Activity In Hepatocellular Carcinoma Research Articles

EGFR bypass activation mediates acquired resistance to regorafenib in hepatocellular carcinoma.

Regorafenib, a tyrosine kinase inhibitor (TKI), is used in the treatment of unresectable hepatocellular carcinoma (HCC). However, the occurrence of acquired resistance limits its antitumor efficacy. While multiple studies have highlighted the crucial role of bypass activation in acquired TKI resistance, few have focused on bypass activation in regorafenib resistance in HCC. High-throughput proteomics was used to identify differential proteins associated with bypass activation between acquired regorafenib-resistant cells and parental cells. The ability of epidermal growth factor receptor (EGFR) bypass inhibition to reverse resistance was evaluated both in vitro and in vivo using direct microscopic observation, the CCK-8 assay, colony formation assay, Annexin V-FITC/propidium iodide double staining, cell cycle analysis, western blotting, and a xenograft model. The expression of EGFR, a member of the receptor tyrosine kinase (RTK) family, was significantly increased in acquired regorafenib-resistant HCC cells compared with parental cells. Pharmacological inhibition of EGFR with gefitinib restored the sensitivity of regorafenib-resistant HCC cells to regorafenib. In a xenograft mouse model, gefitinib sensitized resistant tumors to regorafenib. Additionally, levels of RAS, RAF, and P-ERK1/2, components of the downstream EGFR signaling pathway, were positively associated with EGFR expression. EGFR overexpression promotes acquired resistance to regorafenib through RAS/RAF/ERK bypass activation in HCC. Inhibition of EGFR restores sensitivity to regorafenib, and the combination of gefitinib and regorafenib demonstrates significant antitumor efficacy both in vivo and in vitro. These findings suggest that this combination could be a potential strategy for patients with advanced HCC.

Integrated ubiquitomics characterization of hepatocellular carcinomas.

Patients with aggressive HCC have limited therapeutic options. Therefore, a better understanding of HCC pathogenesis is needed to improve treatment. Genomic studies of HCC have improved our understanding of cancer biology. However, the ubiquitomic characteristics of HCC remain poorly understood. We aimed to reveal the ubiquitomic characteristics of HCC and provide clinical feature biomarkers of the aggressive HCC that may be used for diagnosis or therapy in the clinic. The comprehensive proteomic, phosphoproteomic, and ubiquitomic analyses were performed on tumors and adjacent normal liver tissues from 85 patients with HCC. HCCs displayed overexpression of drugable targets CBR1-S151 and CPNE1-S55. COL4A1, LAMC1, and LAMA4 were highly expressed in the disease free survival-poor patients. Phosphoproteomic and ubiquitomic features of HCC revealed cross talk in metabolism and metastasis. Ubiquitomics predicted diverse prognosis and clarified HCC subtype-specific proteomic signatures. Expression of biomarkers TUBA1A, BHMT2, BHMT, and ACY1 exhibited differential ubiquitination levels and displayed high prognostic risk scores, suggesting that targeting these proteins or their modified forms may be beneficial for future clinical treatment. We validated that TUBA1A K370 deubiquitination drove severe HCC and labeled an aggressive subtype of HCCs. TUBA1A K370 deubiquitination was at least partly attributed to protein kinase B-mediated USP14 activation in HCC. Notably, targeting AKT-USP14-TUBA1A complex promoted TUBA1A degradation and blocked liver tumorigenesis in vivo. This study expands our knowledge of ubiquitomic signatures, biomarkers, and potential therapeutic targets in HCC.

TSC/mTORC1 mediates mTORC2/AKT1 signaling in c-MYC-induced murine hepatocarcinogenesis via centromere protein M.

