更新于：2024-11-01

PMS2

更新于：2024-11-01

基本信息

别名

DNA mismatch repair protein PMS2、H_DJ0042M02.9、HNPCC4

+ [7]

简介

Component of the post-replicative DNA mismatch repair system (MMR) (PubMed:30653781, PubMed:35189042). Heterodimerizes with MLH1 to form MutL alpha. DNA repair is initiated by MutS alpha (MSH2-MSH6) or MutS beta (MSH2-MSH3) binding to a dsDNA mismatch, then MutL alpha is recruited to the heteroduplex. Assembly of the MutL-MutS-heteroduplex ternary complex in presence of RFC and PCNA is sufficient to activate endonuclease activity of PMS2. It introduces single-strand breaks near the mismatch and thus generates new entry points for the exonuclease EXO1 to degrade the strand containing the mismatch. DNA methylation would prevent cleavage and therefore assure that only the newly mutated DNA strand is going to be corrected. MutL alpha (MLH1-PMS2) interacts physically with the clamp loader subunits of DNA polymerase III, suggesting that it may play a role to recruit the DNA polymerase III to the site of the MMR. Also implicated in DNA damage signaling, a process which induces cell cycle arrest and can lead to apoptosis in case of major DNA damages. Possesses an ATPase activity, but in the absence of gross structural changes, ATP hydrolysis may not be necessary for proficient mismatch repair (PubMed:35189042).

关联

项与 PMS2 相关的药物

NP-1867

靶点

PMS2

作用机制

PMS2抑制剂

在研机构

NeoPhore Ltd.初创企业

原研机构

NeoPhore Ltd.初创企业

在研适应症

肿瘤

非在研适应症-

最高研发阶段临床前

首次获批国家/地区-

首次获批日期1800-01-20

100 项与 PMS2 相关的临床结果

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100 项与 PMS2 相关的转化医学

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0 项与 PMS2 相关的专利（医药）

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2,220

项与 PMS2 相关的文献（医药）

2024-12-31·OncoImmunology

DNA mismatch repair defect and intratumor heterogeneous deficiency differently impact immune responses in diffuse large B-cell lymphoma

Article

作者: Xu, Bing ; Sohani, Aliyah R. ; Visco, Carlo ; Wang, Nicholas T. ; Dybkaer, Karen ; Au, Qingyan ; Zu, Youli ; Fan, Xiangshan ; Tam, Wayne ; Yuan, Alyssa F. ; Tzankov, Alexandar ; Ferreri, Andrés J.M. ; Go, Heounjeong ; Chiu, April ; O’Malley, Dennis ; Hsi, Eric D. ; Møller, Michael B. ; Young, Ken H. ; Song, Wenting ; Nunns, Harry ; Abramson, Jeremy S. ; Bhagat, Govind ; Luo, Cancan ; Parsons, Benjamin M. ; Montes-Moreno, Santiago ; Yu, Li ; Sakhdari, Ali ; Xu-Monette, Zijun Y. ; Li, Yong ; Perry, Anamarija M. ; Ponzoni, Maurilio

Deficient (d) DNA mismatch repair (MMR) is a biomarker predictive of better response to PD-1 blockade immunotherapy in solid tumors. dMMR can be caused by mutations in MMR genes or by protein inactivation, which can be detected by sequencing and immunohistochemistry, respectively. To investigate the role of dMMR in diffuse large B-cell lymphoma (DLBCL), MMR gene mutations and expression of MSH6, MSH2, MLH1, and PMS2 proteins were evaluated by targeted next-generation sequencing and immunohistochemistry in a large cohort of DLBCL patients treated with standard chemoimmunotherapy, and correlated with the tumor immune microenvironment characteristics quantified by fluorescent multiplex immunohistochemistry and gene-expression profiling. The results showed that genetic dMMR was infrequent in DLBCL and was significantly associated with increased cancer gene mutations and favorable immune microenvironment, but not prognostic impact. Phenotypic dMMR was also infrequent, and MMR proteins were commonly expressed in DLBCL. However, intratumor heterogeneity existed, and increased DLBCL cells with phenotypic dMMR correlated with significantly increased T cells and PD-1⁺ T cells, higher average nearest neighbor distance between T cells and PAX5⁺ cells, upregulated immune gene signatures, LE4 and LE7 ecotypes and their underlying Ecotyper-defined cell states, suggesting the possibility that increased T cells targeted only tumor cell subsets with dMMR. Only in patients with MYC¯ DLBCL, high MSH6/PMS2 expression showed significant adverse prognostic effects. This study shows the immunologic and prognostic effects of genetic/phenotypic dMMR in DLBCL, and raises a question on whether DLBCL-infiltrating PD-1⁺ T cells target only tumor subclones, relevant for the efficacy of PD-1 blockade immunotherapy in DLBCL.

2024-12-15·International Journal of Cancer

Performance evaluation of predictive models for detecting MMR gene mutations associated with Lynch syndrome in cancer patients in a Chinese cohort in Taiwan

Article

作者: Wang, Yong Alison ; Yang, An‐Suei ; Hsieh, Ling‐Ling ; Hung, Fei‐Hung ; Hung, Chen‐Fang ; Peng, Hung‐Pin

AbstractIdentifying Lynch syndrome significantly impacts cancer risk management, treatment, and prognosis. Validation of mutation risk predictive models for mismatch repair (MMR) genes is crucial for guiding genetic counseling and testing, particularly in the understudied Asian population. We evaluated the performance of four MMR mutation risk predictive models in a Chinese cohort of 604 patients with colorectal cancer (CRC), endometrial cancer (EC), or ovarian cancer (OC) in Taiwan. All patients underwent germline genetic testing and 36 (6.0%) carried a mutation in the MMR genes (MLH1, MSH2, MSH6, and PMS2). All models demonstrated good performance, with area under the receiver operating characteristic curves comparable to Western cohorts: PREMM5 0.80 (95% confidence interval [CI], 0.73–0.88), MMRPro 0.88 (95% CI, 0.82–0.94), MMRPredict 0.82 (95% CI, 0.74–0.90), and Myriad 0.76 (95% CI, 0.67–0.84). Notably, MMRPro exhibited exceptional performance across all subgroups regardless of family history (FH+ 0.88, FH‐ 0.83), cancer type (CRC 0.84, EC 0.85, OC 1.00), or sex (male 0.83, female 0.90). PREMM5 and MMRPredict had good accuracy in the FH+ subgroup (0.85 and 0.82, respectively) and in CRC patients (0.76 and 0.82, respectively). Using the ratio of observed and predicted mutation rates, MMRPro and PREMM5 had good overall fit, while MMRPredict and Myriad overestimated mutation rates. Risk threshold settings in different models led to different positive predictive values. We suggest a lower threshold (5%) for recommending genetic testing when using MMRPro, and a higher threshold (20%) when using PREMM5 and MMRPredict. Our findings have important implications for personalized mutation risk assessment and counseling on genetic testing.

