The mTORC2-Akt1 Cascade Is Crucial for c-Myc to Promote Hepatocarcinogenesis in Mice and Humans

High-fat diet promotes liver tumorigenesis via palmitoylation and activation of AKT

OBJECTIVE

Whether and how the PI3K-AKT pathway, a central node of metabolic homeostasis, is responsible for high-fat-induced non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) remain a mystery. Characterisation of AKT regulation in this setting will provide new strategies to combat HCC.

DESIGN

Metabolite library screening disclosed that palmitic acid (PA) could activate AKT. In vivo and in vitro palmitoylation assay were employed to detect AKT palmitoylation. Diverse cell and mouse models, including generation of AKT1C77S and AKT1C224S knock-in cells, Zdhhc17 and Zdhhc24 knockout mice and Akt1C224S knock-in mice were employed. Human liver tissues from patients with NASH and HCC, hydrodynamic transfection mouse model, high-fat/high-cholesterol diet (HFHCD)-induced NASH/HCC mouse model and high-fat and methionine/choline-deficient diet (HFMCD)-induced NASH mouse model were also further explored for our mechanism studies.

RESULTS

By screening a metabolite library, PA has been defined to activate AKT by promoting its palmitoyl modification, an essential step for growth factor-induced AKT activation. Biologically, a high-fat diet could promote AKT kinase activity, thereby promoting NASH and liver cancer. Mechanistically, palmitoyl binding anchors AKT to the cell membrane in a PIP3-independent manner, in part by preventing AKT from assembling into an inactive polymer. The palmitoyltransferases ZDHHC17/24 were characterised to palmitoylate AKT to exert oncogenic effects. Interestingly, the anti-obesity drug orlistat or specific penetrating peptides can effectively attenuate AKT palmitoylation and activation by restricting PA synthesis or repressing AKT modification, respectively, thereby antagonising liver tumorigenesis.

CONCLUSIONS

Our findings elucidate a novel fine-tuned regulation of AKT by PA-ZDHHC17/24-mediated palmitoylation, and highlight tumour therapeutic strategies by taking PA-restricted diets, limiting PA synthesis, or directly targeting AKT palmitoylation.

Non-coding RNA mediated regulation of PI3K/Akt pathway in hepatocellular carcinoma: Therapeutic perspectives

Hepatocellular carcinoma (HCC) is among the primary reasons for fatalities caused by cancer globally, highlighting the need for comprehensive knowledge of its molecular aetiology to develop successful treatment approaches. The PI3K/Akt system is essential in the course of HCC, rendering it an intriguing candidate for treatment. Non-coding RNAs (ncRNAs), such as long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are important mediators of the PI3K/Akt network in HCC. The article delves into the complex regulatory functions of ncRNAs in influencing the PI3K/Akt system in HCC. The study explores how lncRNAs, miRNAs, and circRNAs impact the expression as well as the function of the PI3K/Akt network, either supporting or preventing HCC growth. Additionally, treatment strategies focusing on ncRNAs in HCC are examined, such as antisense oligonucleotide-based methods, RNA interference, and small molecule inhibitor technologies. Emphasizing the necessity of ensuring safety and effectiveness in clinical settings, limitations, and future approaches in using ncRNAs as therapies for HCC are underlined. The present study offers useful insights into the complex regulation system of ncRNAs and the PI3K/Akt cascade in HCC, suggesting possible opportunities for developing innovative treatment approaches to address this lethal tumor.

Network pharmacology prediction and experiment validation of anti-liver cancer activity of Curcumae Rhizoma and Hedyotis diffusa Willd

Objective

This study aims to elucidate anti-liver cancer components and potential mechanisms of Curcumae Rhizoma and Hedyotis diffusa Willd (CR-HDW).

Methods

Effective components and targets of CR-HDW were identified from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. Liver cancer-related genes were collected from GeneCards, Gene-Disease Association (DisGeNET), and National Center for Biotechnology Information (NCBI). Protein-protein interaction networks, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were conducted to analyze the identified genes. Molecular docking was used to simulate binding of the active components and their target proteins. Cell activity assay, western blot, and senescence-associated β-galactosidase (SA-β-gal) experiments were conducted to validate core targets identified from molecular docking.

Results

Ten active compounds of CR-HDW were identified including quercetin, 3-epioleanic acid and hederagenin. The primary core proteins comprised Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Protein Kinase B(AKT1), etc. The pathways for Phosphoinositide 3-kinase (PI3K)/ AKT, cellular senescence, Fork head boxO (FOXO) were revealed as important for anti-cancer activity of CR-HDW. Molecular docking demonstrated strong binding between liver cancer target proteins and major active components of CR-HDW. In-vitro experiments confirmed that hederagenin and 3-epioleolic acid inhibited HuH-7 cell growth, reduced expression of PI3K, AKT, and mechanistic target of rapamycin (mTOR) proteins. Hederagenin also induced HuH-7 senescence.

Conclusions

In summary, The authors' results suggest that the CR-HDW component (Hederagenin, 3-epoxy-olanolic acid) can inhibit the proliferation of HuH-7 cells by decreasing PI3K, AKT, and mTOR. Hederagenin also induced HuH-7 senescence.

Integrated analyses for identification of a three-gene signature associated with Chaihu Shugan San formula for hepatocellular carcinoma treatment

Chaihu Shugan San (CSS) is a well-known traditional herbal formula that has the potential to ameliorate hepatocellular carcinoma (HCC); however, its mechanism of action remains unknown. Here, we identified the key targets of CSS against HCC and developed a prognostic model to predict the survival of patients with HCC. The effect of CSS plus sorafenib on HCC cell proliferation was evaluated using the MTT assay. LASSO-Cox regression was used to establish a three-gene signature model targeting CSS. Correlations between immune cells, immune checkpoints and risk score were determined to evaluate the immune-related effects of CSS. The interactions between the components and targets were validated using molecular docking and Surface Plasmon Resonance (SPR) assays. CSS and sorafenib synergistically inhibited HCC cell proliferation. Ten core compounds and 224 targets were identified using a drug compound-target network. The prognostic model of the three CSS targets (AKT1, MAPK3 and CASP3) showed predictive ability. Risk scores positively correlated with cancer-promoting immune cells and high expression of immune checkpoint proteins. Molecular docking and SPR analyses confirmed the strong binding affinities of the active components and the target genes. Western blot analysis confirmed the synergistic effect of CSS and sorafenib in inhibiting the expression of these three targets. In conclusion, CSS may regulate the activity of immune-related factors in the tumour microenvironment, reverse immune escape, enhance immune responses through AKT1, MAPK3, and CASP3, and synergistically alleviate HCC. The co-administration of sorafenib with CSS has a strong clinical outlook against HCC.

Hepatoprotective Effect Assessment of C-Phycocyanin on Hepatocellular Carcinoma Rat Model by Using Photoacoustic Spectroscopy

Hepatocellular carcinoma (HCC) is the most common primary neoplasia of the liver with elevated mortality. Experimental treatment with antioxidants has a beneficial effect on the experimental models of HCC. Arthrospira maxima (spirulina) and its phycocyanin have antitumoral action on different tumoral cells. However, it is unknown whether phycocyanin is the responsible molecule for the antitumoral effect on HCC. Photoacoustic spectroscopy (PAS) stands out among other spectroscopy techniques for its versatility of samples analyzed. This technique makes it possible to obtain the optical absorption spectrum of solid or liquid, dark or transparent samples. Previous studies report that assessing liver damage in rats produced by the modified resistant hepatocyte model (MRHM) is possible by analyzing their blood optical absorption spectrum. This study aimed to investigate, by PAS, the effect of phycocyanin obtained from spirulina on hepatic dysfunction. The optical absorption spectra analysis of the rat blood indicates the damage level induced by the MRHM group, being in concordance with the carried out biological conventional studies results, indicating an increase in the activity of hepatic enzymes, oxidative stress, Bax/Bcl2 ratio, cdk2, and AKT2 expression results, with a reduction in p53 expression. Also, PAS results suggest that phycocyanin decreases induced damage, due to the prevention of the Bax, AKT2, and p53 altered expression and the tumor progression in a HCC rat model.

Hijacking and rewiring of host CircRNA/miRNA/mRNA competitive endogenous RNA (ceRNA) regulatory networks by oncoviruses during development of viral cancers

A significant portion of human cancers are caused by oncoviruses (12%-25%). Oncoviruses employ various strategies to promote their replication and induce tumourigenesis in host cells, one of which involves modifying the gene expression patterns of the host cells, leading to the rewiring of genes and resulting in significant changes in cellular processes and signalling pathways. In recent studies, a specific mode of gene regulation known as circular RNA (circRNA)-mediated competing endogenous RNA (ceRNA) networks has emerged as a key player in this context. CircRNAs, a class of non-coding RNA molecules, can interact with other RNA molecules, such as mRNAs and microRNAs (miRNAs), through a process known as ceRNA crosstalk. This interaction occurs when circRNAs, acting as sponges, sequester miRNAs, thereby preventing them from binding to their target mRNAs and modulating their expression. By rewiring the host cell genome, oncoviruses have the ability to manipulate the expression and activity of circRNAs, thereby influencing the ceRNA networks that can profoundly impact cellular processes such as cell proliferation, differentiation, apoptosis, and immune responses. This review focuses on a comprehensive evaluation of the latest findings on the involvement of virus-induced reprogramming of host circRNA-mediated ceRNA networks in the development and pathophysiology of human viral cancers, including cervical cancer, gastric cancer, nasopharyngeal carcinoma, Kaposi's sarcoma, hepatocellular carcinoma, and diffuse large B cell lymphoma. Understanding these mechanisms can improve our knowledge of how oncoviruses contribute to human tumourigenesis and identify potential targets for developing optimised therapies and diagnostic tools for viral cancers.

