Acetyl-coenzyme A carboxylase alpha promotion of glucose-mediated fatty acid synthesis enhances survival of hepatocellular carcinoma in mice and patients

Targeting lipid metabolism via nanomedicine: A prospective strategy for cancer therapy

Lipid metabolism has been increasingly recognized to play an influencing role in tumor initiation, progression, metastasis, and therapeutic drug resistance. Targeting lipid metabolic reprogramming represents a promising therapeutic strategy. Despite their structural complexity and poor targeting efficacy, lipid-metabolizing drugs, either used alone or in combination with chemotherapeutic agents, have been employed in clinical practice. The advent of nanotechnology offers new approaches to enhancing therapeutic effects, includingthe targeted delivery and integration of lipid metabolic reprogramming with chemotherapy, photodynamic therapy (PDT), and immunotherapy. The integrated nanoformulation, nanomedicine, could significantly advance the field of lipid metabolism therapy. In this review, we will briefly introduce the concept of cancer lipid metabolism reprogramming, then elaborate the latest advances in engineered nanomedicine for targeting lipid metabolism during cancer treatment, and finally provide our insights into future perspectives of nanomedicine for interference with lipid metabolism in the tumor microenvironment.

From genes to therapy: a lipid Metabolism-Related genetic risk model predicts HCC outcomes and enhances immunotherapy

BACKGROUND

Hepatocellular Carcinoma (HCC) is related to dysregulated lipid metabolism and immunosuppressive microenvironment. This study developed a genetic risk model using lipid metabolism-related genes to predict survival and immune patterns in HCC patients.

METHODS

Differentially expressed genes (DEGs) related to lipid metabolism were identified in HCC via the TCGA-LIHC dataset. A risk model for survival prediction was constructed via DEGs related to survival. The immune signature associated with the risk model was also evaluated by the CIBERSORT algorithm, tumor immune dysfunction and exclusion algorithm, and single sample gene set enrichment analysis.

RESULTS

This study identified six lipid metabolism-related genes, ADH4, LCAT, CYP2C9, CYP17A1, LPCAT1, and ACACA, to construct a lipid metabolism-related gene risk model that can divide HCC patients into low- and high-risk groups. Internal and external validation verified that the risk model could be a signature that could effectively predict HCC patient prognosis. High-risk patients showed disrupted immune cell profiles, reduced tumor-killing capacity, and increased expression of immune checkpoint genes. However, they responded more favorably to immune checkpoint inhibitor (ICB) therapy. The top ten hub genes related to the risk model were associated with tumor progression and deteriorating prognosis. In vitro experiments verified that the downregulation of the top 1 hub gene CDK1 was correlated to the HCC cell proliferation.

CONCLUSION

The risk model constructed using lipid metabolism-related genes could effectively predict prognosis and was related to the immunosuppressive microenvironment and ICB immunotherapy. The hub genes related to the risk model were potential therapeutic targets.

Comprehensive insights of etiological drivers of hepatocellular carcinoma: Fostering targeted nano delivery to anti-cancer regimes

Hepatocellular carcinoma (HCC) stands as one of the most prevalent and deadliest malignancies on a global scale. Its complex pathogenesis arises from multifactorial etiologies, including viral infections, metabolic syndromes, and environmental carcinogens, all of which drive genetic and molecular aberrations in hepatocytes. This intricate condition is associated with multiple causative factors, resulting in the abnormal activation of various cellular and molecular pathways. Given that HCC frequently manifests within the context of a compromised or cirrhotic liver, coupled with the tendency of late-stage diagnoses, the overall prognosis tends to be unfavorable. Systemic therapy, especially conventional cytotoxic drugs, generally proves ineffective. Despite advancements in therapeutic interventions, conventional treatments such as chemotherapy often exhibit limited efficacy and substantial systemic toxicity. In this context, nanomedicine, particularly lipid-based nanoparticles (LNPs), has emerged as a promising strategy for enhancing drug delivery specificity and reducing adverse effects. This review provides a comprehensive overview of the molecular and metabolic underpinnings of HCC. Furthermore, we explored the role of lipid-based nano-formulations including liposomes, solid lipid nanoparticles, and nanostructured lipid carriers in targeted drug delivery for HCC. We have highlighted recent advances in LNP-based delivery approaches, FDA-approved drugs, and surface modification strategies to improve liver-specific delivery and therapeutic efficacy. It will provide a comprehensive summary of various treatment strategies, recent clinical advances, receptor-targeting strategies and the role of lipid composition in cellular uptake. The review concludes with a critical assessment of existing challenges and future prospects in nanomedicines-driven HCC therapy.

Lipid metabolism analysis reveals that DGAT1 regulates Th17 survival by controlling lipid peroxidation in uveitis

Lipid metabolism is closely linked with antitumor immunity and autoimmune disorders. However, the precise role of lipid metabolism in uveitis pathogenesis is not clear. In our study, we analyzed the single-cell RNA-Seq (scRNA-Seq) data from cervical draining lymph nodes (CDLNs) of mice with experimental autoimmune uveitis (EAU), revealing an increased abundance of fatty acids in Th17 cells. Subsequent scRNA-Seq analysis identified the upregulation of DGAT1 expression in EAU and its marked reduction under various immunosuppressive agents. Suppression of DGAT1 prevented the conversion of fatty acids into neutral lipid droplets, resulting in the accumulation of lipid peroxidation and subsequent reduction in the proportion of Th17 cells. Inhibiting lipid peroxidation by Ferrostatin-1 effectively restored Th17 cell numbers that were decreased by DGAT1 inhibitor. Moreover, we validated the upregulation of DGAT1 in CD4+ T cells from patients with Vogt-Koyanagi-Harada (VKH) disease, a human uveitis. Inhibiting DGAT1 induced lipid peroxidation in human CD4+ T cells and reduced the proportion of Th17 cells. Collectively, our study focused on elucidating the regulatory mechanisms underlying Th17 cell survival and proposed that targeting DGAT1 may hold promise as a therapeutic approach for uveitis.

