SRSF6

本文为转化医学网原创，转载请注明出处 作者：Jerry 导读： 结直肠癌的发生和发展与异常的选择性剪接有关，但其分子机制仍未被充分探索。 7月24日，中国医科大学李丰研究团队在期刊《Cell Death&Disease》上发表了研究论文，题为“MORC2 regulates RBM39-mediated CDK5RAP2 alternative splicing to promote EMT and metastasis in colon cancer”，本研究中，研究人员发现CDK5RAP2 S促进结直肠癌细胞体外侵袭和体内转移。机制上，CDK5RAP2 S特异性地招募PHD指蛋白8，通过去除Slug启动子处的抑制性组蛋白标记来促进Slug的转录。此外，CDK5RAP2 S，而不是CDK5RAP2 L，在MORC2或RBM39诱导的上皮-间充质转化的促进必不可少。而且，MORC2, RBM39和Slug的高表达与结直肠癌患者的转移和不良临床结局密切相关。 综上所述，本研究发现揭示了MORC2通过RBM39介导的pre-CDK5RAP2选择性剪接促进结直肠癌转移的新机制，并表明了MORC2/RBM39/CDK5RAP2轴作为结直肠癌的潜在治疗靶点。 https://www.nature.com/articles/s41419-024-06908-y#Sec11 背景知识 01 结直肠癌（CRC）是全球第三大诊断出的恶性疾病，也是癌症相关死亡的主要原因之一。除了基因突变外，异常的前体mRNA剪接已成为反映结直肠癌细胞异常的另一个主要事件。已证实剪接因子介导的替代剪接（AS）与结直肠癌进展密切相关。例如，SRSF6通过直接与ZO-1基因外显子23中的序列结合，调节ZO-1的异常剪接，从而促进结直肠癌进展。因此，进一步研究参与结直肠癌发生和发展的替代剪接事件及其相应的病理特征，有助于开发结直肠癌的生物标志物和治疗靶点。 微小核体家族CW型锌指蛋白2（MORC2）是高度保守的MORC家族蛋白质的成员。它在表观遗传基因沉默、DNA修复、脂质生成和葡萄糖代谢中发挥着重要作用。研究发现，MORC2在多种癌症中上调表达，包括乳腺癌、胃癌、结直肠癌和肝癌。它促进癌细胞的生长、迁移、侵袭和转移。然而，MORC2对结肠癌中可变剪接的影响及其机制尚未被阐明。 RNA结合结构域蛋白39（RBM39）是一种参与转录共调控和前mRNA选择性剪接的RNA结合蛋白。多项转录组学研究也表明，RBM39调节多种基因的选择性剪接，其中包括与细胞周期相关的基因。RBM39介导的选择性剪接也与多种癌症的发生和发展有关，包括急性髓细胞白血病（AML）、乳腺癌、结直肠癌和肺癌。吲哚胺（E7070）是一种抗癌磺胺类化合物，可选择性招募RBM39至CUL4-DCAF15 E3泛素连接酶，并通过蛋白酶体降解对其进行降解，在小鼠模型中对神经母细胞瘤具有良好的疗效。然而，尚不清楚MORC2是否调节RBM39介导的选择性剪接在结肠癌中的作用。 CDK5RAP2 S在体外促进结肠癌细胞迁移和侵袭，在体内促进肿瘤转移 02 研究人员研究了两种CDK5RAP2亚型在结肠癌细胞中的分子功能。通过慢病毒感染SW480-luc细胞中CDK5RAP2敲低后过表达CDK5RAP2 L或CDK5RAP2 S，研究人员发现CDK5RAP2 S而非CDK5RAP2 L促进结肠癌细胞的迁移和侵袭。然后用蛋白质免疫印迹实验检测EMT标志物和几个重要的EMT转录因子的表达。结果表明，cdk5rap2l过表达上调钙黏蛋白E，下调神经钙粘素、波形蛋白、Slug和Twist1的表达。而过表达CDK5RAP2 S则下调钙黏蛋白E，上调神经钙粘素、波形蛋白、Zeb1、Slug和Twist1的表达，提示CDK5RAP2 L和CDK5RAP2 S在结肠癌细胞EMT中可能具有不同的作用。然后将四组SW480-luc细胞注射到裸鼠尾静脉，利用活体生物发光成像(BLI)检测CDK5RAP2 L或CDK5RAP2 S对肿瘤转移的影响。在注射癌细胞10分钟后，在小鼠肺中观察到等量的生物发光。每周对小鼠进行一次成像，结果显示，对照组和shCDK5RAP2 + CDK5RAP2 S组在注射后第3周开始发生转移，而此时shCDK5RAP2和shCDK5RAP2 + CDK5RAP2 L组未发现转移。在研究终点，与对照组相比，shCDK5RAP2和shCDK5RAP2 + CDK5RAP2 L组肺转移明显减少，而shCDK5RAP2 + CDK5RAP2 S组肺转移明显增加。肺组织荧光成像与肺组织HE染色结果一致。综上所述，这些发现表明CDK5RAP2 S在体内促进结肠癌细胞的转移。 MORC2和RBM39通过cdk5rap2s促进结肠癌细胞的EMT、迁移和侵袭 MORC2和RBM39通过CDK5RAP2 S促进结肠癌细胞的EMT、迁移和侵袭 03 MORC2通过调控EMT过程促进三阴性乳腺癌和胆管癌的转移。然而，RBM39在EMT过程中的作用尚不清楚。然后研究人员验证了MORC2和RBM39促进结肠癌细胞的EMT。此外，数据表明，CDK5RAP2 S过表达，而不是CDK5RAP2 L，部分恢复了由RBM39敲低或MORC2敲低引起的迁移和侵袭抑制作用。另外，研究人员发现过表达CDK5RAP2 S，而不是CDK5RAP2 L，逆转了RBM39敲低对钙黏蛋白E表达的促进作用，以及对神经钙粘素、波形蛋白、Zeb1、Slug和Twist1表达的抑制作用，并且使用胰岛素得到了一致的结果。而且，敲低MORC2也得到了类似的结果。综上所述，MORC2和RBM39通过CDK5RAP2 S促进结肠癌细胞的EMT，迁移和侵袭。 MORC2、RBM39和Slug蛋白高表达与结直肠癌转移相关 04 研究人员分析了MORC2和RBM39在结直肠癌患者中的表达。研究人员发现MORC2和RBM39的RNA和蛋白表达水平在队列的结直肠癌组织中显著升高。MORC2表达与肿瘤大小(p = 0.018)，临床分期(p = 0.003)，淋巴结转移(pN) (p = 0.010)和远处转移(pM) (p = 0.030)显著相关。同时，RBM39的表达与临床分期显著相关(p = 0.046)(表2)。研究人员还发现在结直肠癌组织中CDK5RAP2 L的表达降低，CDK5RAP2 S的表达升高。最后，对30例癌旁组织、60例原发癌无转移组织、40例原发癌伴淋巴结和远处转移组织连续切片进行免疫组织化学染色。结果表明，MORC2、RBM39和Slug在转移的结直肠癌组织中高表达，而钙黏蛋白E不表达或低表达。相关性分析显示，MORC2与RBM39、MORC2与Slug、RBM39与Slug在结直肠癌转移中表达呈正相关。同时，MORC2与钙黏蛋白E、RBM39与钙黏蛋白E、Slug与E-cadherin表达呈负相关。 研究小结 05 综上所述，本研究结果揭示了MORC2通过与RBM39相互作用促进CDK5RAP2 L亚型向CDK5RAP2 S亚型转换从而促进结直肠癌发展的一种新机制。本研究结果不仅提供了一种新的机制，而且为结直肠癌的治疗提供了一种靶向MORC2/RBM39/CDK5RAP2轴的治疗策略。 参考资料： https://www.nature.com/articles/s41419-024-06908-y#Sec11 【关于投稿】 转化医学网（360zhyx.com）是转化医学核心门户，旨在推动基础研究、临床诊疗和产业的发展，核心内容涵盖组学、检验、免疫、肿瘤、心血管、糖尿病等。如您有最新的研究内容发表，欢迎联系我们进行免费报道（公众号菜单栏-在线客服联系），我们的理念：内容创造价值，转化铸就未来！ 转化医学网（360zhyx.com）发布的文章旨在介绍前沿医学研究进展，不能作为治疗方案使用；如需获得健康指导，请至正规医院就诊。 热门·直播/活动 🕓 北京｜09月20日-21日 ▶ 第五届单细胞技术应用研讨会暨空间组学前沿研讨会欢迎您的参与！ 点击对应文字 查看详情

