Gores, Gregory J.

Background: NASH is the progressive form of NAFLD characterized by lipotoxicity, hepatocyte injury, tissue inflammation, and fibrosis. Previously, Rho-associated protein kinase (ROCK) 1 has been implicated in lipotoxic signaling in hepatocytes in vitro and high-fat diet-induced lipogenesis in vivo. However, whether ROCK1 plays a role in liver inflammation and fibrosis during NASH is unclear. Here, we hypothesized that pathogenic activation of ROCK1 promotes murine NASH pathogenesis. Methods and Results: Patients with NASH had increased hepatic ROCK1 expression compared with patients with fatty liver. Similarly, hepatic ROCK1 levels and activity were increased in mice with NASH induced by a western-like diet that is high in fat, fructose, and cholesterol (FFC). Hepatocyte-specific ROCK1 knockout mice on the FFC diet displayed a decrease in liver steatosis, hepatic cell death, liver inflammation, and fibrosis compared with littermate FFC-fed controls. Mechanistically, these effects were associated with a significant attenuation of myeloid cell recruitment. Interestingly, myeloid cell-specific ROCK1 deletion did not affect NASH development in FFC-fed mice. To explore the therapeutic opportunities, mice with established NASH received ROCKi, a novel small molecule kinase inhibitor of ROCK1/2, which preferentially accumulates in liver tissue. ROCK inhibitor treatment ameliorated insulin resistance and decreased liver injury, inflammation, and fibrosis. Conclusions: Genetic or pharmacologic inhibition of ROCK1 activity attenuates murine NASH, suggesting that ROCK1 may be a therapeutic target for treating human NASH.

Abstract Background: Cholangiocarcinoma (CCA) is a lethal disease with limited therapeutic options. We have previously discovered LCK driving signaling through AXL, a TAM receptor tyrosine kinase (RTK), by phosphoproteomic analysis of CCA (J Hepatol 2022). AXL mediates acquired drug resistance in solid cancers. However, the exact role of AXL in CCA still remains to be elucidated. Here, we investigated the significance of AXL expression as a potential therapeutic target in CCA and the role of phosphorylated AXL Y866. Methods: We first evaluated the expression levels of AXL in CCA and its associations with patient outcomes using The Cancer Genome Atlas (TCGA) database. Next, to evaluate whether AXL inhibition sensitizes CCA cells to gemcitabine and cisplatin (GemCis) therapy, AXL downregulation was achieved via the siRNA approach and the selective inhibitor bemcentinib. We examined the 50% inhibitory concentration (IC50) value of HuCCT1, a well-characterized CCA cell line, on GemCis therapy with or without AXL knockdown using cell viability assay. Then we assessed the efficacy of the combinatorial therapy of GemCis and bemcentinib utilizing Calcusyn software. Apoptosis was evaluated by Annexin V assay. In vivo efficacy was assessed using an SB-1 (murine CCA cell line) and a syngeneic murine model of CCA treated with vehicle, GemCis, bemcentinib, and the combination of GemCis and bemcentinib. Finally, to investigate the role of AXL Y866 in CCA, we performed BioID to identify and compare the interactomes of AXL WT and AXL Y866F in HuCCT1 cells. Results: In the TCGA cohorts, AXL is significantly expressed in CCA (P < 0.01), and disease-free survival and overall survival in the low AXL expression group are significantly longer than those in the high AXL expression group (P = 0.04, 0.01). In in vitro study, the IC50 value of GemCis was decreased from 685nM to 129nM after AXL knockdown. A synergistic effect was observed with CI = 0.17 and Fa = 0.50 in the combinatorial therapy. The combinatorial therapy caused significantly increased apoptosis compared to GemCis or bemcentinib alone (P < 0.01, P < 0.01). In in vivo study, the combinatorial therapy significantly suppressed the tumor growth compared to GemCis or bemcentinib alone (P = 0.04, 0.01), and the expression levels of Ki67 and the phosphorylation levels of PEAK1 decreased in the combinatorial therapy group compared to other groups in immunostaining examination. In BioID experiments, among the 222 proteins detected in both AXL WT and AXL Y866F interactomes, PEAK1 kinase, which localizes to actin cytoskeleton and focal adhesions, was the kinase most affected by AXL Y866. In gene ontology analysis to characterize the interactome of AXL Y866, cell-cell adhesion and focal adhesion-related proteins were enriched. Conclusions: AXL inhibition sensitizes CCA cells to cytotoxic chemotherapy in the preclinical model. AXL Y866-PEAK1 signaling axis is a potential target for the treatment of CCA. Citation Format: Shohei Takaichi, Dong-Gi Mun, Jennifer L. Tomlinson, Amro M. Abdelrahman, Danielle M. Carlson, Alaa Abou Daher, Nathan W. Werneburg, Xinyan Wu, Akhilesh Pandey, Gregory J. Gores, Rory L. Smoot. Axl inhibition sensitizes cholangiocarcinoma cells to cytotoxic chemotherapy. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4996.