2024-12-01·Hormones

The molecular genetics of adrenal cushing

Review

作者: Vaduva, Patricia ; Bertherat, Jerome

Adrenal Cushing represents 20% of cases of endogenous hypercorticism. Unilateral cortisol-producing adenoma (CPA), a benign tumor, and adrenocortical carcinoma (ACC), a malignant tumor, are more frequent than bilateral adrenal nodular diseases (primary bilateral macronodular adrenal hyperplasia (PBMAH) and primary pigmented nodular adrenal disease (PPNAD)).In cortisol-producing adrenal tumors, the signaling pathways mainly altered are the protein kinase A and Wnt/β-catenin pathways. Studying components of these pathways and exploring syndromic and familial cases of these tumors has historically enabled identification of many of the predisposing genes. More recently, pangenomic sequencing revealed alterations in sporadic tumors.In ACC, mainly due to TP53 alterations causing Li-Fraumeni syndrome, germline predisposition is frequent in children, while it is rare in adults. Pathogenic variants in the DNA mismatch repair genes MLH1, MSH2, MSH6, and PMS2, which cause Lynch syndrome or alterations of IGF2 and CDKN1C (11p15 locus) in Beckwith-Wiedemann syndrome, can also cause ACC. Rarely, ACC is described in other hereditary tumor syndromes due to germline pathogenic variants in MEN1 or APC and, in very rare cases, NF1, SDH, PRKAR1A, or BRCA2. Concerning ACC somatic alterations, TP53 and genetic or epigenetic alterations at the 11p15 locus are also frequently described, as well as CTNNB1 and ZNRF3 pathogenic variants.CPAs mainly harbor somatic pathogenic variants in PRKACA and CTNNB1 and, less frequently, PRKAR1A, PRKACB, or GNAS1 pathogenic variants. Isolated PBMAH is due to ARMC5 inactivating pathogenic variants in 20 to 25% of cases and to KDM1A pathogenic variants in food-dependent Cushing. Syndromic PBMAH may be due to germline pathogenic variants in MEN1, APC, or FH, causing type 1 multiple endocrine neoplasia, familial adenomatous polyposis, or hereditary leiomyomatosis-kidney cancer syndrome, respectively. PRKAR1A germline pathogenic variants are the main alteration causing PPNAD (isolated or part of Carney complex).

项与 PMS2 相关的新闻（医药）

2024-05-30

·GlobeNewswire-Health Care

Bionano Announces Robust Presence at Upcoming Cytogenetics Conferences ESHG and ACC with 39 Scientific Presentations and Posters Highlighting the Utility of the Optical Genome Mapping Workflow

