Inhibition of GSK-3β activity suppresses HCC malignant phenotype by inhibiting glycolysis via activating AMPK/mTOR signaling

Exploring the impact of circRNAs on cancer glycolysis: Insights into tumor progression and therapeutic strategies

Cancer cells exhibit altered metabolic pathways, prominently featuring enhanced glycolytic activity to sustain their rapid growth and proliferation. Dysregulation of glycolysis is a well-established hallmark of cancer and contributes to tumor progression and resistance to therapy. Increased glycolysis supplies the energy necessary for increased proliferation and creates an acidic milieu, which in turn encourages tumor cells' infiltration, metastasis, and chemoresistance. Circular RNAs (circRNAs) have emerged as pivotal players in diverse biological processes, including cancer development and metabolic reprogramming. The interplay between circRNAs and glycolysis is explored, illuminating how circRNAs regulate key glycolysis-associated genes and enzymes, thereby influencing tumor metabolic profiles. In this overview, we highlight the mechanisms by which circRNAs regulate glycolytic enzymes and modulate glycolysis. In addition, we discuss the clinical implications of dysregulated circRNAs in cancer glycolysis, including their potential use as diagnostic and prognostic biomarkers. All in all, in this overview, we provide the most recent findings on how circRNAs operate at the molecular level to control glycolysis in various types of cancer, including hepatocellular carcinoma (HCC), prostate cancer (PCa), colorectal cancer (CRC), cervical cancer (CC), glioma, non-small cell lung cancer (NSCLC), breast cancer, and gastric cancer (GC). In conclusion, this review provides a comprehensive overview of the significance of circRNAs in cancer glycolysis, shedding light on their intricate roles in tumor development and presenting innovative therapeutic avenues.

DNMT1-targeting remodeling global DNA hypomethylation for enhanced tumor suppression and circumvented toxicity in oral squamous cell carcinoma

BACKGROUND

The faithful maintenance of DNA methylation homeostasis indispensably requires DNA methyltransferase 1 (DNMT1) in cancer progression. We previously identified DNMT1 as a potential candidate target for oral squamous cell carcinoma (OSCC). However, how the DNMT1- associated global DNA methylation is exploited to regulate OSCC remains unclear.

METHODS

The shRNA-specific DNMT1 knockdown was employed to target DNMT1 on oral cancer cells in vitro, as was the use of DNMT1 inhibitors. A xenografted OSCC mouse model was established to determine the effect on tumor suppression. High-throughput microarrays of DNA methylation, bulk and single-cell RNA sequencing analysis, multiplex immunohistochemistry, functional sphere formation and protein immunoblotting were utilized to explore the molecular mechanism involved. Analysis of human samples revealed associations between DNMT1 expression, global DNA methylation and collaborative molecular signaling with oral malignant transformation.

RESULTS

We investigated DNMT1 expression boosted steadily during oral malignant transformation in human samples, and its inhibition considerably minimized the tumorigenicity in vitro and in a xenografted OSCC model. DNMT1 overexpression was accompanied by the accumulation of cancer-specific DNA hypomethylation during oral carcinogenesis; conversely, DNMT1 knockdown caused atypically extensive genome-wide DNA hypomethylation in cancer cells and xenografted tumors. This novel DNMT1-remodeled DNA hypomethylation pattern hampered the dual activation of PI3K-AKT and CDK2-Rb and inactivated GSK3β collaboratively. When treating OSCC mice, targeting DNMT1 achieved greater anticancer efficacy than the PI3K inhibitor, and reduced the toxicity of blood glucose changes caused by the PI3K inhibitor or combination of PI3K and CDK inhibitors as well as adverse insulin feedback.

CONCLUSIONS

Targeting DNMT1 remodels a novel global DNA hypomethylation pattern to facilitate anticancer efficacy and minimize potential toxic effects via balanced signaling synergia. Our study suggests DNMT1 is a crucial gatekeeper regarding OSCC destiny and treatment outcome.

Osthole inhibits GSK-3β/AMPK/mTOR pathway-controlled glycolysis and increases radiosensitivity of subcutaneous transplanted hepatocellular carcinoma in nude mice

PURPOSE

Osthole possesses anti-tumor activities. However, whether osthole can have a radiosensitization effect on hepatic cancer remains unclear. Here, an HCC-LM3 cells-inoculated subcutaneous transplanted tumor was adopted to explore the effect of osthole.

METHODS

The tumor-bearing mice were treated with 100 mg/kg osthole for 12 days, 4 Gy irradiation twice, or their combination. The tumor volume and weight, lactic acid content, glycolytic enzyme activities, and protein expression of glycogen synthase kinase 3β (GSK-3β), p‑GSK-3β, mammalian target of rapamycin (mTOR), p‑mTOR, AMP-activated protein kinase (AMPK), p‑AMPK, glucose transporter 1/3, and pyruvate kinase M2 were determined. The GSK-3β-overexpressed HCC-LM3 or SK-Hep‑1 cell models were also adopted to verify the effects of osthole on expression of these proteins.

RESULTS

The tumor volume and weight, lactic acid content, and glycolytic enzyme activities in tumor tissues were lower in the osthole + radiation group than in the radiation group. Moreover, osthole could reverse the radiation-induced increments of p‑GSK-3β/GSK-3β and p‑mTOR/mTOR protein ratios and the expression of glucose transporter 1/3 and pyruvate kinase M2 proteins in tumor tissues, and increase the protein ratio of p‑AMPK/AMPK. The effects of osthole on these glycolysis-related proteins were also observed in GSK-3β-overexpressed HCC-LM3 or SK-Hep‑1 cell models.

CONCLUSION

Osthole has a radiosensitizing effect on subcutaneous transplanted hepatocellular carcinoma, and its mechanism may be related to inhibition of GSK-3β/AMPK/mTOR pathway-controlled glycolysis.

Caffeine in Hepatocellular Carcinoma: Cellular Assays, Animal Experiments, and Epidemiological Investigation

The use of caffeine in treating various liver diseases has made substantial progress in the past decade owing to advances in science, technology, and medicine. However, whether caffeine has a preventive effect on hepatocellular carcinoma (HCC) and its mechanism are still worth further investigation. In this review, we summarize and analyze the efficacy and safety of caffeine in the prevention of HCC. We conducted a review of articles published in PubMed and Web of Science in the past 2 decades until December 6, 2023, which were searched for using the terms "Caffeine" and "Hepatocellular Carcinoma." Studies have found that coffee intake is negatively correlated with HCC risk, especially caffeinated coffee. Recent studies have found that caffeine has beneficial effects on liver health, decreasing levels of enzymes responsible for liver damaging and slowing the progression of hepatic fibrosis and cirrhosis. Caffeine also acts against liver fibrosis through adenosine receptors (ARs), which promote tissue remodeling by inducing fibrin and collagen production. Additionally, new studies have found that moderate consumption of caffeinated beverages can decrease various the levels of various collagens in patients with chronic hepatitis C. Furthermore, polyphenolic compounds in coffee can improve fat homeostasis, reduce oxidative stress, and prevent liver steatosis and fibrosis. Moreover, many in vitro studies have shown that caffeine can protect liver cells and inhibit the activation and proliferation of hepatic stellate cells. Taken together, we describe the benefits of caffeine for liver health and highlight its potential values as a drug to prevent various hepatic diseases. As a protective agent of liver inflammation, non-selective AR inhibitor caffeine can inhibit the growth of HCC cells by inhibiting adenosine and AR binding to initiate immune response, providing a basis for the future development of caffeine as an adjuvant drug against HCC.

NR0B1 augments sorafenib resistance in hepatocellular carcinoma through promoting autophagy and inhibiting apoptosis

NR0B1 is frequently activated in hepatocellular carcinoma (HCC). However, the role of NR0B1 is controversial in HCC. In this study, we observed that NR0B1 was an independent poor prognostic factor, negatively correlated with the overall survival of HCC and the relapse-free survival of patients treated with sorafenib. Meanwhile, NR0B1 promoted the proliferation, migration, and invasion of HCC cells, inhibited sorafenib-induced apoptosis, and elevated the IC50 of sorafenib in HCC cells. NR0B1 was further displayed to increase sorafenib-induced autophagic vesicles and activate Beclin1/LC3-II-dependent autophagy pathway. Finally, NR0B1 was revealed to transcriptionally suppress GSK3β that restrains AMPK/mTOR-driven autophagy and increases BAX-mediated apoptosis. Collectively, our study uncovered that the ectopic expression of NR0B1 augmented sorafenib-resistance in HCC cells by activating autophagy and inhibiting apoptosis. Our findings supported that NR0B1 was a detrimental factor for HCC prognosis.

BTF3 promotes proliferation and glycolysis in hepatocellular carcinoma by regulating GLUT1

Hepatocellular carcinoma (HCC) is a grievous tumor with an increasing incidence worldwide. Basic transcription factor 3 (BTF3) is discovered to regulate the expression of glucose transporter 1 (GLUT1), which benefits glycolysis, a momentous signature of tumors, through transactivation of the forkhead box M1 (FOXM1) expression. BTF3 is highly expressed in HCC. However, whether BTF3 promotes GLUT1 expression through FOXM1 to modulate glycolysis in HCC remains unclear. The expression profile of BTF3 were determined by online database, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. The role and mechanism of BTF3 in the proliferation and glycolysis of HCC cells were examined by cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) incorporation, XF96 Extracellular Flux analyzer, spectrophotometry and western blot analysis. In addition, the direct interaction between BTF3 and FOXM1 was verified by dual-luciferase reporter and co-immunoprecipitation assays. Moreover, the role of BTF3 was also explored in a xenografted mice model. The expression of BTF3 was increased in HCC cells and tumor tissues. Knockdown of BTF3 reduced the cell viability, Edu positive cells, extracellular acidification rate (ECAR), glucose consumption and lactate production in both Huh7 and HCCLM3 cells. The expressions of FOXM1 and GLUT1 were increased in HCC tissues, which were positively correlated with the BTF3 expression. Moreover, a direct interaction existed between BTF3 and FOXM1 in HCC cells. Downregulation of BTF3 decreased the relative protein levels of FOXM1 and GLUT1, which were rescued with overexpression of FOXM1 in both cells. More importantly, overexpression of FOXM1 restored the cell viability, ECAR, glucose consumption and lactate production in both Huh7 and HCCLM3 cells transfected with siBTF3#1. Furthermore, inhibition of BTF3 decreased tumor weight and volume, and the relative level of BTF3, FOXM1, GLUT1 and Ki-67 in tumor tissues from mice xenografted with Huh7 cells. BTF3 enhanced the cell proliferation and glycolysis through FOXM1/GLUT1 axis in HCC.

