Abstract Primary liver malignancies—including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA)—originate from the oncogenic conversion of hepatocytes and cholangiocytes, respectively. Loss or attenuation of phosphatase and tensin homolog (PTEN), a critical negative regulator of the PI3K-AKT signaling axis, is frequently observed in roughly 70% of CCA and 50% of HCC cases. Intriguingly, the incidence of PTEN mutations is approximately doubled in tumors manifesting a combined HCC-CCA phenotype relative to tumors classified as either HCC or CCA alone. Using lineage-specific liver-specific PTEN-deficient mouse models, we show that PTEN loss drives cellular dedifferentiation and oncogenic progression, a process that exhibits strict dependence on AKT2. Mechanistically, we show that PTEN deficiency induces upregulation of NOTCH and SOX9 signal, with SOX9 playing important roles in tumor cell transformation. Furthermore, PTEN loss deficiency enhances the susceptibility of tumor cells to TGFβ, with TGFβ treatment repressing the expression of SOX9 in the absence of PTEN. Together, our study identifies PTEN-AKT2 signaling as a key regulator of hepatocyte lineage fidelity and reveals how its disruption enables the reprogramming of mature hepatocytes or cholangiocytes into liver cancer stem cells (LCSCs). We further delineate the cooperative interplay between NOTCH and TGFβ pathways in PTEN loss-driven liver tumorigenesis. Citation Format: Qi Tang, Yiwei Gu, Lina Jingyu chen, He, Ni Zeng, Shunan Hu, Slarve Ielyzaveta, Diala Alhousari, Guo Zhang, Zifei Xu, Phillip Nguyen, Gray Kanel, Shefali Chopra, Liyun Yuan, Bangyan L. Stiles. AKT2 loss inhibits mixed lineage liver malignancy induced by PTEN loss involving TGFb-Notch-SOX9 signal [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 599.

Primary liver cancers, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), arise from the neoplastic transformation of hepatocytes and cholangiocytes, respectively. Loss or downregulation of PTEN, a tumor suppressor negatively regulating the PI3K/AKT pathway, is frequently observed in CCA and HCC. Notably, PTEN mutations are observed at nearly twice the frequency in combined CCA-HCC tumors than either HCC or CCA alone. Using lineage-specific liver-targeted PTEN-deficient mouse models, we demonstrate that PTEN loss drives cellular dedifferentiation and tumorigenesis, a process that is critically dependent on AKT2. Mechanistically, PTEN deficiency induces activation of NOTCH and upregulation of transcriptional factor SOX9, which plays a central role in tumor cell transformation. In parallel, PTEN loss increases SMAD4 expression and sensitizes the tumor cells to TGFβ signaling, with TGFβ treatment repressing SOX9 expression in tumor cells lacking PTEN. Together, our study defined a critical role for PTEN-AKT2 signaling in maintaining liver epithelial lineage fidelity and revealed how its disruption promotes the conversion of mature hepatocytes or cholangiocytes into liver cancer stem-like cells (LCSCs). Furthermore, we identify a PTEN-dependent crosstalk between NOTCH and TGFβ pathways that governs liver tumor development. Together, this work provides mechanistic insight into lineage plasticity in liver cancer with implications for pathway-directed therapy.

Primary liver cancers, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), arise from the neoplastic transformation of hepatocytes and cholangiocytes, respectively. Loss or downregulation of PTEN, a tumor suppressor negatively regulating the PI3K/AKT pathway, is frequently observed in CCA and HCC. Notably, PTEN mutations are observed at nearly twice the frequency in combined CCA-HCC tumors than either HCC or CCA alone. Using lineage-specific liver-targeted PTEN-deficient mouse models, we demonstrate that PTEN loss drives cellular dedifferentiation and tumorigenesis, a process that is critically dependent on AKT2. Mechanistically, PTEN deficiency induces activation of NOTCH and upregulation of transcriptional factor SOX9, which plays a central role in tumor cell transformation. In parallel, PTEN loss increases SMAD4 expression and sensitizes the tumor cells to TGFβ signaling, with TGFβ treatment repressing SOX9 expression in tumor cells lacking PTEN. Together, our study defined a critical role for PTEN-AKT2 signaling in maintaining liver epithelial lineage fidelity and revealed how its disruption promotes the conversion of mature hepatocytes or cholangiocytes into liver cancer stem-like cells (LCSCs). Furthermore, we identify a PTEN-dependent crosstalk between NOTCH and TGFβ pathways that governs liver tumor development. Together, this work provides mechanistic insight into lineage plasticity in liver cancer with implications for pathway-directed therapy.

