FZD10

本研究发现在肝癌CSCs中高表达的FZD10一方面可以通过激活β-catenin和YAP1促进肝脏CSCs的自我更新、肿瘤发生和转移，另一方面可以通过c-Jun/MEK/ERK通路导致肝癌细胞对仑伐替 肝细胞癌（HCC）是世界上第六大常见恶性肿瘤，也是癌症相关死亡的第四大主要原因[1]。 中国肝癌患者中，HBV感染患者和中晚期患者占比较高，患者预后差，5年生存率仅12.1%。虽然仑伐替尼已被批准用于晚期HCC的一线治疗，但大多数HCC患者在接受治疗后几个月内仍会出现病情进展。 总体而言，耐药是目前HCC相关死亡的主要原因之一，但对其背后的机制仍知之甚少。 近日，同济大学医学院附属东方医院、海军军医大学第三附属医院和上海长海医院的研究人员，在胃肠疾病领域权威期刊Gastroenterology发表了最新研究成果[2]。 在该研究中，他们发现FZD10在肝癌肿瘤干细胞（CSCs）中表达上调，并在肝癌细胞自我更新、致瘤性、转移和仑伐替尼耐药中发挥重要作用，提示FZD10是一种新的肝CSCs生物标志物，有望成为对仑伐替尼耐药HCC治疗的潜在靶点。 论文首页截图 CSCs是具有长期致瘤能力的肿瘤细胞的一个小亚群，是肿瘤内具有持续分裂、分化能力的一群细胞。通常这类的细胞被认为有形成肿瘤，发展成癌症的潜力，在癌症的发展和治疗耐药性中起着关键作用。在HCC患者中，大量CSCs的存在预示着较差的临床结果。然而，肝脏CSCs增殖的潜在机制仍不清楚。 因此，研究人员首先利用转录组学分析筛选出了可能与HCC中CSCs特性相关的潜在靶点，在所有上调的379个基因中，FZD10是上调倍数最多的，而且其表达水平与肝脏CSCs标记物EpCAM和CD24呈正相关。随着连续传代，FZD10的表达水平在原发性HCC球形细胞中逐渐升高。 考虑到肝CSCs与HCC复发、转移和化疗耐药密切相关，研究人员比较了FZD10在复发、转移和化疗耐药HCC组织中的表达。结果发现与原发病灶相比，FZD10在复发HCC、HCC转移灶中的表达显著上调。此外，仑伐替尼耐药HCC患者组织中FZD10的表达明显高于仑伐替尼敏感HCC患者组织。 总的来说，上述结果表明肝癌干细胞中FZD10表达上调，预示HCC患者预后不良。 FZD10在肝脏CSCs中表达上调，预示着HCC预后不良 为了研究FZD10的临床意义，研究人员进一步分析了HCC患者FZD10的表达情况。相关回归分析显示，HCC组织中FZD10的高表达与侵袭性临床特征相关。Kaplan-Meier生存分析显示，HCC中FZD10的高表达与较短的无病生存期和总生存期相关。 随后，研究人员使用敲低、过表达实验探究了FZD10在肝脏CSCs中的潜在作用。结果发现FZD10敲低后，HCC的多能转录因子表达减少、球体形成受损、肝脏CSCs比例降低；相反，FZD10过表达则增加了HCC多能转录因子的数量、增强了HCC球体的形成能力、导致HCC细胞中CSCs比例增加，说明FZD10促进了肝脏CSCs的扩增。 此外，他们还注意到敲低FZD10削弱了HCC细胞的迁移和侵袭能力、显著降低肿瘤发生率，而FZD10的过表达则增强了细胞的迁移和侵袭能力，增加了肿瘤发病率，在小鼠中形成了更多的肺转移病灶。 FZD10促进肝脏CSCs的扩增 为了阐明FZD10促进肝脏CSCs扩增的机制，研究人员使用RNA测序分析了FZD10过表达的HCC细胞中的基因表达情况。 KEGG信号通路富集分析显示，在过表达FZD10的HCC细胞中，MAPK、WNT/β-catenin和Hippo是前三大富集信号通路。鉴于已有研究报道WNT/β-catenin/TCF和Hippo信号通路在调控CSCs扩增中发挥重要作用，因此研究人员重点着眼于FZD10对WNT/β-catenin和Hippo信号通路的调控。 研究结果显示，FZD10敲除的HCC细胞中β-catenin的转录活性明显下调，核β-catenin的水平及其下游靶基因的表达均显著降低；而在FZD10过表达的HCC细胞中β-catenin的转录活性上调，核β-catenin的水平及其下游靶基因的表达明显增加。与之类似，过表达FZD10的HCC中YAP1核易位和靶基因表达上调，而FZD10敲除则观察到相反的结果。 此外，HCC患者的数据也进一步佐证了上述结果。在HCC患者中，FZD10的表达水平与核β-catenin和YAP1的水平呈正相关，β-catenin、YAP1高表达对应肝癌患者较短的生存期。 