LCAT deficiency promotes hepatocellular carcinoma progression and lenvatinib resistance by promoting triglyceride catabolism and fatty acid oxidation

Lecithin cholesterol acyltransferase (LCAT), a crucial enzyme in lipid metabolism, plays important yet poorly understood roles in tumours, especially in hepatocellular carcinoma (HCC). In this study, our investigation revealed that LCAT is a key downregulated metabolic gene and an independent risk factor for poor prognosis in patients with HCC. Functional experiments showed that LCAT inhibited HCC cell proliferation, migration and invasion. Mechanistically, LCAT interacts with caveolin-1 (CAV1) to promote the binding of CAV1 to PRKACA and inhibit its phosphorylation, thereby inhibiting triglyceride (TAG) catabolism. On the other hand, LCAT inhibits fatty acid oxidation (FAO) by interacting with CPT1A to promote its ubiquitination and degradation. These events result in an inadequate supply of raw materials and energy and inhibit the malignant behaviours of HCC cells. In addition, LCAT is a reliable predictive biomarker for the efficacy of lenvatinib treatment in HCC patients, and the inhibition of FAO can increase lenvatinib sensitivity in patients with LCATlow HCC. This study revealed that LCAT plays a critical role in the regulation of lipid metabolic reprogramming and is a reliable predictive biomarker for the efficacy of lenvatinib treatment in HCC patients.

Metabolic reprogramming in hepatocellular carcinoma: mechanisms and therapeutic implications

Hepatocellular carcinoma features extensive metabolic reprogramming. This includes alterations in major biochemical pathways such as glycolysis, the pentose phosphate pathway, amino acid metabolism and fatty acid metabolism. Moreover, there is a complex interplay among these altered pathways, particularly involving acetyl-CoA (coenzyme-A) metabolism and redox homeostasis, which in turn influences reprogramming of other metabolic pathways. Understanding these metabolic changes and their interactions with cellular signaling pathways offers potential strategies for the targeted treatment of hepatocellular carcinoma and improved patient outcomes. This review explores the specific metabolic alterations observed in hepatocellular carcinoma and highlights their roles in the progression of the disease.

Mitochondrial alterations and signatures in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer worldwide. Its primary risk factors are chronic liver diseases such as metabolic fatty liver disease, non-alcoholic steatohepatitis, and hepatitis B and C viral infections. These conditions contribute to a specific microenvironment in liver tumors which affects mitochondrial function. Mitochondria are energy producers in cells and are responsible for maintaining normal functions by controlling mitochondrial redox homeostasis, metabolism, bioenergetics, and cell death pathways. HCC involves abnormal mitochondrial functions, such as accumulation of reactive oxygen species, oxidative stress, hypoxia, impairment of the mitochondrial unfolded protein response, irregularities in mitochondrial dynamic fusion/fission mechanisms, and mitophagy. Cell death mechanisms, such as necroptosis, pyroptosis, ferroptosis, and cuproptosis, contribute to hepatocarcinogenesis and play a significant role in chemoresistance. The relationship between mitochondrial dynamics and HCC is thus noteworthy. In this review, we summarize the recent advances in mitochondrial alterations and signatures in HCC and attempt to elucidate its molecular biology. Here, we provide an overview of the mitochondrial processes involved in hepatocarcinogenesis and offer new insights into the molecular pathology of the disease. This may help guide future research focused on improving patient outcomes using innovative therapies.

Metabolic Crossroad Between Macrophages and Cancer Cells: Overview of Hepatocellular Carcinoma

The metabolic interplay between macrophages and cancer cells mirrors the plasticity of both kinds of cells, which adapt to the microenvironment by sustaining cell growth and proliferation. In this way, cancer cells induce macrophage polarization, and, on the other hand, tumor-associated macrophages (TAMs) contribute to the survival of cancer cells. In a simplified manner, macrophages can assume two opposite subtypes: M1, pro-inflammatory and anti-tumor phenotype, and M2, anti-inflammatory and protumor phenotype. How do cancer cells induce macrophage polarization? Any actor involved in tumor growth, including the mitochondria, releases molecules into the tumor microenvironment (TME) that trigger a subtype transition. These metabolic changes are the primary cause of this polarization. Hepatocellular carcinoma (HCC), the prevalent type of liver primary tumor, is characterized by cells with extensive metabolic adaptions due to high flexibility in different environmental conditions. This review focuses on the main metabolic features of M1 and M2 macrophages and HCC cells underlying their metabolic behavior in response to TME.

The role of metabolic reprogramming in liver cancer and its clinical perspectives

Primary liver cancer (PLC), which includes hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), remains a leading cause of cancer-related death worldwide. Chronic liver diseases, such as hepatitis B and C infections and metabolic dysfunction-associated steatotic liver disease (MASLD), are key risk factors for PLC. Metabolic reprogramming, a defining feature of cancer, enables liver cancer cells to adapt to the demands of rapid proliferation and the challenging tumor microenvironment (TME). This manuscript examines the pivotal role of metabolic reprogramming in PLC, with an emphasis on the alterations in glucose, lipid, and amino acid metabolism that drive tumor progression. The Warburg effect, marked by increased glycolysis, facilitates rapid energy production and biosynthesis of cellular components in HCC. Changes in lipid metabolism, including elevated de novo fatty acid synthesis and lipid oxidation, support membrane formation and energy storage essential for cancer cell survival. Amino acid metabolism, particularly glutamine utilization, supplies critical carbon and nitrogen for nucleotide synthesis and maintains redox homeostasis. These metabolic adaptations not only enhance tumor growth and invasion but also reshape the TME, promoting immune escape. Targeting these metabolic pathways presents promising therapeutic opportunities for PLC. This review underscores the interaction between metabolic reprogramming and tumor immunity, suggesting potential metabolic targets for innovative therapeutic strategies. A comprehensive understanding of PLC's intricate metabolic landscape may lead to more effective treatments and better patient outcomes. Integrating metabolomics, genomics, and proteomics in future research will be vital for identifying precise therapeutic targets and advancing personalized therapies for liver cancer.