Abstract Background: Cholangiocarcinoma (CCA) is a heterogeneous malignancy arising from the biliary epithelium. Its diverse molecular landscape and aggressive biology render many anti-cancer therapies ineffective. Nanovesicle technology provides an opportunity for therapeutic inhibition of oncogenic targets that have been previously classified as undruggable. EpCAM is an epithelial-specific, transmembrane glycoprotein with increased expression in human and murine CCA which can be used for nanovesicle targeting. As a proof of concept study, we designed and validated a novel strategy to direct therapeutic milk-derived nanovesicles (tMNVs) to CCA tumors. Methods: tMNVs were decorated with RNA nanoparticles containing a validated aptamer (EpDT3) against EpCAM conjugated to a cholesterol-triethylene-glycol (TEG) scaffold containing an Alexa647 fluorophore. Human and murine CCA cell lines were treated with aptamer directed tMNVs and assessed for nanovesicle uptake by fluorescent microscopy. CCA tumor tissue, derived from orthotopic implantation of a syngeneic CCA cell line, SB1, into a C57BL/6 mouse, was collected and treated with either aptamer-directed or bare tMNVs ex vivo, and compared with adjacent normal liver tissue. Flow cytometry was utilized to characterize tMNVs absorption profile. C57BL/6 mice who had previously undergone SB1 orthotopic and flank implantation were treated with aptamer-directed tMNVs by tail-vein injection and subsequently euthanized. Tissue was collected for biodistribution analyses by fluorescent microscopy. The experiment was repeated in NOD-scid mice following orthotopic implantation of patient derived xenograft (PDX) CCA tumor. Results: Both human and murine CCA cells treated with aptamer-directed tMNVs demonstrated high fluorescent signal consistent with tMNV absorption within 12 hours of application. Flow cytometry analysis showed aptamer-directed tMNVs were absorbed at a higher proportion by CCA tumors than bare tMNVs ex vivo. Aptamer-directed tMNVs also had better absorption by CCA tumors compared to adjacent normal liver tissue. Following treatment with aptamer-directed or bare tMNVs in vivo, fluorescent microscopy demonstrated that aptamer-directed tMNVs were significantly better absorbed in the orthotopic SB1 tumors, followed by the subcutaneous tumors. Minimal fluorescent signal was noted in the normal adjacent liver. Orthotopically implanted PDX tumors also demonstrated high fluorescent signals following intravenous treatment with aptamer-directed tMNVs. Conclusions: Utilizing a novel targeting strategy, we were able to design tMNVs capable of reliably and specifically targeting CCA in preclinical models. This work is foundational to the future application of nanovesicle technology in the CCA treatment paradigm. Citation Format: Mincheng Yu, Jennifer L. Tomlinson, Emilien J. Loeuillard, Ryan D. Watkins, Caitlin B. Conboy, Shohei Takaichi, Nathan W. Werneburg, Roberto Alva-Ruiz, Amro Abdelrahman, Danielle M. Carlson, Jingchun Yang, Sumera I. Ilyas, Gregory J. Gores, Tushar Patel, Rory L. Smoot. Novel strategy for aptamer-directed nanovesicle targeting in cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 814.

INTRODUCTION: Intrahepatic cholangiocarcinoma (iCCA) is a primary liver malignancy with poor prognosis. Current prognostic methods are most accurate for patients with surgically resectable disease. However, a significant proportion of patients with iCCA are not surgical candidates. We aimed to develop a generalizable staging system based on clinical variables to determine prognosis of all patients with iCCA. METHODS: The derivation cohort included 436 patients with iCCA seen between 2000 and 2011. For external validation, 249 patients with iCCA seen from 2000 to 2014 were enrolled. Survival analysis was performed to identify prognostic predictors. All-cause mortality was the primary end point. RESULTS: Eastern Cooperative Oncology Group status, tumor number, tumor size, metastasis, albumin, and carbohydrate antigen 19-9 were incorporated into a 4-stage algorithm. Kaplan-Meier estimates for 1-year survival were 87.1% (95% confidence interval [CI] 76.1–99.7), 72.7% (95% CI 63.4–83.4), 48.0% (95% CI 41.2–56.0), and 16% (95% CI 11–23.5), respectively, for stages I, II, III, and IV. Univariate analysis yielded significant differences in risk of death for stages II (hazard ratio [HR] 1.71; 95% CI 1.0–2.8), III (HR 3.32; 95% CI 2.07–5.31), and IV (HR 7.44; 95% CI 4.61–12.01) compared with stage I (reference). Concordance indices showed the new staging system was superior to the TNM staging for predicting mortality in the derivation cohort, P < 0.0001. In the validation cohort, however, the difference between the 2 staging systems was not significant. DISCUSSION: The proposed independently validated staging system uses nonhistopathologic data to successfully stratify patients into 4 stages. This staging system has better prognostic accuracy compared with the TNM staging and can assist physicians and patients in treatment of iCCA.