PDUFA Target Action Date of June 26, 2024 Eight posters including two oral presentations support potential of ensifentrine, an investigational, first-in-class, selective, dual inhibitor of PDE3 and PDE4 LONDON and RALEIGH, N.C., May 02, 2024 (GLOBE NEWSWIRE) -- Verona Pharma plc (Nasdaq: VRNA) (“Verona Pharma” or the “Company”), announces eight posters, including two mini oral symposia, on additional analyses from its successful Phase 3 ENHANCE studies with ensifentrine for the treatment of chronic obstructive pulmonary disease (“COPD”) will be presented at the American Thoracic Society International Conference (“ATS”) 2024. Pooled analysis demonstrating reductions in the rate and risk of exacerbations with ensifentrine will be presented as part of the ‘Late Breaking Mini Symposium’ designed to highlight new breakthroughs. The posters are published on the ATS website and in the publication, American Journal of Respiratory and Critical Care Medicine. Ensifentrine is a novel selective dual inhibitor of the enzymes phosphodiesterase 3 and phosphodiesterase 4 (“PDE3 and PDE4”) that combines bronchodilator and non-steroidal anti-inflammatory effects in one molecule. The investigational product is currently under review by the US FDA, and, if approved, is expected to be the first novel inhaled mechanism for the maintenance treatment of COPD in more than 20 years. The posters are based on pooled analyses from the ENHANCE-1 and ENHANCE-2 trials, first reported by the Company on December 20, 2022, and August 9, 2022, respectively. Ensifentrine met the primary endpoint in both ENHANCE-1 and ENHANCE-2 demonstrating statistically significant improvements in lung function across both primary and secondary endpoints. In a pre-specified endpoint, ensifentrine substantially reduced the rate and risk of moderate/severe exacerbations in a pooled analysis of ENHANCE-1 and ENHANCE-2. The posters will summarize the efficacy and safety endpoints of ensifentrine when added to a long-acting muscarinic antagonist (“LAMA”) or a long-acting beta-agonist/inhaled corticosteroids (“LABA/ICS”), reductions in the rate of exacerbations regardless of eosinophil count and delayed progression of exacerbations, and the impact of ensifentrine on improving dyspnea. In addition, the Company will host an exhibition booth exploring the role of phosphodiesterase (“PDE”) in inflammation and lung function impairment in COPD as well as three innovation hub presentations led by clinical experts. Frank Sciurba, MD, Associate Professor of Medicine at the University of Pittsburgh School of Medicine, commented: “These pooled analyses from the ENHANCE