目的:PTEN-AKT通路在肝外胆管癌(eCCA)中经常发生改变。我们的目的是评估PTEN在eCCA发病机理中的作用,并找到针对该疾病的新疗法。
方法:使用Cre-loxp系统将胆管上皮细胞中的Pten基因进行基因缺失。对病理进行了宏观和组织学评估。通过免疫组织化学(IHC)进一步分析特征,RT-PCR,细胞培养,和RNAseq。将一些特征与人eCCA样品中的特征进行比较。进一步的机制研究利用Trp53和Aurora激酶A(Aurka)基因的条件性敲除。使用Aurka抑制剂测试实验疗法。
结果:我们观察到肝外胆管上皮和导管周围腺中Pten基因的遗传缺失引发小鼠硬化性胆管炎样病变,导致小鼠肝外胆管扩大和扭曲早在一个月大。组织学上,这些病变表现出上皮增殖增加,炎性细胞浸润,和纤维化。随着年龄的增长,病变由低度发育不良发展为浸润性癌.Trp53失活进一步加速了疾病进展,可能通过下调衰老。进一步的机理研究表明,人和小鼠eCCA均显示出AURKA的高表达。值得注意的是,Aurka的基因缺失完全消除了Pten缺乏引起的肝外胆管病变。此外,药物抑制Aurka缓解疾病进展。
结论:肝外胆管细胞和胆管周围腺体的Pten缺乏通过Aurka依赖性方式导致胆管炎到胆管癌的连续性。这些发现为肝外CCA的预防和治疗干预提供了新的见解。
■异常的PTEN-PI3K-AKT信号通路通常在人肝外胆管癌(eCCA)中观察到,预后不良的疾病。在我们的研究中,我们通过在肝外胆管上皮细胞和胆管周围腺体中通过Pdx1-Cre有条件地删除Pten基因,开发了一种模拟胆管炎对eCCA进展的小鼠模型。这些细胞中有条件的Pten缺失导致胆管炎,逐渐发展为发育不良,最终导致eCCA。Pten的丢失增强了Akt信号,细胞增殖,炎症,纤维化,DNA损伤,表观遗传信号,上皮-间质转化(EMT),细胞发育不良,和细胞衰老。Aurka的遗传缺失或药理学抑制成功地阻止了疾病进展。该模型对于测试新疗法和揭示eCCA肿瘤发生的机制将是有价值的。
OBJECTIVE: The PTEN-AKT pathway is frequently altered in extrahepatic cholangiocarcinoma (eCCA). We aimed to evaluate the role of PTEN in the pathogenesis of eCCA and identify novel therapeutic targets for this disease.
METHODS: The Pten gene was genetically deleted using the Cre-loxp system in biliary epithelial cells. The pathologies were evaluated both macroscopically and histologically. The characteristics were further analyzed by immunohistochemistry, reverse-transcription PCR, cell culture, and RNA sequencing. Some features were compared to those in human eCCA samples. Further mechanistic studies utilized the conditional knockout of Trp53 and Aurora kinase A (Aurka) genes. We also tested the effectiveness of an Aurka inhibitor.
RESULTS: We observed that genetic deletion of the Pten gene in the extrahepatic biliary epithelium and peri-ductal glands initiated sclerosing cholangitis-like lesions in mice, resulting in enlarged and distorted extrahepatic bile ducts in mice as early as 1 month after birth. Histologically, these lesions exhibited increased epithelial proliferation, inflammatory cell infiltration, and fibrosis. With aging, the lesions progressed from low-grade dysplasia to invasive carcinoma. Trp53 inactivation further accelerated disease progression, potentially by downregulating senescence. Further mechanistic studies showed that both human and mouse eCCA showed high expression of AURKA. Notably, the genetic deletion of Aurka completely eliminated Pten deficiency-induced extrahepatic bile duct lesions. Furthermore, pharmacological inhibition of Aurka alleviated disease progression.
CONCLUSIONS: Pten deficiency in extrahepatic cholangiocytes and peribiliary glands led to a cholangitis-to-cholangiocarcinoma continuum that was dependent on Aurka. These findings offer new insights into preventive and therapeutic interventions for extrahepatic CCA.
UNASSIGNED: The aberrant PTEN-PI3K-AKT signaling pathway is commonly observed in human extrahepatic cholangiocarcinoma (eCCA), a disease with a poor prognosis. In our study, we developed a mouse model mimicking cholangitis to eCCA progression by conditionally deleting the Pten gene via Pdx1-Cre in epithelial cells and peribiliary glands of the extrahepatic biliary duct. The conditional Pten deletion in these cells led to cholangitis, which gradually advanced to dysplasia, ultimately resulting in eCCA. The loss of Pten heightened Akt signaling, cell proliferation, inflammation, fibrosis, DNA damage, epigenetic signaling, epithelial-mesenchymal transition, cell dysplasia, and cellular senescence. Genetic deletion or pharmacological inhibition of Aurka successfully halted disease progression. This model will be valuable for testing novel therapies and unraveling the mechanisms of eCCA tumorigenesis.