Primary liver cancer, including hepatocellular carcinoma (HCC) and Cholangiocarcinoma (CCA), arise from the neoplastic transformation of hepatocytes and cholangiocytes in the liver. Their association with liver cancer stem-like cell (LCSC) makers presents a more aggressive behavior and high lethal rate. PTEN is a tumor suppressor gene that negatively regulates the PI3K/AKT pathway. Downregulation of Pten is observed in up to 70% of the cases in CCA and 50% of the cases in HCC. In mouse models lacking PTEN, CCA develops in 100% of the mice at 12 months of age regardless of whether the whole liver cells (LiPTEN, PtenloxP/loxP; Alb-Cre+), hepatocytes-only (HpPTEN, PtenloxP/loxP; R26RYFP; AAV8-TBG-Cre), or cholangiocytes-only (ChoPten, PtenloxP/loxP; R26RYFP; SOX9-CreERT) are targeted. Treatment of these mice with DDC at 3 months to obstruct the bile duct leads to an earlier CCA oncogenesis at 6 months of age. Using YFP to follow the lineage of tumor cells in the HpPTEN and ChoPTEN mice, we found that PTEN loss allows for transdifferentiation from cholangiocytes to hepatocytes or vice versa. To explore the mechanism for how PTEN regulates cell fate, we focused on SOX9, a transcription factor that plays a critical role in embryonic development and is believed to be the downstream target of NOTCH signaling. Hyperactivation of the SOX9 and NOTCH signaling are observed at the tumor stage of all the PTEN loss mouse models. We showed that knocking down SOX9 with siRNA reduced the sphere-forming ability of liver cells established from the mice mentioned above, indicating SOX9 promotes LCSC proliferation and sustains the tumorigenic potential of these liver cells. Gain-of-function assays of the Notch signaling through exposure to Jag1 ligand-coated extracellular matrix or transfection of Notch intracellular domain (NICD) both induced the expression of SOX9 significantly. The treatment of Pten-deleted mice with DAPT to inhibit NOTCH signaling showed concurrently decreased expression of Notch target Hes1 and SOX9. We also addressed the roles of AKTs in this PTEN-regulated CCA development. Our data show that deletion of Akt2 in the LiPTEN mice (LiPTEN-A2, Akt2loxP/loxP; PtenloxP/loxP; Alb-Cre+) significantly attenuates tumor development. Compared with the LiPTEN mice, loss of AKT2 in LiPTEN-A2 mice robustly and significantly reduces the expression of SOX9/NOTCH signaling and manifests a bile duct malformation at 12 months of age. Together, this finding suggests NOTCH activation regulates SOX9 and collaborates with PTEN loss to drive liver cancer progression, and inhibiting AKT2 specifically can block HCC-CCA formation through SOX9/NOTCH downregulation. Qi Tang, Jingyu Chen, Guo Zhang, Ielyzaveta Slarve, Ni Zeng, Lina He, Diala Alhousari, Phillip Nguyen, Shunan Hu, Shefali Chopra, Liyun Yuan, Bangyan L. Stiles. Blocking AKT2 downregulates SOX9/Notch signaling inhibiting PTEN-null driven liver tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 261.

Background & Aims: Steatosis is a comorbid factor for cancer development. Patients with steatosis do not respond well to current immune checkpoint therapy (CPI) treatment. We explored the roles of neutrophil-activating chemokines (NACs) in the response of steatosis/liver cancer to CPI. Methods: We used a steatosis-driven liver cancer model induced by the deletion of Pten in the liver (LiPten) and a high-fat diet + carbon tetrachloride (CCl4) fibrosis model to study the effects of targeting CXCL5. We also studied the role of CXCL5 in the liver immune microenvironment in vitro and in vivo. ANOVA/t tests were used for data analysis. Results: Using LiPten steatosis-tumor mice, we identified CXCL5 as the NAC most robustly upregulated as steatosis progresses to cancer (>100 fold, n = 6–11). We also validated this observation in patient samples. When used together with αPD-1, inhibiting the NAC receptor CXCR2 promoted (100% vs. 80% in untreated LiPten mice), whereas anti-CXCL5 suppressed (25%), tumor progression (n = 4–6) suggesting unique functions of CXCL5 independent of CXCR2. Similar effects were observed for anti-CXCL5 (0/4 with fibrosis) vs. CXCR2 inhibition (4/4 with fibrosis) of fibrosis in the HFD + CCl4 model. Using a Transwell assay, we identified a novel inhibitory function of CXCL5 in the recruitment of CD4+ T cells (p <0.02, n = 4) and potentiation of CD8+ T cell cytotoxicity (p <0.001, n = 4). In vivo, we showed that neutralizing CXCL5 increased the CD8/CD4 ratio (p = 0.03 and 0.07) and synergized with αPD-1 for its anti-tumor and anti-fibrosis activity (n = 4–6). Conclusions: Our discovery of the novel inhibitory role of CXCL5 in T cells suggests that NACs have additional functions in modulating the immune system beyond neutrophil chemotaxis. The discovery of this novel CXCL5 role presents additional therapeutical targets alongside current immune checkpoint therapy. Impact and implications: In this study, we investigated the role of CXCL5 in the progression from steatosis to liver cancer. We uncovered a novel inhibitory role of CXCL5 in T cell recruitment, with implications for NAC-targeted therapy and immune checkpoint synergy in liver cancer. We believe our findings will be of interest to physicians, researchers, and patients interested in therapeutic development and translational research in liver disease.

