Altered Growth Factor Pathways in Biliary Cancer

描述（由申请人提供）：肝内胆管癌（ICC）是一种高度恶性的原发性肿瘤，由于其发病率增加、死亡率高、治疗选择有限，通常表现为晚期致命性疾病，因此被认为是临床重要和治疗具有挑战性的肿瘤。ICC的一个显著特征是显著的间质增生，富含α-平滑肌肌动蛋白阳性的癌症相关成纤维细胞（α-SMA+CAFs）。然而，尽管α-SMA+CAFs可能在促进ICC进展中起着至关重要的作用，但这种肌成纤维样细胞促进侵袭性ICC的具体机制仍然难以捉摸。上一个资助周期的主要进展是我们建立了ICC进展的原位同基因大鼠模型，该模型概括了人类结缔组织增殖性ICC早期和晚期的关键病理、分子和临床特征。最近，我们还成功地开发并部分表征了一种新的胆管癌三维器官型共培养模型，以补充我们的体内ICC模型。通过共培养，我们进一步发现原位大鼠ICC衍生的α-SMA+CAFs在体外显著促进胆管癌细胞的导管生长和侵袭性，并刺激与ICC侵袭性生长和进展相关的特定基因（如CXCR4、HGF、Muc1）的上调。我们进一步证明，在我们的大鼠体内模型中，由ICC中α-SMA+CAFs合成和分泌的基质细胞蛋白periostin在快速生长的侵袭性ICC中比在缓慢生长的低侵袭性ICC中表达得更高。作为这些发现的合理延伸，我们现在提出两个具体目标。具体目标1侧重于阐明骨膜蛋白作为ICC进展的潜在重要介质的功能作用。在此目的下，我们还将验证我们的假设，即α-SMA+CAFs通过periostin/integrin ß4、HGF/Met和SDF-1/ cxcr4介导的FAK/PI3K-Akt/Rac1的激活，向胆管癌细胞产生趋同的促侵入信号。Specific Aim 2将利用我们独特的大鼠器官型胆管癌细胞培养和原位ICC模型，以及临床相关的靶向药物，在联合靶向与ICC进展相关的α-SMA+CAF/胆管癌细胞通路（例如，hedgehog信号通路、HGF/Met和SDF-1/CXCR4）的基础上，验证一种创新的ICC治疗分子策略。我们期望通过提出的研究结果来阐明骨膜蛋白在ICC进展中的作用，并阐明其与选择生长因子/趋化因子介导的信号通路的关系

DESCRIPTION (provided by applicant): Intrahepatic cholangiocarcinoma (ICC) is a highly malignant primary neoplasm that is considered to be clinically important and therapeutically challenging due to its increasing incidence, high mortality rates, and limited treatment options for patients who most often present with advanced fatal disease. A hallmark feature of ICC is a prominent desmoplastic stroma enriched in α-smooth muscle actin-positive cancer-associated fibroblastic cells (α-SMA+CAFs). However, while it is becoming increasingly apparent that α-SMA+CAFs may be playing a crucial role in promoting ICC progression, specific mechanisms through which such myofibroblastic-like cells may act to promote aggressive ICC remain elusive. A major development of the previous grant cycle was our establishment of an orthotopic syngeneic rat model of ICC progression that recapitulates key pathological, molecular, and clinical features of early and advanced stages of human desmoplastic ICC. Recently, we also succeeded in developing and partially characterizing a novel three- dimensional organotypic co-culture model of cholangiocarcinoma that complements our in vivo ICC model. Using co-culturing, we further showed α-SMA+CAFs derived from orthotopic rat ICC to significantly promote cholangiocarcinoma cell ductal growth and invasiveness in vitro, as well as to stimulate up-regulation of specific genes associated with ICC invasive growth and progression (e.g., CXCR4, HGF, Muc1). We further demonstrated periostin, a matricellular protein synthesized and secreted by α-SMA+CAFs in ICC, to be more highly expressed in rapidly growing, invasive ICCs than in slow growing, low invasive ICCs formed in our rat in vivo model. As a logical extension of these findings, we are now proposing two Specific Aims. Specific Aim 1 is focused on clarifying the functional role of periostin as a potentially important mediator of ICC progression. Under this aim, we will also test our hypothesis that α-SMA+CAFs generate convergent proinvasive signals to cholangiocarcinoma cells through periostin/integrin ß4, HGF/Met, and SDF-1/CXCR4-mediated activation of FAK/PI3K-Akt/Rac1. Specific Aim 2 will utilize our unique rat organotypic cholangiocarcinoma cell culture and orthotopic ICC models, together with clinically relevant targeted agents, to preclinically validate an innovative moleculr strategy for ICC therapy based on combinational targeting of interactive α-SMA+CAF/ cholangiocarcinoma cell pathways (e.g., hedgehog signaling pathway, HGF/Met, and SDF-1/CXCR4) associated with ICC progression. We anticipate the results generated by the proposed research to clarify the role of periostin in ICC progression and elucidate its relationship to select growth factor/chemokine-mediated signaling pathways by which α-SMA+CAFs cross-talk with cholangiocarcinoma cells to facilitate aggressive malignant behavior. Moreover, we believe data generated from the proposed research will be of real value in identifying more potentially effective and rational treatment strategies for patients with progressive ICC, which hopefully will lead in a meanigful way to the development of new clinical trials.