CD90 is regulated by notch1 and hallmarks a more aggressive intrahepatic cholangiocarcinoma phenotype.

Intrahepatic Cholangiocarcinoma (iCCA) is characterized by a strong stromal reaction playing a role in tumor progression. Thymus cell antigen 1 (THY1), also called Cluster of Differentiation 90 (CD90), is a key regulator of cell-cell and cell-matrix interaction. In iCCA, CD90 has been reported to be associated with a poor prognosis. In an iCCA PDX model, we recently found that CD90 was downregulated in mice treated with the Notch γ-secretase inhibitor Crenigacestat. The study aims to investigate the role of CD90 in relation to the NOTCH pathway. THY1/CD90 gene and protein expression was evaluated in human iCCA tissues and xenograft models by qRT-PCR, immunohistochemistry, and immunofluorescence. Notch1 inhibition was achieved by siRNA. THY1/CD90 functions were investigated in xenograft models built with HuCCT1 and KKU-M213 cell lines, engineered to overexpress or knockdown THY1, respectively. CD90 co-localized with EPCAM, showing its epithelial origin. In vitro, NOTCH1 silencing triggered HES1 and THY1 down-regulation. RBPJ, a critical transcriptional regulator of NOTCH signaling, exhibited putative binding sites on the THY1 promoter and bound to the latter, implying CD90 as a downstream NOTCH pathway effector. In vivo, Crenigacestat suppressed iCCA growth and reduced CD90 expression in the PDX model. In the xenograft model, Crenigacestat inhibited tumor growth of HuCCT1 cells transfected to overexpress CD90 and KKU-M213 cells constitutively expressing high levels of CD90, while not affecting the growth of HuCCT1 control cells and KKU-M213 depleted of CD90. In an iCCA cohort, patients with higher expression levels of NOTCH1/HES1/THY1 displayed a significantly shorter survival. iCCA patients with higher NOTCH1/HES1/THY1 expression have the worst prognosis, but they are more likely to benefit from Notch signaling inhibition. These findings represent the scientific rationale for testing NOTCH1 inhibitors in clinical trials, taking the first step toward precision medicine for iCCA.

Mancarella S ，Serino G ，Gigante I ，Cigliano A ，Ribback S ，Sanese P ，Grossi V ，Simone C ，Armentano R ，Evert M ，Calvisi DF ，Giannelli G ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Crenigacestat, a selective NOTCH1 inhibitor, reduces intrahepatic cholangiocarcinoma progression by blocking VEGFA/DLL4/MMP13 axis.

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

Targeting cancer-associated fibroblasts/tumor cells cross-talk inhibits intrahepatic cholangiocarcinoma progression via cell-cycle arrest.

Cancer-associated fibroblasts (CAFs), mainly responsible for the desmoplastic reaction hallmark of intrahepatic Cholangiocarcinoma (iCCA), likely have a role in tumor aggressiveness and resistance to therapy, although the molecular mechanisms involved are unknown. Aim of the study is to investigate how targeting hCAF/iCCA cross-talk with a Notch1 inhibitor, namely Crenigacestat, may affect cancer progression. We used different in vitro models in 2D and established new 3D hetero-spheroids with iCCA cells and human (h)CAFs. The results were confirmed in a xenograft model, and explanted tumoral tissues underwent transcriptomic and bioinformatic analysis. hCAFs/iCCA cross-talk sustains increased migration of both KKU-M213 and KKU-M156 cells, while Crenigacestat significantly inhibits only the cross-talk stimulated migration. Hetero-spheroids grew larger than homo-spheroids, formed by only iCCA cells. Crenigacestat significantly reduced the invasion and growth of hetero- but not of homo-spheroids. In xenograft models, hCAFs/KKU-M213 tumors grew significantly larger than KKU-M213 tumors, but were significantly reduced in volume by Crenigacestat treatment, which also significantly decreased the fibrotic reaction. Ingenuity pathway analysis revealed that genes of hCAFs/KKU-M213 but not of KKU-M213 tumors increased tumor lesions, and that Crenigacestat treatment inhibited the modulated canonical pathways. Cell cycle checkpoints were the most notably modulated pathway and Crenigacestat reduced CCNE2 gene expression, consequently inducing cell cycle arrest. In hetero-spheroids, the number of cells increased in the G2/M cell cycle phase, while Crenigacestat significantly decreased cell numbers in the G2/M phase in hetero but not in homo-spheroids. The hCAFs/iCCA cross-talk is a new target for reducing cancer progression with drugs such as Crenigacestat.