Roles of Rictor alterations in gastrointestinal tumors (Review)

Gastrointestinal tumors account for five of the top 10 causes of mortality from all cancers (colorectal, liver, stomach, esophageal and pancreatic cancer). Mammalian target of rapamycin (mTOR) signaling is commonly dysregulated in various human cancers. As a core component of the mTOR complex 2 (mTORC2), Rictor is a key effector molecule of the PI3K/Akt pathway. A high alteration rate of Rictor has been observed in gastrointestinal tumors, and such Rictor alterations are often associated with resistance to chemotherapy and related adverse clinical outcomes. However, the exact roles of Rictor in gastrointestinal tumors remain elusive. The aim of the present study was to critically discuss the following: i) Mutation and biological characteristics of Rictor in tumors with a detailed overview of Rictor in cell proliferation, angiogenesis, apoptosis, autophagy and drug resistance; ii) the role of Rictor in tumors of the digestive system, particularly colorectal, hepatobiliary, gastric, esophageal and pancreatic cancer and cholangiocarcinoma; and iii) the current status and prospects of targeted therapy for Rictor by inhibiting Akt activation. Despite the growing realization of the importance of Rictor/mTORC2 in cancer, the underlying mechanistic details remain poorly understood; this needs to change in order for the development of efficient targeted therapies and re‑sensitization of therapy‑resistant cancers to be made possible.

MASLD and the Development of HCC: Pathogenesis and Therapeutic Challenges

Metabolic-dysfunction-associated steatotic liver disease (MASLD, previously known as non-alcoholic fatty liver disease (NAFLD)) represents a rapidly increasing cause of chronic liver disease and hepatocellular carcinoma (HCC), mirroring increasing rates of obesity and metabolic syndrome in the Western world. MASLD-HCC can develop at an earlier stage of fibrosis compared to other causes of chronic liver disease, presenting challenges in how to risk-stratify patients to set up effective screening programmes. Therapeutic decision making for MASLD-HCC is also complicated by medical comorbidities and disease presentation at a later stage. The response to treatment, particularly immune checkpoint inhibitors, may vary by the aetiology of the disease, and, in the future, patient stratification will be key to optimizing the therapeutic pathways.

Clinicopathological Characteristics, Prognosis, and Correlated Tumor Cell Function of Tropomodulin-3 in Pancreatic Adenocarcinoma

BACKGROUND

Pancreatic adenocarcinoma (PAAD) is a frequent malignant tumor with a high mortality rate. Searching for novel biomarkers that can influence its prognosis may help patients. It has been shown that tropomodulin-3 (TMOD3) may influence tumor progression, but its role in pancreatic cancer is not clear. We aimed to explore the expression and prognostic value of TMOD3 in PAAD.

METHODS

We used bioinformatics analysis to analyze the relationship between TMOD3 expression and clinicopathological features and prognosis and verified it with clinical data from tissue microarray. We also conducted in vitro cell experiments to explore the effects of TMOD3 on the function of PAAD cells.

RESULTS

TMOD3 expression was found to be significantly higher in PAAD tissues than in matched paracancerous tissues (P < 0.05). Meanwhile, high TMOD3 expression was associated with significantly poorer overall survival (P < 0.05). Analysis of relevant clinicopathological characteristics data obtained from TCGA showed that high TMOD3 expression correlated with age, TNM stage, N stage, and M stage (P < 0.05). Analysis of correlation data obtained from tissue microarrays showed that high TMOD3 expression was associated with lymph node invasion, nerve invasion, macrovascular invasion, and TNM stage (P < 0.05). In addition, siRNA knockdown of TMOD3 significantly reduced the migration and invasion of PAAD cells.

CONCLUSION

Our study shows that TMOD3 may be associated with the progression of PAAD cells, and that it is an independent risk factor for poor pathological features and prognosis of PAAD. It may be helpful as a prognostic indicator of clinical outcomes in PAAD patients.

RBM45 reprograms lipid metabolism promoting hepatocellular carcinoma via Rictor and ACSL1/ACSL4

Reprogramming of lipid metabolism during hepatocarcinogenesis is not well elucidated. Here, we aimed to explore pivotal RNA-binding motif proteins (RBMs) in lipid metabolism and their therapeutic potential in hepatocellular carcinoma (HCC). Through bioinformatic analysis, we identified RBM45 as a critical gene of interest among differentially expressed RBMs in HCC, with significant prognostic relevance. RBM45 influenced the malignant biological phenotype and lipid metabolism of HCC cells. Mechanically, RBM45 promotes de novo lipogenesis in HCC by directly targeting two key enzymes involved in long-chain fatty acid synthesis, ACSL1 and ACSL4. RBM45 also targets Rictor, which has been demonstrated to modulate lipid metabolism profoundly. RBM45 also aided lipid degradation through activating a key fatty acid β oxidation enzyme, CPT1A. Thus, RBM45 boosted lipid synthesis and decomposition, indicating an enhanced utility of lipid fuels in HCC. Clinically, body mass index was positively correlated with RBM45 in human HCCs. The combination of a PI3K/AKT/mTOR pathway inhibitor in vitro or Sorafenib in orthotopic liver cancer mouse models with shRBM45 has a more significant therapeutic effect on liver cancer than the drug alone. In summary, our findings highlight the versatile roles of RBM45 in lipid metabolism reprogramming and its therapeutic potential in HCC. Lipids induced RBM45 expression. In turn, RBM45 promoted the utility of lipid in HCCs through accelerating both de novo lipogenesis and fatty acid β oxidation, which required the participation of Rictor, a core component of mTORC2 that has been demonstrated to modulate lipid metabolism potently, as well as ACSL1/ACSL4, two key enzymes of long-chain fatty acid synthesis. When the first-line chemotherapy drug sorafenib is combined with a PI3K/AKT/mTOR pathway inhibitor (MK2206 is an AKT inhibitor, rapamycin is a mTOR inhibitor, and inhibiting RBM45 can significantly inhibit Rictor), cell cycle, proliferation, lipid metabolism reprogramming, and hepatocarcinogenesis can be significantly inhibited, while apoptosis can be significantly enhanced.

miR-192 inhibits the activation of hepatic stellate cells by targeting Rictor

The activation of hepatic stellate cells (HSCs) is regarded as the primary driving factor of liver fibrosis. miR-192, a miRNA associated with hepatocellular carcinoma and enriched in HSCs, has an undisclosed role in HSC activation and liver fibrosis. In this study, a CCl4-induced rat liver fibrosis model and transforming growth factor-beta 1 (TGF-β1)-treated HSC lines (LX-2 and HSC-T6) were used to detect miR-192 and Rictor levels in vivo and in vitro. Bioinformatic analysis and a dual luciferase assay were used to predict and confirm the interaction of Rictor with miR-192. Gain- and/or loss-of-function methods evaluated molecular changes and HSC activation phenotypes, detected by quantitative real-time PCR, western blotting, and immunofluorescence. We observed a gradual downregulation of miR-192 and upregulation of Rictor during CCl4-induced liver fibrosis/cirrhosis in rats. Enriched miR-192 was downregulated, while Rictor was upregulated in TGF-β1-activated HSCs. miR-192 inhibited the activation of HSCs by directly targeting Rictor. High miR-192/low Rictor expression attenuated the fibrotic-related gene expression by AKT/mTORC2 signaling. In conclusion, miR-192 could inhibit the activation of HSCs by directly targeting Rictor in the AKT/mTORC2 signaling pathway. This study provides insights into potential therapeutic targets for liver fibrosis and cirrhosis.

MYC in liver cancer: mechanisms and targeted therapy opportunities

MYC, a major oncogenic transcription factor, regulates target genes involved in various pathways such as cell proliferation, metabolism and immune evasion, playing a critical role in the tumor initiation and development in multiple types of cancer. In liver cancer, MYC and its signaling pathways undergo significant changes, exerting a profound impact on liver cancer progression, including tumor proliferation, metastasis, dedifferentiation, metabolism, immune microenvironment, and resistance to comprehensive therapies. This makes MYC an appealing target, despite it being previously considered an undruggable protein. In this review, we discuss the role and mechanisms of MYC in liver physiology, chronic liver diseases, hepatocarcinogenesis, and liver cancer progression, providing a theoretical basis for targeting MYC as an ideal therapeutic target for liver cancer. We also summarize and prospect the strategies for targeting MYC, including direct and indirect approaches to abolish the oncogenic function of MYC in liver cancer.