Activated mTORC2/AKT signaling plays a role in hepatocellular carcinoma (HCC). Research has shown that TSC/mTORC1 and FOXO1 are distinct downstream effectors of AKT signaling in liver regeneration and metabolism. However, the mechanisms by which these pathways mediate mTORC2/AKT activation in HCC are not yet fully understood. Amplification and activation of c-MYC are key molecular events in HCC. In this study, we explored the roles of tuberous sclerosis complex/mTORC1 (TSC/mTORC1) and FOXO1 as downstream effectors of mTORC2/AKT1 in c-MYC-induced hepatocarcinogenesis. Using various genetic approaches in mice, we found that manipulating the FOXO pathway had a minimal effect on c-MYC-induced HCC. In contrast, loss of mTORC2 inhibited c-MYC-induced HCC, an effect that was completely reversed by ablation of TSC2, which activated mTORC1. Additionally, we discovered that p70/RPS6 and 4EBP1/eIF4E acted downstream of mTORC1, regulating distinct molecular pathways. Notably, the 4EBP1/eIF4E cascade is crucial for cell proliferation and glycolysis in c-MYC-induced HCC. We also identified centromere protein M (CENPM) as a downstream target of the TSC2/mTORC1 pathway in c-MYC-driven hepatocarcinogenesis, and its ablation entirely inhibited c-MYC-dependent HCC formation. Our findings demonstrate that the TSC/mTORC1/CENPM pathway, rather than the FOXO cascade, is the primary signaling pathway regulating c-MYC-driven hepatocarcinogenesis. Targeting CENPM holds therapeutic potential for treating c-MYC-driven HCC.

Development of Novel Indole-Based Covalent Inhibitors of TEAD as Potential Antiliver Cancer Agents.

Abnormal activation of the YAP transcriptional signaling pathway drives proliferation in many hepatocellular carcinoma (HCC) and hepatoblastoma (HB) cases. Current treatment options often face resistance and toxicity, highlighting the need for alternative therapies. This article reports the discovery of a hit compound C-3 from docking-based virtual screening targeting TEAD lipid binding pocket, which inhibited TEAD-mediated transcription. Optimization led to the identification of a potent and covalent inhibitor CV-4-26 that exhibited great antitumor activity in HCC and HB cell lines in vitro, xenografted human HCC, and murine HB in vivo. These outcomes signify the potential of a highly promising therapeutic candidate for addressing a subset of HCC and HB cancers. In the cases of current treatment challenges due to high upregulation of YAP-TEAD activity, these findings offer a targeted alternative for more effective interventions against liver cancer.

Research Progress on Dendritic Cells in Hepatocellular Carcinoma Immune Microenvironments.

Dendritic cells (DCs) are antigen-presenting cells that play a crucial role in initiating immune responses by cross-presenting relevant antigens to initial T cells. The activation of DCs is a crucial step in inducing anti-tumor immunity. Upon recognition and uptake of tumor antigens, activated DCs present these antigens to naive T cells, thereby stimulating T cell-mediated immune responses and enhancing their ability to attack tumors. It is particularly noted that DCs are able to cross-present foreign antigens to major histocompatibility complex class I (MHC-I) molecules, prompting CD8+ T cells to proliferate and differentiate into cytotoxic T cells. In the malignant progression of hepatocellular carcinoma (HCC), the inactivation of DCs plays an important role, and the activation of DCs is particularly important in anti-HCC immunotherapy. In this review, we summarize the mechanisms of DCs activation in HCC, the involved regulatory factors and strategies to activate DCs in HCC immunotherapy. It provides a basis for the study of HCC immunotherapy through DCs activation.

Oncogenic role of PMEPA1 and its association with immune exhaustion and TGF-β activation in HCC