因此，上述实验结果表明，在肝癌患者肿瘤干细胞中高表达的FZD10通过WNT/β-catenin和Hippo通路增强了肝脏CSCs的特性，促进了肝脏CSCs的自我更新，最终导致肿瘤的发生和转移。 越来越多的证据表明，肝脏CSCs与耐药性密切相关[3]，基于上述研究结果，研究人员自然而然地想到，既然HCC中高表达的FZD10可以促进肝脏CSCs的特性，它是否也与肝癌患者对仑伐替尼的治疗耐受相关呢？ Kaplan-Meier分析显示，FZD10低表达的HCC患者在仑伐替尼治疗后存活时间更长，而FZD10高表达的患者对仑伐替尼治疗表现出较强的耐药性。与之相对应，FZD10过表达导致肝癌细胞抵抗仑伐替尼诱导的生长抑制和细胞凋亡。 进一步，研究人员利用患者源性肿瘤类器官（PDOs）和患者源性异种移植（PDXs）模型，验证了FZD10表达水平与仑伐替尼耐药性之间的相关性。结果发现FZD10表达水平较高的原发性HCC衍生的PDOs对仑伐替尼治疗具有耐药性，而FZD10表达水平较低的原发性HCC衍生的PDXs对仑伐替尼治疗极为敏感，仑伐替尼可以几乎完全阻断FZD10表达水平较低的PDXs的生长。 上述结果表明，FZD10低表达的HCC患者可能对仑伐替尼的治疗更为敏感，提示肝癌患者肿瘤中的FZD10水平，可以作为推断其对仑伐替尼反应性的可靠预测因子。 FZD10表达水平与HCC患者仑伐替尼的治疗耐药性相关 研究人员还探究了FZD10高表达导致仑伐替尼耐药的机制。根据已有文献报道，MAPK信号通路异常激活与仑伐替尼耐药密切相关[4]。 与先前的研究结果相一致，本研究的RNA-seq数据显示MAPK信号通路在过表达FZD10的HCC细胞中富集。相比于对仑伐替尼仑伐替尼治疗敏感的HCC细胞系，对仑伐替尼耐药的HCC细胞系中MAPK信号通路之一c-Jun/MEK/ERK通路的表达水平显著上调，在仑伐替尼耐药的PDXs和仑伐替尼治疗后的临床复发肿瘤中，FZD10和c-Jun/MEK/ERK通路的表达水平也明显上调。 这表明c-Jun/MEK/ERK的激活与仑伐替尼耐药有关，肝癌中高表达的FZD10通过c-Jun/MEK/ERK通路导致HCC对仑伐替尼产生耐药性。 最后，研究人员评估了以FZD10为靶点对仑伐替尼耐药HCC的治疗潜力。 他们发现使用FZD10抑制剂可以恢复HCC对仑伐替尼治疗的敏感性，说明FZD10有望成为治疗仑伐替尼耐药HCC的潜在靶点。 靶向FZD10可恢复HCC对仑伐替尼的敏感性 总的来说，本研究发现在肝癌CSCs中高表达的FZD10一方面可以通过激活β-catenin和YAP1促进肝脏CSCs的自我更新、肿瘤发生和转移，另一方面可以通过c-Jun/MEK/ERK通路导致肝癌细胞对仑伐替尼治疗产生耐药性。 机制示意图 好消息是，靶向FZD10可以恢复HCC对仑伐替尼的治疗敏感性，提高其临床治疗效果，这也意味着FZD10可以作为一种新的肝癌预后生物标志物和仑伐替尼耐药HCC的治疗靶点。 参考文献： [1] Siegel RL, Miller KD, Fuchs HE, et al. Cancer Statistics, 2021. CA Cancer J Clin 2021;71:7-33. [2] Wang J, Yu H, Dong W, Zhang C, Hu M, Ma W, Jiang X, Li H, Yang P, Xiang D. M6A-mediated upregulation of FZD10 regulates liver cancer stem cells properties and lenvatinib resistance through WNT/β-catenin and Hippo signaling pathways. Gastroenterology. 2023 Feb 8:S0016-5085(23)00114-2. [3] Han T, Zhang Y, Yang X, et al. miR-552 Regulates Liver Tumor-Initiating Cell Expansion and Sorafenib Resistance. Mol Ther Nucleic Acids 2020;19:1073-1085. [4] Jin H, Shi Y, Lv Y, et al. EGFR activation limits the response of liver cancer to lenvatinib. Nature 2021.