PYCR2 promotes growth and aerobic glycolysis in human liver cancer by regulating the AKT signaling pathway

Hepatocellular carcinoma (HCC) is the world's third most fatal cancer. Because metabolic rewiring is a hallmark of HCC, studies into the causes of aberrant glycolysis could provide insight into novel HCC therapeutic strategies. Pyrroline-5-carboxylate reductase 2 (PYCR2), a key enzyme of proline synthesis, has previously been found to play vital roles in various malignancies regarding amino acid metabolism and oxidative stress response. Our study investigated the mechanistic function of PYCR2 in HCC. We used Gene Expression Profiling Interactive Analysis to perform bioinformatics analysis of PYCR2 expression and survival in human HCC patients based on the Cancer Genome Atlas database. The function of PYCR2 in cell viability and glycolysis was assessed using CCK-8 and ECAR assays. Transducing shRNA or overexpression vectors into the HCC cell line altered the expression status of PYCR2. PYCR2 expression was validated using quantitative real-time PCR and Western blot. In mouse xenograft models, the role of PYCR2 in HCC tumor formation was confirmed. PYCR2 was overexpressed in human HCC tumor tissue and was associated with a poor prognosis. The functional assay revealed that silencing PYCR2 inhibited cell viability, glycolysis, and AKT activation. Furthermore, the xenograft experiment demonstrated that silencing PYCR2 significantly inhibited tumor growth and Ki67 expression. On the other hand, PYCR2 overexpression significantly promoted cell viability and glycolysis, which could be inhibited by either a glycolysis inhibitor or an AKT inhibitor, indicating that PYCR2 may function via glycolysis and the AKT pathway. Moreover, despite the overexpression of PYCR2 in vivo, treatment with a glycolysis inhibitor may considerably suppress tumor growth. Our findings suggest that PYCR2 may play an oncogenic role in HCC growth by promoting glycolysis and activating AKT, emphasizing PYCR2's clinical relevance in HCC management as a novel potential therapeutic target.

Glycolysis maintains AMPK activation in sorafenib-induced Warburg effect

Hepatocellular carcinoma (HCC) is the second deadly cancer in the world and still lacks curative treatment. Aerobic glycolysis, or Warburg effect, is a major resistance mechanism induced by first-line treatment of HCC, sorafenib, and is regulated by the master regulator of metabolism, AMPK. Activation of AMPK is required for resistance; however, activation dynamics of AMPK and its regulation is rarely studied. Engineering cells to express an AMPK activity biosensor, we monitor AMPK activation in single HCC cells in a high throughput manner during sorafenib-induced drug resistance. Sorafenib induces transient activation of AMPK, duration of which is dependent on glucose. Inhibiting glycolysis shortens AMPK activation; whereas increasing glycolysis increases its activation duration. Our data highlight that activation duration of AMPK is important for cancer evasion of therapeutic treatment and glycolysis is a key regulator of activation duration of AMPK.

Linggui Zhugan decoction delays ventricular remodeling in rats with chronic heart failure after myocardial infarction through the Wnt/β-catenin signaling pathway

CONTEXT

Traditional Chinese medicine plays an important role in the prevention and treatment of heart failure (HF). Linggui Zhugan decoction has been approved for clinical treatment of chronic HF. However, the mechanism is still unclear.

OBJECTIVE

The effect of Linggui Zhugan decoction on the Wnt/β-catenin signaling pathway in rat myocardium was studied to investigate the mechanism by Linggui Zhugan decoction effects ventricular remodeling in rats with heart failure after myocardial infarction.

METHOD

A rat model of HF after myocardial infarction was prepared by ligating the left anterior descending coronary artery. After 6 weeks of intervention with Linggui Zhugan decoction, the effect of Linggui Zhugan decoction on the cardiac function of chronic HF model rats was observed. Myocardial infarct size was measured by triphenyl tetrazolium chloride (TTC) staining. Enzyme linked immunosorbent assays (ELISAs) were used to measure NT-proBNP and sST-2 concentrations in rat serum. Hematoxylin and eosin (H&E) staining, and Masson's trichrome staining were used to observe the morphology of myocardial tissue; immunohistochemistry was used to detect the protein expression of type I collagen and type III collagen in myocardial tissue; and mRNA expression levels of Wnt3a, GSK-3β, β-catenin, and c-Myc in the infarct marginal zone were detected using PCR. Protein expression of Wnt3a, p-GSK-3β, GSK-3β, and β-catenin in the infarct marginal zone was detected using western blot.

RESULTS

Compared with the control, Linggui Zhugan decoction reduced the levels of serum ST-2 and NT-proBNP, improved cardiac function, and reduced the deposition of collagen fiber. In addition, Linggui Zhugan decoction inhibited the expression of Wnt3a, p-GSK-3β, and β-catenin in cardiomyocytes.

CONCLUSION

Linggui Zhugan decoction inhibits the expression of several key proteins in the Wnt/β-catenin signaling pathway, delays cardiomyocyte hypertrophy and fibrosis, and improves cardiac function.

Ginsenoside Rh4 inhibits inflammation-related hepatocellular carcinoma progression by targeting HDAC4/IL-6/STAT3 signaling

This study aimed to investigate the effects of Ginsenoside Rh4 (Rh4) on inflammation-related hepatocellular carcinoma (HCC) progression and the underlying mechanism. HCC cells (HUH7 and LM3) were induced by lipopolysaccharide (LPS) to establish an inflammatory environment in the absence or presence of Rh4. CCK-8, wound healing and transwell assays were employed to analyze the viability, migration and invasion of HCC cells. Ki67 expression was detected by immunofluorescence method. Besides, the levels of glucose and lactic acid were tested by kits. The expression of proteins related to migration, glycolysis and histone deacetylase 4 (HDAC4)/IL-6/STAT3 signaling was measured with western blot. The transplantation tumor model of HCC in mice was established to observe the impacts of Rh4 on the tumor growth. Results indicated that Rh4 restricted the viability and Ki67 expression in HCC cells exposed to LPS. The elevated migration and invasion of HCC cells triggered by LPS were reduced by Rh4. Additionally, Rh4 treatment remarkably decreased the contents of glucose and lactic acid and downregulated LDHA and GLUT1 expression. The database predicated that Rh4 could target HDAC4, and our results revealed that Rh4 downregulated HDAC4, IL-6 and p-STAT3 expression. Furthermore, the enforced HDAC4 expression alleviated the effects of Rh4 on the proliferation, migration, invasion and glycolysis of HCC cells stimulated by LPS. Taken together, Rh4 could suppress inflammation-related HCC progression by targeting HDAC4/IL-6/STAT3 signaling. These findings clarify a new anti-cancer mechanism of Rh4 on HCC and provide a promising agent to limit HCC development.

Versatile function of AMPK signaling in osteosarcoma: An old player with new emerging carcinogenic functions

AMP-activated protein kinase (AMPK) signaling has a versatile role in Osteosarcoma (OS), an aggressive bone malignancy with a poor prognosis, particularly in cases that have metastasized or recurred. This review explores the regulatory mechanisms, functional roles, and therapeutic applications of AMPK signaling in OS. It focuses on the molecular activation of AMPK and its interactions with cellular processes like proliferation, apoptosis, and metabolism. The uncertain role of AMPK in cancer is also discussed, highlighting its potential as both a tumor suppressor and a contributor to carcinogenesis. The therapeutic potential of targeting AMPK signaling in OS treatment is examined, including direct and indirect activators like metformin, A-769662, resveratrol, and salicylate. Further research is needed to determine dosing, toxicities, and molecular mechanisms responsible for the anti-osteosarcoma effects of these compounds. This review underscores the complex involvement of AMPK signaling in OS and emphasizes the need for a comprehensive understanding of its molecular mechanisms. By elucidating the role of AMPK in OS, the aim is to pave the way for innovative therapeutic approaches that target this pathway, ultimately improving the prognosis and quality of life for OS patients.

CLPX regulates mitochondrial fatty acid β-oxidation in liver cells

Mitochondrial fatty acid oxidation (β-oxidation) is an essential metabolic process for energy production in eukaryotic cells, but the regulatory mechanisms of this pathway are largely unknown. In the present study, we found that several enzymes involved in β-oxidation are associated with CLPX, the AAA+ unfoldase that is a component of the mitochondrial matrix protease ClpXP. The suppression of CLPX expression increased β-oxidation activity in the HepG2 cell line and in primary human hepatocytes without glucagon treatment. However, the protein levels of enzymes involved in β-oxidation did not significantly increase in CLPX-deleted HepG2 cells (CLPX-KO cells). Coimmunoprecipitation experiments revealed that the protein level in the immunoprecipitates of each antibody changed after the treatment of WT cells with glucagon, and a part of these changes was also observed in the comparison of WT and CLPX-KO cells without glucagon treatment. Although the exogenous expression of WT or ATP-hydrolysis mutant CLPX suppressed β-oxidation activity in CLPX-KO cells, glucagon treatment induced β-oxidation activity only in CLPX-KO cells expressing WT CLPX. These results suggest that the dissociation of CLPX from its target proteins is essential for the induction of β-oxidation in HepG2 cells. Moreover, specific phosphorylation of AMP-activated protein kinase and a decrease in the expression of acetyl-CoA carboxylase 2 were observed in CLPX-KO cells, suggesting that CLPX might participate in the regulation of the cytosolic signaling pathway for β-oxidation. The mechanism for AMP-activated protein kinase phosphorylation remains elusive; however, our results uncovered the hitherto unknown role of CLPX in mitochondrial β-oxidation in human liver cells.