Background & AimsTransforming growth factor β (TGF-β) has an oncogenic role in advanced cancer by promoting cell proliferation, metastasis and immunosuppression. PMEPA1 (prostate transmembrane protein androgen induced 1) has been shown to promote TGF-β oncogenic effects in other tumour types. Thus, we aimed to explore the role of PMEPA1 in hepatocellular carcinoma (HCC). MethodsWe analysed n=1097 tumours from HCC patients, including a discovery (n=228) and validation cohort (n=361) with genomic and clinicopathological data. PMEPA1 levels were assessed by qPCR (n=228), gene expression data (n=869) and at the single-cell level (n=54). Genetically engineered mouse models overexpressing MYC+PMEPA1 compared to MYC were generated and HCCs obtained were molecularly analysed. ResultsPMEPA1 was overexpressed in 18% of HCC samples [FC>2; n=201/1097], a feature associated with TGF-β signalling activation (p<0.05) and absence of gene body hypomethylation (p<0.01). HCCs showing both TGF-β signalling and high PMEPA1 levels (12% of cases) were linked to immune exhaustion, Late TGF-β activation, aggressiveness and higher recurrence rates after resection, in contrast to HCCs with only TGF-β signalling (8%) or PMEPA1 overexpression (9%). Single-cell RNA-sequencing analysis identified PMEPA1 expression in HCC and stromal cells. PMEPA1-expressing tumoural cells were predicted to interact with CD4+ Tregs and CD4+ CXCL13+ and CD8+ exhausted T cells. In vivo, overexpression of MYC+PMEPA1 led to HCC development in ∼60% of mice and a decreased survival compared to mice overexpressing MYC alone (p=0.014). MYC+PMEPA1 tumours were enriched in TGF-β signalling, paralleling our human data. ConclusionsIn human HCC, PMEPA1 upregulation is linked to TGF-β activation, immune exhaustion, and an aggressive phenotype. Overexpression of PMEPA1+MYC led to tumoural development in vivo, demonstrating the oncogenic role of PMEPA1 in HCC for the first time. Impact and implicationsPMEPA1 can enhance the tumour-promoting effects of TGF-β in cancer. In this study, we describe that PMEPA1 is highly expressed in ∼18% of HCC patients, a feature associated with poor prognosis, TGF-β activation and exhaustion of immune cells. Similarly, in mouse models, PMEPA1 overexpression promotes HCC development, which demonstrates its oncogenic role. The identification of PMEPA1 as oncogenic driver in HCC and its role in immune exhaustion and poor clinical outcomes enhances our understanding of HCC pathogenesis and opens new avenues for targeted therapeutic interventions.

The cumulative antitumor effects of regorafenib and radiotherapy in hepatocellular carcinoma.

Regorafenib is a second-line standard treatment for hepatocellular carcinoma (HCC). However, the efficacy of regorafenib is often limited due to drug resistance, individual differences among patients, and irrational drug use. Radiotherapy (RT) is an important method of localized HCC treatment, and combining RT with other therapies may exert a synergetic antitumor effect. Platelet-derived growth factor receptor-like (PDGFRL) is a tumor suppressor in various solid tumors. However, the function of PDGFRL in HCC is still unknown. In this study, we explored whether regorafenib and RT exert a synergetic effect on the treatment of HCC.The antitumor effect and mechanisms of the combination of regorafenib and RT were verified in a xenograft mouse model in vivo and in HCC cells in vitro.The combination treatment significantly inhibited cell proliferation and promoted apoptosis both in vitro and in vivo.PDGFRL, a potential target of regorafenib, was increased after cumulative treatment in HCC cells, and PDGFRL suppressed HCC cell proliferation and promoted apoptosis by inhibiting STAT3 pathway activation. Furthermore, the cumulative antitumor effect was dependent on the upregulated expression of PDGFRL and inhibition of STAT3 signaling pathway activation in HCC cells.This study increased the understanding of the molecular mechanism underlying the effect of regorafenib plus RT on HCC and provided a theoretical basis for the clinical practice of HCC.

Chalcomoracin promotes apoptosis and endoplasmic reticulum stress in hepatocellular carcinoma cells.

Chalcomoracin (CMR), a Diels-Alder adduct obtained from mulberry leaves, demonstrated wide-spectrum anti-cancer activity. Herein, we aimed to explore the function of CMR and how it works in hepatocellular carcinoma (HCC). Human HCC cell lines Hep3B and SNU-387 were cultured and treated with various concentrations of CMR (1.5, 3, and 6 µM). Subsequently, the effects of CMR on cell viability, colony formation, apoptosis, migration, and invasion abilities were studied in vitro. Furthermore, the levels of endoplasmic reticulum (ER) stress-related proteins and mitogen-activated protein kinase (MAPK) pathway-related proteins in cells under CMR exposure were detected using western blot. Experiments in vivo were conducted to examine the effects of CMR on tumor growth in HCC. CMR administration inhibited the viability and clonogenic, migration, and invasion abilities, as well as promoted cell apoptosis and ER stress in Hep3B and SNU-387 cells. In addition, CMR treatment reduced the phosphorylation levels of ERK, P38, and JNK in the MAPK pathway. Moreover, an in vivo study showed that CMR administration could inhibit tumorigenesis and MAPK pathway activity in HCC. Our data indicate that CMR has the potential to inhibit the development of HCC, potentially through the inhibition of the MAPK pathway. These findings suggest that CMR may have promising applications as an anticancer agent in future therapeutics for HCC.