A record 31 scientific presentations and posters at the 2024 European Society for Human Genetics (ESHG) Annual Conference and 8 scientific presentations and posters at the 2024 American Cytogenomics Conference (ACC) will highlight the application of optical genome mapping (OGM) in genetic disorder, rare disease, and cancer research applicationsBionano will host a sponsored session at ESHG featuring an overview of the Company’s OGM workflow delivered by Bionano’s chief medical officer, Dr. Alka Chaubey, a presentation from Dr. Laura Batlle Masó at Vall d’Hebron Institute of Research (Spain) on OGM’s potential utility in resolving hereditary angioedema (HAE) cases, a presentation from Dr. Bart van der Sanden at Radboud UMC (Netherlands) on how OGM may be useful for the detection of structural variants (SVs) relevant to rare disease, and a presentation from Marlene Ek at Karolinska Institute (Sweden) highlighting OGM’s ability to unveil more cytogenomic insights into multiple myeloma samples than traditional cytogenetic methods At ACC, a sponsored session will feature Dr. Mike Gallagher, market development manager at Bionano, highlighting OGM’s ability to enhance detection of pathogenic variants and to advance genetic disease research. Dr. Gallagher will also introduce the latest innovations in the OGM workflow, including the Stratys™ system and VIA™ software SAN DIEGO, May 30, 2024 (GLOBE NEWSWIRE) -- Bionano Genomics, Inc. (Nasdaq: BNGO) today announced the Company’s robust participation at two upcoming cytogenetics conferences, the 2024 European Society for Human Genetics (ESHG) Annual Conference and the 2024 American Cytogenomics Conference (ACC), with a record 39 scientific presentations and posters across the two conferences that highlight the utility of the Company’s OGM workflow for applications in genetic disease, cancer, and rare disease research and discussing the latest advances to the Company’s suite of products, including the high throughput Stratys system and VIA software. ESHG brings together industry and academic professionals annually to discuss new technologies and advances in the field of human genetics. ESHG sessions will take place June 1-4, 2024 virtually and in Berlin, Germany. ACC is a biennial conference focused on new technologies and advances in the field of cytogenetics. ACC will be held June 2-5, 2024 in Norfolk, Virginia. Bionano will host a sponsored session at ESHG featuring an overview of the Company’s OGM workflow delivered by Bionano’s chief medical officer, Dr. Alka Chaubey, a presentation from Dr. Laura Batlle Masó at Vall d’Hebron Institute of Research (Spain) on OGM’s potential utility in resolving hereditary angioedema (HAE) cases, a presentation from Dr. Bart van der Sanden at Radboud UMC (Netherlands) covering how OGM may be useful for the detection of SVs relevant to rare disease, and a presentation from Marlene Ek at Karolinska Institute (Sweden) highlighting OGM’s ability to unveil more cytogenomic insights into multiple myeloma samples than traditional cytogenetic methods. At ACC, a sponsored session will feature Dr. Mike Gallagher, market development manager at Bionano, highlighting OGM’s ability to enhance detection of pathogenic variants and to advance genetic disease research. Dr. Gallagher will also introduce the latest innovations in the OGM workflow, including the Stratys system and VIA software. Erik Holmlin, PhD, president and chief executive officer of Bionano, stated, “We are excited to see the progress that the global OGM community is making, which is highlighted by the growth in the number of scientific posters and presentations on OGM from the last time the ESHG and ACC conferences were held. We believe this expansion demonstrates the increased customer adoption of OGM, with routine and repeated utilization for innovative research into genetic disorders, cancer and rare disease.” ESHG scientific presentations and poster sessions: Scientific presentations and poster sessions on OGM at ESHG take place in the exhibition halls unless otherwise noted. Abstract/ Poster NumberTitleAuthorsPresentedP14.015.ADeciphering a complex short size RERE rearrangement: importance of combined approaches for duplication interpretationFauqueux J.June 2, 202410:15-11:15 AM CESTP01.065.AA Canadian lab’s experience using optical genome mapping to clinically genotype hematological neoplasmsHamadeh Z.June 2, 202410:15-11:15 AM CESTP03.025.ACharacterization of a complex rearrangement between three chromosomes in a fetus with skeletal anomalies by optical genome mappingHeinrich U.June 2, 202410:15-11:15 AM CESTP16.077.AAccurate identification of pathogenic structural variants guided by multi-platform comparisonMoeinzadeh M.June 2, 202410:15-11:15 CESTP01.163.BDeciphering the molecular complexity of the IKZF1 plus profile using optical genome mappingLühmann J.June 2, 202416:45-17:45 PM CESTP12.023.BSORD and SORD2P inversion: long read sequencing identifies a novel genetic mechanism underlying inherited neuropathyManini A.June 2, 202416:45-17:45 PM CESTP04.029.BOptical genome mapping facilitates rapid characterization of structural variants in families with developmental eye anomaliesMerepa S.June 2, 202416:45-17:45 PM CESTP01.007.CLarge genomic rearrangement: tandem duplication and triplication in BRCA1 gene causative for hereditary breast and ovarian cancerAldrige Allister B.June 3, 202410:15-11:15 AM CESTP15.102.CEstablishing ultra-rapid genome sequencing in neonatal and pediatric intensive care units in Germany – project Baby LionAuber B.June 3, 202410:15-11:15 AM CESTP14.029.COptical genome mapping of a patient with ring chromosome 3 shows the importance of choosing the proper reference genome for the analysisBurssed B.June 3, 202410:15-11:15 AM CESTP14.025.CPositive predictive value of balanced structural variants reported through short-read genome sequencing: do we need orthogonal confirmation?Chatron N.June 3, 202410:15-11:15 AM CESTP14.013.COptical genome mapping identifies hidden structural variants in 58 undiagnosed rare disease patient-parent triosHoischen A.June 3, 202410:15-11:15 AM CESTP01.160.CDeciphering copy number variations within the complex genomic region of the PMS2 gene using optical genome mappingMaier J.June 3, 202410:15-11:15 AM CESTP12.032.CThe WWOX gene variants detection in patient with cerebellar ataxia using optical genome mappingRutkowska K.June 3, 202410:15-11:15 AM CESTP01.051.CEnhanced cytogenomic analysis of complex karyotype in myelodysplastic syndrome using optical genome mappingValkama A.June 3, 202410:15-11:15 AM CESTP21.065.DAdvancing genetic diagnostics: optical genome mapping’s efficacy in identifying structural variants for autosomal recessive diseasesBeyza Ogutlu O.June 3, 202416:45-17:45 PM CESTP15.079.DBenefits of the analysis of a complex chromosomal rearrangement in the implementation of long read approachesChambon P.June 3, 202416:45-17:45 PM CESTP04.011.DA combined approach of innovative DNA- and RNA-technologies reveals hidden LINE-1/ERV insertion in IQCB1 as causative variant for Senior Løken syndromede Bruijn S.June 3, 202416:45-17:45 PM CESTP01.056.DExome sequencing identified rare recurrent copy number variants and hereditary breast cancer susceptibilityMantere T.June 3, 202416:45-17:45 PM CESTP15.091.DA multimodal approach to molecular diagnosis in NF1 highlights the need for bespoke analysis in undiagnosed patientsMcAleese-Park E.June 3, 202416:45-17:45 PM CESTP10.021.DOptical genome mapping finally unveils the genetic cause of aniridia and intellectual disability in a 17-year-old after seven years of diagnostic odysseyTelman W.June 3, 202416:45-17:45 PM CESTE-posterOptical genome mapping for comprehensive genomic rearrangement analysisFlunkert J.OnlineE-posterOptical genome mapping: lighting the way in complex clinical casesMonge Lobo I.OnlineE-posterRefining genotype-phenotype correlation in complex chromosomal rearrangements using optical genome mapping – case reportVallova V.OnlineE-posterUnraveling the mysteries of balanced rearrangements: optical genome mapping spotlights BCL11B misregulation in a familial translocationAlcalá San Martín A.OnlineE-posterOptical genome mapping (OGM) allows the characterization of a complex