Effect of NOTCH-γ-secretase inhibitor LY3039478 therapy on patient derived xenograft (PDX) mouse model of intrahepatic cholangiocarcinoma

Intrahepatic Cholangiocarcinoma (iCCA) is a deadly disease with rising incidence and few treatment options. Recently, aberrant Notch signaling was reported in iCCA carcinogenesis. Specifically, altered expression and/or activation of the receptors Notch1/2 suggests a role for Notch pathway overactivation during iCCA formation and progression. In this study, we examined the effects of Notch inhibition by γ-secretase inhibitor, LY3039478 in human iCCA cell lines and in an excellent patient derived-xenograft (PDX) model. Expression of several Notch pathway components, including NICD, Hes1, and DLL4, were reduced after GSI treatment. Moreover, LY3039478 inhibits cell migration and invasion while in GSI-treated mice, tumor growth was delayed compared to vehicle and chemotherapy. These results support the notion that Notch inhibition by GSI may reduce in vivo tumorigenesis. In addition, GSI reduces in PDX model VEGFA and MMP13 involved in capillary tube formation and tumor progression. Here, we therefore show a link between the efficacy of Notch inhibition and the tumor microenvironment through LY3039478 that slows tumor progression compared to control mice blocking angiogenesis via MMP13 downregulation.

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Mancarella S, Serino G, Dituri F, Cigliano A, Ribback S, Wang J, Chen X, Calvisi DF, Giannelli G