Sorafenib and Piperine co-loaded PLGA nanoparticles: Development, characterization, and anti-cancer activity against hepatocellular carcinoma cell line

Hepatocellular carcinoma (HCC) exhibits high mortality rates in the advanced stage (>90 %). Sorafenib (SORA) is a targeted therapy approved for the treatment of advanced HCC; however, the reported response rate to such a therapeutic is suboptimal (<3%). Piperine (PIP) is an alkaloid demonstrated to exert a direct tumoricidal activity in HCC and improve the pharmacokinetic profiles of anticancer drugs including SORA. In this study, we developed a strategy to improve efficacy outcomes in HCC using PIP as an add-on treatment to support the first-line therapy SORA using biodegradable Poly (D, L-Lactide-co-glycolide, PLGA) nanoparticles (NPs). SORA and PIP (both exhibit low aqueous solubility) were co-loaded into PLGA NPs (PNPs) and stabilized with various concentrations of polyvinyl alcohol (PVA). The SORA and PIP-loaded PNPs (SP-PNPs) were characterized using Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Powder Diffraction (XRD), Dynamic Light Scattering (DLS), and Scanning Electron Microscopy (SEM), Release of these drugs from SP-PNPs was investigated in vitro at both physiological and acidic pH, and kinetic models were employed to assess the mechanism of drug release. The in vitro efficacy of SP-PNPs against HCC cells (HepG2) was also evaluated. FTIR and XRD analyses revealed that the drugs encapsulated in PNPs were in an amorphous state, with no observed chemical interactions among the drugs or excipients. Assessment of drug release in vitro at pH 5 and 7.4 showed that SORA and PIP loaded in PNPs with 0.5 % PVA were released in a sustained manner, unlike pure drugs, which exhibited relatively fast release. SP-PNPs with 0.5 % PVA were spherical, had an average size of 224 nm, and had a high encapsulation efficiency (SORA ∼ 82 %, PIP ∼ 79 %), as well as superior cytotoxicity compared to SORA monotherapy in vitro. These results suggest that combining PIP with SORA using PNPs may be an effective strategy for the treatment of HCC and may set the stage for a comprehensive in vivo study to evaluate the efficacy and safety of this novel formulation using a murine HCC model.

Activity of Tepotinib in Hepatocellular Carcinoma With High-Level MET Amplification: Preclinical and Clinical Evidence.

MET amplification (METamp) has been reported in 1%-5% of patients with hepatocellular carcinoma (HCC) and may be sensitive to MET inhibition. Tepotinib, a selective MET inhibitor, has shown promising activity in HCC with MET overexpression. We investigated the preclinical and clinical activity of tepotinib in HCC with METamp (MET gene copy number [GCN] ≥5), including high-level METamp (MET GCN ≥10). Preclinical antitumor activity of tepotinib 100 mg/kg (orally, days 1-5, every 7 days, 3-5 weeks; 3-12 replicates) was evaluated according to METamp status, as determined using the nCounter platform (NanoString), in 37 HCC patient-derived xenografts (PDXs) in immunodeficient mice. Clinical outcomes were evaluated in patients with METamp by fluorescence in situ hybridization who received tepotinib 500 mg (450 mg active moiety) in two phase Ib/II trials in HCC with MET overexpression. Across the PDX models, tepotinib induced complete or near-complete tumor regression in the only two models with high-level METamp. Median tumor volume reductions were 100% and 99.8% in models with MET GCN 47.1 and 44.0, respectively. Across the two clinical trials, 15/121 patients had METamp. Disease control was achieved by 11/15 patients with METamp (complete response [CR], n = 1; partial response [PR], n = 4; stable disease [SD], n = 6) and 4/4 with high-level METamp (CR, n = 1; PR, n = 2; SD, n = 1). All three patients with high-level METamp and objective response received treatment for >1 year, including one patient who received first-line tepotinib for >6 years. High-level METamp may be an oncogenic driver in HCC that is sensitive to MET inhibitors such as tepotinib.