RNA-binding protein CCDC137 activates AKT signaling and promotes hepatocellular carcinoma through a novel non-canonical role of DGCR8 in mRNA localization

BACKGROUND

RNA binding proteins (RBPs)-regulated gene expression play a vital role in various pathological processes, including the progression of cancer. However, the role of RBP in hepatocellular carcinoma (HCC) remains much unknown. In this study, we aimed to explore the contribution of RBP CCDC137 in HCC development.

METHODS

We analyzed the altered expression level and clinical significance of CCDC137 in database and HCC specimens. In vitro cell assays and in vivo spontaneous mouse models were used to assess the function of CCDC137. Finally, the molecular mechanisms of how CCDC137 regulates gene expression and promotes HCC was explored.

RESULTS

CCDC137 is aberrantly upregulated in HCC and correlates with poor clinical outcomes in HCC patients. CCDC137 markedly promoted HCC proliferation and progression in vitro and in vivo. Mechanistically, CCDC137 binds with FOXM1, JTV1, LASP1 and FLOT2 mRNAs, which was revealed by APOBEC1-mediated profiling, to increase their cytoplasmic localization and thus enhance their protein expressions. Upregulation of FOXM1, JTV1, LASP1 and FLOT2 subsequently synergistically activate AKT signaling and promote HCC. Interestingly, we found that CCDC137 binds with the microprocessor protein DGCR8 and DGCR8 has a novel non-canonical function in mRNA subcellular localization, which mediates the cytoplasmic distribution of mRNAs regulated by CCDC137.

CONCLUSIONS

Our results identify a critical proliferation-related role of CCDC137 and reveal a novel CCDC137/DGCR8/mRNA localization/AKT axis in HCC progression, which provide a potential target for HCC therapy.

Salvigenin Suppresses Hepatocellular Carcinoma Glycolysis and Chemoresistance Through Inactivating the PI3K/AKT/GSK-3β Pathway

Salvigenin is a Trimethoxylated Flavone enriched in Scutellariae Barbatae Herba and Scutellariae Radix and is demonstrated to have anti-tumor properties in colon cancer. Notwithstanding, the function and mechanism of Salvigenin in hepatocellular carcinoma (HCC) are less well studied. Different doses of Salvigenin were taken to treat HCC cells. Cell viability, colony formation ability, cell migration, invasion, apoptosis, glucose uptake, and lactate production levels were detected. As shown by the data, Salvigenin concentration dependently dampened HCC cell proliferation, migration, and invasion, weakened glycolysis by abating glucose uptake and lactate generation, and suppressed the profiles of glycolytic enzymes. Moreover, Salvigenin strengthened HCC cells' sensitivity to 5-fluorouracil (5-FU) and attenuated HCC 5-FU-resistant cells' resistance to 5-FU. Through network pharmacological analysis, we found Salvigenin potentially regulates PI3K/AKT pathway. As shown by the data, Salvigenin repressed the phosphorylated levels of PI3K, AKT, and GSK-3β. The PI3K activator 740Y-P induced PI3K/AKT/GSK-3β pathway activation and promotive effects in HCC cells. However, Salvigenin substantially weakened 740Y-P-mediated effects. In-vivo assay revealed that Salvigenin hampered the growth and promoted apoptosis of HCC cells in nude mice. Collectively, Salvigenin impedes the aerobic glycolysis and 5-FU chemoresistance of HCC cells by dampening the PI3K/AKT/GSK-3β pathway.

The regulatory role of PI3K in ageing-related diseases

Ageing is a physiological/pathological process accompanied by the progressive damage of cell function, triggering various ageing-related disorders. Phosphatidylinositol 3-kinase (PI3K), which serves as one of the central regulators of ageing, is closely associated with cellular characteristics or molecular features, such as genome instability, telomere erosion, epigenetic alterations, and mitochondrial dysfunction. In this review, the PI3K signalling pathway was firstly thoroughly explained. The link between ageing pathogenesis and the PI3K signalling pathway was then summarized. Finally, the key regulatory roles of PI3K in ageing-related illnesses were investigated and stressed. In summary, we revealed that drug development and clinical application targeting PI3K is one of the focal points for delaying ageing and treating ageing-related diseases in the future.

Paclitaxel inhibits hepatocellular carcinoma tumorigenesis by regulating the circ_0005785/miR-640/GSK3β

Paclitaxel (PTX) is an effective chemotherapeutic agent for cancer patients. It has been reported that circular RNA (circRNA) circ_0005785is involved in the progression of hepatocellular carcinoma (HCC). The purpose of this study is to explore the role and mechanism of circ_0005785 in the PTX resistance of HCC. Cell viability, proliferation, invasion, migration, apoptosis, and angiogenesis were detected using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), colony formation, transwell, wound-healing, flow cytometry, and tube formation assay. Circ_0005785, microRNA-640 (miR-640), and Glycogen synthase kinase-3 beta (GSK3β) levels were detected using real-time quantitative polymerase chain reaction. Protein levels of Proliferating cell nuclear antigen (PCNA), Bcl-2, and GSK3β were measured using western blot assay. After being predicted using Circular RNA interactome or TargetScan, binding between miR-640 and circ_0005785 or GSK3β was verified using dual-luciferase reporter and RNA Immunoprecipitation assay. PTX treatment could repress HCC cell viability, decrease circ_0005785 and GSK3β expression, and increase the miR-640 level in HCC cell lines. Furthermore, circ_0005785 and GSK3β were increased, and miR-640 was decreased in HCC tissues and cell lines. Moreover, circ_0005785 knockdown hindered proliferation, migration, invasion, angiogenesis, and boosted apoptosis in PTX-treated HCC cells in vitro. In addition, circ_0005785 silencing improved the PTX sensitivity of HCC in vivo. Mechanistically, circ_0005785 acted as a sponge of miR-640 to regulate GSK3β expression. PTX restrained HCC tumorigenesis partly via regulating the circ_0005785/miR-640/GSK3β axis, hinting at a promising therapeutic target for the HCC treatment.

Impairing Tumor Metabolic Plasticity via a Stable Metal-Phenolic-Based Polymeric Nanomedicine to Suppress Colorectal Cancer

Targeting metabolic vulnerability of tumor cells is a promising anticancer strategy. However, the therapeutic efficacy of existing metabolism-regulating agents is often compromised due to tolerance resulting from tumor metabolic plasticity, as well as their poor bioavailability and tumor-targetability. Inspired by the inhibitive effect of N-ethylmaleimide on the mitochondrial function, a dendronized-polymer-functionalized metal-phenolic nanomedicine (pOEG-b-D-SH@NP) encapsulating maleimide-modified doxorubicin (Mal-DOX) is developed to enable improvement in the overall delivery efficiency and inhibition of the tumor metabolism via multiple pathways. It is observed that Mal-DOX and its derived nanomedicine induces energy depletion of CT26 colorectal cancer cells more efficiently than doxorubicin, and shifts the balance of programmed cell death from apoptosis toward necroptosis. Notably, pOEG-b-D-SH@NP simultaneously inhibits cellular oxidative phosphorylation and glycolysis, thus potently suppressing cancer growth and peritoneal intestinal metastasis in mouse models. Overall, the study provides a promising dendronized-polymer-derived nanoplatform for the treatment of cancers through impairing metabolic plasticity.

Resveratrol-induced SIRT1 activation inhibits glycolysis-fueled angiogenesis under rheumatoid arthritis conditions independent of HIF-1α

OBJECTIVE

This study investigated the impacts of SIRT1 activation on rheumatoid arthritis (RA)-related angiogenesis.

METHODS

HUVECs were cultured by different human serum. Intracellular metabolites were quantified by UPLC-MS. Next, HUVECs and rat vascular epithelial cells under different inflammatory conditions were treated by a SIRT1 agonist resveratrol (RSV). Cytokines and biochemical indicators were detected by corresponding kits. Protein and mRNA expression levels were assessed by immunoblotting and PCR methods, respectively. Angiogenesis capabilities were evaluated by migration, wound-healing and tube-formation experiments. To down-regulate certain signals, gene-specific siRNA were applied.

RESULTS

Metabolomics study revealed the accelerated glycolysis in RA serum-treated HUVECs. It led to ATP accumulation, but did not affect GTP levels. RSV inhibited pro-angiogenesis cytokines production and glycolysis in both the cells, and impaired the angiogenesis potentials. These effects were mimicked by an energy metabolism interrupter bikini in lipopolysaccharide (LPS)-primed HUVECs, largely independent of HIF-1α. Both RSV and bikinin can inhibit the activation of the GTP-dependent pathway Rho/ROCK and reduce VEGF production. Abrogation of RhoA signaling reinforced HIF-1α silencing-brought changes in LPS-stimulated HUVECs, and overshadowed the anti-angiogenesis potentials of RSV.

CONCLUSION

Glycolysis provides additional energy to sustain Rho/ROCK activation in RA subjects, which promotes VEGF-driven angiogenesis and can be inhibited by SIRT1 activation.