studies provide further evidence of ensifentrine’s potential to become an important therapy in a broad population of COPD patients. The substantial reduction in exacerbation rate and risk with ensifentrine is particularly exciting for patients and physicians.” Details of Verona Pharma’s posters and the symposia are listed below and linked to the ATS website. Late-Breaking Mini Symposium:Ensifentrine Reduces Exacerbation Frequency and Delays Progression from Gold B to Gold E Presenter: Frank Sciurba, MD, University of Pittsburgh Medical Center Session: B14 – Late Breaking Abstracts: Science that will impact clinical care Mini Symposium: Ensifentrine added on to LAMA Therapy Improved Lung Function and Reduced Exacerbations in Symptomatic Subjects with Moderate-to-Severe COPD Presenter: Mark Dransfield, MD, University of Alabama Birmingham & Birmingham VA Medical Center Session: C95 – New clinical trial results in chronic lung disease Poster: P624 – Ensifentrine, A Novel, Selective Inhibitor of PDE3 and PDE4, Reduced Moderate/Severe Exacerbation Rate and Risk in Subjects With COPD Regardless of Baseline Blood Eosinophils Participant: Frank Sciurba, MD, University of Pittsburgh Medical Center Session: B52 – Evidence for therapeutic strategies in COPD: from established to emerging Poster: P625 – Ensifentrine Added on to LABA/ICS Therapy Improved Lung Function and Reduced Exacerbations in Symptomatic Subjects With Moderate-to-Severe COPD Presenter: Nathan Marchetti, MD, Thoracic Medicine and Surgery, Lewis Katz School of Medicine at Temple University Session: B52 – Evidence for therapeutic strategies in COPD: from established to emerging Poster: P704 – Improvements in Breathlessness, COPD Symptoms and Quality of Life Reported With Ensifentrine in a Pooled Analysis of the ENHANCE Trials Presenter: Dave Singh, Professor of Respiratory Pharmacology at the University of Manchester Session: A101 – Full metal jacket targeting COPD and chronic airways disease Poster: P901 – Ensifentrine Added on to LAMA Therapy Improved COPD Symptoms and Quality of Life in Subjects With Symptomatic Moderate-to-Severe COPD Presenter: Ravi Kalhan, MD, Pulmonology and Critical Care, Northwestern University Session: A27 – Emerging treatments and therapeutic strategies in COPD: results of clinical trials and observational studies Poster: P909 – Ensifentrine, A Novel, Selective Inhibitor of PDE3 and PDE4, Improved Dyspnea in Subjects With Symptomatic, Moderate-to-Severe COPD Over 24 Weeks Presenter: Donald Mahler, MD, Valley Regional Hospital in Claremont Session: A27 – Emerging treatments and therapeutic strategies in COPD: results of clinical trials and observational studies Poster: P911 – Ensifentrine Added on to LABA/ICS Therapy Reduced Dyspnea and Improved Quality of Life in Subjects With Symptomatic Moderate-to-Severe COPD Presenter: Antonio Anzueto, MD, Medicine/Pulmonary Critical Care, South Texas Veterans Healthcare System Session: A27 – Emerging treatments and therapeutic strategies