USP35 promotes HCC development by stabilizing ABHD17C and activating the PI3K/AKT signaling pathway

S-palmitoylation is a reversible protein lipidation that controls the subcellular localization and function of targeted proteins, including oncogenes such as N-RAS. The depalmitoylation enzyme family ABHD17s can remove the S-palmitoylation from N-RAS to facilitate cancer development. We previously showed that ABHD17C has oncogenic roles in hepatocellular carcinoma (HCC) cells, and its mRNA stability is controlled by miR-145-5p. However, it is still unclear whether ABHD17C is regulated at the post-translational level. In the present study, we identified multiple ubiquitin-specific proteases (USPs) that can stabilize ABHD17C by inhibiting the ubiquitin-proteasome-mediated degradation. Among them, USP35 is the most potent stabilizer of ABHD17C. We found a positive correlation between the elevated expression levels of USP35 and ABHD17C, together with their association with increased PI3K/AKT pathway activity in HCCs. USP35 knockdown caused decreased ABHD17C protein level, impaired PI3K/AKT pathway, reduced proliferation, cell cycle arrest, increased apoptosis, and mitigated migration and invasion. USP35 can interact with and stabilize ABHD17C by inhibiting its ubiquitination. Overexpression of ABHD17C can rescue the defects caused by USP35 knockdown in HCC cells. In support of these in vitro observations, xenograft assay data also showed that USP35 deficiency repressed HCC development in vivo, characterized by reduced proliferation and disrupted PI3K/AKT signaling. Together, these findings demonstrate that USP35 may promote HCC development by stabilization of ABHD17C and activation of the PI3K/AKT pathway.

RETRACTED ARTICLE: Investigating EGFR-VEGF-mediated apoptotic effect of cucurbitacin D and I combination with sorafenib via Ras/Raf/MEK/ERK and PI3K/Akt signaling pathways.

Sorafenib, which is a type of systemic multi-kinase inhibitor drug, is used for first-line therapy in treating hepatocellular carcinoma (HCC). In this study, the anticarcinogenic effects of sorafenib-cucurbitacin D and sorafenib-cucurbitacin I combination on HepG2 cell line were investigated. Cell inhibition, migration, apoptosis, cell cycle distribution, mitochondrial membrane potential (ΔΨm), colony formation, and wound healing were investigated by applying cucurbitacin D and I alone or in combination with sorafenib to HepG2 cells. In addition, in order to reveal how cucurbitacins affect the signal pathways known to affect sorafenib; proteins and genes involved in VEGF, EGFR, MMP-2, caspase cascade, PI3K/AKT/mTOR, Raf/MEK/ERK signaling pathways were assessed by western blot and qRT-PCR. It has been shown that cucurbitacin D and I have an antiproliferative effect at low concentrations and show a synergistic effect when combined with sorafenib. Combined administrations induced apoptosis by increasing caspase-9, Bax activity and inhibiting Bcl-xL activation, blocking the cell cycle in G2/M phase and causing loss of ΔΨm. The combinations also suppressed MMP-2 and VEGF, reduced cell migration. The combined cucurbitacin-sorafenib applications inhibited the expression of proteins and genes involved in EGFR and PI3K/AKT/mTOR, Raf/MEK/ERK signaling pathways. Due to showing the synergetic effect of cucurbitacins with sorafenib and their targeting of similar signaling pathways reveal that their combination may increase the efficacy of sorafenib by suppressing angiogenic, metastatic and proliferative activity in HCC.

The deubiquitinating enzyme USP19 facilitates hepatocellular carcinoma progression through stabilizing YAP

Hippo pathway plays a crucial role in the progression of hepatocellular carcinoma (HCC), and yes-associated protein (YAP) is one of the major factors of the Hippo pathway. However, the mechanism of abnormal YAP activation in HCC has not been well elucidated. Here, we screened a Deubiquitinating enzymes’ (DUB) siRNA library targeting DUBs, and identified Ubiquitin Specific Peptidase 19 (USP19) as a specific deubiquitinating enzyme of YAP in HCC, which could stabilize YAP at K76 and K90 sites via removing the K48- and K11-linked ubiquitin chains. USP19 knockdown decreased the expression of YAP protein and its target gene (CTGF, CYR61, ANKRD1) expression. Through substantial in vivo and in vitro experiments, we prove that USP19 facilities the proliferation and migration of HCC. More importantly, we found that USP19 was upregulated in HCC tissues and associated with poor prognosis. In general, our research revealed a novel post-translational mechanism between USP19 and YAP in HCC, suggesting that USP19 may be a pivotal therapeutic target for HCC treatment.