Mixed acinar neuroendocrine carcinoma of the pancreas (MANEC-P) is an extremely rare malignancy with a poor prognosis. However, epidemiological estimates of MANEC-P remain unknown. This study aimed to estimate and compare the incidence, prevalence, and cancer-specific survival (CSS) of MANEC-P in the United States (US). Patients with MANEC-P were identified through the Surveillance, Epidemiology, and End Results (SEER) and National Program of Cancer Registries databases between 2000–2017. The primary outcomes included age-adjusted incidence rate, limited-duration prevalence, and CSS. A total of 630 patients were identified for the incidence analysis and 149 for the prevalence and CSS analyses. The MANEC-P incidence rate was 0.011 per 100,000 individuals, which was the lowest among pancreatic cancer histologic subtypes. The incidence rate was significantly higher in men and Black races and peaked at 75–79 years of age. The incidence rate was the lowest in the midwestern region (0.009) and the highest in the northeastern US (0.013). The 17-year prevalence was 0.00005%, indicating that 189 patients were alive in the United States at the beginning of 2018. The median CSS of MANEC-P was estimated to be 41 (23, 69) months. In conclusion, MANEC-P is very rare, and its incidence rate has been steady in the US over the last two decades. MANEC-P has a poor prognosis and is the 5th leading cause of pancreatic cancer-related death in the US.

591 Background: Cholangiocarcinoma (CCA) is a lethal disease with limited therapeutic options. We have demonstrated the interaction of Src-family kinase LCK with AXL, a TAM receptor tyrosine kinase (RTK), by phosphoproteomic analysis in CCA ( J Hepatol 2022). AXL is reported to act as a mechanism of acquired drug resistance in solid cancers. However, the role of AXL in CCA remains to be elucidated. Here, we investigated the significance of AXL expression as a potential therapeutic target in CCA. Methods: We first evaluated the expression levels of AXL in CCA and the associations with patient outcome using publicly available data from The Cancer Genome Atlas (TCGA). Next, to evaluate whether AXL inactivation sensitizes CCA cells to gemcitabine and cisplatin (GemCis) therapy as a standard therapy. AXL downregulation was achieved via siRNA approach and the selective inhibitor bemcentinib. We examined 50% inhibitory concentration (IC50) value of HuCCT1, a well characterized CCA cell line, on GemCis therapy with and without AXL knockdown using CellTiter-Glo cell viability assay. Then we assessed the efficacy of the combinatorial therapy of GemCis and bemcentinib utilizing Calcusyn software. Finally, apoptosis was evaluated by Annexin V assay. In vivo efficacy was assessed using a SB-1 (murine CCA cell line) and syngeneic murine model of CCA in C57Bl/6J mice treated with vehicle, GemCis, bemcentinib, and the combination of GemCis and bemcentinib. Results: In the TCGA cohorts, AXL is significantly expressed in CCA (P < 0.01), and disease-free survival and overall survival in low AXL expression group are significantly longer than those in high AXL expression group (P = 0.04, 0.01). In in vitro study, IC50 value of GemCis was decreased from 685nM to 129nM after AXL knockdown. Synergy effect was observed with the value of CI = 0.17 and Fa = 0.50 in the combinatorial therapy. The combinatorial therapy caused significantly increased apoptosis compared to GemCis or bemcentinib alone (P < 0.01, P < 0.01). In in vivo study, the combinatorial therapy significantly suppressed the tumor growth compared to GemCis or bemcentinib alone (P = 0.04, 0.01). Conclusions: Targeting AXL sensitizes CCA cell lines and preclinical models to standard of care GemCis combinatorial therapy. Our study suggests that the addition of AXL targeted therapy to cytotoxic chemotherapy can increase the response in CCA patients and is a promising combination.