Microtubule-associated protein 4 promotes epithelial mesenchymal transition in hepatocellular cancer cells via regulating GSK3β/β-catenin pathway

Metastasis is a major obstacle in the treatment of hepatocellular carcinoma (HCC). Microtubule-associated protein 4 (MAP4) plays an important role as a coordinator between microtubules and microfilaments. However, the role of MAP4 in HCC migration and epithelial mesenchymal transition (EMT) is unclear. We compared the protein and mRNA levels of MAP4 in human HCC and adjacent normal tissues using western blotting, immunohistochemistry and RT-qPCR. The migration and invasion abilities and the levels of EMT markers (E-Cadherin, N-Cadherin, Vimentin, and Snail) were compared between MAP4-knockdown and MAP4-overexpressed HCC cells. Finally, we examined whether β-catenin and glycogen synthase kinase 3β (GSK3β) are involved in the stimulatory effects of MAP4 on HCC migration, invasion and EMT. The results revealed that MAP4 levels were higher in the HCC tissues than in the normal hepatic tissues. More importantly, MAP4 knockdown suppressed migration and invasion abilities and EMT processes in HCC cells, which were confirmed by the stimulatory effects of MAP4 overexpression on EMT processes in HCC cells. Further evidence demonstrated that the up-regulation of β-catenin activity induced by the interaction between MAP4 and GSK3β possibly accounted for the pro-migration and pro-EMT effects of MAP4 on HCC cells. Taken together, these results suggest that MAP4 promotes migration, invasion, and EMT in HCC cells by regulating the GSK3β/β-catenin pathway.

Effects of lactate on metabolism and differentiation of CD4+T cells

BACKGROUND

Lactate accumulation caused by abnormal tumor metabolism can induce the formation of an inhibitory immune microenvironment through a variety of pathways, which is characterized by regulatory T cells (Treg) infiltration and effector T cells (Teff) depletion. Studies have found that the key reason why Treg cells can survive in harsh environments lies in their flexible metabolic mode, which can use lactate in tumor microenvironment (TME) as an alternative energy substance to maintain their inhibitory activity. In addition, lactate could also promote the differentiation of CD4⁺T cells into Treg, but the mechanism was not completely clear. The purpose of this study was to investigate the possible mechanism by which lactate is utilized by CD4⁺T cells to influence Th17/Treg ratio.

METHODS

Basal cytokines (anti-CD3, anti-CD28, TGF-β) and 10 mM lactate was added into Naïve CD4⁺T cells basal medium for 3 days. After TCR stimulation, Naïve CD4⁺T converted to CD4⁺T. Flow cytometry was used to detect the proportion of Treg cells; ELISA was used to detect the activity of LDHA, LDHB and NADH and the amount of α -Ketoglutaric Acid (α-KG) and 2-Hydroxyglutaric Acid (2HG) after lactate entered the cells; Western Blot and RT-PCR were used to detect the protein and gene expression of Foxp3, RORγt, LDHA and LDHB. In the validation experiment, lactate uptake inhibitor AZD3965, LDHA inhibitor GSK2837808A and NADH conversion inhibitor Rotenone were added respectively to observe the differentiation ratio of Treg cells and confirm the key points of metabolism; the degradation of Treg cell transcription factor Foxp3 was interfered with ubiquitination inhibitors to observe whether it co-ubiquitinated with HIF-1α; the expression and activity of LDHA, LDHB and NADH in mitochondria and cytoplasm were detected to confirm cell localization.

RESULTS

When basal cytokines (anti-CD3, anti-CD28, TGF-β) stimulated, lactate was added to the culture medium, and CD4⁺T cells absorbed a large amount of lactate not only through MCT1 (monocarboxylic acid transporter), but also increased the expression of lactate dehydrogenase and accelerated the intracellular metabolism of lactate. LDHB in cytoplasm mainly catalyzed the dehydrogenation of lactate to pyruvate, accompanied by the transformation reaction between NAD⁺ and NADH. The latter further entered the mitochondria and participates in the tricarboxylic acid cycle metabolism. In addition, lactate could significantly increase the level of LDHA in mitochondria and promote the transformation of α-KG to 2HG, accompanied by the transformation of NADH to NAD⁺. These metabolic changes eventually led to an increase in the intracellular 2HG/α-KG ratio. Abnormal 2HG increased the proportion of Treg by inhibiting ATP5B-mediated phosphorylation of mTOR and the synthesis of HIF-1α, causing it not be enough to ubiquitinate and degrade with Foxp3.

CONCLUSIONS

Lactate plays an important role in regulating the differentiation of Treg cells, inducing the expression and function of LDHA and promoting the transformation of α-KG to 2HG may be an important mechanism.

Osthole increases the radiosensitivity of hepatoma cells by inhibiting GSK-3β/AMPK/mTOR pathway-controlled glycolysis

Osthole is a natural coumarin substance that has an inhibitory effect on hepatic cancer, but its radiosensitization effect on hepatoma cells has not been reported. This study aimed to investigate the effect of osthole. Human HCC-LM3 and SK-Hep-1 hepatoma cells were used and treated with or without osthole, irradiation, or their combination; the cell survival, migration, colony formation, DNA damage repair, intracellular lactic acid content, and glycolysis-related glycogen synthase kinase-3β (GSK-3β), p-GSK-3β, AMP-activated protein kinase (AMPK), p-AMPK, mammalian target of rapamycin (mTOR), p-mTOR, glucose transporter-1 (GLUT-1), GLUT-3, and pyruvate kinase isozyme type M2 (PKM2) protein expressions were determined. Compared with the irradiation group, the osthole plus irradiation group could further decrease the survival rate, migration, colony formation, and DNA damage repair of both hepatoma cells, indicating a synergistic effect of the combination treatment. Moreover, the combination of osthole and irradiation could decrease the content of intracellular lactic acid, ratios of intracellular p-GSK-3β/GSK-3β and p-mTOR/mTOR proteins, and expressions of intracellular GLUT-1/3 and PKM2 proteins, and increase the ratio of intracellular p-AMPK/AMPK proteins. Osthole can increase the radiosensitivity of hepatoma cells, and its radiosensitization mechanisms may be related to glycolytic inhibition by attenuating the GSK-3β/AMPK/mTOR pathway.

Phase separation in Cancer: From the Impacts and Mechanisms to Treatment potentials

Cancer is a public health problem of great concern, and it is also one of the main causes of death in the world. Cancer is a disease characterized by dysregulation of diverse cellular processes, including avoiding growth inhibitory factors, avoiding immune damage and promoting metastasis, etc. However, the precise mechanism of tumorigenesis and tumor progression still needs to be further elucidated. Formations of liquid-liquid phase separation (LLPS) condensates are a common strategy for cells to achieve diverse functions, such as chromatin organization, signal transduction, DNA repair and transcriptional regulation, etc. The biomolecular aggregates formed by LLPS are mainly driven by multivalent weak interactions mediated by intrinsic disordered regions (IDRs) in proteins. In recent years, aberrant phase separations and transition have been reported to be related to the process of various diseases, such as neurodegenerative diseases and cancer. Herein, we discussed recent findings that phase separation regulates tumor-related signaling pathways and thus contributes to tumor progression. We also reviewed some tumor virus-associated proteins to regulate the development of virus-associated tumors via phase separation. Finally, we discussed some possible strategies for treating tumors by targeting phase separation.

The Effects of Qinghao-Kushen and Its Active Compounds on the Biological Characteristics of Liver Cancer Cells

Background and Aims. Artemisia annua (Qinghao) and Sophora flavescens (Kushen) are traditional Chinese medicines (TCMs). They are widely used in disease therapy, including hepatocellular carcinoma (HCC). However, their key compounds and targets for HCC treatment are unclear. This article mainly analyzed the vital active compounds and the mechanism of Qinghao-Kushen acting on HCC. Methods. First, we chose a traditional Chinese medicine, which has an excellent clinical effect on HCC by network meta-analysis. Then, we composed the Qinghao-Kushen herb pair and prepared the medicated serum. The active compounds of Qinghao-Kushen were verified by the LC-MS method. Next, we detected key targets from PubChem, SymMap, SwissTargetPrediction, DisGeNET, and GeneCards databases. Subsequently, the mechanism of Qinghao-Kushen was predicted by network pharmacology strategy and primarily examined in HuH-7 cells, HepG2 cells, and HepG2215 cells. Results. The effect of the Qinghao-Kushen combination was significantly better than that of single Qinghao or single Kushen in HepG2 and HuH-7 cells. Qinghao-Kushen increased the expression of activated caspase-3 protein than Qinghao or Kushen alone in HepG2 and HepG2215 cells. Network analyses and the LC-MS method revealed that the pivotal compounds of Qinghao-Kushen were matrine and scopoletin. GSK-3β was one of the critical molecules related to Qinghao-Kushen. We confirmed that Qinghao-Kushen and matrine-scopoletin decreased the expression of GSK-3β in HepG2 cells while increased GSK-3β expression in HepG2215 cells. Conclusions. This work not only illustrated that the practical components of Qinghao-Kushen on HCC were matrine and scopoletin but shed light on the inhibitory of Qinghao-Kushen and matrine-scopoletin on liver cancer cells. Moreover, Qinghao-Kushen and matrine-scopoletin had a synergistic effect over the drug alone in HuH-7, HepG2, or HepG2215 cells. GSK-3β may be a potential target for HCC therapy.

Sex-determining Region Y-box transcription factor 13 promotes breast cancer cell proliferation and glycolysis by activating the tripartite motif containing 11-mediated Wnt/β-catenin signaling pathway

Breast cancer is the most frequent cancer among women and the second highest mortality in female across the world. Recent studies have illustrated that sex-determining region Y (SRY)-box protein (SOX) family plays essential roles in regulating various cancers. Nevertheless, the detailed effects of SOX13 on breast cancer are still uncovered. In our present study, SOX13 protein level was measured by using western blot assay in tissues and cells, and the results showed that SOX13 was upregulated in breast cancer tissues and cells compared with normal samples. Moreover, silencing SOX13 inhibited breast cancer cell viability, arrested cell cycle at G1/S phase and suppressed glycolysis, while overexpression of SOX13 reversed these events. Additionally, SOX13 knockdown reduced the level of proteins related to Wnt/β-catenin signaling pathway, whereas overexpression of tripartite motif containing 11 (TRM11) efficiently attenuated the effects, indicating that SOX13 controlled Wnt/β-catenin pathway depending on TRIM11. Furthermore, the data gained from xenograft tumor model illustrated that silencing SOX13 suppressed the tumor growth in nude mice and the glycolysis of tissues. In conclusion, our investigation illustrated that SOX13 facilitated breast cancer cell proliferation and glycolysis by modulating Wnt/β-catenin signaling pathway affected via TRIM11.

