) was incubated with human umbilical vein endothelial cells (HUVECs) for 24 h. Overexpression of IQGAP1 in HUVECs, flow cytometry, and mitochondrial superoxide staining revealed increased levels of ROS. Moreover, the mitochondrial tracker with dsDNA co-localization showed the release of mtDNA into the cytoplasm increased, which activated the DNA receptor cGAS-STING. Protein blotting and TUNEL staining revealed that IQGAP1 promoted NLRP3mediated pyroptosis. Furthermore, cGAS or STING small-molecule inhibitors RU.521 or C-176 reverse IQGAP1-promoted HUVECs from undergoing NLRP3-mediated pyroptosis. These results suggest that IQGAP1 promotes oxidative stress and mtDNA release, activates the DNA sensor cGAS-STING, and leads to NLRP3mediated pyroptosis. The present study provides new insights into the mechanisms underlying AS and identifies new pharmacological targets for treatment.

摘要： Background: C3 glomerulopathy (C3G) is a rare kidney disorder associated with complement alternative pathway (AP) dysregulation and C3 deposition within the glomerulus. Proteinuria and nephrotic syndrome are present at onset in 90% and 30% of C3G ...