in COPD: results of clinical trials and observational studies About Verona Pharma Verona Pharma is a biopharmaceutical company focused on developing and commercializing innovative therapies for the treatment of chronic respiratory diseases with significant unmet medical needs. In the third quarter of 2023, the US Food and Drug Administration accepted for review the Company’s NDA for ensifentrine for the maintenance treatment of patients with COPD and assigned a PDUFA target action date of June 26, 2024. If approved, ensifentrine has the potential to become the first inhaled non-steroidal therapy for the treatment of respiratory diseases that combines bronchodilator and anti-inflammatory activities in one molecule, and the first novel inhaled mechanism for the maintenance treatment of COPD in more than 20 years. The Company has evaluated nebulized ensifentrine in its Phase 3 clinical program ENHANCE (“Ensifentrine as a Novel inHAled Nebulized COPD thErapy”) for COPD maintenance treatment. Ensifentrine met the primary endpoint in both ENHANCE-1 and ENHANCE-2 trials demonstrating statistically significant and clinically meaningful improvements in lung function. In addition, ensifentrine substantially reduced the rate and risk of COPD exacerbations in a pooled analysis from ENHANCE-1 and ENHANCE-2. Two additional formulations of ensifentrine have been evaluated in Phase 2 trials for the treatment of COPD: dry powder inhaler (“DPI”) and pressurized metered-dose inhaler (“pMDI”); and a fixed-dose combination formulation with ensifentrine and glycopyrrolate, a LAMA, is currently under development, also for the treatment of COPD. Ensifentrine also has potential applications in cystic fibrosis, non-cystic fibrosis bronchiectasis, asthma and other respiratory diseases. For more information, please visit . For further information please contact: Verona Pharma plc US Tel: +1-833-417-0262 UK Tel: +44 (0)203 283 4200 Victoria Stewart, Senior Director of Investor Relations and Communications IR@veronapharma.com Argot Partners US Investor Enquiries Tel: +1-212-600-1902 verona@argotpartners.com Ten Bridge Communications International / US Media Enquiries Tel: +1-312-523-5016 tbcverona@tenbridgecommunications.com Leslie Humbel Forward-Looking Statements This press release contains forward-looking statements. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, but not limited to, statements relating to the timing of the FDA’s potential approval of the NDA for ensifentrine by the PDUFA date of June 26, 2024, or at any other time, statements regarding the potential for ensifentrine to be the first novel inhaled mechanism available for the maintenance treatment of COPD in over 20 years, the first therapy for the treatment of respiratory diseases to combine bronchodilator and non-steroidal anti-inflammatory effects in one molecule, and the potential of ensifentrine to become an important therapy in a broad population of COPD patients, the potential of ensifentrine in the