Liver cancer is the third most common cause of cancer-related mortality worldwide. Mice with liver-specific Pten loss (PtenloxP/loxP; albumin [Alb]-Cre-/+; LiPten) develop predominantly intrahepatic cholangiocarcinoma (ICC) and some hepatocellular carcinoma (HCC) by 12 months of age. Pten loss results in activation of the serine/threonine kinase AKT. Of the three AKT isoforms identified to date, AKT1 isoform is implicated in regulation of cell growth, proliferation, and survival. The present study investigated the role of AKT1 in mediating PTEN-loss induced liver cancer development. To generate mice with liver-specific Pten and Akt1 deletion (PtenloxP/loxP; Akt1loxP/loxP; Alb-Cre-/+; LiPtenA1), LiPten mice were crossed with mice that have liver-specific Akt1 loss (Akt1loxP/loxP; Alb-Cre-/+; LiA1). Whole livers from 12-month-old WT, LiA1, LiPten, and LiPtenA1 mice were analyzed for tumor prevalence and morphology via hematoxylin and eosin staining, and for markers of HCC and ICC via qPCR and immunofluorescence. All male LiA1 mice displayed WT-like phenotype. Like LiPten mice, all male LiPtenA1 mice develop steatosis followed by tumors by 12 months of age. Compared to LiPten mice, LiPtenA1 animals displayed predominantly HCC phenotype based on morphology, increased HCC markers (Hnf4a, Alb), and decreased ICC markers (Sox9, Spp1, Hes1, Ck19). AKT1 loss in LiPten mice did not prevent development of steatosis and liver tumorigenesis but resulted in predominantly HCC rather than ICC phenotype, suggesting the role of AKT1 in mediating ICC development. These results contribute to the understanding of the role of AKT isoforms in regulating liver tumorigenesis, and further investigation into signaling mechanisms underlying these observations is required. Ielyzaveta Slarve, Yining Ding, Yushan Wang, Qi Tang, Zifei Xu, Lina He, Bangyan Stiles. AKT1 mediates PTEN-loss induced intrahepatic cholangiocarcinoma development in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4135.

Elevated levels of osteopontin (OPN), an inflammatory cytokine, are correlated with chronic inflammatory conditions and liver cancer. In this study, we explored the regulation of OPN in liver and hepatocytes by AKT1 vs. AKT2, the two AKT isoforms expressed in hepatocytes and livers. Using a mouse model lacking PTEN (phosphatase and tensin homologue deleted on chromosome 10), the negative regulator of phosphatidylinositol 3-kinase (PI3K)/AKT signaling, expression of secreted phosphoprotein 1 (Spp1), the gene encoding OPN, was found to be the topmost significantly upregulated gene in the liver. Using an add-back experiment in hepatocytes isolated from these mice, we show that PTEN regulates the expression of Spp1 mRNA as well as OPN protein levels. Exploring how PTEN regulates the expression of Spp1/OPN, we investigated the differential roles of AKT1 vs. AKT2 using hepatocytes isolated from mice lacking each AKT isoform in the liver. We showed here that levels of Spp1/OPN in hepatocytes are lost with deletion of Akt2 but not Akt1. Deletion of Akt2 significantly attenuated both basal expression of OPN and its response to IGF-1 stimulation. AKT1 loss, on the other hand, permitted more robust induction of OPN by IGF-1 stimulation. Furthermore, mice lacking AKT2 and PTEN exhibit significantly lower OPN expression in the liver. Together, this study showed that OPN levels are regulated by the PI3K/AKT signal in hepatocytes and that AKT2 but not AKT1 is responsible for its induction in response to stimulation of the PI3K signaling pathway.

