BETA-CATENIN AS A THERAPEUTIC TARGET IN HEPATOCELLULAR CANCER

β-连环蛋白作为肝细胞癌的治疗靶点

• 批准号: 7810587
• 负责人: Satdarshan Singh Monga
• 金额: $ 24.94万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7810587
• 关键词: Address; Affect; Albumins; BALB/c Nude Mouse; Biological Assay; Biology; Breeding; Chemicals; Chemoprophylaxis; Clinical Research; Clinical Trials; Data; Development; Diet; Disease; Embryo; Enhancers; Epidermal Growth Factor Receptor; Etodolac; Event; Fetoprotein; Gene Targeting; Glutamates; Hematologic Neoplasms; Hepatic; Hepatocarcinogenesis; Hepatocyte; Hepatomegaly; In Vitro; Institutes; Investigation; Knock-out; Knockout Mice; Laboratories; Liver; Liver Regeneration; Longevity; Malignant Neoplasms; Modeling; Molecular; Mus; Mutate; Mutation; Non-Steroidal Anti-Inflammatory Agents; Nuclear Translocation; Pathway interactions; Patients; Peptide Hydrolases; Pharmaceutical Preparations; Phase; Phenobarbital; Phenotype; Primary carcinoma of the liver cells; Protocols documentation; Rattus; Refractory; Regulation; Research Personnel; Role; Series; System; Therapeutic; Transgenic Mice; Transgenic Model; Tyrosine; Tyrosine Phosphorylation; Work; Xenograft Model; base; beta catenin; enantiomer; hepatoma cell; in vitro Assay; in vivo; inhibitor/antagonist; liver cell proliferation; mutant; novel; outcome forecast; oval cell; overexpression; programs; promoter; therapeutic target; tumor; tumor xenograft

DESCRIPTION (provided by applicant): Aberrant activation of ¿-Catenin occurs in many cancers including HCC. Although the activation of ¿-catenin in HCC has been shown to be multifactorial, all events converge at ¿-catenin, making it an attractive therapeutic target in HCC. We have shown pro-proliferative effect of ¿-catenin in liver in transgenic mice, liver regeneration, liver development & in hepatocyte cultures. To more efficiently elucidate its role in hepatic biology, we have generated conditional ¿-catenin knockout mice using the cre- lox system. ¿-Catenin floxed mice (Ex2-6) were bred to Albumin-Cre or a-fetoprotein-albumin-Cre mice to generate ¿-catenin conditional null mice: Ctnnb1 loxP/loxp:Alb-Cre OR Ctnnb1 loxP/loxp:aFP-Alb-Cre respectively. Both these mice are born normally & show about 95% loss of ¿-catenin by 2 weeks that persists throughout their normal life span in the former, while 100% loss of ¿-catenin occurs in the latter by 4-5 months and succumb due to diminished liver size & function. In addition, we have recently characterized the normal ¿-catenin over-expressing transgenic (TG) mice under albumin promoter/enhancer. These mice have a higher basal hepatocyte proliferation, with ensuing hepatomegaly. More recently we have generated TG mice that over expresses stable form of ¿-catenin (Ser45 mutated). These mice are being characterized, and demonstrate a more robust phenotype than normal ¿-catenin TG mice. These models give us a unique opportunity to conclusively address the role of ¿-catenin in HCC induction and progression. We propose to employ the DEN/phenobarbital model to investigate hepatocarcinogenesis in absence of ¿-catenin or presence of stable ¿-catenin. In addition, we propose to investigate oval cell activation, a preneoplastic event in liver, in knockout and transgenic mice to assertively address role of ¿-catenin in this event. Lastly, we would explore the role of therapeutic inhibition of ¿-catenin in transgenic models. We have identified role of R-Etodolac (enantiomer of NSAID Etolodolac, lacking cox-2 inhibition) in inhibiting ¿-catenin in hepatoma cells. This drug is in phase-ll clinical trials in refractory CLL. We propose to examine the effect of R-Etodolac in our transgenic mice and in tumor xenograft models in a series of both in vitro and in vivo studies to ascertain its role as an anti- ¿-catenin for treatment or chemoprophylaxis in HCC. Thus this proposal will lay the ground work for initiating clinical studies directed against ¿-catenin in HCC.

描述（由申请人提供）：¿-Catenin的异常激活发生在许多癌症中，包括HCC。虽然HCC中-catenin的激活是多因素的，但所有事件都集中在-catenin上，使其成为HCC中一个有吸引力的治疗靶点。我们已经在转基因小鼠的肝脏、肝脏再生、肝脏发育和肝细胞培养中显示了-连环蛋白的促增殖作用。为了更有效地阐明其在肝脏生物学中的作用，我们使用cre- lox系统产生了条件-catenin敲除小鼠。将-Catenin捆绑小鼠（Ex2-6）与Albumin-Cre或a-fetoprotein-albumin-Cre小鼠杂交，分别产生-Catenin条件无小鼠：Ctnnb1 loxP/ loxP:Alb-Cre或Ctnnb1 loxP/ loxP:aFP-Alb-Cre。这两种小鼠都是正常出生的，在前两周内-连环蛋白损失约95%，并在前者的正常寿命中持续存在，而后者在4-5个月时发生100%的-连环蛋白损失，并因肝脏大小和功能缩小而死亡。此外，我们最近对白蛋白启动子/增强子作用下正常-连环蛋白过表达转基因（TG）小鼠进行了表征。这些小鼠有较高的基底肝细胞增殖，随后肝肿大。最近，我们产生了过度表达稳定形式的¿-catenin （Ser45突变）的TG小鼠。这些小鼠正在被表征，并表现出比正常的¿-catenin TG小鼠更健壮的表型。这些模型为我们提供了一个独特的机会来最终解决¿-catenin在HCC诱导和进展中的作用。我们建议采用DEN/苯巴比妥模型来研究缺乏-catenin或存在稳定-catenin时的肝癌发生情况。此外，我们建议在敲除小鼠和转基因小鼠中研究肝脏肿瘤前事件卵圆细胞活化，以确定¿-catenin在这一事件中的作用。最后，我们将探讨¿-catenin在转基因模型中的治疗性抑制作用。我们已经确定了r -依托度酸（非甾体抗炎药依托度酸的对映体，缺乏cox-2抑制）在肝癌细胞中抑制¿-catenin的作用。该药正处于难治性CLL的ii期临床试验中。我们建议通过一系列体外和体内研究来检验r -依托度酸在我们的转基因小鼠和肿瘤异种移植模型中的作用，以确定其作为抗-catenin在HCC治疗或化学预防中的作用。因此，这一建议将为启动针对HCC中¿-catenin的临床研究奠定基础。