treatment of cystic fibrosis, non-cystic fibrosis bronchiectasis, asthma and other respiratory diseases, and the potential of the DPI and pMDI formulations of ensifentrine. These forward-looking statements are based on management's current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from our expectations expressed or implied by the forward-looking statements, including, but not limited to, the following: our limited operating history; our need for additional funding to complete development and commercialization of ensifentrine, which may not be available and which may force us to delay, reduce or eliminate our development or commercialization efforts; the reliance of our business on the success of ensifentrine, our only product candidate under development; economic, political, regulatory and other risks involved with international operations; the lengthy and expensive process of clinical drug development, which has an uncertain outcome; serious adverse, undesirable or unacceptable side effects associated with ensifentrine, which could adversely affect our ability to develop or commercialize ensifentrine; we may not be successful in developing ensifentrine for multiple indications; our ability to obtain approval for and commercialize ensifentrine in multiple major pharmaceutical markets; misconduct or other improper activities by our employees, consultants, principal investigators, third-party service providers and licensees; our inability to realize the anticipated benefits under licenses granted by us to third parties to develop and commercialize ensifentrine, our future growth and ability to compete depends on retaining our key personnel and recruiting additional qualified personnel; material differences between our “top-line” data and final data; our reliance on third parties, including clinical research organizations, clinical investigators, manufacturers and suppliers, and the risks related to these parties’ ability to successfully develop and commercialize ensifentrine; lawsuits related to patents covering ensifentrine and the potential for our patents to be found invalid or unenforceable; lawsuits related to our licensing of patents and know-how with third parties for the development and commercialization of ensifentrine; changes in our tax rates, unavailability of certain tax credits or reliefs or exposure to additional tax liabilities or assessments could affect our profitability, and audits by tax authorities could result in additional tax payments for prior periods; and our vulnerability to natural disasters, global economic factors, geo-political actions and unexpected events, including health epidemics or pandemics. These and other important factors under the caption “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023, as updated in our Quarterly Reports on Form 10-Q and our other reports filed with the SEC, could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management's estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.