The Role of Fatty Acid Metabolism, the Related Potential Biomarkers, and Targeted Therapeutic Strategies in Gastrointestinal Cancers

Gastrointestinal cancer has emerged as a significant global health concern due to its high incidence and mortality, limited effectiveness of early detection, suboptimal treatment outcomes, and poor prognosis. Metabolic reprogramming is a prominent feature of cancer, and fatty acid metabolism assumes a pivotal role in bridging glucose metabolism and lipid metabolism. Fatty acids play important roles in cellular structural composition, energy supply, signal transduction, and other lipid-related processes. Changes in the levels of fatty acid metabolite may indicate the malignant transformation of gastrointestinal cells, which have an impact on the prognosis of patients and can be used as a marker to monitor the efficacy of anticancer therapy. Therefore, targeting key enzymes involved in fatty acid metabolism, either as monotherapy or in combination with other agents, is a promising strategy for anticancer treatment. This article reviews the potential mechanisms of fatty acid metabolism disorders in the occurrence and development of gastrointestinal tumors, and summarizes the related potential biomarkers and anticancer strategies.

Regulation of fatty acid synthase on tumor and progress in the development of related therapies

ABSTRACT

Fatty acid synthase (FASN) is an essential molecule in lipid metabolic pathways, which are crucial for cancer-related studies. Recent studies have focused on a comprehensive understanding of the novel and important regulatory effects of FASN on malignant biological behavior and immune-cell infiltration, which are closely related to tumor occurrence and development, immune escape, and immune response. FASN-targeting antitumor treatment strategies are being developed. Therefore, in this review, we focused on the effects of FASN on tumor and immune-cell infiltration and reviewed the progress of related anti-tumor therapy development.

Forkhead box M1 mediates metabolic reprogramming in human colorectal cancer cells

Metabolic reprogramming is recognized as a hallmark of cancer, enabling cancer cells to acquire essential biomolecules for cell growth, often characterized by upregulated glycolysis and/or fatty acid synthesis-related genes. The transcription factor forkhead box M1 (FOXM1) has been implicated in various cancers, contributing significantly to their development, including colorectal cancer (CRC), a major global health concern. Despite FOXM1's established role in cancer, its specific involvement in the Warburg effect and fatty acid biosynthesis in CRC remains unclear. We analyzed The Cancer Genome Atlas (TCGA) Colonic Adenocarcinoma and Rectal Adenocarcinoma (COADREAD) datasets to derive the correlation of the expression levels between FOXM1 and multiple genes and the survival prognosis based on FOXM1 expression. Using two human CRC cell lines, HT29 and HCT116, we conducted RNAi or plasmid transfection procedures, followed by a series of assays, including RNA extraction, quantitative real-time polymerase chain reaction, Western blot analysis, cell metabolic assay, glucose uptake assay, Oil Red O staining, cell viability assay, and immunofluorescence analysis. Higher expression levels of FOXM1 correlated with a poorer survival prognosis, and the expression of FOXM1 was positively correlated with glycolysis-related genes SLC2A1 and LDHA, de novo lipogenesis-related genes ACACA and FASN, and MYC. FOXM1 appeared to modulate AKT/mammalian target of rapamycin (mTOR) signaling, the expression of c-Myc, proteins related to glycolysis and fatty acid biosynthesis, and glucose uptake, as well as extracellular acidification rate in HT29 and HCT116 cells. In summary, FOXM1 plays a regulatory role in glycolysis, fatty acid biosynthesis, and cellular energy consumption, thereby influencing CRC cell growth and patient prognosis.NEW & NOTEWORTHY Transcription factor forkhead box M1 (FOXM1) regulates glycolysis, fatty acid biosynthesis, and cellular energy consumption, which, together, controls cell growth and patient prognosis in colorectal cancer (CRC).

Roles of the peroxisome proliferator-activated receptors (PPARs) in the pathogenesis of hepatocellular carcinoma (HCC)

Hepatocellular carcinoma (HCC) holds a prominent position among global cancer types. Classically, HCC manifests in individuals with a genetic predisposition when they encounter risk elements, particularly in the context of liver cirrhosis. Peroxisome proliferator-activated receptors (PPARs), which are transcription factors activated by fatty acids, belong to the nuclear hormone receptor superfamily and play a pivotal role in the regulation of energy homeostasis. At present, three distinct subtypes of PPARs have been recognized: PPARα, PPARγ, and PPARβ/δ. They regulate the transcription of genes responsible for cellular development, energy metabolism, inflammation, and differentiation. In recent years, with the rising incidence of HCC, there has been an increasing focus on the mechanisms and roles of PPARs in HCC. PPARα primarily mediates the occurrence and development of HCC by regulating glucose and lipid metabolism, inflammatory responses, and oxidative stress. PPARβ/δ is closely related to the self-renewal ability of liver cancer stem cells (LCSCs) and the formation of the tumor microenvironment. PPARγ not only influences tumor growth by regulating the glucose and lipid metabolism of HCC, but its agonists also have significant clinical significance for the treatment of HCC. Therefore, this review offers an exhaustive examination of the role of the three PPAR subtypes in HCC progression, focusing on their mediation of critical cellular processes such as glucose and lipid metabolism, inflammation, oxidative stress, and other pivotal signaling pathways. At the end of the review, we discuss the merits and drawbacks of existing PPAR-targeted therapeutic strategies and suggest a few alternative combinatorial therapeutic approaches that diverge from conventional methods.