Targeting VPS72 inhibits ACTL6A/MYC axis activity in HCC progression

BACKGROUND AND AIMS

HCC is a highly heterogeneous disease that is caused largely by genomic copy number variations. Herein, the mechanistic and therapeutically targeted role of vacuolar protein sorting 72 homologue (VPS72), a novel copy number variation cis-driven gained gene identified by genome-wide copy number variation and transcriptome analyses in HCC, is not well understood.

APPROACH AND RESULTS

First, overexpression of VPS72 enhanced the initiation and progression of HCC in vitro and in vivo . Mechanistically, VPS72 interacted with the oncoproteins MYC and actin-like 6A (ACTL6A) and promoted the formation of the ACTL6A/MYC complex. Furthermore, ACTL6A regulated VPS72 protein stability by weakening the interaction between tripartite motif containing 21 (TRIM21) and VPS72. Thus, the interaction between VPS72 and ACTL6A enhanced the affinity of MYC for its target gene promoters and promoted their transcription, thereby contributing to HCC progression, which was inhibited by adeno-associated virus serotype 8 (AAV8)-mediated short hairpin RNA (shRNA) against VPS72.

CONCLUSIONS

This study reveals the molecular mechanism of ACTL6A/VPS72/MYC in HCC, providing a theoretical basis and therapeutic target for this malignancy.

Revealing the Preventable Effects of Fu-Zheng-Qu-Xie Decoction against Recurrence and Metastasis of Postoperative Early-Stage Lung Adenocarcinoma Based on Network Pharmacology Coupled with Metabolomics Analysis

Fu-Zheng-Qu-Xie (FZQX) decoction is a traditional Chinese herbal prescription for the treatment of lung cancer and exerts proapoptotic and immunomodulatory effects. It has been clinically suggested to be effective in improving the survival of postoperative early-stage lung adenocarcinoma (LUAD), but the mechanism remains unclear. In this study, we used network pharmacology coupled with metabolomics approaches to explore the pharmacological action and effective mechanism of FZQX against the recurrence and metastasis of postoperative early-stage LUAD. Network pharmacology analysis showed that FZQX could prevent the recurrence and metastasis of postoperative early-stage LUAD by regulating a series of targets involving vascular endothelial growth factor receptor 2, estrogen receptor 1, sarcoma gene, epidermal growth factor receptor, and protein kinase B and by influencing the Ras, PI3K-Akt, and mitogen-activated protein kinase signaling pathways. In liquid chromatography-mass spectrometry analysis, 11 differentially expressed metabolites, including PA(12:0/18:4(6Z,9Z,12Z,15Z)), PC(16:0/0:0)[U], LysoPC(18:1(11Z)), and LysoPC(18:0), were discovered in the FZQX-treated group compared to those in the model group before treatment or normal group. They were enriched in cancer metabolism-related signaling pathways such as central carbon metabolism in cancer, choline metabolism, and glycerol phospholipid metabolism. Collectively, our results suggest that the multicomponent and multitarget interaction network of FZQX inhibits the recurrence and metastasis of postoperative early-stage LUAD by activating the receptor signal transduction pathway to inhibit proliferation, induce cell apoptosis, inhibit aerobic glycolysis, and reprogram tumor lipid metabolism.

Coptidis rhizoma and evodiae fructus against lipid droplet deposition in nonalcoholic fatty liver disease-related liver cancer by AKT

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. NAFLD has become one of the major factors contributing to hepatocellular carcinoma (HCC) development. However, there are no clear targets and therapeutic drugs for NAFLD-related liver cancer. This study explored the active compounds, target and mechanism of coptidis rhizoma and evodiae fructus in the treatment of NAFLD-related liver cancer based on the network pharmacology and experimental verification. There were 455 intersection targets of NAFLD-related liver cancer, and 65 drug-disease common targets. AKT1 has the highest degree, indicating that it may be a key target of coptidis rhizoma and evodiae fructus in the treatment of NAFLD-related liver cancer. The expression level of AKT1 was high in high-risk group, and the overall survival rate was lower than that in low-risk group. After oleic acid induction, p-AKT expression and lipid droplet deposition were promoted in HepG2 cells. Quercetin and resveratrol reduced lipid droplet deposition in vivo. Moreover, quercetin inhibited p-AKT expression, resveratrol both reduced the expression of p-AKT and AKT. The overall findings suggested that quercetin inhibited AKT in the treatment of NAFLD-related liver cancer.

SCARB2 drives hepatocellular carcinoma tumor initiating cells via enhanced MYC transcriptional activity

CSCs (Cancer stem cells) with distinct metabolic features are considered to cause HCC (hepatocellular carcinoma) initiation, metastasis and therapeutic resistance. Here, we perform a metabolic gene CRISPR/Cas9 knockout library screen in tumorspheres derived from HCC cells and find that deletion of SCARB2 suppresses the cancer stem cell-like properties of HCC cells. Knockout of Scarb2 in hepatocytes attenuates HCC initiation and progression in both MYC-driven and DEN (diethylnitrosamine)-induced HCC mouse models. Mechanistically, binding of SCARB2 with MYC promotes MYC acetylation by interfering with HDCA3-mediated MYC deacetylation on lysine 148 and subsequently enhances MYC transcriptional activity. Screening of a database of FDA (Food and Drug Administration)-approved drugs shows Polymyxin B displays high binding affinity for SCARB2 protein, disrupts the SCARB2-MYC interaction, decreases MYC activity, and reduces the tumor burden. Our study identifies SCARB2 as a functional driver of HCC and suggests Polymyxin B-based treatment as a targeted therapeutic option for HCC.

mTORC2 orchestrates monocytic and granulocytic lineage commitment by an ATF5-mediated pathway

Myeloid hematopoiesis is a finely controlled consecutive developmental process, which is essential to maintain peripheral innate immune homeostasis. Herein, we found that Rictor deletion caused the remarkable reduction of granulocyte-monocyte progenitors (GMPs), monocytes, and macrophages, while the levels of neutrophils were unaffected. Adoptive transfer of Rictor-deleted GMPs or common myeloid progenitors (CMPs) in syngeneic mice showed poor re-constitution of monocytes compared to wild-type GMPs or CMPs. In addition to decreasing the proliferation of CMPs/GMPs, Rictor deletion preferentially inhibited Ly6C+ monocyte differentiation, while enhancing neutrophil differentiation, as determined by colony formation assays. mTORC2 promotes monocyte development by downregulation of the AKT-Foxo4-activating transcription factor 5 (ATF5)-mitochondrial unfolded protein response (mtUPR) pathway. Genetic overexpression of ATF5 or exposure to ethidium bromide significantly rescued monocyte/macrophage differentiation defects of Rictor-deficient myeloid progenitors. Therefore, Rictor is required for CMP/GMP proliferation and acts as an important switch to balance monocytic and granulocytic lineage commitment in bone marrow.

Nucleolar HEAT Repeat Containing 1 Up-regulated by the Mechanistic Target of Rapamycin Complex 1 Signaling Promotes Hepatocellular Carcinoma Growth by Dominating Ribosome Biogenesis and Proteome Homeostasis

BACKGROUND & AIMS

Hyperactivation of ribosome biogenesis leads to hepatocyte transformation and plays pivotal roles in hepatocellular carcinoma (HCC) development. We aimed to identify critical ribosome biogenesis proteins that are overexpressed and crucial in HCC progression.

METHODS

HEAT repeat containing 1 (HEATR1) expression and clinical correlations were analyzed using The Cancer Genome Atlas and Gene Expression Omnibus databases and further evaluated by immunohistochemical analysis of an HCC tissue microarray. Gene expression was knocked down by small interfering RNA. HEATR1-knockdown cells were subjected to viability, cell cycle, and apoptosis assays and used to establish subcutaneous and orthotopic tumor models. Chromatin immunoprecipitation and quantitative polymerase chain reaction were performed to detect the association of candidate proteins with specific DNA sequences. Endogenous coimmunoprecipitation combined with mass spectrometry was used to identify protein interactions. We performed immunoblot and immunofluorescence assays to detect and localize proteins in cells. The nucleolus ultrastructure was detected by transmission electron microscopy. Click-iT (Thermo Fisher Scientific) RNA imaging and puromycin incorporation assays were used to measure nascent ribosomal RNA and protein synthesis, respectively. Proteasome activity, 20S proteasome foci formation, and protein stability were evaluated in HEATR1-knockdown HCC cells.

RESULTS

HEATR1 was the most up-regulated gene in a set of ribosome biogenesis mediators in HCC samples. High expression of HEATR1 was associated with poor survival and malignant clinicopathologic features in patients with HCC and contributed to HCC growth in vitro and in vivo. HEATR1 expression was regulated by the transcription factor specificity protein 1, which can be activated by insulin-like growth factor 1-mammalian target of rapamycin complex 1 signaling in HCC cells. HEATR1 localized predominantly in the nucleolus, bound to ribosomal DNA, and was associated with RNA polymerase I transcription/processing factors. Knockdown of HEATR1 disrupted ribosomal RNA biogenesis and impaired nascent protein synthesis, leading to reduced cytoplasmic proteasome activity and inhibitory-κB/nuclear factor-κB signaling. Moreover, HEATR1 knockdown induced nucleolar stress with increased nuclear proteasome activity and inactivation of the nucleophosmin 1-MYC axis.