引言受阻的自噬可能通过引起凋亡来损害胰岛β细胞功能，其中DAP相关的凋亡诱导激酶-2（DRAK2）是一个关键调节因子。2024年2月7日，中国科学院上海药物研究所李静雅，谭敏佳和浙江大学孟卓贤，上海交通大学吴琳石共同通讯在Science Translational Medicine 在线发表题为“DRAK2 suppresses autophagy by phosphorylating ULK1 at Ser56 to diminish pancreatic β cell function upon overnutrition”的研究论文，该研究发现在2型糖尿病（T2D）的人类、猕猴和小鼠的胰腺组织中DRAK2显著上调。在小鼠中的进一步研究表明，胰岛β细胞条件性敲除（cKO）DRAK2可以保护β细胞功能免受高脂饮食的影响，并维持自噬和线粒体功能。通过对孤立的小鼠原代胰岛进行磷酸化蛋白组学分析发现，DRAK2直接在Ser56位点磷酸化unc-51样自噬激活激酶1（ULK1），随后发现这会诱导ULK1泛素化并抑制自噬。ULK1-S56A突变或DRAK2的药物抑制保护了小鼠原代胰岛、Min6细胞或INS-1E细胞对脂质毒性的线粒体功能和胰岛素分泌。这些发现共同表明DRAK2-ULK1轴在代谢挑战下胰岛β细胞中的不可或缺的作用，为保护T2D中的β细胞功能提供了一个潜在的靶点。2型糖尿病（T2D）是一种慢性代谢性疾病，其主要表现为由于胰岛β细胞的胰岛素绝对或相对缺乏，或靶细胞对胰岛素的敏感性降低而导致的高血糖。导致胰岛素产生不足的一个关键事件是由于凋亡引起的β细胞功能障碍。后者可能由多种因素触发，包括氧化应激、内质网（ER）应激、线粒体损伤、葡萄糖毒性、脂质毒性或胰岛炎症、纤维化和胰岛淀粉样多肽（IAPP）沉积。在其中，线粒体功能障碍在最近的研究中得到了强烈的证实。例如，β细胞功能障碍的早期阶段，表现为受损的葡萄糖刺激胰岛素分泌（GSIS），与线粒体产生的三磷酸腺苷（ATP）不足密切相关。在2型糖尿病患者的胰岛标本中也发现了线粒体功能障碍，这些患者显示出β细胞功能失败以及形态损伤。β细胞中线粒体的正常功能在很大程度上依赖于线粒体生物发生和线粒体动力学，尤其是线粒体周转。作为通过自噬对受损或功能异常线粒体的选择性清除的机制，线粒体自噬是线粒体的重要质量控制途径，为GSIS提供燃料。与此一致，自噬功能障碍已被认为是导致胰岛β细胞功能障碍和失败的主要驱动因素。例如，在胰岛β细胞中诱导自噬蛋白Atg7的条件性敲除可以导致β细胞凋亡，从而由于胰岛素产生不足而导致葡萄糖耐量不良。DAP相关凋亡诱导激酶2（DRAK2）[也称为丝氨酸/苏氨酸激酶17B（STK17B）]属于DAPK家族，该家族还参与了自噬调节。DRAK2在丝氨酸-12位点上对自身进行自磷酸化，而赖氨酸-62位点是其与ATP结合的重要决定因子。最近的研究表明，DRAK2可能通过凋亡影响胰岛β细胞的存活。DRAK2的药物抑制可以保护胰岛免受棕榈酸（PA）诱导的凋亡并保持GSIS。另外，通过在胰岛β细胞中使用Drak2小干扰RNA（siRNA）阻断游离脂肪酸诱导的该激酶上调已被证明可以防止β细胞凋亡。在非酒精性脂肪性肝炎（NASH）患者和小鼠中，肝脏DRAK2明显上调，并且随着肝脂肪堆积向NASH进展，由于SRSF6介导的线粒体功能相关基因（例如Polg2和Rnase I）的剪接而导致线粒体功能障碍变得更加明显。DRAK2-ULK1介导胰岛β细胞线粒体稳态调控的模式图(Credit: Science Translational Medicine)该研究探索了DRAK2上调在T2D进展中介导的病理机制。该研究评估了β细胞特异性敲除DRAK2小鼠的胰岛功能和线粒体功能，结果表明DRAK2的敲除可以抵抗高脂饮食介导的T2D。从机制上讲，Unc-51样自噬激活激酶1（ULK1）作为DRAK2的磷酸化下游底物，并在T2D进展期间通过损害自噬导致β细胞功能障碍。这项研究表明DRAK2可能是胰岛β细胞功能障碍治疗T2D的潜在靶点。原文链接https://www.science.org/doi/10.1126/scitranslmed.ade8647责编|探索君排版|探索君文章来源|“iNature”End往期精选围观一文读透细胞死亡(Cell Death) | 24年Cell重磅综述（长文收藏版）热文Science最新发布：全世界最前沿的125个科学问题热文Nature | 2024年值得关注的七项技术热文Nature | 自身免疫性疾病能被治愈吗？科学家们终于看到了希望热文Nature | 癌症与神经系统的致命舞蹈