Altered Growth Factor Pathways in Biliary Cancer

描述(申请人提供)：肝内胆管细胞癌(ICC)是一种高度恶性的原发肿瘤，由于其发病率增加，死亡率高，治疗选择有限，通常伴有晚期致命疾病，因此被认为具有临床重要性和治疗挑战性。肝细胞癌的一个显著特征是显著的促结缔组织间质，富含α-平滑肌肌动蛋白阳性的癌症相关成纤维细胞(α-SMA CAF)。然而，尽管越来越明显的是，α-SMA CAF可能在促进ICC进展中发挥关键作用，但这种肌成纤维样细胞促进侵袭性ICC进展的具体机制仍然不清楚。前一个资助周期的一个主要进展是我们建立了原位同基因大鼠的ICC进展模型，该模型概括了人类促结缔组织增生性ICC早期和晚期的关键病理、分子和临床特征。最近，我们还成功地开发了一种新的胆管癌细胞三维器型共培养模型，并对其进行了部分表征，该模型是对我们体内ICC模型的补充。通过共培养，我们进一步展示了来自原位大鼠胆管癌细胞的α-SMA CAF在体外显著促进胆管癌细胞的生长和侵袭，并刺激与胆管癌细胞侵袭生长和进展相关的特定基因的上调(例如，CXCR4、HGF、MUC1)。我们进一步证明了Periostin，一种由α-SMA CAF在ICC中合成和分泌的基质细胞蛋白，在快速生长的侵袭性ICCs中比在我们的大鼠体内模型中形成的缓慢生长的低侵袭性ICCs中更高表达。作为这些发现的合乎逻辑的延伸，我们现在提出两个具体目标。具体目标1侧重于阐明Periostin作为ICC进展的潜在重要调节因子的功能作用。在这一目标下，我们还将检验我们的假设，即α-SMACAF通过Periostin/整合素/4、肝细胞生长因子/蛋氨酸和SDF1/CXCR4介导的FAK/PI3K-Akt/rac1的激活而向胆管癌细胞产生会聚的侵袭前信号。具体目标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，在临床前验证基于与ICC进展相关的互动α-SMACAF/胆管癌细胞通路(例如，刺激性信号通路、肝细胞生长因子/蛋氨酸和SDF1/CXCR4)的组合靶向，用于ICC治疗的创新分子策略。我们期待由拟议的研究产生的结果，以阐明Periostin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。 α-SMA CAF与胆管癌细胞相互作用，促进侵袭性恶性行为。此外，我们相信，拟议研究产生的数据将在为进展性ICC患者确定更具潜在有效性和合理性的治疗策略方面具有真正的价值，这有望以一种有意义的方式导致新的临床试验的发展。

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.