-- Novel approach to creating R-spondin-mimetics establishes proof-of-concept for targeted regenerative antibodies -- SOUTH SAN FRANCISCO, Calif., Aug. 19, 2020 (GLOBE NEWSWIRE) -- Surrozen Inc., a biotechnology company pioneering a new class of targeted regenerative antibodies, today announced a peer-reviewed publication describing its novel platform for the generation of potent and selective R-spondin mimetics. The article, “Tissue-targeted R-spondin mimetics for liver regeneration” was published online in Scientific Reports, a Nature Research journal. The article describes Surrozen’s R-spondin-mimetic program, culminating in a hepatocyte-targeted bispecific antibody that potently and selectively enhances the Wnt signaling pathway in the liver. The publication describes a novel approach to the regeneration of hepatocytes, and highlights the potential for the approach in treating a range of severe liver diseases. “This publication underscores Surrozen’s mission of developing targeted therapeutics for safe and effective tissue regeneration via the Wnt pathway. Conceived and engineered in house, Surrozen’s R-spondin mimetic platform provides an entirely new approach to targeted regeneration for various diseases. I am proud of all the scientists who contributed to this body of work,” said Wen-Chen Yeh MD, PhD, chief scientific officer of Surrozen and a co-author on the paper. “This approach, which complements our Wnt-mimetic platform, is the second proprietary platform for selectively activating the Wnt pathway that Surrozen has described in a peer-reviewed publication.” Notable results in the publication include the discovery that hepatocyte-specific Wnt agonism can be directed through replacing LGR binding with a liver specific receptor, ASGR1. Through mutating R-spondin to replace LGR binding with ASGR1 while maintaining ZNRF3/RNF43 signaling, Surrozen has shown the ability to effectively and robustly enhance Wnt stimulation within the liver, leading to the proliferation and maturation of hepatocytes. The molecule described in the paper, αASGR1-RSPO2-RA, upregulated Wnt target genes in hepatocytes and stimulated cell proliferation specifically in the liver. Other Wnt-sensitive tissues were not responsive to administration of the R-spondin mutant. Significantly, αASGR1-RSPO2-RA showed the ability to improve liver function in diseased mice within three days. “These results suggest that a targeted R-spondin-mimetic can stimulate functional regeneration in a cell-specific manner,” said Yang Li, PhD, vice president of Biology at Surrozen and a co-author on the paper. “The novel Wnt pathway engineering method described in the article can be tailored to diseased tissues with high levels of endogenous Wnt ligand and specific cell surface receptors, highlighting the potential of the technology to impact multiple disease areas. This publication describes the constructs and experiments that have led to SZN-043, our preclinical candidate for severe liver diseases.” About Wnt SignalingWnt signaling plays key roles in the control of development, homeostasis, and regeneration of many essential organs and tissues, including liver, intestine, lung, kidney, central nervous system, cochlea, bone, and others. Modulation of Wnt signaling pathways has potential for treatment of degenerative diseases and tissue injuries. There are 19 Wnt ligands (Wnts) in mammals, and they signal through Frizzled receptors 1-10 and co-receptors LRP5 or 6, two families of receptors. Endogenous Wnts bind to multiple Frizzled receptors and are heavily modified post-translationally, making them difficult to manufacture consistently. R-spondin stabilizes Frizzled receptors, enhancing the body’s response to endogenous Wnts. About Surrozen’s Proprietary Antibody Platforms and Harnessing Wnt Signaling Since its founding in 2016, Surrozen has developed two proprietary platforms to selectively modulate the Wnt pathway for the potential treatment of injury and disease. Surrozen Wnt-mimetics, also referred to as SWAP (Surrozen Wnt signal activating proteins), are bi-specific full-length human (IgG) antibodies that directly activate the canonical Wnt signaling pathway in target tissue. Surrozen R-spondin-mimetics, also referred to as SWEETS (Surrozen Wnt signal enhancers engineered for tissue specificity), are antibody-based molecules that enhance Wnt signaling by stabilizing Frizzled receptors on targeted cells. About SZN-043 Preclinical Candidate for Severe Liver DiseasesSZN-043 is the first development candidate designed using Surrozen’s SWEETS platform. In preclinical animal models of liver injury and fibrosis, SZN-043 has been shown to selectively activate Wnt signaling in the liver, stimulate hepatocyte proliferation, improve synthetic function, and reduce fibrosis. The Company’s goal is to clinically evaluate the candidate in settings of drastic hepatocyte loss, such as severe acute alcoholic hepatitis (AAH), where SZN-043 may have a rapid impact on hepatocyte regeneration, as well as settings of advanced chronic disease conditions of cirrhosis. Liver cirrhosis is characterized by a decline in liver synthetic function and an increase in liver fibrosis, culminating in various complications such as portal hypertension, ascites, varices, and hepatic encephalopathy. About Surrozen Surrozen is a biotechnology company pioneering a new class of targeted regenerative antibodies to repair a broad range of tissues and organs damaged by serious disease. Surrozen is designing tissue-specific antibodies that engage the body’s own biological repair mechanisms resulting in a broad pipeline of disease-specific therapies to help patients across multiple disease areas, including severe liver diseases, inflammatory bowel disease, retinopathies, hearing loss, lung and airway diseases, and certain neurological disorders. For more information, please visit surrozen.com.