ER-stress Inhibitors Study on HCC

BackgroundEndoplasmic reticulum (ER) stress and its adaptive signaling through the unfolded protein response (UPR) are increasingly implicated in driving tumor progression and reshaping the tumor microenvironment in hepatocellular carcinoma (HCC). Among the UPR sensors, PERK (EIF2AK3) is thought to play a central role in enabling tumor cell survival under stress and promoting stromal activation, fibrosis, and inflammatory signaling. Additionally, ER stress–regulated secreted factors such as GP73 (GOLM1) and extracellular GRP78 may mediate communication between malignant cells and surrounding stromal populations, contributing to a pro-tumorigenic microenvironment.ObjectiveThe overall objective of both projects is to investigate how modulation of ER stress and UPR signaling influences HCC development, tumor progression, and tumor–stroma interactions. Specifically, the first project aims to determine whether pharmacological inhibition of PERK using a selective small-molecule inhibitor (AMG-PERK 44) can suppress ER stress-driven tumor growth and stromal activation, and to define the molecular mechanisms underlying ER stress-dependent communication between malignant cells and hepatic stellate cells, with a focus on GP73- and GRP78-mediated signaling. The second project seeks to evaluate whether alleviation of ER stress using the chemical chaperone tauroursodeoxycholic acid (TUDCA) can reduce early tumorigenesis, fibrosis, inflammation, and malignant phenotypes. Together, these studies aim to characterize ER stress-regulated transcriptional and cellular programs and to assess the therapeutic and preventive potential of targeting ER stress pathways in HCC. Approach - Model Systems: Project 1 (AMG-PERK inhibitor): Chemically induced mouse model of HCC, in vitro HCC cell lines, and patient-derived organoids were used to assess the impact of PERK inhibition across multiple biological contexts. Project 2 (TUDCA inhibitor): Chemically induced mouse model of HCC and in vitro HCC cell lines were used to evaluate the effects of ER stress inhibition on tumor development, fibrosis, inflammation, and tumor progression. - Pharmacologic Intervention: Project 1: Use of the selective PERK inhibitor AMG-PERK 44 to assess its effects on PERK signaling, tumor behavior, and tumor–stroma interactions. Project 2: Treatment with tauroursodeoxycholic acid (TUDCA), a liver-derived bile acid conjugate known to reduce ER stress signaling, to alleviate ER stress and limit early hepatocarcinogenesis. - Mechanistic Studies: Project 1: Investigate the role of GP73 as a mediator of ER stress–dependent tumor–stroma communication, and examine its interaction with extracellular GRP78 and downstream PERK–CHOP signaling in hepatic stellate cells. Project 2: Assess how TUDCA modulates UPR sensors and downstream fibrogenic, proinflammatory, and EMT pathways in liver tissue and HCC cell lines. Molecular and Cellular Profiling: Project 1: Single-cell RNA sequencing, bulk transcriptomics, and immunohistochemistry to identify cell populations expressing PERK, GP73, and GRP78 (BiP), and to characterize ER stress–associated transcriptional programs, including proliferation, EMT, and inflammation. Project 2: Gene expression analyses and immunohistochemistry to measure UPR sensor expression, EMT markers, fibrosis, and inflammatory markers in liver tissue and HCC cell lines following exposure to TUDCA treatment.