GSK-3α/β Activity Negatively Regulates MMP-1/9 Expression to Suppress Mycobacterium tuberculosis Infection

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) infection is the deadliest infectious disease and a global health problem. Macrophages (Mφs) and neutrophils that can phagocytose Mtb represent the first line of immune response to infection. Glycogen synthase kinase-3α/β (GSK-3α/β) represents a regulatory switch in host immune responses. However, the efficacy and molecular mechanisms of how GSK-3α/β interacts with Mtb infection in Mφs remain undefined. Here, we demonstrated that Mtb infection downregulated GSK-3α/β activity and promoted matrix metalloproteinase-1 (MMP-1) and MMP-9 expressions in Mφs derived from acute monocytic human leukemia THP-1 cells (THP-1-Mφs). We confirmed the upregulation of MMP-9 expression in tissues of TB patients compared with patients of chronic inflammation (CI). In THP-1-Mφs and C57BL/6 mice, GSK-3α/β inhibitor SB216763 significantly increased MMP-1/9 production and facilitated Mtb load, while MMP inhibitors blocked MMP-1/9 expression and Mtb infection. Consistently, GSK-3α/β silencing significantly increased MMP-1/9 expression and Mtb infection, while overexpression of GSK-3α/β and constitutive activated GSK-3α/β mutants significantly reduced MMP-1/9 expression and Mtb infection in THP-1-Mφs. MMP-1/9 silencing reduced Mtb infection, while overexpression of MMP-1/9 promoted Mtb infection in THP-1-Mφs. We further found that GSK-3α/β inhibition increased Mtb infection and MMP-1/9 expression was blocked by ERK1/2 inhibitor. Additionally, we showed that protein kinase C-δ (PKC-δ) and mammalian target of rapamycin (mTOR) reduced GSK-3α/β activity and promoted MMP-1/9 production in Mtb-infected THP-1-Mφs. In conclusion, this study suggests that PKC-δ-mTOR axis suppresses GSK-3α/β activation with acceleration of MMP-1/9 expression through phospho-ERK1/2. These results reveal a novel immune escape mechanism of Mtb and a novel crosstalk between these critical signaling pathways in anti-TB immunity.

Ad-apoptin inhibits glycolysis, migration and invasion in lung cancer cells targeting AMPK/mTOR signaling pathway

Ad-apoptin is a recombinant oncolytic adenovirus constructed by our laboratory that can express apoptin. It can selectively kill tumor cells without damaging normal cells. This study investigated the effects of Ad-apoptin on glycolysis, migration and invasion of non-small cell lung cancer. Cell viability and apoptosis were detected by CCK-8 and flow cytometry, respectively. Glycolysis was investigated by glucose consumption, lactic acid production and glycolytic key enzyme protein levels. Migration and invasion were evaluated via wound healing, transwell assays and epithelial-mesenchymal transition (EMT) protein levels. The interaction between apoptin and AMPK was detected by Co-IP. A nude mice tumor model was established to investigate the anti-cancer role of Ad-apoptin in vivo. The results showed that Ad-apoptin inhibits cell viability and induces apoptosis of A549 and NCI-H23 cells. Ad-apoptin can reduce the glucose uptake and lactic production in lung cancer cells, and reduce the expression of related glycolysis-limiting enzymes. At the same time, Ad-apoptin inhibited the migration and invasion of lung cancer. Immunoprecipitation showed that apoptin and AMPK could interact directly. Moreover, knockdown of AMPK significantly attenuated the inhibitory effect of Ad-apoptin on glycolysis, migration and invasion of A549 and NCI-H23 cells. Ad-apoptin can inhibit the growth of tumors in nude mice. Compared with the control group, Ad-apoptin had a significant inhibitory effect on AMPK knockdown tumors. The immunohistochemical results of tumor tissues were consistent with those in vitro. Collectively, Ad-apoptin targets AMPK and inhibits glycolysis, migration and invasion of lung cancer cells through the AMPK/mTOR signaling pathway. This suggests that Ad-apoptin may have therapeutic potential for lung cancer by targeting AMPK activation.

Targeting the PI3K/Akt/mTOR Pathway in Hepatocellular Carcinoma

Despite advances in the treatment of cancers through surgical procedures and new pharmaceuticals, the treatment of hepatocellular carcinoma (HCC) remains challenging as reflected by low survival rates. The PI3K/Akt/mTOR pathway is an important signaling mechanism that regulates the cell cycle, proliferation, apoptosis, and metabolism. Importantly, deregulation of the PI3K/Akt/mTOR pathway leading to activation is common in HCC and is hence the subject of intense investigation and the focus of current therapeutics. In this review article, we consider the role of this pathway in the pathogenesis of HCC, focusing on its downstream effectors such as glycogen synthase kinase-3 (GSK-3), cAMP-response element-binding protein (CREB), forkhead box O protein (FOXO), murine double minute 2 (MDM2), p53, and nuclear factor-κB (NF-κB), and the cellular processes of lipogenesis and autophagy. In addition, we provide an update on the current ongoing clinical development of agents targeting this pathway for HCC treatments.

Identification of Gene Signature as Diagnostic and Prognostic Blood Biomarker for Early Hepatocellular Carcinoma Using Integrated Cross-Species Transcriptomic and Network Analyses

Background: Hepatocellular carcinoma (HCC) is considered the most common type of liver cancer and the fourth leading cause of cancer-related deaths in the world. Since the disease is usually diagnosed at advanced stages, it has poor prognosis. Therefore, reliable biomarkers are urgently needed for early diagnosis and prognostic assessment. Methods: We used genome-wide gene expression profiling datasets from human and rat early HCC (eHCC) samples to perform integrated genomic and network-based analyses, and discovered gene markers that are expressed in blood and conserved in both species. We then used independent gene expression profiling datasets for peripheral blood mononuclear cells (PBMCs) for eHCC patients and from The Cancer Genome Atlas (TCGA) database to estimate the diagnostic and prognostic performance of the identified gene signature. Furthermore, we performed functional enrichment, interaction networks and pathway analyses. Results: We identified 41 significant genes that are expressed in blood and conserved across species in eHCC. We used comprehensive clinical data from over 600 patients with HCC to verify the diagnostic and prognostic value of 41-gene-signature. We developed a prognostic model and a risk score using the 41-geneset that showed that a high prognostic index is linked to a worse disease outcome. Furthermore, our 41-gene signature predicted disease outcome independently of other clinical factors in multivariate regression analysis. Our data reveals a number of cancer-related pathways and hub genes, including EIF4E, H2AFX, CREB1, GSK3B, TGFBR1, and CCNA2, that may be essential for eHCC progression and confirm our gene signature's ability to detect the disease in its early stages in patients' biological fluids instead of invasive procedures and its prognostic potential. Conclusion: Our findings indicate that integrated cross-species genomic and network analysis may provide reliable markers that are associated with eHCC that may lead to better diagnosis, prognosis, and treatment options.

QNZ alleviated hepatocellular carcinoma by targeting inflammatory pathways in a rat model

The pathogenicity of HCC could be enhanced by TNF-α and NFκB, which are crucial parts of the inflammatory pathway inside the HCC microenvironment. Therefore, we aimed to discover the therapeutic effects of QNZ, an inhibitor of both TNF-α and NFκB, in an experimental model of HCC in rats. HCC was experimentally induced in rats by thioacetamide, and some of the rats were treated with QNZ. The expression levels of nuclear factor (NF)κB, tumor necrosis factor (TNF)-α, apoptosis signal regulating kinase (ASK)-1, β-catenin, glycogen synthase kinase (GSK)-3 and TNF receptor-associated factor (TRAF) were examined in hepatic samples. In addition, hepatic tissues were stained with hematoxylin/eosin and anti-TNF-α antibodies. QNZ blocked HCC-induced expression of both NFκB and TNF-α. It significantly reduced both α-fetoprotein and the average number of nodules and increased the survival rate of the HCC rats. Moreover, hematoxylin and eosin liver sections from the HCC rats showed vacuolated cytoplasm and necrotic nodules. All of these effects were alleviated by QNZ treatment. Finally, treating HCC rats with QNZ resulted in a reduction in the expression of TRAF, ASK-1 and β-catenin, as well as increased expression of GSK-3. In conclusion, inhibition of the inflammatory pathway in HCC with QNZ produced therapeutic effects, as indicated by an increased survival rate, reduced serum α-fetoprotein levels, decreased liver nodules and improved the hepatocyte structure. In addition, QNZ significantly reduced the expression of TRAF, ASK-1 and β-catenin that were associated with increased expression of GSK-3.