Abstract Hepatocellular carcinoma (HCC) is hallmarked by inflammatory cell infiltration. Chemokines secreted during inflammation are crucial at directing immune cell infiltration during cancer development. We screened patient dataset from different etiologies including HBV, HCV, alcohol and non-alcoholic steatohepatitis (NASH) and identified CXCL5 as the only chemokine consistently upregulated in HCC. Immunohistochemistry (IHC) of patient liver tumor tissues further showed the production of CXCL5 by tumor surrounding non parenchymal cells. Using a mouse model (Pte loxP/loxP; Alb-Cre+, Pten null) which recapitulates human liver disease progression from non-alcoholic fatty liver disease (NAFLD) to NASH to liver cancer, we found that CXCL5 was expression was gradually increased during disease progression. Further analysis using IHC and flow cytometry analysis showed that CXCL5 is predominantly expressed by Kupffer cells in Pten null livers bearing tumors. Furthermore, we found that LPS stimulated the expression and secretion of CXCL5 in Kupffer cells, but not other macrophages including peritoneal macrophage and macrophage cell line Raw264.7 cells. We hypothesized that the Kupffer cell-secreted CXCL5 in response to LPS promotes tumor progression by promoting HCC cell proliferation and regulating HCC associated immune cell infiltration. To investigate whether CXCL5 increases tumor cell proliferation, we treated wild type and Pten null hepatocytes with various concentrations of CXCL5. Our results showed that CXCL5 increased hepatocytes viability in a dose dependent manner. BrdU incorporation assay further confirmed that CXCL5 treatments induces HCC cell proliferation through its receptor CXCR2. We further demonstrated that CXCR2 knockdown led to reduced xenograft tumor growth using HepG2 cells. Additionally, we injected Pten null mice with CXCR2 inhibitor to block CXCL5 signal and observed partial response. We analyzed the immune cell profile of the responder mice vs. non-responder mice and showed that tumor inhibition is correlated with T cell infiltration. To test whether Kupffer cells regulate T cells through CXCL5, we isolated primary Kupffer cells from murine livers. We performed transwell migration assay using immune cells from murine spleens. Our results indicate that LPS stimulation in Kupffer cells reduced the ratio of migrated CD4+ T cells, while blocking CXCL5 using a CXCL5 antibody significantly increased CD4+ T cell recruitment to the LPS-stimulated Kupffer cells and moderately decreased neutrophil recruitment. Consistently, we found that recombinant CXCL5 protein reduces CD4+ T cell migration independent of neutrophils. In summary, our study suggests that Kupffer cell secreted CXCL5 reduces liver CD4+ T cell recruitment and increases liver cancer cell proliferation. Citation Format: Taojian Tu, Handan Hong, Lina He, Mario Alba, Tang Qi, Curtis T. Okamoto, Bangyan L. Stiles. Dual role of Kupffer cell secreted CXCL5 in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5328.