Mancarella S ，Gigante I ，Pizzuto E ，Serino G ，Terzi A ，Dituri F ，Maiorano E ，Vincenti L ，De Bellis M ，Ardito F ，Calvisi DF ，Giannelli G ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

The Tumor Microenvironment Drives Intrahepatic Cholangiocarcinoma Progression.

Mancarella S ，Serino G ，Coletta S ，Armentano R ，Dituri F ，Ardito F ，Ruzzenente A ，Fabregat I ，Giannelli G ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

Crenigacestat blocking notch pathway reduces liver fibrosis in the surrounding ecosystem of intrahepatic CCA viaTGF-β inhibition.

Intrahepatic cholangiocarcinoma (iCCA) is a highly malignant tumor characterized by an intensive desmoplastic reaction due to the exaggerated presence of the extracellular (ECM) matrix components. Liver fibroblasts close to the tumor, activated by transforming growth factor (TGF)-β1 and expressing high levels of α-smooth muscle actin (α-SMA), become cancer-associated fibroblasts (CAFs). CAFs are deputed to produce and secrete ECM components and crosstalk with cancer cells favoring tumor progression and resistance to therapy. Overexpression of Notch signaling is implicated in CCA development and growth. The study aimed to determine the effectiveness of the Notch inhibitor, Crenigacestat, on the surrounding microenvironment of iCCA. We investigated Crenigacestat's effectiveness in a PDX model of iCCA and human primary culture of CAFs isolated from patients with iCCA. In silico analysis of transcriptomic profiling from PDX iCCA tissues treated with Crenigacestat highlighted "liver fibrosis" as one of the most modulated pathways. In the iCCA PDX model, Crenigacestat treatment significantly (p < 0.001) reduced peritumoral liver fibrosis. Similar results were obtained in a hydrodynamic model of iCCA. Bioinformatic prediction of the upstream regulators related to liver fibrosis in the iCCA PDX treated with Crenigacestat revealed the involvement of the TGF-β1 pathway as a master regulator gene showing a robust connection between TGF-β1 and Notch pathways. Consistently, drug treatment significantly (p < 0.05) reduced TGF-β1 mRNA and protein levels in tumoral tissue. In PDX tissues, Crenigacestat remarkably inhibited TGF-β signaling and extracellular matrix protein gene expression and reduced α-SMA expression. Furthermore, Crenigacestat synergistically increased Gemcitabine effectiveness in the iCCA PDX model. In 31 iCCA patients, TGF-β1 and α-SMA were upregulated in the tumoral compared with peritumoral tissues. In freshly isolated CAFs from patients with iCCA, Crenigacestat significantly (p < 0.001) inhibited Notch signaling, TGF-β1 secretion, and Smad-2 activation. Consequently, Crenigacestat also inactivated CAFs reducing (p < 0.001) α-SMA expression. Finally, CAFs treated with Crenigacestat produced less (p < 005) ECM components such as fibronectin, collagen 1A1, and collagen 1A2. Notch signaling inhibition reduces the peritumoral desmoplastic reaction in iCCA, blocking the TGF-β1 canonical pathway.

Mancarella S ，Gigante I ，Serino G ，Pizzuto E ，Dituri F ，Valentini MF ，Wang J ，Chen X ，Armentano R ，Calvisi DF ，Giannelli G ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》