Glycolysis-related gene expression profiling serves as a novel prognosis risk predictor for human hepatocellular carcinoma

Metabolic pattern reconstruction is an important factor in tumor progression. Metabolism of tumor cells is characterized by abnormal increase in anaerobic glycolysis, regardless of high oxygen concentration, resulting in a significant accumulation of energy from glucose sources. These changes promotes rapid cell proliferation and tumor growth, which is further referenced a process known as the Warburg effect. The current study reconstructed the metabolic pattern in progression of cancer to identify genetic changes specific in cancer cells. A total of 12 common types of solid tumors were included in the current study. Gene set enrichment analysis (GSEA) was performed to analyze 9 glycolysis-related gene sets, which are implicated in the glycolysis process. Univariate and multivariate analyses were used to identify independent prognostic variables for construction of a nomogram based on clinicopathological characteristics and a glycolysis-related gene prognostic index (GRGPI). The prognostic model based on glycolysis genes showed high area under the curve (AUC) in LIHC (Liver hepatocellular carcinoma). The findings of the current study showed that 8 genes (AURKA, CDK1, CENPA, DEPDC1, HMMR, KIF20A, PFKFB4, STMN1) were correlated with overall survival (OS) and recurrence-free survival (RFS). Further analysis showed that the prediction model accurately distinguished between high- and low-risk cancer patients among patients in different clusters in LIHC. A nomogram with a well-fitted calibration curve based on gene expression profiles and clinical characteristics showed good discrimination based on internal and external cohorts. These findings indicate that changes in expression level of metabolic genes implicated in glycolysis can contribute to reconstruction of tumor-related microenvironment.

Inhibition of FSTL3 abates the proliferation and metastasis of renal cell carcinoma via the GSK-3β/β-catenin signaling pathway

Renal cell carcinoma (RCC) is a lethal malignancy of the genitourinary system. Follistatin-like 3 (FSTL3), which mediates cell differentiation and growth, acts as a biomarker of tumors and participates in cancer development and progression. Presently, the FSTL3’s functions in RCC were investigated. Quantitative reverse transcription PCR (qRT-PCR), Western Blot, and enzyme linked immunosorbent assay (ELISA) were conducted to verify FSTL3 expression in RCC tissues and cell lines. BrdU assay and CCK8 experiment were made to monitor cell proliferation. Transwell was implemented to examine the invasion of the cells. Flow cytometry analyzed cell apoptosis, and Western Blot evaluated the protein levels of E-cadherin, Twist, and Slug. In the meantime, the protein profiles of the GSK-3β, β-catenin, and TGF-β signaling pathways were ascertained. Moreover, the Xenograft tumor model was constructed in nude mice for measuring tumor growth in vivo. The statistics showed that FSTL3 presented an overexpression in RCC, and patients with a lower expression of FSTL3 manifested a better prognosis. Down-regulated FSTL3 hampered the proliferation, invasion, EMT, and tumor growth of RCC cells and caused cell apoptosis. On the contrary, FSTL3 overexpression enhanced the malignant behaviors of RCC cells. Furthermore, FSTL3 knockdown bolstered GSK-3β, suppressed β-catenin, and reduced BMP1-SMAD pathway activation. Inhibited β-catenin substantially mitigated FSTL3-mediated promoting functions in RCC. In short, FSTL3 functions as an oncogene in RCC by modulating the GSK-3β/β-catenin signaling pathway.

Inositol serves as a natural inhibitor of mitochondrial fission by directly targeting AMPK

Mitochondrial dynamics regulated by mitochondrial fusion and fission maintain mitochondrial functions, whose alterations underline various human diseases. Here, we show that inositol is a critical metabolite directly restricting AMPK-dependent mitochondrial fission independently of its classical mode as a precursor for phosphoinositide generation. Inositol decline by IMPA1/2 deficiency elicits AMPK activation and mitochondrial fission without affecting ATP level, whereas inositol accumulation prevents AMPK-dependent mitochondrial fission. Metabolic stress or mitochondrial damage causes inositol decline in cells and mice to elicit AMPK-dependent mitochondrial fission. Inositol directly binds to AMPKγ and competes with AMP for AMPKγ binding, leading to restriction of AMPK activation and mitochondrial fission. Our study suggests that the AMP/inositol ratio is a critical determinant for AMPK activation and establishes a model in which AMPK activation requires inositol decline to release AMPKγ for AMP binding. Hence, AMPK is an inositol sensor, whose inactivation by inositol serves as a mechanism to restrict mitochondrial fission.

Phosphorylation of NF-κBp65 drives inflammation-mediated hepatocellular carcinogenesis and is a novel therapeutic target

BACKGROUND

Nuclear factor-κB (NF-κB) plays a vital role in hepatocellular carcinoma (HCC). β-arrestin1 (ARRB1) has been proved to enhance the activity of NF-κBp65, and our previous study indicated that ARRB1 promotes hepatocellular carcinogenesis and development of HCC. However, it remains unknown whether p65 is involved in hepatocellular carcinogenesis through the ARRB1-mediated pathway.

METHODS

The levels of NF-κBp65 and NF-κBp65 phosphorylation (p-p65) were assessed in including normal liver, primary HCC and paired paracancerous tissues. Liver-specific p65 knockout mice were used to examine the role of p65 and p-p65 in hepatocarcinogenesis. The mechanism of NF-κBp65 and p-p65 in hepatocarcinogenesis via ARRB1 was also studied both in vitro and in vivo.

RESULTS

Phosphorylation of NF-κBp65 was markedly upregulated in inflammation-related HCC patients and was significantly increased in mouse hepatic inflammation models, which were induced by tetrachloromethane (CCl₄), diethylnitrosamine (DEN), TNF-α, as well as DEN-induced HCC. Hepatocyte-specific p65-deficient mice markedly decreased in the HCC incidence and size of tumours by the repressing of the proliferation of malignant cells in a DEN-induced HCC model. Furthermore, ARRB1 directly bounds p65 to promote the phosphorylation of NF-κBp65 at ser536, resulted in cell malignant proliferation through GSK3β/mTOR signalling.

CONCLUSION

The data demonstrated that phosphorylation of NF-κBp65 drives hepatocellular carcinogenesis in response to inflammation-mediated ARRB1, and that inhibition of the phosphorylation of NF-κBp65 restrains the hepatocellular carcinogenesis. The results indicate that phosphorylation of NF-κBp65 is a novel therapeutic target for HCC.

Inhibition of cell proliferation and promotion of acinus-like structure formation from goat mammary epithelial cells via Wnt/β-catenin signaling

Mammary epithelial cells have been suggested to be central to control the expansion and remodeling of mammary gland. Wnt/β-catenin signaling modulates cell fate in animals throughout their life span, and represents indispensable roles in tissue homeostasis, cell renewal, and regeneration in organs. Here, we utilized the small molecule 6-bromoindirubin-3'-oxime (BIO), an activator of Wnt/β-catenin signaling, and investigated whether Wnt/β-catenin signaling regulated the proliferation and acinus-like structure formation of goat mammary epithelial cells (GMECs). We showed that isolated GMECs displayed the typical epithelial cobblestone morphology and expressed specific markers of mammary epithelial cells. BIO inhibited the proliferation of GMECs and decreased the expression of proliferation marker c-myc and cell cycle protein cyclin D1. However, the ability of GMECs to form spheroids was accelerated, and the level of E-cadherin mRNA was upregulated with BIO treatment. E-cadherin showed a bright cytomembrane with DMSO treatment, yet E-cadherin was present in cytomembrane and cytoplasm in GMECs with BIO treatment. Meanwhile, BIO increased the protein level of β-catenin and enhanced the translocation of β-catenin into the nucleus in GMECs. Furthermore, the mRNA level of Axin2 was also upregulated. This study suggested that Wnt/β-catenin signaling may play an important role in the proliferation and the acinus-like formation of GMECs.

HBx induces hepatocellular carcinogenesis through ARRB1-mediated autophagy to drive the G1/S cycle

The hepatitis B virus X protein (HBx) is involved in the process of hepatocellular carcinoma via the activation of various oncogenes. Our previous study indicated that ARBB1 (arrestin beta 1) promotes hepatocellular carcinogenesis (HCC). However, the role of ARRB1 in HBx-related HCC remains unclear. Herein, we identified that ARRB1 was upregulated by HBx in vivo and in vitro. Arrb1 deficiency suppressed HBx-induced hepatocellular carcinogenesis in several mouse models. Furthermore, knockdown of ARRB1 blocked HBx-induced macroautophagic/autophagic flux and disrupted the formation of autophagosomes. ARRB1 interacted with HBx, and the autophagic core protein MAP1LC3/LC3, a scaffolding protein, was essential for complete autophagy. Inhibition of autophagy by 3-methyladenine or interference of ATG5 or ATG7 attenuated HBx-induced cell cycle acceleration and the subsequent proliferative response via the induction of G₁/S arrest. The absence of autophagy abolished the phosphorylation of CDK2 and the activity of the CDK2-CCNE1 complex. Our results demonstrate that ARRB1 plays a critical role in HBV-related HCC via modulating autophagy and the CDKN1B-CDK2-CCNE1-E2F1 axis and indicate that ARRB1 may be a potential therapeutic target for HCC.

Propofol activates AMPK to inhibit the growth of HepG2 cells in vitro and hepatocarcinogenesis in xenograft mouse tumor models by inducing autophagy

Background

Hepatocellular carcinoma (HCC) is a fatal malignant tumor with a poor prognosis, and is the third leading cause of cancer-related deaths worldwide. This study aimed to investigate the anti-tumor effect of propofol on the proliferation, apoptosis, and cell cycle of HCC by regulating adenosine monophosphate-activated protein kinase (AMPK) in vivo and in vitro.

Methods

The cell counting Kit-8 (CCK-8) assay was employed to screen the effect of propofol on HepG2 cell viability at various concentrations (0.3, 0.6, 1.2, 2.5, 5, 10, 20, 40, 80 and 160 µM). We selected propofol at concentrations of 5, 10 and 20 µM for subsequent experiments. Flow cytometry was used to examine the apoptosis and cell cycle of HCC. Quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) was applied to measure the messenger ribonucleic acid (mRNA) expression levels of proliferating cell nuclear antigen (PCNA) and survivin. Western blotting was applied to measure the protein expression levels of PCNA, survivin, cleaved caspase-3, cleaved caspase-9, p27 (Kip1), and cyclin A. The effects of propofol were evaluated by establishing a xenograft tumor model.