Abstract Introduction: HCC is the most common form of liver cancer and is the sixth most common cancer globally. Despite the clinical advancement of immune checkpoint inhibitors, median survival continues to be less than twenty months and most patients develop resistance making it one of the deadliest malignancies. The rate of liver cancer continues to rise, which is coupled to the high prevalence of steatosis and steatohepatitis that accounts for about 25% in the general population. Pathologically, 80% of liver cancer occurs in patients with an underlying liver disease that displays liver steatosis. Thus, it is paramount to better characterize the transition from steatosis to HCC. Methods: Utilizing a Pten deleted mouse model (PtenloxP/loxP; Alb-Cre+) that recapitulates HCC progression, protein and lipid fractions were isolated to explore differentially expressed proteins and their correlations with bioactive lipid metabolism. Global untargeted differential proteomics was done with fractionation using a qExactive. Lipid fractions were analyzed using a Sciex 6500 for targeted lipidomic analysis. In addition, genetic knockout hepatocyte cell lines of each AKT isoform were used to explore the involvement of the PI3K/AKT signal. Further, a phosphoproteomic enrichment was performed to discover downstream signaling targets. Results: The PTEN regulated PI3K/AKT signal is induced in 54% of all liver cancers and represents the dominant signaling pathway regulating liver cancer progression. Untargeted differential proteomic analysis of Pten deleted mice livers revealed significant dysregulation in oxidative stress and eicosanoid metabolism among the top enriched disease and biological functions when the phenotype progressed from steatosis to HCC. Analysis of publicly available liver cancer patient samples from the NCI Proteomic Data Commons further shows strong correlation between PTEN protein abundance and the expression of enzymes involved in eicosanoid metabolism. Our analysis using a bio-active lipid multi reaction monitoring panel of Pten deleted mouse livers further validates significant decreases in resolving eicosanoid levels along with increases in proinflammatory eicosanoid precursors as steatosis progress to HCC. These data suggest a potential hepatic AKT-dependency in regulating the shift towards proinflammatory eicosanoids. Primary isolated hepatocytes from mouse livers lacking either AKT1 or AKT2 were analyzed to elucidate AKT’s regulatory role in hepatic eicosanoid metabolism. Proteomic and lipidomic analysis of these hepatocytes supported a unique AKT isoform specific role in the regulation of eicosanoids via potential isoform specific signaling interactions with MAPK. Conclusion: Eicosanoid metabolism dysregulation plays a key role in the progression from steatosis to HCC and appears to be regulated in an AKT isoform specific manner via interactions with MAPK signaling. Citation Format: Mario Alba, Ielyzaveta Slarve, Brandon Ebright, Yiren Zhou, Whitaker Cohn, Yunyi Jia, Elizabeth Elton, Jared Khan, Aditi Datta, Lina He, Qi Tang, Pranav Pammidimukkala, Taojian Tu, Phillip Nguyen, Jonathan Katz, Julian Whitelegge, Stan Louie, Bangyan Stiles. Hepatic steatosis induced by bioactive lipids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4449.

Abstract Cholangiocarcinoma (CCA) is the second most dominant primary liver malignancy next to hepatocellular carcinoma (HCC), and among the most mortal among human cancers. The PI3K/AKT signaling pathway was considered a permissive signal for the development of CCA. To explore how the PI3K/AKT signal contributes to CCA development, we deleted Pten, the lipid phosphatase that negatively regulates the PI3K/AKT signal in the liver. The Lv-PTEN (PtenloxP/loxP; Alb-Cre+) mice developed a mixed HCC and CCA tumor phenotype with all mice developing CCA by 12-month age. Treatment of Lv-PTEN mice with DDC at 3 months to obstruct the bile duct leads to an earlier CCA oncogenesis. Deletion of Akt2 in the Lv-PTEN mice (Lv-DM, Akt2loxP/loxP; PtenloxP/loxP; Alb-Cre+) significantly attenuates tumor development. Compared with the Lv-PTEN mice, loss of AKT2 in Lv-DM mice robustly and significantly reduced the expression of SOX9, a cholangiocyte gene. This data suggests that the AKT signal may permit a cholangiocyte fate by inducing SOX9 expression. Supporting the role of PTEN/AKT in permitting a cholangiocyte fate, SOX9 expression is also induced in the livers of mice where Pten deletion is targeted to the hepatocytes via injection of AAV8-TGB-Cre (Hp-PTEN, PtenloxP/loxP; R26RYFP; AAV8-TBG-Cre). Similar to the Lv-PTEN mice, treatment with DDC induced early onset of CCA development in the Hp-PTEN mice. We next explore Notch signal for its crosstalk with PTEN loss that permits CCA development. Notch signal is robustly induced in the tumors of the Lv-PTEN mice and induced with DDC treatment in both Lv-PTEN and Hp-PTEN livers. We showed that exposure to Jag1 ligand-coated extracellular matrix or expression of NICD also induced the expression of SOX9 while DAPT time-dependently attenuated the expression of SOX9. In the Hp-Pten mice treated with DDC, inhibiting the Notch pathway with DAPT attenuated ductal reaction and led to downregulation of SOX9 in the Lv-PTEN livers, suggesting a positive regulatory role of Notch on SOX9. These data support that Notch activation regulates SOX9 and collaborates with PTEN loss to drive cholangiocyte fate and CCA development. Citation Format: Qi Tang, Jingyu Chen, Ni Zeng, Lina He, Shefali Chopra, Diala Alhousari, Phillip Nguyen, Guo Zhang, Bangyan L. Stiles. PTEN/AKT signal promotes cholangiocyte fate in liver tumorigenesis by inducing SOX9 overexpression and crosstalk with Notch activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4367.