Ficolin 3 promotes ferroptosis in HCC by downregulating IR/SREBP axis-mediated MUFA synthesis

BACKGROUND

Targeting ferroptosis has been identified as a promising approach for the development of cancer therapies. Monounsaturated fatty acid (MUFA) is a type of lipid that plays a crucial role in inhibiting ferroptosis. Ficolin 3 (FCN3) is a component of the complement system, serving as a recognition molecule against pathogens in the lectin pathway. Recent studies have reported that FCN3 demonstrates inhibitory effects on the progression of certain tumors. However, whether FCN3 can modulate lipid metabolism and ferroptosis remains largely unknown.

METHODS

Cell viability, BODIPY-C11 staining, and MDA assay were carried out to detect ferroptosis. Primary hepatocellular carcinoma (HCC) and xenograft models were utilized to investigate the effect of FCN3 on the development of HCC in vivo. A metabonomic analysis was conducted to assess alterations in intracellular and HCC intrahepatic lipid levels.

RESULTS

Our study elucidates a substantial decrease in the expression of FCN3, a component of the complement system, leads to MUFA accumulation in human HCC specimens and thereby significantly promotes ferroptosis resistance. Overexpression of FCN3 efficiently sensitizes HCC cells to ferroptosis, resulting in the inhibition of the oncogenesis and progression of both primary HCC and subcutaneous HCC xenograft. Mechanistically, FCN3 directly binds to the insulin receptor β (IR-β) and its pro-form (pro-IR), inhibiting pro-IR cleavage and IR-β phosphorylation, ultimately resulting in IR-β inactivation. This inactivation of IR-β suppresses the expression of sterol regulatory element binding protein-1c (SREBP1c), which subsequently suppresses the transcription of genes related to de novo lipogenesis (DNL) and lipid desaturation, and consequently downregulates intracellular MUFA levels.

CONCLUSIONS

These findings uncover a novel regulatory mechanism by which FCN3 enhances the sensitivity of HCC cells to ferroptosis, indicating that targeting FCN3-induced ferroptosis is a promising strategy for HCC treatment.

Smilax China L. polysaccharide prevents HFD induced-NAFLD by regulating hepatic fat metabolism and gut microbiota

BACKGROUND

The increasing incidence of nonalcoholic fatty liver disease (NAFLD) has urged the development of new therapeutics. NAFLD is intimately linked to gut microbiota due to the hepatic portal system, and utilizing natural polysaccharides as prebiotics has become a prospective strategy for preventing NAFLD. Smilax china L. polysaccharide (SCP) possesses excellent hepatoprotective and anti-inflammatory activity. However, its protective effects on NAFLD remains unclear.

PURPOSE

The goal of this study was to explore the protective effects of SCP on high-fat diet (HFD)-induced NAFLD mice by regulating hepatic fat metabolism and gut microbiota.

METHODS

Extraction and isolation from Smilax china L. rhizome to obtain SCP. C57BL/6 J mice were distributed to six groups: Control (normal chow diet), HFD-fed mice were assigned to HFD, simvastatin (SVT), and low-, medium-, high-doses of SCP for 12 weeks. The body, liver, and different adipose tissues weights were detected, and lipids in serum and liver were assessed. RT-PCR and Western blot were used to detect the hepatic fat metabolism-related genes and proteins. Gut microbiota of cecum contents was profiled through 16S rRNA gene sequencing.

RESULTS

SCP effectively reversed HFD-induced increase weights of body, liver, and different adipose tissues. Lipid levels of serum and liver were also significantly reduced after SCP intervention. According to the results of RT-PCR and western blot analysis, SCP treatment up-regulated the genes and proteins related to lipolysis were up-regulated, while lipogenesis-related genes and proteins were down-regulated. Furthermore, the HFD-induced dysbiosis of intestinal microbiota was similarly repaired by SCP intervention, including enriching beneficial bacteria and depleting harmful bacteria.

CONCLUSION

SCP could effectively prevent HFD-induced NAFLD, might be considered as a prebiotic agent due to its excellent effects on altering hepatic fat metabolism and maintaining gut microbiota homeostasis.