chromosome rearrangement associated with recurrent pregnancy lossTrost D.OnlineE-posterFocus on deletions and duplications identified by optical genome mapping technique in a cohort of 100 patients: comparison with MCADoco-Fenzy M.OnlineRoomTitlePresenterPresentedPoster presentationOptical genome mapping identifies hidden structural variants in previously undiagnosed rare disease cases in Solve-RDvan der Sanden B.June 1, 202419:00-19:15 PM CEST, Room A8Poster presentationMultiomics and deep phenotyping in MECP2 Duplication syndrome: insight into disease severity, expression variability, and nucleic acid therapeuticsPehlivan D.June 1, 202419:45-20:00 PM CEST, Room A8Poster presentationNext generation cytogenetics by optical genome mappingKanagal-Shamanna R.June 3, 202408:30-10:00 AM CEST, Room A2Sponsored sessionInsights into constitutional disorders and beyond: scaling to new heights with optical genome mappingChaubey A., Batlle Masó L., van der Sanden B., Ek M.June 3, 202414:00-15:30 PM CESTRoom New York 3 (Level 1) ACC scientific presentations and poster sessions: Scientific presentations and poster sessions on OGM at ACC take place in the exhibition hall. Poster/PresentationTitlePresenterPresentedExhibitor theater sessionRevolutionizing cytogenomics with optical genome mapping: high-resolution structural variant detection with an elevated sample-to-answer workflowGallagher M.June 3, 202412:15-12:35 PM ESTPoster presentationEnhanced detection of primary oncogenic drivers in pediatric T-lymphoblastic leukemia (T-ALL) by optical genome mapping (OGM)Raca G.June 3, 20242:00-2:15 PM ESTPoster presentationUtility of optical genome mapping as an additional tool to standard cytogenetic workup in hematological malignanciesToruner G.June 3, 20242:15-2:30 PM ESTPoster presentationA curated research catalogue of structural variation from 809 postnatal cases detected by optical genome mappingPang A.June 3, 20244:00-4:15 PM ESTPoster presentationA search for genetic determinants in neural tube defects using optical genome mappingSahajpal N.June 3, 20244:15-4:30 PM ESTPoster presentationCross-comparison of optical genome mapping and chromosomal microarray data using VIA softwareYu J.June 3, 20244:30-4:45 PM ESTPoster hallEfficient hematological malignancy analysis and reporting workflow using optical genome mappingClifford B. Poster hallIsotachophoresis (ITP) for high-throughput isolation of UHMW gDNA suitable for optical genome mapping (OGM)Yadav M. More details on Bionano’s presence at the ESHG conference can be found here, and virtual posters will be shown here; more details on Bionano’s presence at the ACC conference can be found here. About Bionano Bionano is a provider of genome analysis solutions that can enable researchers and clinicians to reveal answers to challenging questions in biology and medicine. The Company’s mission is to transform the way the world sees the genome through OGM solutions, diagnostic services and software. The Company offers OGM solutions for applications across basic, translational and clinical research. The Company also offers an industry-leading, platform-agnostic genome analysis software solution and nucleic acid extraction and purification solutions using proprietary isotachophoresis (ITP) technology. Through its Lineagen, Inc. d/b/a Bionano Laboratories business, the Company also offers OGM-based diagnostic testing services. For more information, visit www.bionano.com, www.bionanolaboratories.com or www.purigenbio.com. Unless specifically noted otherwise, Bionano’s OGM products are for research use only and not for use in diagnostic procedures. Forward-Looking Statements of Bionano This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as “ability,” “believe,” “may,” “potential,” “will,” and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) convey uncertainty of future events or outcomes and are intended to identify these forward-looking statements. Forward-looking statements include statements regarding our intentions, beliefs, projections, outlook, analyses or current expectations concerning, among other things, OGM’s utility for genetic disorder, rare disease, and cancer research applications; OGM’s ability and utility for resolving HAE cases; the ability and utility of OGM to detect SVs relevant to rare disease; the ability of OGM to unveil more cytogenomic insights into multiple myeloma samples than traditional cytogenetic methods; OGM’s ability to enhance detection of pathogenic variants and to advance genetic disease research; the utility of the latest innovations in OGM workflows, including the Stratys system and VIA software; the utility of OGM for research in the areas reported in the presentations given and the posters made available at the ESHG Annual Conference 2024 and AAC 2024; the growth and adoption of OGM for use in genetic disorder, rare disease, and cancer research applications; the ability and utility of our OGM solutions to drive market adoption of OGM; and any other statements not of historical fact. Each of these forward-looking statements involves risks and uncertainties. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include the risks and uncertainties associated with: global and macroeconomic events, such as the impact of the global pandemics, bank failures, interest rate changes, supply disruptions, and the ongoing conflicts in the Ukraine and Russia and between Israel and Hamas, and related sanctions, on our business and the global economy; general market conditions; changes in the competitive landscape and the introduction of competitive technologies or improvements to existing technologies; the failure of OGM’s utility for genetic disorder, rare disease, and cancer research applications; the failure of OGM to resolve HAE cases; the failure of OGM to detect SVs relevant to rare disease; the failure of OGM to unveil more cytogenomic insights into multiple myeloma samples than traditional cytogenetic methods; the failure of OGM to enhance detection of pathogenic variants and to advance genetic disease research; the failure of our latest innovations in OGM workflows, including the Stratys system and VIA software; the failure of OGM for research in the areas reported in the presentations given and the posters made available at the ESHG Annual Conference 2024 and AAC 2024; the growth and adoption of OGM for use in genetic disorder, rare disease, and cancer research applications; the ability and utility of our OGM solutions to drive market adoption of OGM; the ability of our OGM solutions to offer the anticipated benefits for and contributions to the areas reported in the presentations given and posters made available at the ESHG Annual Conference 2024 and AAC 2024; future study results contradicting the results reported in the presentations given and posters made available at the ESHG Annual Conference 2024 and AAC 2024; changes in our strategic and commercial plans; our ability to obtain sufficient financing to fund our strategic plans and commercialization efforts; the ability of medical and research institutions to obtain funding to support adoption or continued use of our technologies; our ability to obtain sufficient financing to fund our strategic plans and commercialization efforts and to continue as a "going concern”; and the risks and uncertainties associated with our business and financial condition in general, including the risks and uncertainties described in our filings with the Securities and Exchange Commission, including, without limitation, our Annual Report on Form 10-K for the year ended December 31, 2023 and in other filings subsequently made by us with the Securities and Exchange Commission. All forward-looking statements contained in this press release speak only as of the date on which they were made and are based on management’s assumptions and estimates as of such date. We do not undertake any obligation to publicly update any forward-looking statements, whether as a result of the receipt of new information, the occurrence of future events or otherwise. CONTACTS Company Contact:Erik Holmlin, CEOBionano Genomics, Inc.+1 (858) 888-7610eholmlin@bionano.com Investor Relations:David HolmesGilmartin Group+1 (858) 888-7625IR@bionano.com