Liver malignancies consist of hepatocellular carcinoma (HCC) with the highest occurrence, intrahepatic cholangiocarcinoma (iCCA), and serval rare subtypes, which is the third lethal cause among all cancer types worldwide. PTEN is a well-known tumor suppressor gene, liver-specific loss of PTEN leads to the development of liver tumors from tumor-initiating cells (TICs). A mouse model that specifically mutant PTEN in hepatocytes (PM mice, PTENloxP/loxP; Alb-Cre+) has been used to mimic the natural progression of liver malignancy and study the mechanism of liver tumorigenesis. AKT, also known as protein kinase B, is a downstream kinase that is negatively regulated by PTEN. PTEN loss will unequivocally result in AKT phosphorylation and activation of the AKT pathway. In this study, we explored the role of AKT2, the most abundant liver isoform of AKT in the PTEN loss-driven liver malignancy by generating a new double mutant mouse model (DM mice, PTENloxP/loxP; AKT2loxP/loxP; Alb-Cre+). Our data demonstrated that only PM mice developed tumors starting from a 6-month age. A moderate reactive duct/oval cell accumulation phenotype is observed in the PM livers with Von Meyenbury complex (VMC) formation. And both HCC and iCCA phenotypes are observed following steatosis development in PM mice. AKT2 loss arrested tumor development at the pre-malignant stage. The DM mice also developed VMC condition with minimum steatosis starting from 9-month age and some of them manifest an advanced stage called polycystic liver disease. No tumors are observed in these mice up to 16 months of age. Our preliminary data showed that the deletion of AKT2 attenuated the accumulation of TICs marked by Sox9 suggesting a potential role of SOX9 in the regulation of PTEN-driven tumorigenesis. In summary, our result shows that AKT2 is a determining factor in PTEN loss-induced liver malignancy. Citation Format: Qi Tang, LIna He, Chien-Yu Chen, Shefali Chopra, Bangyan L. Stiles. AKT2 as the determining factor for PTEN loss-induced liver malignancy [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 2583.

Obesity confers an independent risk for carcinogenesis. Classically viewed as a genetic disease, owing to the discovery of tumor suppressors and oncogenes, genetic events alone are not sufficient to explain the progression and development of cancers. Tumor development is often associated with metabolic and immunological changes. In particular, obesity is found to significantly increase the mortality rate of liver cancer. As its role is not defined, a fundamental question is whether and how metabolic changes drive the development of cancer. In this review, we will dissect the current literature demonstrating that liver lipid dysfunction is a critical component driving the progression of cancer. We will discuss the involvement of inflammation in lipid dysfunction driven liver cancer development with a focus on the involvement of liver macrophages. We will first discuss the association of steatosis with liver cancer. This will be followed with a literature summary demonstrating the importance of inflammation and particularly macrophages in the progression of liver steatosis and highlighting the evidence that macrophages and macrophage produced inflammatory mediators are critical for liver cancer development. We will then discuss the specific inflammatory mediators and their roles in steatosis driven liver cancer development. Finally, we will summarize the molecular pattern (PAMP and DAMP) as well as lipid particle signals that are involved in the activation, infiltration and reprogramming of liver macrophages. We will also discuss some of the therapies that may interfere with lipid metabolism and also affect liver cancer development.

The estrogen-related receptor (ERR) family of orphan nuclear receptors are transcriptional activators for genes involved in mitochondrial bioenergetics and metabolism. The goal of this study was to explore the role of ERRα in lipid metabolism and the potential effect of inhibiting ERRα on the development of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). In the current study, three experimental mouse models: high-fat diet, high-carbohydrate diet, and a genetic model of hepatic insulin resistance where the liver hyperinsulinemia signal is mimicked via hepatic deletion of Pten (phosphatase and tensin homolog deleted on chromosome 10), the negative regulator of the insulin/phosphatidylinositol 3-kinase signaling pathway, were used. A recently developed small-molecule inhibitor for ERRα was used to demonstrate that inhibiting ERRα blocked NAFLD development induced by either high-carbohydrate diet or high-fat diet feeding. ERRα inhibition also diminished lipid accumulation and attenuated NASH development in the Pten null mice. Glycerolipid synthesis was discovered as an additional mechanism for ERRα-regulated NAFLD/NASH development and glycerophosphate acyltransferase 4 was identified as a novel transcriptional target of ERRα. In summary, these results establish ERRα as a major transcriptional regulator of lipid biosynthesis in addition to its characterized primary function as a regulator for mitochondrial function. This study recognizes ERRα as a potential target for NAFLD/NASH treatment and elucidates novel signaling pathways regulated by ERRα.