Tumor suppressive and oncogenic properties of TGF-beta signaling in intrahepatic cholangiocarcinoma: role of Smad3 phosphorylation and long noncoding RNAs

肝内胆管细胞癌（intrahepatic cholangiocarcinoma，ICC）是一种侵袭性肝癌，预后差，发病率上升，治疗机会有限。迫切需要新的治疗方案来提高患者的生存率。靶向肿瘤微环境（或基质）已被提出作为治疗癌症的新兴方法。这是一个特别有前途的策略，在ICC中，致密基质的存在是一个突出的特点。细胞因子在肿瘤细胞与间质的相互作用中起着至关重要的作用。靶向这些介质是阻止肿瘤发展过程的有希望的策略。转化生长因子-β（TGF β）在癌症发病机制中起关键作用，我们最近发现间质中TGF β的表达是ICC患者预后不良的预测因子。然而，TGF β的作用是复杂的，因为它表现出肿瘤抑制和致癌特性，这取决于肿瘤阶段。为了提供靶向治疗的基本原理，我们的合作TGF β-ICC项目旨在确定在ICC细胞中形成TGF β反应的背景决定因素。基于我们实验室和其他实验室的初步数据，我们假设Smad 3在C-末端和/或接头位点（pSmad 3C/L）和长非编码RNA（lncRNA）的差异磷酸化驱动ICC中TGF β的肿瘤抑制特性与致癌特性。因此，我们将探索i）差异Smad 3磷酸化和ii）TGF β调节的lncRNA在ICC中的作用和功能后果。将由两个合作伙伴建立临床注释良好的ICC集合，并通过免疫染色（IHC，IF）进行形态学表征，并通过基因表达谱在分子水平上进行表征。来自患者的ICC组织和ICC细胞系将用于描绘Smad磷酸化及其在ICC发育中的调节。将进行功能获得和丧失实验、功能测试和基因组分析，以阐明pSmad 3C/L信号传导和与TGF-β相关的lncRNA的作用，包括T-LINC 1，我们小组最近鉴定的由TGF-β诱导的lncRNA。这些发现的临床相关性将通过整合基因组学使用临床上注释良好的ICC肿瘤的基因表达谱进行测试。我们希望我们的TGFbeta-ICC项目能够在基础和翻译水平上为ICC领域带来新的曙光。在基础科学方面，我们期望更好地了解形成ICC及其环境中TGF β信号后果的背景决定因素。在翻译水平上，该项目将通过识别从干扰TGF β信号传导中受益的患者来提供分层医学的基本原理。

Intrahepatic cholangiocarcinoma (ICC) is an aggressive liver cancer with poor prognosis, rising incidence and limited therapeutic opportunities. New therapy regimens are urgently required to improve patient survival. Targeting the tumor microenvironment (or stroma) has been proposed as an emerging approach to tackle cancer. This is a particularly promising strategy in ICC, for which the presence of a dense stroma is a prominent feature. Cytokines play a crucial role in the interaction between tumor cells and stroma. Targeting these mediators is a promising strategy to impede the course of tumor development. Transforming growth factor-beta (TGFbeta) plays a key role in cancer pathogenesis and we showed recently that the expression of TGFbeta in the stroma is a predictor of poor prognosis in patients with ICC. However, the action of TGFbeta is complex given that it exhibits both tumor suppressive and oncogenic properties, depending on tumor stage. In order to provide a rationale for targeted therapies, our collaborative TGFbeta-ICC project aims at identifying the contextual determinants that shape the TGFbeta response in ICC cells. Based on preliminary data from our labs and others, we hypothesize that differential Smad3 phosphorylation at C-terminal and/or linker sites (pSmad3C/L) and long non-coding RNA (lncRNA) drive tumor suppressive vs oncogenic properties of TGFbeta in ICC. Accordingly, we will explore the role and the functional consequences of i) differential Smad3 phosphorylation and ii) TGFbeta regulated lncRNA in ICC. Collections of clinically well-annotated ICC will be established by the two partners and characterized morphologically by immunostainings (IHC, IF) and at a molecular level by gene expression profiling. ICC tissue from patients and ICC cell lines will be used to delineate Smad phosphorylation and its regulation in ICC development. Gain and loss of function experiments, functional tests and genomic analysis will be performed to elucidate the role of pSmad3C/L signaling and lncRNA associated with TGF-beta, including T-LINC1, a lncRNA induced by TGF-beta recently identified by our group. Clinical relevance of the findings will be tested by integrative genomics using the gene expression profiles of clinically well-annotated ICC tumors. We expect our TGFbeta-ICC project to shed new light on the field of ICC, both at the basic and translational level. In terms of basic science, we expect a better knowledge of the contextual determinants that shape the consequences of TGFbeta signals in ICC and its environment. At a translational level, the project will provide a rationale for stratified medicine by identifying patients that benefit from interference with TGFbeta signaling.