Results

After treatment with propofol, the mRNA expression levels of PCNA and survivin were decreased compared with the 0 µM propofol (control) group. The colony formation assay showed that the colony formation rate was obviously down-regulated. Flow cytometry demonstrated that HepG2 cell apoptosis was increased. G0/G1 was enhanced compared with the control group, while G2/M was restrained. The levels of cleaved caspase-3, cleaved caspase-9, p27, phospho-AMP-activated protein kinase α1 (p-AMPKα1), phospho-mammalian target of rapamycin (p-mTOR), and phospho-Unc-51 like autophagy activating kinase 1 (p-ULK1) were notably elevated, while the levels of cyclin A were suppressed. The xenograft tumor volume declined in vivo compared with the HepG2 xenograft group. The expression levels of cell proliferation markers (PCNA) were significantly down-regulated markedly, while the expression levels of cell cycle markers (p27) were notablyup-regulated. Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining showed that cell apoptosis was increased. The levels of p-AMPKα1 were also up-regulated.

Conclusions

Propofol inhibits the proliferation, apoptosis, and cell cycle of HCC by regulating AMPK in vivo and in vitro.

UBE2O promotes hepatocellular carcinoma cell proliferation and invasion by regulating the AMPKα2/mTOR pathway

The ubiquitin-conjugating enzyme (E2) is a critical component of the ubiquitin-proteasome system and regulates hepatocarcinogenesis by controlling protein degradation. Ubiquitin-conjugating enzyme E2 O (UBE2O), a member of the E2 family, functions as an oncogene in human cancers. Nevertheless, the role of UBE2O in hepatocellular carcinoma (HCC) remains unknown yet. Here, we demonstrated that the UBE2O level was markedly upregulated in HCC compared with adjacent noncancerous tissues. UBE2O overexpression was also confirmed in HCC cell lines. UBE2O overexpression was prominently associated with advanced tumor stage, high tumor grade, venous infiltration, and reduced HCC patients' survivals. UBE2O knockdown inhibited the migration, invasion, and proliferation of HCCLM3 cells. UBE2O overexpression enhanced the proliferation and mobility of Huh7 cells. Mechanistically, UBE2O mediated the ubiquitination and degradation of AMP-activated protein kinase α2 (AMPKα2) in HCC cells. UBE2O silencing prominently increased AMPKα2 level and reduced phosphorylated mechanistic target of rapamycin kinase (p-mTOR), MYC, Cyclin D1, HIF1α, and SREBP1 levels in HCCLM3 cells. UBE2O depletion markedly activated the AMPKα2/mTOR pathway in Huh7 cells. Moreover, AMPKα2 silencing reversed UBE2O downregulation-induced mTOR pathway inactivation. Rapamycin, an inhibitor of mTOR, remarkably abolished UBE2O-induced mTOR phosphorylation and HCC cell proliferation and mobility. To conclude, UBE2O was highly expressed in HCC and its overexpression conferred to the poor clinical outcomes of patients. UBE2O contributed to the malignant behaviors of HCC cells, including cell proliferation, migration, and invasion, by reducing AMPKα2 stability and activating the mTOR pathway.

AT1R/GSK-3β/mTOR Signaling Pathway Involved in Angiotensin II-Induced Neuronal Apoptosis after HIE Both In Vitro and In Vivo

Objective

The focus of the present study is to evaluate the effects of Angiotensin II (Ang II) on neuronal apoptosis after HIE and the potential underlying mechanisms.

Methods

Primary neonatal rat cortical neurons were used to study the oxygen-glucose deprivation (OGD) cell model. The expressions of Ang II, AT1R, GSK-3β, p-GSK-3β, mTOR, p-mTOR, Bax, Bcl-2, and cleaved caspase-3 were detected via western blot. IF and flow cytometry were used to evaluate neuronal apoptosis. Hypoxic-ischemic encephalopathy (HIE) was established to evaluate the therapeutic effects of Ang II in vivo. Cerebral infarction areas were detected by 2,3,5-Triphenyltetrazolium chloride staining. The righting and geotaxis reflexes were also recorded. In addition, Fluoro-Jade C staining and TUNEL staining were performed to evaluate neuronal degeneration and apoptosis.

Results

Ang II significantly increased the rate of neuronal apoptosis, upregulated the expression of cleaved caspase-3, and downregulated Bcl-2/Bax ratio after OGD insult. For vivo assay, the expressions of endogenous Ang II and AT1R gradually increased and peaked at 24 h after HIE. Ang II increased NeuN-positive AT1R cell expression. In addition, Ang II increased the area of cerebral infarction, promoted neuronal degeneration and apoptosis, aggravated neurological deficits on righting and geotaxis reflexes, and was accompanied by increased expressions of phosphorylated GSK-3β and mTOR. The application of valsartan (Ang II inhibitor) or SB216763 (GSK-3β inhibitor) reversed these phenomena triggered by Ang II following HIE.

Conclusion

Ang II increased neuronal apoptosis through the AT1R/GSK-3β/mTOR signaling pathway after experimental HIE both in vitro and in vivo, and Ang II may serve as a novel therapeutic target to ameliorate brain injury after HIE.

NMIIA promotes tumorigenesis and prevents chemosensitivity in colorectal cancer by activating AMPK/mTOR pathway

Non-muscle myosin IIA (NMIIA) has been reported to be involved in the carcinogenesis and malignant progression of various human tumors. However, the role and potential mechanism of NMIIA in the biological functions and apoptosis in colorectal cancer (CRC) remain elusive. In this study, we found that NMIIA was overexpressed in CRC tissues and significantly associated with poor survival in CRC patients. In addition, NMIIA promoted CRC cell proliferation and invasion via activating the AMPK/mTOR pathway in vitro, and NMIIA knockdown inhibited CRC growth in vivo. Meanwhile, NMIIA knockdown downregulated the CSCs markers (CD44 and CD133) expression in CRC cells. Furthermore, AMPK/mTOR pathway activation effectively reversed the NMIIA knockdown-induced inhibition of proliferation, invasion and stemness in CRC cells. Finally, NMIIA protects CRC cells from 5-FU-induced apoptosis and proliferation inhibition through the AMPK/mTOR pathway. Taken together, these results indicate that NMIIA plays a pivotal role in CRC growth and progression by regulating AMPK/mTOR pathway activation, and it may act as a novel therapeutic target prognostic factor in CRC.

Circular RNA circ_0000517 regulates hepatocellular carcinoma development via miR-326/IGF1R axis

BACKGROUND

Circular RNAs (circRNAs) play vital roles in hepatocellular carcinoma development. However, the role and mechanism of circRNA hsa_circ_0000517 (circ_0000517) in hepatocellular carcinoma development were largely unknown.

METHODS

45 paired tumor and adjacent nontumor samples were collected from hepatocellular carcinoma patients. The levels of circ_0000517, miR-326 and insulin-like growth factor type 1 receptor (IGF1R) were detected via quantitative reverse transcription polymerase chain reaction or western blot. Cell viability, colony ability, migration, invasion and glycolysis were assessed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, western blot, transwell assay, glucose consumption, lactate production or adenosine triphosphate (ATP) production. The target correlation between miR-326 and circ_0000517 or IGF1R was analyzed via dual-luciferase reporter analysis. The function of circ_0000517 in vivo was assessed via xenograft model.

RESULTS

circ_0000517 expression was elevated in hepatocellular carcinoma tissues and cell lines. circ_0000517 knockdown suppressed cell viability, colony formation, migration, invasion and glycolysis. miR-326 was sponged via circ_0000517 and miR-326 knockdown reversed the effect of circ_0000517 silence on hepatocellular carcinoma development. miR-326 overexpression inhibited hepatocellular carcinoma development through targeting IGF1R. circ_0000517 knockdown decreased IGF1R expression by modulating miR-326. circ_0000517 downregulation reduced xenograft tumor growth.

CONCLUSION

circ_0000517 knockdown repressed hepatocellular carcinoma development in vitro and in vivo by modulating miR-326 and IGF1R.

MiR-5683 suppresses glycolysis and proliferation through targeting pyruvate dehydrogenase kinase 4 in gastric cancer

Gastric cancer (GC) is one of the most deadly malignancies at global scale, and is particularly common in eastern Asia. MicroRNA‐5683 (miR‐5683) was confirmed to be downregulated in GC by analyzing data from the Cancer Genome Atlas. We packaged miR‐5683‐mimics and miR‐5683‐inhibitors into lentivirus vectors and transfected them into GC cells. MiR‐5683 expression and possible target genes were detected by employing quantitative real‐time polymerase chain reaction. In vitro, cell proliferation and apoptosis were analyzed using CCK‐8, colony formation assay, and flow cytometric assay. We verified the direct interaction between miR‐5683 and the possible downstream target gene pyruvate dehydrogenase kinase 4 (PDK4) through luciferase reporter assay. The role of miR‐5683 in vivo was explored by injecting stably transfected GC cells subcutaneously into nude mice. Here we show that miR‐5683 was downregulated in GC and the decreased level of miR‐5683 enhances GC cell proliferation and impairs apoptosis. Tumor oncogene PDK4, which is associated with GC overall survival and disease‐free survival, has been identified as the target gene of miR‐5683. Besides, we demonstrate that the inhibition of miR‐5683 promotes glycolysis by upregulating the PDK4 expression, thus leading to GC progression. Our study determines that miR‐5683 represses GC glycolysis and progression through targeting PDK4. MiR‐5683 overexpression may thus become a new treatment strategy for GC.

WHSC1 Promotes Cell Proliferation, Migration, and Invasion in Hepatocellular Carcinoma by Activating mTORC1 Signaling

Background

Wolf-Hirschhorn syndrome candidate gene-1 (WHSC1) plays key regulatory roles in cancer development and progression. However, its specific functions and potential mechanisms of action remain to be described in hepatocellular carcinoma (HCC).