Lactosylated Chitosan Nanoparticles Potentiate the Anticancer Effects of Telmisartan In Vitro and in a N-Nitrosodiethylamine-Induced Mice Model of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related mortality worldwide. Telmisartan (TLM), a BSC class II drug, has been reported to have antiproliferative activity in HCC. However, its therapeutic activity is limited by poor bioavailability and unpredictable distribution. This work aimed to enhance TLM's liver uptake for HCC management through passive and active targeting pathways utilizing chitosan nanoparticles decorated with lactose (LCH NPs) as a delivery system. In vitro cell cytotoxicity and cellular uptake studies indicated that TLM-LCH NPs significantly (p < 0.05) enhanced the antiproliferative activity and cellular uptake percentage of TLM. In vivo bioavailability and liver biodistribution studies indicated that TLM-LCH NPs significantly (p < 0.05) enhanced TLM concentrations in plasma and the liver. The relative liver uptake of TLM from TLM-LCH NPs was 2-fold higher than that of unmodified NPs and 5-fold higher than that of plain TLM suspension. In vivo studies of a N-nitrosodiethylamine-induced HCC model revealed that administration of TLM through LCH NPs improved liver histology and resulted in lower serum alpha-fetoprotein (AFP), matrix metalloproteinase 2 (MMP-2), vascular endothelial growth factor (VEGF) levels, and liver weight index compared to plain TLM and TLM-loaded unmodified NPs. These results reflected the high potentiality of LCH NPs as a liver-targeted delivery system for TLM in the treatment of HCC.

Physalin A Induces Apoptosis and Autophagy in Hepatocellular Carcinoma via Inhibition of PI3K/Akt Signaling Pathway.

Physalin A (PA) is a bioactive withanolide with multiple pharmacological properties and has been indicated to be cytotoxic to hepatocellular carcinoma (HCC) cell line HepG2. This study aims to explore the mechanisms underlying PA antitumor activity in HCC. HepG2 cells were exposed to various concentrations of PA. Cell counting kit-8 assay and flow cytometry were implemented for evaluating cell viability and apoptosis, respectively. Immunofluorescence staining was utilized for detecting autophagic protein LC3. Western blotting was employed for measuring levels of autophagy-, apoptosis- and phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signaling-related proteins. A xenograft mouse model was established to verify the antitumor activity of PA in vivo. PA impaired HepG2 cell viability, and triggered apoptosis as well as autophagy. Inhibiting autophagy augmented PA-evoked HepG2 cell apoptosis. PA repressed PI3K/Akt signaling in HCC cells and activating PI3K/Akt reversed PA-triggered apoptosis and autophagy. PA treatment inhibited tumor growth in tumor-bearing mice. PA triggers HCC cell apoptosis and autophagy by inactivating PI3K/Akt signaling.

Phase II study on safety and efficacy of NMS-01940153E, an MPS1 inhibitor with first-in-class potential, in adult patients with unresectable hepatocellular carcinoma (HCC) previously treated with systemic therapy.