Apigenin Suppresses MED28-Mediated Cell Growth in Human Liver Cancer Cells

Flavonoids exhibit health-promoting benefits against multiple chronic diseases, including cancer. Apigenin (4',5,7-trihydroxyflavone), one flavonoid present in fruits and vegetables, is potentially applicable to chemoprevention. Despite considerable progress in the therapeutic regimen of liver cancer, its prognosis remains poor. MED28, a Mediator subunit for transcriptional activation, is implicated in the development of several types of malignancy; however, its role in liver cancer is unknown at present. In liver cancer, the AKT/mammalian target of rapamycin (mTOR) is one major pathway involved in the oncogenic process. The aim of this study is to investigate the role of apigenin and MED28 in AKT/mTOR signaling in liver cancer. We first identified a connectivity score of 92.77 between apigenin treatment and MED28 knockdown in several cancer cell lines using CLUE, a cloud-based software platform to assess connectivity among compounds and genetic perturbagens. Higher expression of MED28 predicted a poorer survival prognosis; MED28 expression in liver cancer tissue was significantly higher than that of normal tissue, and it was positively correlated with tumor stage and grade in The Cancer Genome Atlas Liver Cancer (TCGA-LIHC) data set. Knockdown of MED28 induced cell cycle arrest and suppressed the AKT/mTOR signaling in two human liver cancer cell lines, HepG2 and Huh 7, accompanied by less lipid accumulation and lower expression and nuclear localization of sterol regulatory element binding protein 1 (SREBP1). Apigenin inhibited the expression of MED28, and the effect of apigenin mimicked that of the MED28 knockdown. On the other hand, the AKT/mTOR signaling was upregulated when MED28 was overexpressed. These data indicated that MED28 was associated with the survival prognosis and the progression of liver cancer by regulating AKT/mTOR signaling and apigenin appeared to inhibit cell growth through MED28-mediated mTOR signaling, which may be applicable as an adjuvant of chemotherapy or chemoprevention in liver cancer.

Loss of lncRNA LINC01056 leads to sorafenib resistance in HCC

BACKGROUND AND AIMS

Sorafenib is a major nonsurgical option for patients with advanced hepatocellular carcinoma (HCC); however, its clinical efficacy is largely undermined by the acquisition of resistance. The aim of this study was to identify the key lncRNA involved in the regulation of the sorafenib response in HCC.

MATERIALS AND METHODS

A clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) single-guide RNA (sgRNA) synergistic activation mediator (SAM)-pooled lncRNA library was applied to screen for the key lncRNA regulated by sorafenib treatment. The role of the identified lncRNA in mediating the sorafenib response in HCC was examined in vitro and in vivo. The underlying mechanism was delineated by proteomic analysis. The clinical significance of the expression of the identified lncRNA was evaluated by multiplex immunostaining on a human HCC microtissue array.

RESULTS

CRISPR/Cas9 lncRNA library screening revealed that Linc01056 was among the most downregulated lncRNAs in sorafenib-resistant HCC cells. Knockdown of Linc01056 reduced the sensitivity of HCC cells to sorafenib, suppressing apoptosis in vitro and promoting tumour growth in mice in vivo. Proteomic analysis revealed that Linc01056 knockdown in sorafenib-treated HCC cells induced genes related to fatty acid oxidation (FAO) while repressing glycolysis-associated genes, leading to a metabolic switch favouring higher intracellular energy production. FAO inhibition in HCC cells with Linc01056 knockdown significantly restored sensitivity to sorafenib. Mechanistically, we determined that PPARα is the critical molecule governing the metabolic switch upon Linc01056 knockdown in HCC cells and indeed, PPARα inhibition restored the sorafenib response in HCC cells in vitro and HCC tumours in vivo. Clinically, Linc01056 expression predicted optimal overall and progression-free survival outcomes in HCC patients and predicted a better sorafenib response. Linc01056 expression indicated a low FAO level in HCC.

CONCLUSION

Our study identified Linc01056 as a critical epigenetic regulator and potential therapeutic target in the regulation of the sorafenib response in HCC.

Regulation of lipid metabolism by E3 ubiquitin ligases in lipid-associated metabolic diseases

Previous studies have progressively elucidated the involvement of E3 ubiquitin (Ub) ligases in regulating lipid metabolism. Ubiquitination, facilitated by E3 Ub ligases, modifies critical enzymes in lipid metabolism, enabling them to respond to specific signals. In this review, we aim to present a comprehensive analysis of the role of E3 Ub ligases in lipid metabolism, which includes lipid synthesis and lipolysis, and their influence on cellular lipid homeostasis through the modulation of lipid uptake and efflux. Furthermore, it explores how the ubiquitination process governs the degradation or activation of pivotal enzymes, thereby regulating lipid metabolism at the transcriptional level. Perturbations in lipid metabolism have been implicated in various diseases, including hepatic lipid metabolism disorders, atherosclerosis, diabetes, and cancer. Therefore, this review focuses on the association between E3 Ub ligases and lipid metabolism in lipid-related diseases, highlighting enzymes critically involved in lipid synthesis and catabolism, transcriptional regulators, lipid uptake translocators, and transporters. Overall, this review aims to identify gaps in current knowledge, highlight areas requiring further research, offer potential targeted therapeutic approaches, and provide a comprehensive outlook on clinical conditions associated with lipid metabolic diseases.

LC-MS/MS method for the quantification of cortisol of hepatocellular carcinoma

The imbalance of steroid hormones is closely related to the occurrence and development of hepatocellular carcinoma (HCC). However, most research has focused on steroid hormone receptors, and reports about the relationship between the serum concentration of cortisol and the development of HCC are rare. The aim of this research was to establish a simple, specific, sensitive and reliable liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for the quantitation of cortisol in human serum and to compare the level of cortisol in serum between 221 HCC patients and 183 healthy volunteers. The results showed that the correlation coefficients of the linear regression with a weighing factor of 1/x2 ranged from 0.9933 to 0.9984 over the range of 2-1,000 ng/ml. The inter- and intra-day precision and accuracy were <10%. The matrix effect and recovery of cortisol were 94.9-102.5% and 96.3-99.8%, respectively. The concentration of cortisol in HCC patients was significantly higher than that in healthy volunteers (p < 0.05) and was not affected by sex, age, menopause or α-fetoprotein (AFP) level. The present study reveals that elevated cortisol might promote the progression of HCC.