临床研究

2024-05-08

·生物制品圈

Enhertu的划时代获批，撒豆成兵的全肿瘤疗法

英雄不问出身，但是肿瘤治疗需要了解病灶。不问心肝脾肺肾地统一打击癌细胞，Enhertu的获批成就了肿瘤学产品开发历史的划时代事件，成为首个获得FDA批准的全肿瘤（Pan-turmor）ADC疗法。1Tumor-agnostic疗法全肿瘤疗法，亦称Tumour-agnostic therapy（肿瘤不特异性疗法），有着“君子不器”的风骨，即肿瘤产品不一城一池地针对某种特定类型的癌症，而是可以高屋建瓴地用来治疗各种类型的癌症，无论癌症的组织学或体内位置如何。这种疗法针对癌症特定的基因组驱动因子或分子改变，而这些因素正是导致癌症生长和扩散的背后推手。它们属于个性化医学的一个分支，被称为精准肿瘤学。这种方法利用基因组分析（对人类遗传物质的实验室分析）来识别患者的生物标志物（biomarker）信息，并协助确定个体化的治疗方案。在精准医学日新月异的时代，Tumour-agnostic疗法已成为一种革命性的癌症治疗新方法，它标志着临床管理中一个重要的新范例。肿瘤基因组特征取代了组织学，为治疗决策提供关键信息。Tumor-agnostic疗法的核心驱动在于使用生物标志物（biomarker）。肿瘤的生物标志物是指在肿瘤发生、发展或治疗过程中，体内可以检测到的特定分子、基因、蛋白质或其他生物学特征。这些标志物可以用于诊断、预测疾病进展、评估治疗反应以及指导个性化治疗方案的制定。生物标志物的类型和特征因肿瘤类型、病理生理状态以及个体差异而异，与癌症进展风险（预后）或对特定治疗的反应（预测）相关。图片来源：Ars Technica肿瘤微卫星不稳定性 (MSI) 和 DNA 错配修复缺陷 (dMMR) 是常见的肿瘤生物标志物，经常同时出现。dMMR 生物标志物根据 MLH1、MSH2、MSH6 和 PMS2 4 个基因的突变或甲基化状态指示肿瘤的 DNA 错配修复 (MMR) 系统是否存在缺陷。随着对肿瘤生物学的更好理解，在Enhertu 2024年的获批之前，已有五种分子生物标志物获得 FDA 的tumor-agnostic批准（表1）：▪ 错配修复缺陷（dMMR）或高微卫星不稳定性（MSI）癌症▪ 肿瘤突变负荷高（TMB-H）癌症（每兆碱基≥10 个突变；mut/Mb）▪ NTRK 融合阳性癌症▪ RET 融合阳性癌症▪ 除结直肠癌以外的 BRAFV600E 突变癌症表1. Enhertu之前FDA批准的tumor-agnostic疗法生物标志物在 AACR （美国肿瘤研究协会）的GENIE 项目中，有4912 个样本含有 BRAFV600E 突变（2.9%），410 个样本含有 NTRK 融合（占所有样本的 0.24%，占结构变异分析样本的 1.6%），396 个样本含有 RET 融合（占所有样本的 0.26%，占结构变异的 1.5%）。此外，25527 个样本（15.2%）被归类为具有高TMB特征（图1）。AACR GENIE 中没有关于 dMMR/MSI 的数据，但其他研究表明其患病率约为 3%。图1. 常见恶性肿瘤中tumor-agnostic生物标志物出现的频率。（图片来源：Clin Cancer Res）生物标志物与特定的临床终点之间可能存在相关性，这种假设成为了FDA加速批准策略的基石。FDA允许使用生物标志物作为替代终点（surrogate endpoint）决定加速批准的授予。生物标志物的优点是它们可以更快地确定临床终点的治疗效果。但需要注意的是，在某些案例中，以生物标志物为基础的结果可能最终无法产生临床益处，因此加速批准撤回的情况也是屡见不鲜。人们对于生物标志物和临床效益之间的确切关联仍然需要深入研究。2Tumor-agnostic获批疗法2017 年 5 月，默沙东PD-1 抑制剂 pembrolizumab（Keytruda）成为首个获批的tumor-agnostic疗法，成为精准医学史上的分水岭。2017年FDA 加速批准pembrolizumab用于治疗患有不可切除或转移性、微卫星不稳定性高 (MSI-H) 或错配修复缺陷 (dMMR) 实体瘤的成人和儿童患者。2020 年，pembrolizumab 还获得批准用于治疗肿瘤突变负荷高 (TMB-H) 癌症。自从2014年针对晚期黑色素瘤首次获批以来，pembrolizumab已经获得了FDA总计47次批准（包括从加速批转转为全面批准，且并非每一次批准均针对tumor-agnostic生物标志物）。图片来源：Merck & Co.拜耳的Larotrectinib（Vitrakvi）是一种原肌球蛋白受体激酶 (TRK) 抑制剂，是第二种进入市场的tumor-agnostic疗法。该药物于 2018 年 11 月获得 FDA 批准，用于治疗具有神经营养性酪氨酸/原肌球蛋白受体激酶 (NTRK) 基因融合的实体瘤。图片来源：Bayer第三款tumor-agnostic疗法是Roche/Chugai的TRK 抑制剂 entrectinib（Rozlytrek），于 2019 年 6 月获得日本厚生劳动省的监管批准，用于治疗 NTRK 融合阳性晚期复发实体瘤的成人和儿童患者。2019年8月，entrectinib被FDA批准用于同一患者群体（治疗后病情进展或没有令人满意的替代疗法的NTRK基因融合实体瘤患者）。除了tumor-agnostic批准之外，entrectinib 还获得 FDA 批准用于治疗 ROS1 阳性转移性非小细胞肺癌 (NSCLC)。图片来源：Everyone.org其它获得FDA批准的tumor-agnostic疗法还包括：▪ Dostarlimab 用于 dMMR/MSI-H 癌症 (2021年)▪ Dabrafenib/trametinib治疗不可切除或转移性 BRAF V600E 突变癌症 (2022年)▪ Selpercatinib 用于治疗 RET 融合阳性癌症 (2022年)3Enhertu获批的历史意义第一三共与阿斯利康共同开发的Enhertu的获批成为了tumor-agnostic疗法开发历史中一件具有划时代意义的事件。它成为了第一款获得FDA批准的tumor-agnostic抗体药物偶联物（ADC），针对任何患有晚期 HER2 阳性癌症的患者，而无论肿瘤位于体内的哪个部位。图片来源：Enhertu.com除了成为第一款tumor-agnostic ADC药物之外，Enhertu也是第一个针对HER2（人类表皮生长因子受体2）的tumor-agnostic 靶向疗法。