Research Project #3: Cell fate decision of liver tumor-initiating stem-like cells induced by alcohol. PROJECT SUMMARY/ABSTRACT Alcohol-associated hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths globally, yet efficacious therapeutic options are still limited. Central to therapy-resistance of HCC is the liver tumor-initiating stem-like cell (TIC) which we successfully isolated from HCC animal models and patients to understand their self-renewal mechanisms. We have identified a novel oncoprotein in TICs, TBC1D15 which facilitates phosphor-inactivation of the polarity protein NUMB by the TLR4-NANOG-AurkA-aPKC? pathway, leading to dissociation of p53 of NUMB, p53 ubiquitination and degradation, and TIC self-renewal. Functional significance of this mechanism is confirmed by marked reductions in liver tumor incidence and tumor-associated NANOG+ TICs by hepatocyte-specific expression of non-phosphorylatable NUMB or hepatocyte-specific deficiency of TBC1D15 in alcohol-fed HCV NS5A Tg mice. However, TBC1D15 expression endows non-transformed p53-deficient mouse hepatoblasts self-renewal activity. This suggests TBC1D15 has an unknown oncogenic mechanism besides promoting p53 loss. We have discovered TBC1D15 interacts with all NOTCH isoforms, activates the NOTCH pathway, and induces Nanog and TIC self-renewal in a NOTCH-dependent manner. Our data suggest TBC1D15 promotes NOTCH activation and antagonizes NUMB-mediated NICD destabilization. Two putative functional CSL/NICD sites in the Nanog gene were identified in a -5kb distal enhancer and a proximal promoter (-212/-151), both required for full Nanog transcription. We also mapped the TBC1D15-NICD interaction domain and identified a novel small molecule inhibitor which blocks the interaction and TBC1D15-dependent NICD-Hey1 and Nanog promoter activities. We hypothesize that TBC1D15 promotes oncogenesis by obligatory cooperation with the NOTCH pathway thus an inhibitor of TBC1D15-NICD interaction is therapeutic. We will pursue the following aims:
Aim -1. Identify how TBC1D15 promotes the NOTCH pathway:
Aim -1.1: Determine the role of TBC1D15-NOTCH interaction in NICD stabilization;
Aim -1.2: Determine if TBC1D15 activates NOTCH.
Aim -2. Identify how TBC1D15-activated NOTCH pathway contributes to TIC self-renewal and tumorigenesis:
Aim -2.1: Determine how NICD supports Nanog transcription;
Aim -2.2: Determine in vivo importance of the putative Nanog CSL/NICD sites in TIC-mediated tumorigenesis;
Aim -2.3. Test the therapeutic efficacy of the novel inhibitor for the TBC1D15-NICD interaction in patient-derived xenograft (PDX) HCC model. Results from the proposed work will provide mechanistic insights into the novel oncogenic property of TBC1D15 and a pre-clinical basis for a future clinical trial using the novel inhibitor that antagonizes the interaction between TBC1D15 and NOTCH.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Specialized Center (P50)
Project #
5P50AA011999-23
Application #
10077271
Study Section
Special Emphasis Panel (ZAA1)
Project Start
1999-01-01
Project End
2023-12-31
Budget Start
2021-01-01
Budget End
2021-12-31
Support Year
23
Fiscal Year
2021
Total Cost
Indirect Cost
Name
University of Southern California
Department
Type
DUNS #
072933393
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Zhao, Qinglan; Wei, Yi; Pandol, Stephen J et al. (2018) STING Signaling Promotes Inflammation in Experimental Acute Pancreatitis. Gastroenterology 154:1822-1835.e2
Edderkaoui, Mouad; Chheda, Chintan; Soufi, Badr et al. (2018) An Inhibitor of GSK3B and HDACs Kills Pancreatic Cancer Cells and Slows Pancreatic Tumor Growth and Metastasis in Mice. Gastroenterology 155:1985-1998.e5
Khanova, Elena; Wu, Raymond; Wang, Wen et al. (2018) Pyroptosis by caspase11/4-gasdermin-D pathway in alcoholic hepatitis in mice and patients. Hepatology 67:1737-1753
Zheng, Han; You, Yang; Hua, Meiyun et al. (2018) Chlorophyllin Modulates Gut Microbiota and Inhibits Intestinal Inflammation to Ameliorate Hepatic Fibrosis in Mice. Front Physiol 9:1671
Lew, Daniel; Wu, Bechien U; Pandol, Stephen J et al. (2018) Disease Course Differences in Acute Pancreatitis Based on Etiology Using the Pancreatitis Activity Scoring System. Pancreas 47:e40-e41
Ogawa, Tomohiro; Li, Yuchang; Lua, Ingrid et al. (2018) Isolation of a unique hepatic stellate cell population expressing integrin ?8 from embryonic mouse livers. Dev Dyn 247:867-881
Tripathi, Anupriya; Debelius, Justine; Brenner, David A et al. (2018) The gut-liver axis and the intersection with the microbiome. Nat Rev Gastroenterol Hepatol 15:397-411
Waldron, Richard T; Su, Hsin-Yuan; Piplani, Honit et al. (2018) Ethanol Induced Disordering of Pancreatic Acinar Cell Endoplasmic Reticulum: An ER Stress/Defective Unfolded Protein Response Model. Cell Mol Gastroenterol Hepatol 5:479-497
Waldron, Richard T; Lugea, Aurelia; Gulla, Aiste et al. (2018) Proteomic Identification of Novel Plasma Biomarkers and Pathobiologic Pathways in Alcoholic Acute Pancreatitis. Front Physiol 9:1215
Wu, Raymond; Murali, Ramachandran; Kabe, Yasuaki et al. (2018) Baicalein Targets GTPase-Mediated Autophagy to Eliminate Liver Tumor-Initiating Stem Cell-Like Cells Resistant to mTORC1 Inhibition. Hepatology 68:1726-1740

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