Materials and Methods

WHSC1 expression in HCC was evaluated using The Cancer Genome Atlas and verified in HCC tissues and cell lines using qRT-PCR, Western blotting, and immunohistochemistry. Functional assays were performed to explore the role of WHSC1 in HCC progression. Immunoprecipitation-mass spectrometry, co-immunoprecipitation, immunofluorescence, and immunohistochemistry were conducted to evaluate the interaction between WHSC1 and prolyl 4-hydroxylase subunit beta (P4HB). Pathway enrichment was performed using gene set enrichment analysis.

Results

WHSC1 was markedly overexpressed in HCC tissues and cell lines. The level of expression was strongly associated with adverse clinicopathological characteristics. Survival analyses revealed that WHSC1 upregulation predicted poor overall survival and higher recurrence rates in patients with HCC. Functional studies revealed that WHSC1 significantly stimulated HCC proliferation, migration, and invasion in vitro and in vivo. WHSC1 was shown to interact with P4HB to stimulate P4HB expression and subsequently activate mTOR1 signaling.

Conclusion

We determined the oncogenic role of WHSC1 in HCC, via P4HB interaction, which activates mTOR1 signaling, and identified WHSC1 as a promising therapeutic target for HCC.

Glucometabolic Reprogramming in the Hepatocellular Carcinoma Microenvironment: Cause and Effect

Hepatocellular carcinoma (HCC) is a tumor that exhibits glucometabolic reprogramming, with a high incidence and poor prognosis. Usually, HCC is not discovered until an advanced stage. Sorafenib is almost the only drug that is effective at treating advanced HCC, and promising metabolism-related therapeutic targets of HCC are urgently needed. The “Warburg effect” illustrates that tumor cells tend to choose aerobic glycolysis over oxidative phosphorylation (OXPHOS), which is closely related to the features of the tumor microenvironment (TME). The HCC microenvironment consists of hypoxia, acidosis and immune suppression, and contributes to tumor glycolysis. In turn, the glycolysis of the tumor aggravates hypoxia, acidosis and immune suppression, and leads to tumor proliferation, angiogenesis, epithelial–mesenchymal transition (EMT), invasion and metastasis. In 2017, a mechanism underlying the effects of gluconeogenesis on inhibiting glycolysis and blockading HCC progression was proposed. Treating HCC by increasing gluconeogenesis has attracted increasing attention from scientists, but few articles have summarized it. In this review, we discuss the mechanisms associated with the TME, glycolysis and gluconeogenesis and the current treatments for HCC. We believe that a treatment combination of sorafenib with TME improvement and/or anti-Warburg therapies will set the trend of advanced HCC therapy in the future.

Emerging roles and the regulation of aerobic glycolysis in hepatocellular carcinoma

Liver cancer has become the sixth most diagnosed cancer and the fourth leading cause of cancer death worldwide. Hepatocellular carcinoma (HCC) is responsible for up to 75–85% of primary liver cancers, and sorafenib is the first targeted drug for advanced HCC treatment. However, sorafenib resistance is common because of the resultant enhancement of aerobic glycolysis and other molecular mechanisms. Aerobic glycolysis was firstly found in HCC, acts as a hallmark of liver cancer and is responsible for the regulation of proliferation, immune evasion, invasion, metastasis, angiogenesis, and drug resistance in HCC. The three rate-limiting enzymes in the glycolytic pathway, including hexokinase 2 (HK2), phosphofructokinase 1 (PFK1), and pyruvate kinases type M2 (PKM2) play an important role in the regulation of aerobic glycolysis in HCC and can be regulated by many mechanisms, such as the AMPK, PI3K/Akt pathway, HIF-1α, c-Myc and noncoding RNAs. Because of the importance of aerobic glycolysis in the progression of HCC, targeting key factors in its pathway such as the inhibition of HK2, PFK or PKM2, represent potential new therapeutic approaches for the treatment of HCC.

LncRNA BCAR4 promotes liver cancer progression by upregulating ANAPC11 expression through sponging miR‑1261

Liver cancer is a malignant tumor that occurs in the liver and can be divided into primary and secondary liver cancer. Long non-coding RNA (lncRNA) breast cancer anti-estrogen resistance 4 (BCAR4) has been demonstrated to promote the development of various types of cancer. However, the function of lncRNA BCAR4 in liver cancer remains unclear. In the present study, the expression of lncRNA BCAR4 was notably elevated in liver cancer compared with adjacent non-tumor tissues. Functional in vitro assays demonstrated that knockdown of lncRNA BCAR4 inhibited the proliferation, migration and invasion of Huh-7 cells. In addition, lncRNA BCAR4 was demonstrated to directly bind to microRNA (miR)-1261, and miR-1261 expression negatively correlated with the expression of lncRNA BCAR4. Through bioinformatics analysis, lncRNA BCAR4 was predicted to target anaphase-promoting complex subunit 11 (ANAPC11) through miR-1261. In addition, the results demonstrated that lncRNA BCAR4 increased the expression of ANAPC11 by inhibiting miR-1261 expression. Consistently, overexpression of ANAPC11 or inhibition of miR-1261 significantly rescued liver cancer cell proliferation induced by knockdown of lncRNA BCAR4. Collectively, the results of the present study demonstrated that lncRNA BCAR4 may promote liver cancer development by directly binding to miR-1261 and targeting ANAPC11.

Synaptopodin-2 promotes hepatocellular carcinoma metastasis via calcineurin-induced nuclear-cytoplasmic translocation

Hepatocellular carcinoma (HCC), a type of malignant liver tumor, has a grim prognosis. As a functional protein, synaptopodin-2 (SYNPO2) has been associated with malignancy; however, the expression profile and function of SYNPO2 in HCC remains unknown. Herein, we revealed that SYNPO2 was transcriptionally downregulated in HCC tissues from both The Cancer Genome Atlas cohort and our cohort, and was also decreased at the translational level as determined by western blotting and immunohistochemical staining. Furthermore, reduced SYNPO2 expression correlated significantly with short overall survival and recurrence free survival of HCC patients. Restoring SYNPO2 expression inhibited the proliferation and aggressiveness of hepatocarcinoma cells. Mechanistically, increasing the ratio of cytoplasmic SYNPO2 to nuclear SYNPO2 was positively associated with recurrence rate in HCC patients; calcineurin (CaN) activity positively correlated with cytoplasmic SYNPO2 levels in HCC tissues; and nuclear-cytoplasmic translocation of SYNPO2 was induced by CaN to facilitate metastasis of HCC through assembly of peripheral actin bundles. In short, our findings uncover a novel role of SYNPO2 in HCC metastasis via the CaN/SYNPO2/F-actin axis, and indicate that SYNPO2 may serve as a possible prognostic marker and novel therapeutic target.

NOD2 inhibits tumorigenesis and increases chemosensitivity of hepatocellular carcinoma by targeting AMPK pathway

Nucleotide binding oligomerization domain 2 (NOD2) is a recognized innate immune sensor which can initiate potent immune response against pathogens. Many innate immune sensors have been reported to be of great importance in carcinogenesis. However, the role of NOD2 in cancer is not well understood. Here we investigated the role of NOD2 in the development of hepatocellular carcinoma (HCC). We demonstrated that NOD2 deficiency promoted hepatocarcinogenesis in N-nitrosodiethylamine (DEN)/carbon tetrachloride (CCl₄) induced HCC mice model and xenograft tumor model. In vitro investigation showed that NOD2 acted as a tumor suppressor and inhibited proliferation, colony formation and invasion of HCC cells. Clinical investigation showed that NOD2 expression was completely lost or significantly downregulated in clinical HCC tissues, and loss of NOD2 expression was significantly correlated with advanced disease stages. Further investigation showed that NOD2 exerted its anti-tumor effect through activating adenosine 5'-monophosphate (AMP) -activated protein kinase (AMPK) signaling pathway, and NOD2 significantly enhanced the sensitivity of HCC cells to sorafenib, lenvatinib and 5-FU treatment through activating AMPK pathway induced apoptosis. Moreover, we demonstrated that NOD2 activated AMPK pathway by directly binding with AMPKα-LKB1 complex, which led to autophagy-mediated apoptosis of HCC cells. Altogether, this study showed that NOD2 acted as a tumor suppressor as well as a chemotherapeutic regulator in HCC cells by directly activating AMPK pathway, which indicated a potential therapeutic strategy for HCC treatment by upregulating NOD2-AMPK signaling axis.

Crosstalks of GSK3 signaling with the mTOR network and effects on targeted therapy of cancer

The introduction of therapeutics targeting specific tumor-promoting oncogenic or non-oncogenic signaling pathways has revolutionized cancer treatment. Mechanistic (previously mammalian) target of rapamycin (mTOR), a highly conserved Ser/Thr kinase, is a central hub of the phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR network, one of the most frequently deregulated signaling pathways in cancer, that makes it an attractive target for therapy. Numerous mTOR inhibitors have progressed to clinical trials and two of them have been officially approved as anticancer therapeutics. However, mTOR-targeting drugs have met with a very limited success in cancer patients. Frequently, the primary impediment to a successful targeted therapy in cancer is drug-resistance, either from the very beginning of the therapy (innate resistance) or after an initial response and upon repeated drug treatment (evasive or acquired resistance). Drug-resistance leads to treatment failure and relapse/progression of the disease. Resistance to mTOR inhibitors depends, among other reasons, on activation/deactivation of several signaling pathways, included those regulated by glycogen synthase kinase-3 (GSK3), a protein that targets a vast number of substrates in its repertoire, thereby orchestrating many processes that include cell proliferation and survival, metabolism, differentiation, and stemness. A detailed knowledge of the rewiring of signaling pathways triggered by exposure to mTOR inhibitors is critical to our understanding of the consequences such perturbations cause in tumors, including the emergence of drug-resistant cells. Here, we provide the reader with an updated overview of intricate circuitries that connect mTOR and GSK3 and we relate them to the efficacy (or lack of efficacy) of mTOR inhibitors in cancer cells.