Enhertu 此前已获得四个适应症批准，用于治疗某些类型的 HER2 阳性乳腺癌、肺癌和胃肠道癌症。还有许多其他表达 HER2 的肿瘤，但目前还没有批准的 HER2 靶向疗法，而且其中许多很难治疗。FDA此次新批准将Enhertu的适应症扩展到过度表达HER2的肿瘤，诸如卵巢癌、膀胱癌、宫颈癌和子宫内膜癌。英雄不问出身太单薄，但很多英雄的出身就是单薄的。2019年第一三共与阿斯利康达成共同开发Enhertu的协议时，很多人对其在HER2过度表达的乳腺癌以外领域的疗效保持怀疑态度。他们认为需要确保某种生物学特征在不同类型的肿瘤中都有相似的重要性或影响，才能认为这个生物学因素在肿瘤治疗中是具有普遍意义的。虽然tumor-agnostic疗法在2019年已经给出了成功案例，但HER2肿瘤领域尚是空白。在经过反复论证之后，两家公司决定开展一项DESTINY-Pantumor02 临床试验，收集Enhertu 在对现有疗法无反应的多种 HER2 阳性肿瘤患者中的数据。最终结果表明：51% 的研究参与者的肿瘤缩小，中位缓解持续时间为 19.4 个月。最终Enhertu修得正果，在2024年4月5日获得了FDA的加速批准，成为历史首款获批的tumor-agnostic ADC疗法。参与DESTINY-PanTumor02 II 期试验的实体瘤研究包括胆道、膀胱、宫颈、子宫内膜、卵巢、胰腺或其他肿瘤。基于这些结果， Enhertu已被纳入《NCCN 肿瘤学临床实践指南》(NCCNGuidelines)，作为多发性转移性肿瘤的治疗选择。FDA的这次批准将推动针对其它广泛表达的表位（例如 TROP2、Nectin-4）的 ADC开发，并且将在整个 HER2+ 实体瘤领域产生关键影响，提高 HER2 表达不太常见的肿瘤（如黑色素瘤、肝细胞癌和头颈癌）的 HER2 检测和治疗率，会提高人们对在乳腺癌以外的更广泛肿瘤类型中进行 HER2 检测重要性的认识。在乳腺癌中，HER2 检测已成为常见做法。4Tumor-agnostic疗法开发的市场意义Tumor-agnostic疗法开发的商业价值，从pembrolizumab身上最好地得到体现。它背后的Keytruda，已经成为了2023年的全球药王，实现了超过250亿美元的全球销售额，是一款典型的PIP （Pipeline-in-a-Pill，自带管线药物）代表。Keytruda单在2023年就获得了FDA的8个适应症批准，从非小细胞肺癌到尿路上皮癌再到晚期膀胱癌。从2014年9月4日首次针对晚期黑色素瘤获批以来，Keytruda获得了47次FDA针对不同适应症的批准（包括加速批准后的常规批准）。Leerink Partners 分析师推测，tumor-agnostic适应症可能会给 Enhertu 2030 年的收入增加约 14 亿美元，其中 5.9 亿美元来自结直肠癌，8.07 亿美元来自 DESTINY-PanTumor02 试验的适应症（胆道癌、膀胱癌、宫颈癌、子宫内膜癌、卵巢癌、胰腺癌等）。Enhertu 2023 年销售额达 31 亿美元，较上一年的 16 亿美元大幅增长。GlobalData 分析师预测其销售额将继续飙升，到 2030 年将达到 136 亿美元。开发tumor-agnostic疗法对肿瘤学产品的商业开发的重要性体现在以下几个方面：▪ 更广泛的患者群体：传统上，癌症治疗方法通常针对特定类型的肿瘤，而tumor-agnostic疗法则不受特定肿瘤类型的限制。这意味着一个有效的tumor-agnostic疗法可以用于多种癌症类型的患者，从而扩大了潜在的市场和受益人群。▪ 个性化医疗趋势：随着个性化医疗的发展，越来越多的治疗方法朝着基于个体患者的特定病理学特征而非肿瘤类型的方向发展。Tumor-agnostic疗法符合这一趋势，因为它们基于肿瘤的生物学特征而非特定的组织类型进行治疗。▪ 减少临床试验成本和时间：传统上，针对特定肿瘤类型的药物研发需要进行大量的临床试验，耗费大量时间和资金。开发tumor-agnostic疗法将减少这种压力，因为这些疗法不受特定肿瘤类型的限制，可以更快地进行临床试验和获得批准。▪ 市场竞争优势：由于tumor-agnostic疗法可以适用于多种癌症类型，因此具有更广泛的市场竞争优势。这意味着在这个领域取得突破的公司可能会获得更大的市场份额和更稳定的收入流。参考文献：1.Boyiadzis, M. M. et al. Significance and implications of FDA approval of pembrolizumab for biomarker-defined disease. Journal for ImmunoTherapy for Cancer. 2018; 6:35. https://doi-org.libproxy1.nus.edu.sg/10.1186/s40425-018-0342-x2.Gouda, M. A. et al. Tumor-Agnostic Precision Medicine from the AACR GENIE Database: Clinical Implications. Clin Cancer Res. 2023 Aug 1; 29(15): 2753–2760.3.Keytruda FDA Approval History. Drugs.com. 16. 01. 2024.4.Looney, A.-M. et al. Tumour-agnostic therapies. Nature Reviews Drug Discovery 19, 383-384 (2020)5.Enhertu approved in the US as first tumour-agnostic HER2-directed therapy for previously treated patients with metastatic HER2-positive solid tumours. AstraZeneca Press Release. 06. 04. 2024.6.Feuerstein, A. The inside story of Enhertu’s pan-tumor approval. STAT. 11. 04. 2024.7.FDA approval makes Enhertu an option for multiple tumour indications. 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抗体药物偶联物AACR会议临床结果