Molecular mechanisms in MASLD/MASH-related HCC

Liver cancer is the third leading cause of cancer-related deaths and ranks as the sixth most prevalent cancer type globally. NAFLD or metabolic dysfunction-associated steatotic liver disease, and its more severe manifestation, NASH or metabolic dysfunction-associated steatohepatitis (MASH), pose a significant global health concern, affecting approximately 20%-25% of the population. The increased prevalence of metabolic dysfunction-associated steatotic liver disease and MASH is parallel to the increasing rates of obesity-associated metabolic diseases, including type 2 diabetes, insulin resistance, and fatty liver diseases. MASH can progress to MASH-related HCC (MASH-HCC) in about 2% of cases each year, influenced by various factors such as genetic mutations, carcinogen exposure, immune microenvironment, and microbiome. MASH-HCC exhibits distinct molecular and immune characteristics compared to other causes of HCC and affects both men and women equally. The management of early to intermediate-stage MASH-HCC typically involves surgery and locoregional therapies, while advanced HCC is treated with systemic therapies, including anti-angiogenic therapies and immune checkpoint inhibitors. In this comprehensive review, we consolidate previous research findings while also providing the most current insights into the intricate molecular processes underlying MASH-HCC development. We delve into MASH-HCC-associated genetic variations and somatic mutations, disease progression and research models, multiomics analysis, immunological and microenvironmental impacts, and discuss targeted/combined therapies to overcome immune evasion and the biomarkers to recognize treatment responders. By furthering our comprehension of the molecular mechanisms underlying MASH-HCC, our goal is to catalyze the advancement of more potent treatment strategies, ultimately leading to enhanced patient outcomes.

MTK, Orlowski SK. Effects of Environmental Enrichments on Welfare and Hepatic Metabolic Regulation of Broiler Chickens

The aims of this study were to find suitable environmental enrichment (EE) and evaluate the combined effect of two EEs, variable light intensity (VL) lighting program and EH, on mental health and hepatic metabolic regulation in commercial broilers. To find the advantageous EEs for broilers, three different EEs (board, hut, and ramp) were tested in trial 1. EEs were placed and the engagement of birds to EEs, dustbathing behavior, and daily physical activity were observed. Birds treated with huts showed higher engagement than the board- or ramp-treated birds (p < 0.05). The results of dustbathing behavior and daily physical activity indicated that the environmental hut (EH) is the most favorable enrichment for broilers. In the second trial, to test the effect of EHs on mental health and hepatic metabolic conditions, the brain and liver were sampled from the four treatment birds (20 lx_Con, 20 lx_Hut, VL_Con and VL_Hut) on day 42. The lower expression of TPH2 (tryptophan hydroxylase 2) of VL_Hut birds than those of VL_Con and 20 lx_Hut treated birds suggests the combining effect of EHs with the VL lighting program on the central serotonergic homeostasis of broilers. Reduced expressions of TH (tyrosine hydroxylase), GR (glucocorticoid receptor), BDNF (brain-derived neurotrophic factor) of VL_Hut treated birds compared to those of VL_Con and 20 lx_Hut birds suggest lower stress, stress susceptibility, and chronic social stress in VL_Hut treated birds. The expression of CPT1A (carnitine palmitoyl transferase 1) increased over three-fold in the liver of VL_Con birds compared to 20 lx_Con birds (p < 0.05). EHs treatment in VL birds (VL_Hut) significantly decreased CPT1A but not in 20 lx birds (20 lx_Hut). The expression of ACCα (acetyl-CoA carboxylase alpha) was significantly decreased in VL_Con birds compared to 20 lx_Con birds. There was no significant difference in the hepatic FBPase (fructose-1,6-bisphosphatase), GR, and 11β-HSD1 (11 β-hydroxysteroid dehydrogenease-1) expression between 20 lx_Con and VL_Con birds, but EHs significantly stimulated GR in 20 lx_Hut birds, and stimulated FBPase and 11β-HSD1 expression in the VL_Hut birds compared to 20 lx_Con birds, suggesting that the VL lighting program reduced fatty acid synthesis and increased fatty acid β-oxidation in the broilers' liver and VL_Hut improved the hepatic de novo glucose production. Taken together, the results suggest that the stimulated voluntary activity by EHs in the light-enriched broiler house improved mental health and hepatic metabolic function of broilers and may indicate that the improved hepatic metabolic function contributes to efficient nutritional support for broilers.

BAP18 acting as a novel peroxisome proliferator-activated receptor α co-regulator contributes to hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) is a common malignancy worldwide with a poor prognosis. The therapeutic outcomes of HCC patients are urgently needed to be improved, and predictive biomarkers for the optimal treatment selection remains to be further defined. In the present study, our results showed that BPTF-associated protein of 18 KDa (BAP18) was highly expressed in HCC tissues. In cultured HCC cells, BAP18 regulated a subset of down-stream genes involved in different functions, particularly including peroxisome proliferator-activated receptor (PPAR) pathway and lipid metabolism. Furthermore, BAP18 co-activated PPARα-mediated transactivation and facilitated the recruitment of nucleosome acetyltransferase of H4 (NuA4)/tat interacting protein 60 (TIP60) complex, thereby increasing histone H4 acetylation on stearoyl-CoA desaturase 1 (SCD1) loci. In addition, BAP18 promoted HCC cell proliferation, increased intracellular lipid levels and enhanced cell survival under the metabolic stress conditions, such as glucose limitation or tyrosine kinase inhibitors (TKIs) treatment. Importantly, higher BAP18 expression was positively correlated with the postoperative recurrence and the poor disease-free survival in clinical patients receiving sorafenib treatment. Altogether, we discovered that BAP18 plays an oncogenic role in the survival and proliferation of HCC cells, and BAP18 may serve as a predictive biomarker for adjunct TKIs treatment in patients with HCC, and further facilitate the precise treatment.

