铁死亡抑制蛋白1在铁死亡相关疾病中的研究进展

铁死亡抑制蛋白1(ferroptosis-suppressor-protein 1,FSP1)是一种黄素蛋白，具有还原型烟酰胺腺嘌呤二核苷酸（NADH）：泛醌（CoQ）10氧化还原酶活性，能够将CoQ10还原为二氢泛醌（CoQH2），后者可以清除细胞内的活性氧和脂质自由基，达到抑制铁死亡的作用。因此，高表达FSP1的肿瘤细胞表现为对多种通过诱导细胞铁死亡发挥作用的抗癌药物的耐药；反之组织中FSP1表达水平的降低会增加其对铁死亡和氧化应激的敏感性，导致部分铁死亡相关疾病的发生和进展。     

Iron-based and BRD4-downregulated strategy for amplified ferroptosis based on pH-sensitive/NIR-II-boosted nano-matchbox

Ferroptosis (FPT), a novel form of programmed cell death, is characterized by overwhelming iron/reactive oxygen species (ROS)-dependent accumulation of lipid peroxidation (LPO). However, the insufficiency of endogenous iron and ROS level limited the FPT therapeutic efficacy to a large extent. To overcome this obstacle, the bromodomain-containing protein 4 (BRD₄)-inhibitor (+)-JQ1 (JQ1) and iron-supplement ferric ammonium citrate (FAC)-loaded gold nanorods (GNRs) are encapsulated into the zeolitic imidazolate framework-8 (ZIF-8) to form matchbox-like GNRs@JF/ZIF-8 for the amplified FPT therapy. The existence of matchbox (ZIF-8) is stable in physiologically neutral conditions but degradable in acidic environment, which could prevent the loaded agents from prematurely reacting. Moreover, GNRs as the drug-carriers induce the photothermal therapy (PTT) effect under the irradiation of near-infrared II (NIR-II) light owing to the absorption by localized surface plasmon resonance (LSPR), while the hyperthermia also boosts the JQ1 and FAC releasing in the tumor microenvironment (TME). On one hand, the FAC-induced Fenton/Fenton-like reactions in TME can simultaneously generate iron (Fe³⁺/Fe²⁺) and ROS to initiate the FPT treatment by LPO elevation. On the other hand, JQ1 as a small molecule inhibitor of BRD₄ protein can amplify FPT through downregulating the expression of glutathione peroxidase 4 (GPX4), thus inhibiting the ROS elimination and leading to the LPO accumulation. Both in vitro and in vivo studies reveal that this pH-sensitive nano-matchbox achieves obvious suppression of tumor growth with good biosafety and biocompatibility. As a result, our study points out a PTT combined iron-based/BRD₄-downregulated strategy for amplified ferrotherapy which also opens the door of future exploitation of ferrotherapy systems.     

CircRPPH1 promotes the stemness of gastric cancer cells by targeting miR-375/SLC7A11 axis

This study mainly focuses on revealing the role of circRPPH1 in gastric cancer cell stemness. In vitro and in vivo experiments were performed to evaluate the effects of circRPPH1 on gastric cancer cell stemness. Luciferase reporter and RIP assays were implemented to reveal the underlying mechanisms. MiR-375 directly bound to circRPPH1 in gastric cancer cells. And circRPPH1 acted as an miR-375 sponge to positively regulate SLC7A11 expression, which has been confirmed to be the direct target of miR-375 in gastric cancer, and thus regulated ferroptosis. Moreover, circRPPH1 promoted the stemness of gastric cancer cells dependent on the miR-375/SLC7A11. This study provides a potential target for gastric cancer progression based on the circRPPH1/miR-375/SLC7A11 regulatory axis.     

ATP结合盒转运蛋白A5在胰腺癌中的预后意义的生物信息学分析与验证

背景与目的 ATP结合盒（ABC）转运蛋白家族的成员ABCA5在多种肿瘤中发挥着重要的作用。然而，ABCA5在胰腺癌中的研究尚不清楚。因此，本研究通过生物信息学分析及临床样本验证，探讨ABCA5在胰腺癌中的表达及与患者预后的关系，同时对ABCA5在胰腺癌中的可能作用机制进行分析。方法 使用TCGA和GEO数据库，分析ABCA5在胰腺癌组织及正常组织中的表达情况，并用Kaplan-Meier方法绘制生存曲线，Cox比例风险模型进行单因素与多因素分析。采用免疫组织化学法检测65例胰腺癌组织和癌旁组织中ABCA5的表达，并分析其与预后及胰腺癌临床病理特征的关系。使用TIMER、STRING和Gene MANIA数据库对ABCA5与免疫细胞浸润、蛋白互相作用网络（PPI）和基因-基因互作网络进行分析。利用基因富集分析（GSEA）和相关性分析对ABCA5在胰腺癌中可能参与的信号通路及其可能的作用机制进行探索。通过癌症药物敏感性基因组学（GDSC）分析ABCA5与治疗药物敏感性的关系。结果 在TCGA和GEO数据集中，ABCA5在胰腺癌组织中的表达明显低于正常组织（均P<0.05）。在TCGA和GSE62452数据集中，ABCA5低表达的患者生存时间明显缩短（均P<0.05）；ABCA5的表达是胰腺癌患者预后的独立影响因素（HR=0.458，P=0.001；HR=0.439，P=0.017）。65例临床病例分析显示，ABCA5在癌组织与癌旁组织相比处于低表达水平，且ABCA5低表达患者的预后更差（均P<0.05），单因素与多因素Cox回归分析表明ABCA5的表达是胰腺癌患者预后的独立影响因素（HR=0.327，P=0.032）。TIMER数据库结果显示，ABCA5表达与免疫浸润密切相关。PPI蛋白互作网络显示，有14个与ABCA5相关的互作蛋白；基因-基因互作关系网络图得到20个与ABCA5相关的互作基因。基因富集分析与相关性分析结果显示，ABCA5在胰腺癌中可能与细胞周期和铁死亡有关。ABCA5高表达患者对5种治疗药物的IC₅₀明显低于ABCA5低表达患者（均P<0.05）。结论 ABCA5在胰腺癌组织中低表达并与患者不良预后相关，其表达水平是胰腺癌患者预后的独立影响因素，ABCA5在胰腺癌中的作用机制可能与细胞周期、免疫调节和铁死亡有关。