2024-04-30

·精准药物

【Nature】拜耳和诺华同时披露合成致死靶点WRN的新型抑制剂

今天分享2篇发表于Nature的小分子抑制剂研发论文。1. WRN合成致死背景介绍抗癌药物开发的目标是发现能够消除癌细胞而不伤害患者正常细胞的化学物质。为此，可利用合成致死机制：当两个基因同时失活导致细胞死亡，但任一基因中的单独失活都是无明显毒性。在发生突变失活的肿瘤中，通过抑制其合成致死配对基因，可获得肿瘤选择性杀死。合成致死已在临床上取得了成功，开发出的聚（ADP-核糖）聚合酶（PARPi）抑制剂，以通过合成致死机制选择性地靶向 BRCA1/2 突变癌症和其他具有 DNA 修复潜在缺陷的癌症。DNA 错配修复(MMR) 通过消除 DNA 复制、长链 DNA 修复合成和重组过程中产生的错误，有助于维持基因组稳定性。细胞突变包括MLH1、MSH2、MSH6 和 PMS2，以及 MMR 成分基因的表观遗传改变会导致高突变表型，其特征是癌症易感性和高度基因组不稳定性，特别是在被称为微卫星的基因组重复区域。由于其重复性，微卫星容易发生 DNA 聚合酶滑动事件，产生主要由 MMR识别和修复的 INDEL（插入和删除）。因此，MMR 缺陷导致一种称为微卫星不稳定性 (MSI) 的表型，其特征是微卫星区域重复长度变化的积累。 MSI 检测具有临床意义，因为与微卫星稳定 (MSS)癌症患者相比，患有 MSI 癌症的患者总体预后更好，肿瘤转移潜力更低。这似乎在一定程度上反映了 MSI 肿瘤的高突变负荷，导致产生新抗原，从而增加免疫原性和对免疫检查点抑制剂的敏感性。在所有癌症类型中MSI的频率均为4%，其中子宫内膜癌(30%)、结肠腺癌(20%) 和胃腺癌 (20%) 的频率较高。目前高 MSI (MSI-H) 癌症的护理标准包括手术、化疗和免疫治疗。免疫疗法已成功治疗MSI-H 癌症患者，但原发性或获得性耐药可能会降低临床反应，从而需要针对该疾病的替代疗法。2019 年，一系列研究独立揭示了WRN 和 MSI 肿瘤之间具有治疗前景的合成致死关系。WRN（Werner Helicase）是一种具有解旋酶和核酸外切酶活性的多功能酶，在维持基因组稳定性至关重要的各种细胞过程中发挥作用，包括 DNA 复制、转录、DNA 修复和端粒维护。WRN 缺失会导致细胞周期停滞、DNA 损伤、有丝分裂缺陷、染色体破碎和细胞凋亡，特别是在 MSI 细胞中。此外，WRN 敲减减少了移植 MSI 细胞的小鼠的异种移植物生长和肿瘤形成。引人注目的是，各种 MMR 成分的急性消耗并没有诱导 MSS 细胞对 WRN 的依赖。相反，在MSI细胞中重新引入缺失的MMR成分的基因拯救实验未能拯救合成致死关系。这些实验表明，WRN 合成致死关系是通过 MMR 功能障碍的突变后果而不是通过 MMR 缺陷本身来发展的。此外，使用解旋酶结构域、核酸外切酶结构域或两者内的功能丧失突变对 WRN 的各种酶活性进行剖析，证明 MSI 细胞中的WRN 依赖性仅与其解旋酶功能有关。WRN 和 MSI 之间合成致死性的假设机制，驱动这种依赖性的潜在机制是非规范二级DNA 结构的增加，这些结构需要 WRN 来解析。TA-二核苷酸重复序列示意图概述了通过 (TA) n 重复扩增形成 MSI 肿瘤的可能途径，WRN抑制剂可以靶向该重复扩增。通过 MMR 基因的种系和/或体细胞改变而获得 MMR 缺陷，是 MSI 和肿瘤发展的必要的第一步。MMR 缺陷细胞可能在发生 MSI 和 (TA) n 重复扩增（顶部分支）之前发生癌变，或在发生癌变之前发生MSI 和 (TA) n 重复扩增（底部分支）导致不同的临床结果。WRN 抑制剂的治疗窗口最终取决于 MSI 状态和 (TA) n 重复扩增的程度。具有 (TA) n 重复扩增的微卫星稳定(MSS) 和 MSI 细胞分别以黄色和红色突出显示。 WRN 抑制剂未来临床成功取决于：药物开发、肿瘤分析和患者分型。开发和完善有效、选择性、生物利用度和相对安全的WRN 抑制剂是绝对必要的。通过深度测序、液体活检和其他技术改进遗传和表观遗传肿瘤分析将提供肿瘤内异质性的更清晰图像。此外，MSI测试需要与 (TA) n 重复扩增分析相结合，以预测 WRN 抑制的潜力。最后，通过癌症建模和生物标志物识别进行风险分析将始终改善患者分层。其合成致死用一张简图概括如下：2. 拜耳共价抑制剂VVD-133214首先，一篇文章是来自Vividion Therapeutics的共价抑制剂VVD-133214。Vividion Therapeutics是由Scripps化学家创立，集中于利用化学蛋白质组学来开发变构调节剂和蛋白质降解剂。利用新颖的发现技术来解锁高价值、传统上不可成药的靶点，并通过精准疗法治疗癌症和免疫疾病。2021年拜耳花费20亿美元收购了 Vividion Therapeutics 来加大对小分子药物发现新方法的投资。研究人员首先开发了一种基于靶向质谱的化学蛋白质组学方法来量化小分子与天然细胞或细胞裂解物中半胱氨酸残基的共价结合（图1a）。该平台使用生物素化的基于碘乙酰胺的共价探针（IAA探针）测量半胱氨酸残基可及性的变化，并提供了一种灵敏的方法来检测共价小分子与半胱氨酸残基的结合。尽管该方法的通量相对于集中生化筛选来说是中等的，但它允许同时评估分子对数百种自然状态下蛋白质的效力和选择性。使用这种方法筛选了细胞裂解物中数千个亲电子小分子的定制文库，针对300 多种在癌症和/或免疫疾病中具有关键作用的蛋白质上的半胱氨酸残基，包括WRN 上的 11 个溶剂暴露的半胱氨酸残基（图 1b）。然后发现了一系列以 VVD-109063 为代表的化合物，它们选择性地结合WRN 上的 C727，具有的半最大靶点结合效力 (TE50 )为低微摩尔浓度（图 1c-e)。C727 位于蛋白质相对于 ATP 结合位点的相反面上，在筛选时尚未被鉴定为具有功能相关性。使用纯化的人WRN 核心解旋酶结构域（hWRN 519–1227 ）进行解旋酶测定，发现 VVD-109063 是一种具有IC50为8μM（图1f）。报道称，WRN C727 与小分子 (H3B-968) 的共价结合，在体外使用纯化的 WRN蛋白抑制 WRN 功能，但在细胞中则无功能。为了进一步表征化合物，作者测量了 VVD-109063 和相关化合物在OCI-AML2 活细胞中的 C727 结合效力。有趣的是，在纤维素分析中出现了两类化合物：一类在活细胞中显示出相对于细胞裂解物的效力降低（I型，以 VVD-109063 为例；图 1e），另一类在活细胞中显示出相对于细胞裂解物的效力有所提高（II型，以VVD-127101为例；图1e）。许多这些早期命中化合物都有一个脱靶半胱氨酸，即来自 TNFAIP3基因的C54，在两种类型的分子的裂解物和活细胞中表现出等价的参与（扩展数据图 1a），这表明细胞通透性的差异可能不会造成细胞效力显著变化。作者认为，活细胞中的ATP 水平较高，但细胞裂解物中的 ATP 水平较低（由于制备过程中样品被大量稀释）。为了直接评估这种可能性，在与hWRN 519–1227 的化合物预孵育步骤中，对解旋酶测定条件进行了调整，以包括ATP；结果证实，当在化合物预孵育步骤中包含 ATP 时，I 型化合物失去了效力，而II 型化合物在 ATP 存在下显示出效力显着提高（图 1f、g，即是合作型调控）。对于I 型和 II 型化合物，在 ATP 存在的情况下，活细胞中的 TE 50 值与解旋酶抑制的 IC 50 值之间存在很强的总体相关性（图 1h）。基于 II 型系列有利的活细胞内的效力、明显的核苷酸合作机制和有利的全局半胱氨酸选择性特征，因此，选择进一步优化该系列。