CONCLUSIONS

Our study revealed that HEATR1 is up-regulated by insulin-like growth factor 1-mammalian target of rapamycin complex 1-specificity protein 1 signaling in HCC and functions as a crucial regulator of ribosome biogenesis and proteome homeostasis to promote HCC development.

The relevance of acid sphingomyelinase as a potential target for therapeutic intervention in hepatic disorders: current scenario and anticipated trends

Acid sphingomyelinase (ASMase) serves as one of the most remarkable enzymes in sphingolipid biology. ASMase facilitates the hydrolysis of sphingomyelin, yielding ceramide and phosphorylcholine via the phospholipase C signal transduction pathway. Owing to its prominent intervention in apoptosis, ASMase, and its product ceramide is now at the bleeding edge of lipid research due to the coalesced efforts of several research institutions over the past 40 years. ASMase-catalyzed ceramide synthesis profoundly alters the physiological properties of membrane structure in response to a broad range of stimulations, orchestrating signaling cascades for endoplasmic reticulum stress, autophagy, and lysosomal membrane permeabilization, which influences the development of hepatic disorders, such as steatohepatitis, hepatic fibrosis, drug-induced liver injury, and hepatocellular carcinoma. As a result, the potential to modulate the ASMase action with appropriate pharmaceutical antagonists has sparked a lot of curiosity. This article emphasizes the fundamental mechanisms of the systems that govern ASMase aberrations in various hepatic pathologies. Furthermore, we present an insight into the potential therapeutic agents used to mitigate ASMase irregularities and the paramountcy of such inhibitors in drug repurposing.

Loss of TP53 cooperates with c-MET overexpression to drive hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is a deadly malignancy with high genetic heterogeneity. TP53 mutation and c-MET activation are frequent events in human HCCs. Here, we discovered that the simultaneous mutations in TP53 and activation of c-MET occur in ~20% of human HCCs, and these patients show a poor prognosis. Importantly, we found that concomitant deletion of Trp53 and overexpression of c-MET (c-MET/sgp53) in the mouse liver led to HCC formation in vivo. Consistent with human HCCs, RNAseq showed that c-MET/sgp53 mouse HCCs were characterized by activated c-MET and Ras/MAPK cascades and increased tumor cell proliferation. Subsequently, a stably passaged cell line derived from a c-MET/sgp53 HCC and corresponding subcutaneous xenografts were generated. Also, in silico analysis suggested that the MEK inhibitor trametinib has a higher inhibition score in TP53 null human HCC cell lines, which was validated experimentally. We consistently found that trametinib effectively inhibited the growth of c-MET/sgp53 HCC cells and xenografts, supporting the possible usefulness of this drug for treating human HCCs with TP53-null mutations. Altogether, our study demonstrates that loss of TP53 cooperates with c-MET to drive hepatocarcinogenesis in vivo. The c-MET/sgp53 mouse model and derived HCC cell lines represent novel and useful preclinical tools to study hepatocarcinogenesis in the TP53 null background.

Involvement of FAM83 Family Proteins in the Development of Solid Tumors: An Update Review

FAM83 family members are a group of proteins that have been implicated in various solid tumors. In this updated review, we mainly focus on the cellular localization, molecular composition, and biological function of FAM83 family proteins in solid tumors. We discussed the factors that regulate abnormal protein expression and alterations in the functional activities of solid tumor cells (including non-coding microRNAs and protein modifiers) and potential mechanisms of tumorigenesis (including the MAPK, WNT, and TGF-β signaling pathways). Further, we highlighted the application of FAM83 family proteins in the diagnoses and treatment of different cancers, such as breast, lung, liver, and ovarian cancers from two aspects: molecular marker diagnosis and tumor drug resistance. We described the overexpression of FAM83 genes in various human malignant tumor cells and its relationship with tumor proliferation, migration, invasion, transformation, and drug resistance. Moreover, we explored the prospects and challenges of using tumor treatments based on the FAM83 proteins. Overall, we provide a theoretical basis for harnessing FAM83 family proteins as novel targets in cancer treatment. We believe that this review opens up open new directions for solid tumor treatment in clinical practice.

Cuproptosis engages in c-Myc-mediated breast cancer stemness

BACKGROUND

Intra-tumoral heterogeneity (ITH) is a distinguished hallmark of cancer, and cancer stem cells (CSCs) contribute to this malignant characteristic. Therefore, it is of great significance to investigate and even target the regulatory factors driving intra-tumoral stemness. c-Myc is a vital oncogene frequently overexpressed or amplified in various cancer types, including breast cancer. Our previous study indicated its potential association with breast cancer stem cell (BCSC) biomarkers.

METHODS

In this research, we performed immunohistochemical (IHC) staining on sixty breast cancer surgical specimens for c-Myc, CD44, CD24, CD133 and ALDH1A1. Then, we analyzed transcriptomic atlas of 1533 patients with breast cancer from public database.

RESULTS

IHC staining indicated the positive correlation between c-Myc and BCSC phenotype. Then, we used bioinformatic analysis to interrogate transcriptomics data of 1533 breast cancer specimens and identified an intriguing link among c-Myc, cancer stemness and copper-induced cell death (also known as "cuproptosis"). We screened out cuproptosis-related characteristics that predicts poor clinical outcomes and found that the pro-tumoral cuproptosis-based features were putatively enriched in MYC-targets and showed a significantly positive correlation with cancer stemness.

CONCLUSION

In addition to previous reports on its oncogenic roles, c-Myc showed significant correlation to stemness phenotype and copper-induced cell toxicity in breast cancer tissues. Moreover, transcriptomics data demonstrated that pro-tumoral cuproptosis biomarkers had putative positive association with cancer stemness. This research combined clinical samples with large-scale bioinformatic analysis, covered description and deduction, bridged classic oncogenic mechanisms to innovative opportunities, and inspired the development of copper-based nanomaterials in targeting highly heterogeneous tumors.

Combination of AFP vaccine and immune checkpoint inhibitors slows hepatocellular carcinoma progression in preclinical models

Many patients with hepatocellular carcinoma (HCC) do not respond to the first-line immune checkpoint inhibitor treatment. Immunization with effective cancer vaccines is an attractive alternative approach to immunotherapy. However, its efficacy remains insufficiently evaluated in preclinical studies. Here, we investigated HCC-associated self/tumor antigen, α-fetoprotein-based (AFP-based) vaccine immunization for treating AFP (+) HCC mouse models. We found that AFP immunization effectively induced AFP-specific CD8+ T cells in vivo. However, these CD8+ T cells expressed exhaustion markers, including PD1, LAG3, and Tim3. Furthermore, the AFP vaccine effectively prevented c-MYC/Mcl1 HCC initiation when administered before tumor formation, while it was ineffective against full-blown c-MYC/Mcl1 tumors. Similarly, anti-PD1 and anti-PD-L1 monotherapy showed no efficacy in this murine HCC model. In striking contrast, AFP immunization combined with anti-PD-L1 treatment triggered significant inhibition of HCC progression in most liver tumor nodules, while in combination with anti-PD1, it induced slower tumor progression. Mechanistically, we demonstrated that HCC-intrinsic PD-L1 expression was the primary target of anti-PD-L1 in this combination therapy. Notably, the combination therapy had a similar therapeutic effect in the cMet/β-catenin mouse HCC model. These findings suggest that combining the AFP vaccine and immune checkpoint inhibitors may be effective for AFP (+) HCC treatment.

Androgen receptor variant 7 exacerbates hepatocarcinogenesis in a c-MYC-driven mouse HCC model

Androgen receptor variant 7 (AR-V7), an AR isoform with a truncated ligand-binding domain, functions as a transcription factor in an androgen-independent manner. AR-V7 is expressed in a subpopulation of hepatocellular carcinoma (HCC), however, its role(s) in this cancer is undefined. In this study, we investigated the potential roles of AR-V7 in hepatocarcinogenesis in vivo in a c-MYC-driven mouse HCC model generated by the hydrodynamic tail-vein injection system. The impacts of AR-V7 on gene expression in mouse HCC were elucidated by RNA-seq transcriptome and ontology analyses. The results showed that AR-V7 significantly exacerbated the c-MYC-mediated oncogenesis in the livers of both sexes. The transcriptome and bioinformatics analyses revealed that AR-V7 and c-MYC synergistically altered the gene sets involved in various cancer-related biological processes, particularly in lipid and steroid/sterol metabolisms. Importantly, AR-V7 suppressed a tumor suppressor Claudin 7 expression, upregulated by c-MYC overexpression via the p53 signaling pathway. Claudin 7 overexpression significantly suppressed the c-MYC-driven HCC development under p53-deficient conditions. Our results suggest that the AR-V7 exacerbates the c-MYC-driven hepatocarcinogenesis by potentiating the oncogenic roles and minimizing the anti-oncogenic functions of c-MYC. Since AR-V7 is expressed in a subpopulation of HCC cases, it could contribute to the inter- and intra-heterogeneity of HCC.