Abstract Primary sclerosing cholangitis (PSC) is a complex bile duct disorder. Its etiology is incompletely understood, but environmental chemicals likely contribute to risk. Patients with PSC have an altered bile metabolome, which may be influenced by environmental chemicals. This novel study utilized state-of-the-art high-resolution mass spectrometry (HRMS) with bile samples to provide the first characterization of environmental chemicals and metabolomics (collectively, the exposome) in PSC patients located in the United States of America (USA) (n = 24) and Norway (n = 30). First, environmental chemical- and metabolome-wide association studies were conducted to assess geographic-based similarities and differences in the bile of PSC patients. Nine environmental chemicals (false discovery rate, FDR &lt; 0.20) and 3143 metabolic features (FDR &lt; 0.05) differed by site. Next, pathway analysis was performed to identify metabolomic pathways that were similarly and differentially enriched by the site. Fifteen pathways were differentially enriched (P &lt; .05) in the categories of amino acid, glycan, carbohydrate, energy, and vitamin/cofactor metabolism. Finally, chemicals and pathways were integrated to derive exposure–effect correlation networks by site. These networks demonstrate the shared and differential chemical–metabolome associations by site and highlight important pathways that are likely relevant to PSC. The USA patients demonstrated higher environmental chemical bile content and increased associations between chemicals and metabolic pathways than those in Norway. Polychlorinated biphenyl (PCB)-118 and PCB-101 were identified as chemicals of interest for additional investigation in PSC given broad associations with metabolomic pathways in both the USA and Norway patients. Associated pathways include glycan degradation pathways, which play a key role in microbiome regulation and thus may be implicated in PSC pathophysiology.

Abstract IQGAP1 is a ubiquitous, cytoskeletal-interacting scaffold protein frequently overexpressed in cancer. CXCR4 is a chemokine receptor that signals upon binding stromal cell-derived factor 1 (SDF-1, CXCL12). CXCR4 regulates lymphocyte migration and development and cancer cell proliferation and metastasis. Here, we show that IQGAP1 potently enhances CXCR4’s expression, trafficking, and function in the Jurkat T cell line and epithelial cancer cells. The SDF-1-induced cell migration and activation of ERK MAPK were impaired in IQGAP1-deficient cells, even after forced CXCR4 overexpression. Exploring the mechanism, we found that SDF-1 treatment induced CXCR4 endocytosis and caused IQGAP1 to bind a-tubulin and localize to EEA-1 endosomes containing endocytosed CXCR4. In IQGAP1-deficient cells, CXCR4-containing EEA-1 endosomes accumulated at the distal ends of microtubules instead of moving towards the centrosome. This inhibited CXCR4’s signaling and cell-surface expression by preventing CXCR4 from trafficking into the Rab11 endosomes previously shown to be a critical site of CXCR4 signaling and recycling to the cell-surface. In contrast, IQGAP1 depletion had no effect on TCR trafficking, which does not require EEA-1 endosomes. Together, these results characterize a novel function of IQGAP1 as a regulator of EEA-1 endosomes, and in addition identify IQGAP1 as a critical enhancer of CXCR4 cell-surface expression and signaling in lymphocytes and epithelial cancer cells.

Abstract Background Some patients with inflammatory bowel disease (IBD) on immunosuppressive therapies may have a blunted response to certain vaccines, including the messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccines. However, few studies have evaluated the cell-mediated immune response (CMIR), which is critical to host defense after COVID-19 infection. The aim of this study was to evaluate the humoral immune response and CMIR after mRNA COVID-19 vaccination in patients with IBD. Methods This prospective study (HERCULES [HumoRal and CellULar initial and Sustained immunogenicity in patients with IBD] study) evaluated humoral immune response and CMIR after completion of 2 doses of mRNA COVID-19 vaccines in 158 IBD patients and 20 healthy control (HC) subjects. The primary outcome was the CMIR to mRNA COVID-19 vaccines in patients with IBD. The secondary outcomes were a comparison of (1) the CMIR in patients with IBD and HC subjects, (2) CMIR and humoral immune response in all participants, and (3) correlation between CMIR and humoral immune response. Results The majority (89%) of patients with IBD developed a CMIR, which was not different vs HC subjects (94%) (P = .6667). There was no significant difference (P = .5488) in CMIR between immunocompetent (median 255 [interquartile range, 146-958] spike T cells per million peripheral blood mononuclear cells) and immunosuppressed patients (median 377 [interquartile range, 123-1440]). There was no correlation between humoral and cell-mediated immunity after vaccination (P = .5215). In univariable analysis, anti-tumor necrosis factor therapy was associated with a higher CMIRs (P = .02) and confirmed in a multivariable model (P = .02). No other variables were associated with CMIR. Conclusions Most patients with IBD achieved CMIR to a COVID-19 vaccine. Future studies are needed evaluating sustained CMIR and clinical outcomes.