随后的先导化合物优化提供了临床候选药物 VVD-133214（图1d）。VVD-133214 显示出有效的细胞TE 50 值（图 1e,h），并且在人和小鼠 WRN 解旋酶中具有同等活性解旋分析。在没有 DNA 的情况下对 hWRN ATPase活性的抑制（图 1i），对 hWRN的选择性优于密切相关的人类BLM 解旋酶（hBLM) 在高达 15 μM 时饱和，这是检测系统可测试的最高浓度。通过共结晶结构解析，可以看到N 端 RecA_1 结构域（蓝色）通过铰链（灰色）连接到 C 端 RecA_2 结构域（橙色）和锌结合结构域（Zn BD，绿色）。显示了锌离子及其四个半胱氨酸残基。 ADP 结合在 ATPase 结构域的底部，共价抑制剂 VVD-133214（1，粉色）结合在 ATPase 结构域的顶部。而且抑制剂VVD-133214 + ADP、ADP 和 ATP 结构中配体结合同一个口袋（PDB: 7GQU、7GQS 和7GQT）。在C727的硫原子和VVD-133214的乙烯基砜的β-C之间，观察到了清晰的电子密度。VVD-133214和WRN之间不存在氢键相互作用，表明形状互补和相对弱的可逆相互作用足以使乙烯基砜亲电试剂对C727进行亲核攻击。更进一步，VVD-133214能够通过共价抑制WRN来驱动MSI-H结直肠癌细胞的合成致死性，而非p53依赖的。此外，在荷瘤小鼠的体内研究中，VVD-13321也能通过抑制WRN杀死MSI型肿瘤。每天口服5mg/kg或更高剂量的VVD-133214即可导致肿瘤细胞死亡。2. 诺华WRN非共价，别构抑制剂HRO761接下来，第二篇来自诺华的非共价的别构抑WRN制剂HRO761，这篇文章高通量筛选和酶活定性都比较有意思。研究人员使用功能缺失突变对 WRN 的解旋酶和核酸外切酶活性进行剖析表明，MSI 细胞中体外和体内的 WRN 依赖性仅与其解旋酶功能相关。在 WRN 敲低后重新引入 WRN WT cDNA 可挽救 DNA 损伤和细胞增殖表型，而解旋酶点突变体WRNK577A cDNA 则不能。鉴于解旋酶在合成致死中的重要功能，研究人员首先建立高通量 WRN 解旋酶测定方案（基于ATPase酶活实验），通过初步的筛选仅识别出共价命中化合物(hit)，正如其他 WRN 命中高通量筛选中所报告的那样。这些化合物被认为是靶向 Cys727 的变构、ATP 竞争性抑制剂。为了识别酶活筛选中未检测到的较弱的非共价命中化合物，作者开发了一种 ATP 结合测定法（基于ATPγS荧光标记的FRET实验）。经验证的 WRN 抑制剂（例如共价命中、ATPγS）在ATP结合 KM的测定的效力大约是 ATPase 测定(Ki)的7 倍，而假阳性（例如，化合物在重新纯化后失去效力）在所有测定中均等价。这是克服主要共价抑制的最大挑战（大量误报）的关键。从 150,000 种化合物库中，研究人员筛选了这两种方案的半最大抑制浓度 (IC50) 值，并使用三倍以上的偏移作为真实命中的指标与精选的命中物结合以进行生物物理验证(酶活是结合IC50的三倍)。这种筛选策略产生了唯一的非共价命中化合物 1（图 1a，酶活:结合=22:3 uM）。它在亲脂效率（lipE，根据水和正辛醇之间的分配系数（logP）校正的效力）的指导下，通过基于结构的设计来提高效力，只能以牺牲高分子量和较差的理化性质为代价来实现，得到细胞工具化合物 2 （图 1b）。药物化学策略是通过使用基于物理的属性预测（logP、3D 极表面积）来系统地搜索异常值转换，同时提高渗透性和 lipE（这两种通常是反相关的属性）。降低 logP 同时提高渗透性的两个转化例子是在化合物 3 中引入邻甲基苯胺，在化合物 4 (HRO761)中引入羟基嘧啶。尽管 HRO761 的分子量为 702 Da，但它具有良好的理化性质和药代动力学 (PK)，以及无脱靶特征。图 1a-bHRO761 与 WRN 核心解旋酶（由两个类似 RecA 的解旋酶结构域 D1 和 D2 组成）形成的复合物的共晶结构表明，HRO761 与 D1-D2 界面上的非保守变构位点结合（图 1c,d)，合理解释了相关 RecQ 解旋酶的高选择性（扩展数据图 2a）。虽然 HRO761 和 ATP 类似物均在 D1-D2 界面结合，且 D2 残基重叠，但相对方向旋转了约 180°（图 1c）。由于残基 728-732 (Thr-Gly-Phe-Asp-Arg) 的构象变化，D1 和 D2 结构域之间铰链的灵活构象。大多数铰链残基与 HRO761 结合，并且 HRO761 的几乎每个重原子都与 WRN 发生极性相互作用（图 1d）。图 1c-e图 1c-eATP 结合残基的参与使得口袋具有异常极性并且富含精氨酸残基。该结构还解释了 ATP 和 DNA 的作用机制（扩展数据图 2c-e，竞争性抑制酶活）。HRO761 诱导的结构域旋转将 ATP 结合位点一分为二并取代 Walker 基序，从而导致HRO761 的变构结合产生混合型ATP竞争性酶活抑制（mixture” of competitive inhibition & uncompetitive inhibition，即别构抑制造成的反竞争抑制，和正构位点的竞争性抑制，比较特殊）。补充图 2 c-e的WRN的D2结构域对ATPγS-和HRO761的叠合，显示HRO761的羟基嘧啶部分模拟了ATP的γ-磷酸盐，并通过催化残基Gln850重现水解水的配位（图1e）。D1 和 D2 结构域上的 DNA 结合位点仍然可结合DNA，这解释了缺乏 DNA 竞争的原因（补充图2b）。补充图2b体外细胞实验证明了，WRN 抑制剂在 MSI 而非 MSS 细胞中重现合成致死性，并导致 DNA 捕获。在高 ATP（20 倍 KM）的 ATP 酶测定中，HRO761 的生化测试 IC50 为 100 nM，转化为半最大生长抑制浓度 (GI50），在MSI 癌细胞中为 50-1,000 nM，而对微卫星稳定 (MSS) 细胞没有影响。对 HRO761 抑制的敏感性与遗传依赖性相关（图 2b）。图2. a-b此外，研究人员表征了HRO761处理对MSI细胞的影响。结果发现，WRN抑制以时间和剂量依赖性方式导致细胞周期阻滞和DNA损伤，但此过程不依赖p53（p53是一种抑癌蛋白，在癌细胞中经常发生突变，限制了许多疗法的有效性（图 3e-g）。接下来，研究人员在SW48细胞来源的异种移植物（CDX）中测试了WRN抑制剂。结果显示，每天口服一次15-60mg/kg HRO761可导致肿瘤消退。通过监测动物体重推断HRO761没有毒性。此外，在不同MSI适应症的CDX和PDX模型中进行的大规模体内筛选结果显示，疾病控制率约为70%，疾病稳定率为35%，部分缓解率为30%，完全缓解率为9%（图 4f-g）。目前有十几款抑制剂在开发中，Vividion Therapeutics的RO7589831（即上文的VVD-133214）和诺华的HRO761进度最快，处于I期临床阶段。Vividion 与Roche在2020年开始合作开发VVD-133214，在今年的AACR会议中即有相关临床数据披露。声明：发表/转载本文仅仅是出于传播信息的需要，并不意味着代表本公众号观点或证实其内容的真实性。据此内容作出的任何判断，后果自负。若有侵权，告知必删！长按关注本公众号粉丝群/投稿/授权/广告等请联系公众号助手觉得本文好看，请点这里↓

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