Metabolic reprogramming in the tumor microenvironment of liver cancer

The liver is essential for metabolic homeostasis. The onset of liver cancer is often accompanied by dysregulated liver function, leading to metabolic rearrangements. Overwhelming evidence has illustrated that dysregulated cellular metabolism can, in turn, promote anabolic growth and tumor propagation in a hostile microenvironment. In addition to supporting continuous tumor growth and survival, disrupted metabolic process also creates obstacles for the anticancer immune response and restrains durable clinical remission following immunotherapy. In this review, we elucidate the metabolic communication between liver cancer cells and their surrounding immune cells and discuss how metabolic reprogramming of liver cancer impacts the immune microenvironment and the efficacy of anticancer immunotherapy. We also describe the crucial role of the gut-liver axis in remodeling the metabolic crosstalk of immune surveillance and escape, highlighting novel therapeutic opportunities.

LncRNAs-circRNAs as Rising Epigenetic Binary Superstars in Regulating Lipid Metabolic Reprogramming of Cancers

As one of novel hallmarks of cancer, lipid metabolic reprogramming has recently been becoming fascinating and widely studied. Lipid metabolic reprogramming in cancer is shown to support carcinogenesis, progression, distal metastasis, and chemotherapy resistance by generating ATP, biosynthesizing macromolecules, and maintaining appropriate redox status. Notably, increasing evidence confirms that lipid metabolic reprogramming is under the control of dysregulated non-coding RNAs in cancer, especially lncRNAs and circRNAs. This review highlights the present research findings on the aberrantly expressed lncRNAs and circRNAs involved in the lipid metabolic reprogramming of cancer. Emphasis is placed on their regulatory targets in lipid metabolic reprogramming and associated mechanisms, including the clinical relevance in cancer through lipid metabolism modulation. Such insights will be pivotal in identifying new theranostic targets and treatment strategies for cancer patients afflicted with lipid metabolic reprogramming.

An integrative view on glucagon function and putative role in the progression of pancreatic neuroendocrine tumours (pNETs) and hepatocellular carcinomas (HCC)

Cancer metabolism research area evolved greatly, however, is still unknown the impact of systemic metabolism control and diet on cancer. It makes sense that systemic regulators of metabolism can act directly on cancer cells and activate signalling, prompting metabolic remodelling needed to sustain cancer cell survival, tumour growth and disease progression. In the present review, we describe the main glucagon functions in the control of glycaemia and of metabolic pathways overall. Furthermore, an integrative view on how glucagon and related signalling pathways can contribute for pancreatic neuroendocrine tumours (pNETs) and hepatocellular carcinomas (HCC) progression, since pancreas and liver are the major organs exposed to higher levels of glucagon, pancreas as a producer and liver as a scavenger. The main objective is to bring to discussion some glucagon-dependent mechanisms by presenting an integrative view on microenvironmental and systemic aspects in pNETs and HCC biology.

Recent advancements in nanomedicine based lipid metabolism for tumour immunotherapy

Therapy on lipid metabolism is emerging as a groundbreaking cancer treatment, offering the unprecedented opportunity to effectively treat and in several cases. Tumorigenesis is inextricably linked to lipid metabolism. In this regard, the features of lipid metabolism include lipid synthesis, decomposition, metabolism and lipid storage and mobilisation from intracellular lipid droplets. Most importantly, the regulation of lipid metabolism is central to the appropriate immune response of tumour cells, and ultimately to exert the immune efforts to realise the perspective of many anti-tumour effects. Different cancers and immune cells have different dependence on lipid metabolism, playing a pivotal role in differentiation and function of immune cells. However, what lies before the immunotherapy targeting lipid metabolism is side effects of systemic toxicity and defects of individual drugs, which strongly highlights that nanodelivery strategy is a magnet for it to enhance drug efficiency, reduce drug toxicity and improve application deficiencies. This review will first focus on emerging research progress of lipid metabolic reprogramming mechanism, and then explore the complex role of lipid metabolism in the tumour cells including the effect on immune cells and their nano-preparations of monotherapy and multiple therapies used in combination, in a shift away from conventional cancer research.HighlightsThe regulation of lipid metabolism is central to the appropriate immune response of tumour cells, and ultimately to exert the immune efforts to realise the perspective of many anti-tumour effects.Preparations of focusing lipid metabolism have side effects of systemic toxicity and defects of individual drugs. It strongly highlights that nanodelivery strategy is a magnet for it to enhance drug efficiency, reduce drug toxicity and improve application deficiencies.This review will first focus on emerging research progress of lipid metabolic reprogramming mechanism, and then explore the complex role of lipid metabolism in the tumour cells including the effect on immune cells as well as their nano-preparations of monotherapy and multiple therapies used in combination, in a shift away from conventional cancer research.

Metabolic reprogramming and its clinical implication for liver cancer

Cancer cells often encounter hypoxic and hypo-nutrient conditions, which force them to make adaptive changes to meet their high demands for energy and various biomaterials for biomass synthesis. As a result, enhanced catabolism (breakdown of macromolecules for energy production) and anabolism (macromolecule synthesis from bio-precursors) are induced in cancer. This phenomenon is called "metabolic reprogramming," a cancer hallmark contributing to cancer development, metastasis, and drug resistance. HCC and cholangiocarcinoma (CCA) are 2 different liver cancers with high intertumoral heterogeneity in terms of etiologies, mutational landscapes, transcriptomes, and histological representations. In agreement, metabolism in HCC or CCA is remarkably heterogeneous, although changes in the glycolytic pathways and an increase in the generation of lactate (the Warburg effect) have been frequently detected in those tumors. For example, HCC tumors with activated β-catenin are addicted to fatty acid catabolism, whereas HCC tumors derived from fatty liver avoid using fatty acids. In this review, we describe common metabolic alterations in HCC and CCA as well as metabolic features unique for their subsets. We discuss metabolism of NAFLD as well, because NAFLD will likely become a leading etiology of liver cancer in the coming years due to the obesity epidemic in the Western world. Furthermore, we outline the clinical implication of liver cancer metabolism and highlight the computation and systems biology approaches, such as genome-wide metabolic models, as a valuable tool allowing us to identify therapeutic targets and develop personalized treatments for liver cancer patients.