The Role of PI3K/AKT/mTOR Signaling in Hepatocellular Carcinoma Metabolism

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths in the world. Metabolic reprogramming is considered a new hallmark of cancer, but it remains unclearly described in HCC. The dysregulation of the PI3K/AKT/mTOR signaling pathway is common in HCC and is, therefore, a topic of further research and the concern of developing a novel target for liver cancer therapy. In this review, we illustrate mechanisms by which this signaling network is accountable for regulating HCC cellular metabolism, including glucose metabolism, lipid metabolism, amino acid metabolism, pyrimidine metabolism, and oxidative metabolism, and summarize the ongoing clinical trials based on the inhibition of the PI3K/AKT/mTOR pathway in HCC.

SLC7A14 imports GABA to lysosomes and impairs hepatic insulin sensitivity via inhibiting mTORC2

Lysosomal amino acid accumulation is implicated in several diseases, but its role in insulin resistance, the central mechanism to type 2 diabetes and many metabolic diseases, is unclear. In this study, we show the hepatic expression of lysosomal membrane protein solute carrier family 7 member 14 (SLC7A14) is increased in insulin-resistant mice. The promoting effect of SLC7A14 on insulin resistance is demonstrated by loss- and gain-of-function experiments. SLC7A14 is further demonstrated as a transporter resulting in the accumulation of lysosomal γ-aminobutyric acid (GABA), which induces insulin resistance via inhibiting mTOR complex 2 (mTORC2)'s activity. These results establish a causal link between lysosomal amino acids and insulin resistance and suggest that SLC7A14 inhibition may provide a therapeutic strategy in treating insulin resistance-related and GABA-related diseases and may provide insights into the upstream mechanisms for mTORC2, the master regulator in many important processes.

Scutellaria baicalensis in the Treatment of Hepatocellular Carcinoma: Network Pharmacology Analysis and Experimental Validation

Objective

The aim of the study was to use a network pharmacological method and experimental validation to examine the mechanism of Scutellaria baicalensis (SB) against hepatocellular carcinoma (HCC).

Methods

The traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP) and GeneCards were used for screening of targets of SB for the treatment of HCC. Cytoscape (3.7.2) software was used to construct the "drug-compound-intersection target interaction" interaction network. The STING database was used to analyze the interactions of the previous intersecting targets. The results were visualized and processed by performing GO (Gene Ontology) enrichment analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) signaling pathway enrichment analysis at the target sites. The core targets were docked with the active components by AutoDockTools-1.5.6 software. We used cellular experiments to validate the bioinformatics predictions.

Results

A total of 92 chemical components and 3258 disease targets including 53 intersecting targets were discovered. The results showed that wogonin and baicalein, the main chemical components of SB, could inhibit the viability and proliferation of hepatocellular carcinoma cells, promote apoptosis through the mitochondrial apoptotic pathway, and effectively act on AKT1, RELA, and JUN targets.

Conclusion

SB has multiple components and targets in the treatment of HCC, providing possible potential targets for the treatment of HCC and providing a basis for further research.

Network analysis of liver cancer: a system biology approach

Aim

Determining critical dysregulated proteins in liver cancer was the main aim of this study.

Background

Liver cancer is a common health problem characterized by difficulties in early diagnosis and rapid progression. Due to the lack of targeted drugs and the other features of the disease, the survival rate for patients is extremely low.

Methods

The related dysregulated proteins for liver cancer were retrieved from the STRING database. The queried proteins were included in a network by Cytoscape software, and the central nodes of the network were enriched via gene ontology.

Results

Among 11 introduced central nodes (GAPDH, TP53, EGFR, MYC, INS, ALB, IL6, AKT1, VEGFA, CDH1, and HRAS), HRAS and AKT1 were highlighted as critical dysregulated proteins which can be considered as possible biomarkers.

Conclusion

Analysis revealed that AKT1, HRAS and the related biochemical pathways (especially "HIF-1 signaling pathway") are the possible diagnostic and therapeutic agents of liver cancer.

UBE2K promotes the malignant progression of hepatocellular carcinoma by regulating c-Myc

Hepatocellular carcinoma (HCC) is a serious threat to human health and life due to its high morbidity and mortality. Ubiquitin-conjugating enzymes are players in the ubiquitin proteasome system and are responsible for a great number of physiological activities in cells. The action of ubiquitin-conjugating enzyme UBE2K in HCC has not been reported. Therefore, we studied the function and role of UBE2K in the malignant progression of HCC. An analysis of UBE2K expression in HCC cells was performed using RT-qPCR and protein immunoblotting. CCK-8, Transwell and sphere formation assays were used to identify the potential effects of UBE2K in HCC cell proliferation, migration and stemness property. RT-qPCR, and protein immunoblotting experiments was taken to explore the regulation between UBE2K and c-Myc. Here, we discovered that UBE2K expression was elevated in HCC cells, and elevated UBE2K predicts worse prognosis for HCC patients. Functionally, UBE2K promote, while UBE2K knockdown suppressed cell proliferation, migration and stemness property of HCC cells. Furthermore, c-Myc was identified as a downstream target of UBE2K. Moreover, functional rescue experiments finally proved that UBE2K facilitates the malignant progression of HCC cells by upregulating c-Myc. We clarified through in vivo experiments that UBE2K expression promotes tumor growth in HCC. Taken together, our study results proved the molecular regulation of UBE2K and c-Myc in HCC and the oncogenic role of UBE2K/c-Myc axis in HCC progression, thus it provides a promising molecular target for the diagnosis and treatment of HCC.

Desmoplastic Adamantinoma-like Thymic Carcinoma: Clinicopathologic, Immunohistochemical, and Molecular Study of 5 Cases

Five cases of a heretofore unreported rare variant of thymic carcinoma characterized by a striking resemblance to adamantinoma of the mandible are described. The tumors occurred in 4 women and 1 man aged 58 to 76 years (mean: 67.8 y); they arose in the anterior mediastinum and measured from 5.3 to 12.0 cm in greatest diameter (mean: 8.9 cm). Presenting symptoms included chest pain, shortness of breath, and in 2 patients, pleural effusion. One tumor was asymptomatic and discovered incidentally. Histologically, the tumors were extensively desmoplastic, and the cellular proliferation was characterized by multiple islands of squamous epithelium with striking peripheral palisading of nuclei and central areas containing clear cells resembling a stellate reticulum. Areas of preexisting spindle cell thymoma were identified in 2 cases; these areas gradually merged with the higher-grade component of the lesion. Cystic changes were noted in 3 cases. Immunohistochemical studies in 3 cases showed the tumor cells were positive for cytokeratins, p40 and p63, and all showed a high proliferation rate (>50% nuclear positivity) with Ki-67. Next-generation sequencing was performed in 2 cases that showed amplification of the AKT1 gene (copy numbers 6 and 13). Clinical follow-up in 3 patients showed recurrence and metastasis after 1 and 2 years; 1 patient passed away 2 years after diagnosis due to the tumor. Desmoplastic adamantinoma-like thymic carcinoma represents an unusual histologic variant of thymic carcinoma that needs to be distinguished from metastases from similar tumors to the mediastinum.

NK cell immunometabolism as target for liver cancer therapy

Natural killer (NK) cells are being used effectively as a potential candidate in tumor immunotherapy. However, the migration and transport of NK cells to solid tumors is inadequate. NK cell dysfunction, tumor invasiveness, and metastasis are associated with altered metabolism of NK cells in the liver cancer microenvironment. However, in liver cancers, metabolic impairment of NK cells is still not understood fully. Evidence from various sources has shown that the interaction of NK cell's immune checkpoints with its metabolic checkpoints is responsible for the regulation of the development and function of these cells. How immune checkpoints contribute to metabolic programming is still not fully understood, and how this can be beneficial needs a better understanding, but they are emerging to be incredibly compelling to rebuilding the function of NK cells in the tumor. It is expected to represent a potential aim that focuses on improving the efficacy of therapies based on NK cells for treating liver cancer. Here, the recent advancements made to understand the NK cell's metabolic reprogramming in liver cancer have been summarized, along with the possible interplay between the immune and the metabolic checkpoints in NK cell function. Finally, an overview of some potential metabolic-related targets that can be used for liver cancer therapy treatment has been presented.

MYC Promotes LDHA Expression through MicroRNA-122-5p to Potentiate Glycolysis in Hepatocellular Carcinoma

MYC is a notorious oncogene in a vast network of malignancies, whereas liver-specific microRNA- (miR-) 122-5p is downregulated in hepatocellular cancer (HCC). Here, we studied the possible correlation between these two and their involvement in glycolysis in HCC. MYC was overexpressed in HCC tissues and cells compared to normal liver tissues and normal hepatocytes NHC, which predicted a poor survival of HCC sufferers. Functional assays demonstrated that silencing of MYC inhibited the glycolysis in HCC cells, as evidenced by significantly weaker glucose consumption, lactate production, adenosine triphosphate (ATP) levels, and downregulated HK1 and HK2 protein expression. Moreover, MYC bound to the miR-122-5p promoter and repressed the miR-122-5p expression. Rescue experiments showed that miR-122-5p inhibitor rescued the diminished glycolysis after MYC silencing. In addition, lactate dehydrogenase (LDHA) was identified as a downstream target of miR-122-5p. The overexpression of LDHA mitigated the effects of si-MYC and miR-122-5p mimic on glycolysis of HCC cells, respectively. In conclusion, the MYC/miR-122-5p/LDHA axis modulates glycolysis in HCC cells and possibly affects HCC progression.