TPS4185 Background: Monopolar Spindle 1 (MPS1) kinase regulates the spindle assembly checkpoint (SAC) which ensures proper division of chromosomes during mitosis. MPS1 is overexpressed in several tumors, including hepatocellular carcinoma (HCC), where it correlates with tumor features and poor overall and disease-free survival. NMS-01940153E is a novel, highly potent and selective small molecule inhibitor of MPS1 kinase with long residence time and strong preclinical anti-tumor activity in different tumor types. In HCC lines, specifically, NMS-01940153E showed ~2-Log higher anti-proliferative activity compared to sorafenib, lenvatinib, and regorafenib. In a previous open-label first-in-human (FIH) study, CL1-81694-001 (EudraCT 2014-002023-10), signs of activity in HCC were detected. Recently, the treatment paradigm for advanced HCC has changed, with immunotherapy combinations in first line and TKIs shifted in later lines. However, the overall prognosis of patients with advanced HCC remains poor, and there is a strong need of new drugs in this setting. NMS-01940153E novel mechanism of action, inhibiting the SAC and interfering with genomic stability in HCC, may offer a new therapeutic option in HCC. Based on the promising FIH results, a Phase I/II study, MPSA-153-001 (EudraCT 2020-001002-26), was initiated in patients with HCC previously treated with more than one systemic therapy. Methods: The Phase II part of the MPSA-293-001 trial is designed as a two-stage study with an interim analysis for futility and safety rules for unacceptable toxicity. The primary objective is to assess the antitumor activity of NMS-01940153E in adult patients with unresectable HCC previously treated with systemic therapy measured as objective response rate (ORR) by investigator-assessed RECIST 1.1. Secondary endpoints are safety, PK, ORR as measured by investigator-assessed mRECIST, DoR, PFS and OS. Exploratory endpoints include biomarkers. NMS-01940153E is administered IV, on days 1, 8 and 15 every 4 weeks at the RP2D of 100 mg/m2/wk, which showed PK in a predicted active range. Key eligibility criteria are 1) diagnosis of HCC; 2) disease progression on standard-of-care treatment including an immune checkpoint inhibitor as first line and at least one TKI; 3) no more than 3 prior systemic treatment lines. Interim evaluation for futility will be undertaken as soon as the first 10 evaluable patients will be enrolled. If at least 1 responder is observed with no safety issues, enrollment will proceed up to 38 evaluable patients. Otherwise, the study will be terminated for futility. An independent DSMB will review the interim results and provide recommendation on the study progress. Recruitment is currently ongoing in Italy and Spain and an FDA “Study May Proceed Notification” was received in January 2023. Clinical trial information: NCT05630937 .

RAD51 Inhibition Shows Antitumor Activity in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC), the major type of liver cancer, causes a high annual mortality worldwide. RAD51 is the critical recombinase responsible for homologous recombination (HR) repair in DNA damage. In this study, we identified that RAD51 was upregulated in HCC and that RAD51 silencing or inhibition reduced the proliferation, migration, and invasion of HCC cells and enhanced cell apoptosis and DNA damage. HCC cells with the combinatorial treatments of RAD51 siRNA or inhibitor and sorafenib demonstrated a synergistic effect in inhibiting HCC cell proliferation, migration, and invasion, as well as inducing cell apoptosis and DNA damage. Single RAD51 silencing or sorafenib reduced RAD51 protein expression and weakened HR efficiency, and their combination almost eliminated RAD51 protein expression and inhibited HR efficiency further. An in vivo tumor model confirmed the RAD51 inhibitor's antitumor activity and synergistic antitumor activity with sorafenib in HCC. RNA-Seq and gene set enrichment analysis (GSEA) in RAD51-inactivated Huh7 cells indicated that RAD51 knockdown upregulated cell apoptosis and G1/S DNA damage checkpoint pathways while downregulating mitotic spindle and homologous recombination pathways. Our findings suggest that RAD51 inhibition exhibits antitumor activities in HCC and synergizes with sorafenib. Targeting RAD51 may provide a novel therapeutic approach in HCC.

Role of β-Catenin Activation in the Tumor Immune Microenvironment and Immunotherapy of Hepatocellular Carcinoma

Recently, the therapeutic combination of atezolizumab and bevacizumab was widely used to treat advanced hepatocellular carcinoma (HCC). According to recent clinical trials, immune checkpoint inhibitors (ICIs) and molecular target agents are expected to be key therapeutic strategies in the future. Nonetheless, the mechanisms underlying molecular immune responses and immune evasion remain unclear. The tumor immune microenvironment plays a vital role in HCC progression. The infiltration of CD8-positive cells into tumors and the expression of immune checkpoint molecules are key factors in this immune microenvironment. Specifically, Wnt/β catenin pathway activation causes “immune exclusion”, associated with poor infiltration of CD8-positive cells. Some clinical studies suggested an association between ICI resistance and β-catenin activation in HCC. Additionally, several subclassifications of the tumor immune microenvironment were proposed. The HCC immune microenvironment can be broadly divided into inflamed class and non-inflamed class, with several subclasses. β-catenin mutations are important factors in immune subclasses; this may be useful when considering therapeutic strategies as β-catenin activation may serve as a biomarker for ICI. Various types of β-catenin modulators were developed. Several kinases may also be involved in the β-catenin pathway. Therefore, combinations of β-catenin modulators, kinase inhibitors, and ICIs may exert synergistic effects.