A Functional Screening Identifies a New Organic Selenium Compound Targeting Cancer Stem Cells: Role of c-Myc Transcription Activity Inhibition in Liver Cancer

Cancer stem cells (CSCs) are reported to play essential roles in chemoresistance and metastasis. Pathways regulating CSC self-renewal and proliferation, such as Hedgehog, Notch, Wnt/β-catenin, TGF-β, and Myc, may be potential therapeutic targets. Here, a functional screening from the focused library with 365 compounds is performed by a step-by-step strategy. Among these candidate molecules, phenyl-2-pyrimidinyl ketone 4-allyl-3-amino selenourea (CU27) is chosen for further identification because it proves to be the most effective compound over others on CSC inhibition. Through ingenuity pathway analysis, it is shown CU27 may inhibit CSC through a well-known stemness-related transcription factor c-Myc. Gene set enrichment analysis, dual-luciferase reporter assays, expression levels of typical c-Myc targets, molecular docking, surface plasmon resonance, immunoprecipitation, and chromatin immunoprecipitation are conducted. These results together suggest CU27 binds c-Myc bHLH/LZ domains, inhibits c-Myc-Max complex formation, and prevents its occupancy on target gene promoters. In mouse models, CU27 significantly sensitizes sorafenib-resistant tumor to sorafenib, reduces the primary tumor size, and inhibits CSC generation, showing a dramatic anti-metastasis potential. Taken together, CU27 exerts inhibitory effects on CSC and CSC-associated traits in hepatocellular carcinoma (HCC) via c-Myc transcription activity inhibition. CU27 may be a promising therapeutic to treat sorafenib-resistant HCC.

Network pharmacology-based study on apigenin present in the methanolic fraction of leaves extract of Cestrum nocturnum L. to uncover mechanism of action on hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer in the world. It is the third leading cause of cancer-related mortality. In more than 80% of people liver cancer-related death is due to its poor prognosis. The flavonoids obtained from natural sources have potent therapeutic effects on HCC. The flavonoid rich methanolic fraction obtained from ethyl acetate extract of leaf of Cestrum nocturnum (MFLCN) was analyzed by UPLC-QTOFMS/MS for the presence of different flavonoids. The physiochemical and pharmacokinetics properties of the identified flavonoids were performed by absorption, distribution, metabolism, excretion, and toxicity (ADMET). It was selected on the basis of Lipinski rule and hepatotoxicity evaluations. The potential gene dataset of HCC were taken from gene card database and targets compounds were selected from target net prediction. Gene ontology and pathway enrichment analysis of HCC was performed via enricher and David web tools. Cytoscape was used to visualize targets and network pathways. MFLCN contains 33 flavonoids. Among these flavonoids, apigenin was selected as principal active compound on the basis of their pharmacokinetic and ADMET properties. Apigenin has 92 targets out of 627 total targets related to HCC, while there was13 pathways in the target-pathway network. Results revealed that apigenin regulates cell proliferation and survival, primarily through different signaling pathways like estrogen, VEGF, PI3K/AKT1, TNF, FoXO, and Ras signaling pathways. Thus, integrating network pharmacology prediction with m-RNA and human protein atlas validation could be an effective method for understanding the molecular mechanism of apigenin on HCC.

The Role of Dexmedetomidine in Tumor-Progressive Factors in the Perioperative Period and Cancer Recurrence: A Narrative Review

Dexmedetomidine, a specific α2 adrenergic receptor agonist, is highly frequently used in the perioperatively for its favorable pharmacology, such as mitigating postoperative cognitive dysfunction. Increasing attention has been recently focused on the effect of whether dexmedetomidine influences cancer recurrence, which urges the discussion of the role of dexmedetomidine in tumor-progressive factors. The pharmacologic characteristics of dexmedetomidine, the tumor-progressive factors in the perioperative period, and the relationships between dexmedetomidine and tumor-progressive factors were described in this review. Available evidence suggests that dexmedetomidine could reduce the degree of immune function suppression, such as keeping the number of CD3+ cells, NK cells, CD4+/CD8+ ratio, and Th1/Th2 ratio stable and decreasing the level of proinflammatory cytokine (interleukin 6 and tumor necrosis factor-alpha) during cancer operations. However, dexmedetomidine exhibits different roles in cell biological behavior depending on cancer cell types. The conclusions on whether dexmedetomidine would influence cancer recurrence could not be currently drawn for the lack of strong clinical evidence. Therefore, this is still a new area that needs further exploration.

The Research Progress of Bufalin in the Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the deadliest cancers in the world with a five-year survival rate of less than 20%. Nonetheless, selecting an appropriate therapeutic agent to inhibit the development of hepatoma cells is still a challenge. Bufalin, a component of the traditional Chinese medicine Chansu, has been shown to inhibit the proliferation, invasion and metastasis of HCC through various signaling pathways. In addition, bufalin and sorafenib demonstrate a synergistic effect in cancer therapeutics. This review highlighted on several focal signaling pathways involved in the inhibitory effects of bufalin on HCC and its synergistic mechanisms with sorafenib. The immunotherapy effect of bufalin has also been discussed as a novel property.

Knockdown of RSPH14 inhibits proliferation, migration, and invasion and promotes apoptosis of hepatocellular carcinoma via RelA

Background

High RSPH14 expression appears to be related to poor prognosis of hepatocellular carcinoma (HCC). This study aimed to investigate the possible roles of RSPH14 in the proliferation, apoptosis, and invasion of HCC cells.

Methods

The UALCAN database and Kaplan–Meier Plotter were used to evaluate the expression level and prognostic role of RSPH14 in HCC. Lentiviral vectors containing shRNA against RSPH14 were constructed to transfect the BEL-7404 and SMMC-7721 HCC cell lines. Cell proliferation was investigated by BrdU, MTT, and colony-formation assays. Apoptosis was detected using flow cytometry. Cell migration and invasion were evaluated using the scratch wound-healing and Transwell assays. Immunohistochemistry and western blot were used to determine the expression levels of the proteins. The function of RSPH14 in vivo was evaluated using a xenograft mouse model.

Results

The expression of RSPH14 was higher in HCC tumor tissues than in adjacent normal tissues and was closely related to unfavorable prognostic factors and poorer survival (all P < 0.05). Knockdown of RSPH14 inhibited the cell proliferation, migration, and invasion of HCC cells and promoted apoptosis (all P < 0.05). Knockdown of RSPH14 inhibited tumor growth in vivo (P < 0.05). RSPH14 knockdown led to decreased expression of RelA (NF-κBp65), CDH2, and AKT1, thereby affecting the functions of the HCC cells (all P < 0.05). RelA overexpression could abate the inhibitory effect of BEL-7404 cell proliferation caused by RSPH14 depletion.

Conclusion

Knockdown of RSPH14 could decrease cell proliferation, migration, and invasion and increase apoptosis of HCC cells by inhibiting RelA expression. RSPH14 could be a new treatment target for HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02515-z.

An Integrated Analysis of the Identified PRPF19 as an Onco-immunological Biomarker Encompassing the Tumor Microenvironment, Disease Progression, and Prognoses in Hepatocellular Carcinoma

Background: Targeting the mRNA splicing process has been identified as a therapeutic strategy for human cancer. PRPF19 is an RNA binding protein that is involved in pre-mRNA processing and repairing DNA damage; the aberrant expression of PRPF19 is potentially associated with carcinogenesis. However, the biological role of PRPF19 in hepatocellular carcinoma (HCC) is still elusive.

Methods: Data obtained from TCGA, Oncomine, and GEO were used to investigate the PRPF19 expression level and its role in tumor immune infiltration, prognosis, and the tumor progression of cohorts from HCC. Using various databases and tools (UALCAN, TIMER, TISMO, and PathCards), we presented the potential mechanisms of PFPF19 upregulation, PRPF19-related pathways, and its biological functions in liver cancer.

Results: For HCC, PRPF19 expression was found upregulated both in single tumor cells and tissues. Furthermore, the increased expression of PRPF19 was significantly correlated to clinical characteristics: advanced stage, vascular invasion, high AFP, and poor prognosis of HCC. According to the tumor-immunological analysis, we found that PRPF19 is positively correlated with infiltrating myeloid-derived suppressor cells (MDSCs). Moreover, the microenvironment of HCC tissues with high expression of PRPF19 is highly immunosuppressive (lower T-lymphocytes, multiple immune checkpoints upregulated). Patients with high expression of PRPF19 and high MDSCs had a worse survival prognosis as well. TP53 mutation may have a positive effect on PRPF19 expression via decreased promoter methylation of PRPF19. By TF-mRNA network analysis, key transcription factors (TFs) in TC-NER and PCS pathways (PRPF19 involved) were identified.

Conclusion: This work implied that PRPF19 is associated with tumor immune evasion and progression, and serves as a prognostic marker for worse clinical outcomes with HCC. Thus, this critical regulator could serve as a potential therapeutic target of HCC.

An RNA-RNA crosstalk network involving HMGB1 and RICTOR facilitates hepatocellular carcinoma tumorigenesis by promoting glutamine metabolism and impedes immunotherapy by PD-L1+ exosomes activity

Hepatocellular carcinoma (HCC) is the global leading cause of cancer-related deaths due to the deficiency of targets for precision therapy. A new modality of epigenetic regulation has emerged involving RNA–RNA crosstalk networks where two or more competing endogenous RNAs (ceRNAs) bind to the same microRNAs. However, the contribution of such mechanisms in HCC has not been well studied. Herein, potential HMGB1-driven RNA–RNA crosstalk networks were evaluated at different HCC stages, identifying the mTORC2 component RICTOR as a potential HMGB1 ceRNA in HBV⁺ early stage HCC. Indeed, elevated HMGB1 mRNA was found to promote the expression of RICTOR mRNA through competitively binding with the miR-200 family, especially miR-429. Functional assays employing overexpression or interference strategies demonstrated that the HMGB1 and RICTOR 3′untranslated regions (UTR) epigenetically promoted the malignant proliferation, self-renewal, and tumorigenesis in HCC cells. Intriguingly, interference against HMGB1 and RICTOR in HCC cells promoted a stronger anti-PD-L1 immunotherapy response, which appeared to associate with the production of PD-L1⁺ exosomes. Mechanistically, the HMGB1-driven RNA-RNA crosstalk network facilitated HCC cell glutamine metabolism via dual mechanisms, activating a positive feedback loop involving mTORC2-AKT-C-MYC to upregulate glutamine synthetase (GS) expression, and inducing mTORC1 signaling to derepress SIRT4 on glutamate dehydrogenase (GDH). Meanwhile, this crosstalk network could impede the efficacy of immunotherapy through mTORC1-P70S6K dependent PD-L1 production and PD-L1⁺ exosomes activity. In conclusion, our study highlights the non-coding regulatory role of HMGB1 with implications for RNA-based therapeutic targeting together with a prediction of anti-PD-L1 immunotherapy in HCC.

Therapeutic Potential of CUDC-907 (Fimepinostat) for Hepatocarcinoma Treatment Revealed by Tumor Spheroids-Based Drug Screening

Background: Cancer is the second leading cause of death globally. However, most of the new anti-cancer agents screened by traditional drug screening methods fail in the clinic because of lack of efficacy. Choosing an appropriate in vitro tumor model is crucial for preclinical drug screening. In this study, we screened anti-hepatocarcinoma (HCC) drugs using a novel spheroid cell culture device. Methods: Four HCC cell lines were three-dimensionally (3D) cultured to screen 19 small molecular agents. 3D-cultured primary HCC cells and a tumor-bearing mouse model were used to verify the candidate anti-hepatocarcinoma agent. Cell function experiments and western blotting were conducted to explore the anti-hepatocarcinoma mechanism of the candidate agent. Results: We found that CUDC-907 can serve as a potent anti-hepatocarcinoma agent. The study data show that CUDC-907 (fimepinostat), a novel dual acting inhibitor of phosphoinositide 3-kinase (PI3K) and histone deacetylase (HDAC), has potent inhibitory effects on HCC cell lines and primary HCC cells in vitro, Animal studies have shown that CUDC-907 can also suppress HCC cells in vivo. Furthermore, we found that CUDC-907 inhibits the PI3K/AKT/mTOR pathway and downregulates the expression of c-Myc, leading to the suppression of HCC cells. Conclusion: Our results suggest that CUDC-907 can be a candidate anti-HCC drug, and the 3D in vitro drug screening method based on our novel spheroid culture device is promising for future drug screening efforts.

Role of mammalian target of rapamycin complex 2 in primary and secondary liver cancer

The mammalian target of rapamycin (mTOR) acts in two structurally and functionally distinct protein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Upon deregulation, activated mTOR signaling is associated with multiple processes involved in tumor growth and metastasis. Compared with mTORC1, much less is known about mTORC2 in cancer, mainly because of the unavailability of a selective inhibitor. However, existing data suggest that mTORC2 with its two distinct subunits Rictor and mSin1 might play a more important role than assumed so far. It is one of the key effectors of the PI3K/AKT/mTOR pathway and stimulates cell growth, cell survival, metabolism, and cytoskeletal organization. It is not only implicated in tumor progression, metastasis, and the tumor microenvironment but also in resistance to therapy. Rictor, the central subunit of mTORC2, was found to be upregulated in different kinds of cancers and is associated with advanced tumor stages and a bad prognosis. Moreover, AKT, the main downstream regulator of mTORC2/Rictor, is one of the most highly activated proteins in cancer. Primary and secondary liver cancer are major problems for current cancer therapy due to the lack of specific medical treatment, emphasizing the need for further therapeutic options. This review, therefore, summarizes the role of mTORC2/Rictor in cancer, with special focus on primary liver cancer but also on liver metastases.

Single-cell transcriptomics reveals opposing roles of Shp2 in Myc-driven liver tumor cells and microenvironment

The mechanisms of Myc-driven liver tumorigenesis are inadequately understood. Herein we show that Myc-driven hepatocellular carcinoma (HCC) is dramatically aggravated in mice with hepatocyte-specific Ptpn11/Shp2 deletion. However, Myc-induced tumors develop selectively from the rare Shp2-positive hepatocytes in Shp2-deficent liver, and Myc-driven oncogenesis depends on an intact Ras-Erk signaling promoted by Shp2 to sustain Myc stability. Despite a stringent requirement of Shp2 cell autonomously, Shp2 deletion induces an immunosuppressive environment, resulting in defective clearance of tumor-initiating cells and aggressive tumor progression. The basal Wnt/β-catenin signaling is upregulated in Shp2-deficient liver, which is further augmented by Myc transfection. Ablating Ctnnb1 suppresses Myc-induced HCC in Shp2-deficient livers, revealing an essential role of β-catenin. Consistently, Myc overexpression and CTNNB1 mutations are frequently co-detected in HCC patients with poor prognosis. These data elucidate complex mechanisms of liver tumorigenesis driven by cell-intrinsic oncogenic signaling in cooperation with a tumor-promoting microenvironment generated by disrupting the specific oncogenic pathway.

RCN1 induces sorafenib resistance and malignancy in hepatocellular carcinoma by activating c-MYC signaling via the IRE1α-XBP1s pathway

The increasing incidence of hepatocellular carcinoma (HCC) is of great concern globally, but the molecular pathogenesis of these tumors remains unclear. Sorafenib is a first-line drug for the treatment of advanced HCC. However, the efficacy of sorafenib in improving patient survival is limited, and most patients inevitably develop resistance to this drug. Recent studies have demonstrated that the activation of the IRE1α–XBP1s pathway might play a protective role in the response to sorafenib and contribute to malignancy in HCC. Here, we found that RCN1, an endoplasmic reticulum resident protein, is significantly upregulated in sorafenib-resistant HCC cells and promotes tumor progression. Our analysis showed that RCN1 may be an independent predictor of tumor recurrence and overall survival. Mechanistically, RCN1 promotes the dissociation of GRP78 from IRE1α in sorafenib-resistant cells by interacting with GRP78 through its EFh1/2 domain. Subsequently, the IRE1α–XBP1s pathway, a branch of the unfolded protein response, is sustainably activated. Interestingly, IRE1α–XBP1s pathway activity is required for c-MYC signaling, one of the most highly activated oncogenic pathways in HCC. These results suggest that RCN1-targeted therapy might be a feasible strategy for the treatment of HCC.

IGFBP-2 as a biomarker in NAFLD improves hepatic steatosis: an integrated bioinformatics and experimental study

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) has become a common chronic liver disease in the world. Simple steatosis (SS) is the early phase of NAFLD. However, the molecular mechanisms underlying the development of steatosis have not yet been fully elucidated.

METHODS

Two public datasets (GSE48452 and GSE89632) through the Gene Expression Omnibus (GEO) database were used to identify differentially expressed genes (DEGs) in the development of steatosis. A total of 72 participants including 38 normal histological controls and 34 SS patients were included in this study. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) network analysis were performed to explore the function of DEGs. The results were further confirmed in high-fat diet (HFD)-fed mice and oleate-treated HepG2 cells.

RESULTS

Total 57 DEGs including 31 up- and 26 down-regulated genes between SS patients and healthy controls were determined. GO and KEGG analysis showed that most of the DEGs were enriched in the ligand-receptor signaling pathways. PPI network construction was used to identify the hub genes of the DEGs. MYC, ANXA2, GDF15, AGTR1, NAMPT, LEPR, IGFBP-2, IL1RN, MMP7, and APLNR were identified as hub genes, and IGFBP-2 expression was found to be reversely associated with hepatic steatosis, fasting insulin, HOMA-IR index, and ALT levels. In HFD-fed mice, hepatic IGFBP-2 was also downregulated and negatively associated with hepatic triglyceride (TG) levels. Moreover, overexpression of IGFBP-2 ameliorated the oleate induced accumulation of TGs in hepatocytes.

CONCLUSIONS

This study identified novel gene signatures in the hepatic steatosis and will provide new understanding and molecular clues of hepatic steatosis.

The Clinicopathologic and Prognostic Significance of c-Myc Expression in Hepatocellular Carcinoma: A Meta-Analysis

Background: The incidence and mortality rates of hepatocellular carcinoma (HCC) are increasing worldwide. Therefore, there is an urgent need to elucidate the molecular drivers of HCC for potential early diagnosis and individualized treatment. Whether c-Myc expression plays a role in the clinicopathology and prognosis of patients with HCC remains controversial. This meta-analysis aimed to survey the prognostic role of c-Myc in HCC.