Abstract 1489: Overexpression of ribosomal L22-like1 (RPL22L1) enhances cancer stem cell properties and promotes tumor progression in hepatocellular carcinoma (HCC)

Abstract The abnormality of ribosomal biogenesis is found to be involved in carcinogenesis and progression in various types of cancer. RPL22L1 gene is a highly homologous paralog of RPL22, both of which belong to the L22E family of ribosomal proteins and take part in encoding a cytoplasmic ribosomal protein that is a component of the 60S subunit of ribosomes. Our previous work has established a CRISPR/Cas9 genome-wide knockout screening profile and developed a two-component mixture model to identify cancer-specific essential genes in 436 cancer cell lines. Bioinformatics analysis reveals that RPL22L1 acts as a feature gene to predict cancer-specific essential genes in human cancer. Previous studies suggest that RPL22L1 is correlated with tumor progression and adverse prognosis in several cancer types, while its role in hepatocellular carcinoma (HCC) is unknown. In the present study, we found that RPL22L1 is highly expressed in embryonic stem cells (ES) and liver progenitor cells, which were acquired from a vitro hepatic differentiation model originating from ES cells. Hence, we hypothesized that RPL22L1 enhances cancer stem cell properties in HCC. Functional assays showed that RPL22L1 would promote sphere formation in vitro. qRT-PCR and Western Blotting results indicated that RPL22L1 could promote stemness-related gene expressions such as CD133, CD44, and SOX9 in HCC cell lines. Overexpression of RPL22L1 increased aldehyde dehydrogenase (ALDH) activity, which was decreased when RPL22L1 was silenced with short hairpin RNA (shRNA). Extreme limiting dilution assay showed that RPL22L1 overexpression stimulated self-renewal ability in immunodeficient mice. Furthermore, higher RPL22L1 expression can also promote cell proliferation and epithelial-mesenchymal-transition, as well as drug resistance to 5-Fluorouracil (5-FU) and cisplatin (CDDP). Silver nitrate staining demonstrated that RPL22L1 overexpression correlated with a larger size and number of nucleoli. The expression of RPL22L1 was also associated with adverse prognosis in HCC clinical samples. In conclusion, our study reveals aberrant ribosomal protein activity in HCC and the role of RPL22L1 in promoting HCC tumor progression. Citation Format: JinLin Huang, Zhenyang Guo, Jie Luo, Beilei Liu, Lanqi Gong, Xiaona Fang, Dora Lai-wan Kwong, Xinyuan Guan. Overexpression of ribosomal L22-like1 (RPL22L1) enhances cancer stem cell properties and promotes tumor progression in hepatocellular carcinoma (HCC) [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 1489.

Anticancer Effects of Antidepressants in Hepatocellular Carcinoma Cells.

An epidemiological investigation indicated that tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) were associated with a lower risk of hepatocellular carcinoma (HCC). Another previous study showed that seven antidepressants inhibited glucocorticoid receptor (GR)-mediated gene transcription, a pathway that is linked to various diseases, including cancer. It is known that the expression levels of GR in cancerous tissues are higher than those in noncancerous tissues in patients with HCC. Notably, among the seven antidepressants, amitriptyline (TCA), desipramine (TCA), and fluoxetine (SSRI) were found to induce apoptosis in HCC cells. Given this, we investigated whether four other GR-specific antidepressants, including mianserin (atypical antidepressant), tianeptine (atypical antidepressant), imipramine (TCA), and moclobemide (monoamine oxidase inhibitor, MAOI) affect the cell viability of HCC. Cell proliferation and IC50 curves were determined by MTT assays. Imipramine and mianserin significantly inhibited HCC cell viability, whereas moclobemide and tianeptine did not. IC50 showed that the same dose of imipramine or mianserin led to significant inhibitory effects on HCC cells whereas there were only slight effects on normal human hepatocytes (HH). According to previous and present findings, TCAs, SSRIs and mianserin may have anti-tumor activity in HCC. However, the appropriate dose, frequency, and route of the administration still need to be determined in future preclinical and clinical studies.