Methods: We searched PubMed, Cochrane Library, Embase, Web of Science, and Google Scholar databases for studies published through March 2020 that examined the association between c-Myc expression and clinicopathology or prognosis in HCC patients. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were used to investigate the prognostic significance of c-Myc expression. Odds ratios were calculated to evaluate the association between c-Myc expression and clinicopathologic features. We also tested for publication bias.

Results: Our meta-analysis included nine studies with 981 patients with HCC published between 1999 and 2016. A meta-analysis of these studies demonstrated that high c-Myc expression indicated a poor overall survival (OS) (HR = 2.260, 95% CI: 1.660–3.080, and p < 0.001) and disease-free survival (DFS) (HR = 1.770, 95% CI: 1.430–2.450, and p < 0.001) in patients with HCC. However, high c-Myc expression was not associated with HBsAg, pathological type, TNM stage, or cirrhosis. We did not find any significant publication bias among the included studies, indicating that our estimates were robust and reliable.

Conclusion: c-Myc overexpression could predict poor OS and DFS in HCC patients. c-Myc could be a useful prognostic biomarker and therapeutic target for HCC.

Lack of Mof reduces acute liver injury by enhancing transcriptional activation of Igf1

Acute liver injury (ALI) is a rapid pathological process that may cause severe liver disease and may even be life-threatening. During ALI, the function of males absent on the first (MOF) has not yet been elucidated. In this study, we unveiled the expression pattern of MOF during carbon tetrachloride (CCl4 )-induced ALI and role of MOF in the regulation of liver regeneration. In the process of ALI, MOF is significantly overexpressed in the liver injury area. Knockdown of Mof attenuated CCl4 -induced ALI, and promoted liver cell proliferation, hepatic stellate cell activation and aggregation to the injured area, and liver fibrosis. Simultaneously, overexpression of Mof aggravated liver dysfunction caused by ALI. By directly binding to the promoter, MOF suppressed the transcriptional activation of Igf1. Knockdown of Mof promotes the expression of Igf1 and activates the Insulin-like growth factor 1 signaling pathway in the liver. Through this pathway, Knockdown of Mof reduces CCl4 -induced ALI and promotes liver regeneration. Our results provide the first demonstration for MOF contributing to ALI. Further understanding of the role of MOF in ALI may lead to new therapeutic strategies for ALI.

Mild chronic hypoxia-induced HIF-2α interacts with c-MYC through competition with HIF-1α to induce hepatocellular carcinoma cell proliferation

PURPOSE

Hepatocellular carcinoma (HCC) has emerged as a leading cause of cancer-related deaths globally, in which hypoxia and activated hypoxia-inducible factors (HIFs) play important roles. The sibling rivalry between HIF-1α and HIF-2α in hypoxic tumor growth and progression still remains to be resolved, including in HCC. In this study, we aimed to analyze the mechanism by which HIF-1α and HIF-2α balance the proliferative response of HCC cells to hypoxia.

METHODS

The expression of HIF-1α, HIF-2α, c-MYC, Rictor and Raptor in corresponding tumor and non-tumor tissues from twenty-six patients with HCC was analyzed. The relationships between HIF-1α and HIF-2α and their respective effects were evaluated further in vitro in hypoxic HCC cells using co-immunoprecipitation, chromatin immunoprecipitation, in situ proximity ligation, annexin V-FITC/PI staining apoptosis and MTT assay. In addition, short hairpin RNA (shRNA) transfections targeting HIF-1α/2α and Rictor and Western blotting were applied in HCC cells to study the underlying mechanism.

RESULTS

We found that HIF-2α expression showed a positive correlation with c-MYC expression in tumor tissues, whereas HIF-1α did not. In vitro, increased HCC cell proliferation and an increased interaction between HIF-2α and c-MYC were observed under mild chronic hypoxic conditions. Although mild hypoxia led to HIF-1α, HIF-2α and c-MYC up-regulation, we found that mTORC2-regulated HIF-2α competed with HIF-1α to bind to c-MYC. Moreover, we found that HIF-2α knockdown decreased the expression of downstream c-MYC, suppressed hypoxic cell proliferation, and induced HCC cell apoptosis, whereas HIF-1α knockdown did not. Additionally, we found that the PI3K inhibitor apitolisib counteracted the effect of HIF-2α, thereby inducing HCC cell apoptosis.

CONCLUSIONS

Our data highlight a role of HIF-2α in activating and binding c-MYC, thereby inducing HCC cell proliferation during mild chronic hypoxia. The PI3K/mTORC2/HIF-2α/c-MYC axis may play a key role in this process. The PI3K inhibitor apitolisib may serve as a potential treatment option for patients suffering from HCC, especially in cases with rapidly growing tumors under mild chronic hypoxic conditions.

Overexpression of Mothers Against Decapentaplegic Homolog 7 Activates the Yes-Associated Protein/NOTCH Cascade and Promotes Liver Carcinogenesis in Mice and Humans

BACKGROUND AND AIMS

Mothers against decapentaplegic homolog (SMAD) 7 is an antagonist of TGF-β signaling. In the present investigation, we sought to determine the relevance of SMAD7 in liver carcinogenesis using in vitro and in vivo approaches.

APPROACH AND RESULTS

We found that SMAD7 is up-regulated in a subset of human HCC samples with poor prognosis. Gene set enrichment analysis revealed that SMAD7 expression correlates with activated yes-associated protein (YAP)/NOTCH pathway and cholangiocellular signature genes in HCCs. These findings were substantiated in human HCC cell lines. In vivo, overexpression of Smad7 alone was unable to initiate HCC development, but it significantly accelerated c-Myc/myeloid cell leukemia 1 (MCL1)-induced mouse HCC formation. Consistent with human HCC data, c-Myc/MCL1/Smad7 liver tumors exhibited an increased cholangiocellular gene expression along with Yap/Notch activation and epithelial-mesenchymal transition (EMT). Intriguingly, blocking of the Notch signaling did not affect c-Myc/MCL1/Smad7-induced hepatocarcinogenesis while preventing cholangiocellular signature expression and EMT, whereas ablation of Yap abolished c-Myc/MCL1/Smad7-driven HCC formation. In mice overexpressing a myristoylated/activated form of AKT, coexpression of SMAD7 accelerated carcinogenesis and switched the phenotype from HCC to intrahepatic cholangiocarcinoma (iCCA) lesions. In human iCCA, SMAD7 expression was robustly up-regulated, especially in the most aggressive tumors, and directly correlated with the levels of YAP/NOTCH targets as well as cholangiocellular and EMT markers.

CONCLUSIONS

The present data indicate that SMAD7 contributes to liver carcinogenesis by activating the YAP/NOTCH signaling cascade and inducing a cholangiocellular and EMT signature.

Targeting mTOR and Glycolysis in HER2-Positive Breast Cancer

Up to one third of all breast cancers are classified as the aggressive HER2-positive subtype, which is associated with a higher risk of recurrence compared to HER2-negative breast cancers. The HER2 hyperactivity associated with this subtype drives tumor growth by up-regulation of mechanistic target of rapamycin (mTOR) pathway activity and a metabolic shift to glycolysis. Although inhibitors targeting the HER2 receptor have been successful in treating HER2-positive breast cancer, anti-HER2 therapy is associated with a high risk of recurrence and drug resistance due to stimulation of the PI3K-Akt-mTOR signaling pathway and glycolysis. Combination therapies against HER2 with inhibition of mTOR improve clinical outcomes compared to HER2 inhibition alone. Here, we review the role of the HER2 receptor, mTOR pathway, and glycolysis in HER2-positive breast cancer, along with signaling mechanisms and the efficacy of treatment strategies of HER2-positive breast cancer.

YY1-mediated reticulocalbin-2 upregulation promotes the hepatocellular carcinoma progression via activating MYC signaling

Hepatocellular carcinoma (HCC) is a common digestive tumor with high fatality worldwide. Previous studies have shown that Reticulocalbin-2 (RCN2) was a crucial factor for HCC proliferation, but invasion and migration mechanism of RCN2 contributing to HCC is poorly investigated. In this study, we estimated the RCN2 expression in both patient tissues and cell lines by polymerase chain reaction (PCR) and western blotting (WB), as well as the clinical information of HCC patients from public databases. Biological function induced by RCN2 in vitro and vivo was also researched through multiple functional experiments. Upstream and downstream signal of RCN2 was identified by bioinformatics. We found that up-regulated RCN2 was related to poorer prognosis in HCC patients and attached significance to HCC proliferation, invasion and migration. Luciferase reporter assay and chromatin immunoprecipitation validated that YY1 as the upstream transcription factor of RCN2, facilitating the expression of RCN2. Gene set enrichment analysis indicated that HCC progression induced by RCN2 might be related to MYC signaling. Furthermore, we demonstrated RCN2 reduced proteasomal degradation of MYC and lead to HCC progression. The effects of overexpressed RCN2 in HCC were attenuated by MYC silencing. In conclusion, our study highlighted the vital role of RCN2 in tumor progression and the potential benefit for the treatment of HCC.