Diminishing acetyl-CoA carboxylase 1 attenuates CCA migration via AMPK-NF-κB-snail axis

Cholangiocarcinoma (CCA), a cancer of the biliary tract, is a significant health problem in Thailand. Reprogramming of cellular metabolism and upregulation of lipogenic enzymes have been revealed in CCA, but the mechanism is unclear. The current study highlighted the importance of acetyl-CoA carboxylase 1 (ACC1), a rate-limiting enzyme in de novo lipogenesis, on CCA migration. ACC1 expression in human CCA tissues was determined by immunohistochemistry. The results demonstrated that increased ACC1 was related to the shorter survival of CCA patients. Herein, ACC1-deficient cell lines (ACC1-KD) were generated by the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (cas9) system and were used for the comparative study. The ACC1 levels in ACC1-KD were 80-90 % lower than in parental cells. Suppression of ACC1 significantly reduced intracellular malonyl-CoA and neutral lipid contents. Two-fold growth retardation and 60-80 % reduced CCA cell migration and invasion were observed in ACC1-KD cells. The reduced 20-40 % of intracellular ATP levels, AMPK activation, lowered NF-κB p65 nuclear translocation, and snail expression were emphasized. Migration of ACC1-KD cells was restored by supplementation with palmitic acid and malonyl-CoA. Altogether, the importance of rate-limiting enzyme in de novo fatty acid synthesis, ACC1, and AMPK-NF-κB-snail axis on CCA progression was suggested herein. These might be the novel targets for CCA drug design. (ACC1, AMPK, Cholangiocarcinoma, De novo lipogenesis, NF-κB, Palmitic acid).

Metabolic Reprogramming of HCC: A New Microenvironment for Immune Responses

Hepatocellular carcinoma is the most common primary liver cancer, ranking third among the leading causes of cancer-related mortality worldwide and whose incidence varies according to geographical area and ethnicity. Metabolic rewiring was recently introduced as an emerging hallmark able to affect tumor progression by modulating cancer cell behavior and immune responses. This review focuses on the recent studies examining HCC's metabolic traits, with particular reference to the alterations of glucose, fatty acid and amino acid metabolism, the three major metabolic changes that have gained attention in the field of HCC. After delivering a panoramic picture of the peculiar immune landscape of HCC, this review will also discuss how the metabolic reprogramming of liver cancer cells can affect, directly or indirectly, the microenvironment and the function of the different immune cell populations, eventually favoring the tumor escape from immunosurveillance.

Multifaceted roles of aerobic glycolysis and oxidative phosphorylation in hepatocellular carcinoma

Liver cancer is a common malignancy with high morbidity and mortality rates. Changes in liver metabolism are key factors in the development of primary hepatic carcinoma, and mitochondrial dysfunction is closely related to the occurrence and development of tumours. Accordingly, the study of the metabolic mechanism of mitochondria in primary hepatic carcinomas has gained increasing attention. A growing body of research suggests that defects in mitochondrial respiration are not generally responsible for aerobic glycolysis, nor are they typically selected during tumour evolution. Conversely, the dysfunction of mitochondrial oxidative phosphorylation (OXPHOS) may promote the proliferation, metastasis, and invasion of primary hepatic carcinoma. This review presents the current paradigm of the roles of aerobic glycolysis and OXPHOS in the occurrence and development of hepatocellular carcinoma (HCC). Mitochondrial OXPHOS and cytoplasmic glycolysis cooperate to maintain the energy balance in HCC cells. Our study provides evidence for the targeting of mitochondrial metabolism as a potential therapy for HCC.

Immunometabolic factors contributing to obesity-linked hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major public health concern that is promoted by obesity and associated liver complications. Onset and progression of HCC in obesity is a multifactorial process involving complex interactions between the metabolic and immune system, in which chronic liver damage resulting from metabolic and inflammatory insults trigger carcinogenesis-promoting gene mutations and tumor metabolism. Moreover, cell growth and proliferation of the cancerous cell, after initiation, requires interactions between various immunological and metabolic pathways that provide stress defense of the cancer cell as well as strategic cell death escape mechanisms. The heterogenic nature of HCC in addition to the various metabolic risk factors underlying HCC development have led researchers to focus on examining metabolic pathways that may contribute to HCC development. In obesity-linked HCC, oncogene-induced modifications and metabolic pathways have been identified to support anabolic demands of the growing HCC cells and combat the concomitant cell stress, coinciding with altered utilization of signaling pathways and metabolic fuels involved in glucose metabolism, macromolecule synthesis, stress defense, and redox homeostasis. In this review, we discuss metabolic insults that can underlie the transition from steatosis to steatohepatitis and from steatohepatitis to HCC as well as aberrantly regulated immunometabolic pathways that enable cancer cells to survive and proliferate in the tumor microenvironment. We also discuss therapeutic modalities targeted at HCC prevention and regression. A full understanding of HCC-associated immunometabolic changes in obesity may contribute to clinical treatments that effectively target cancer metabolism.

A novel fatty acid metabolism-related gene prognostic signature and candidate drugs for patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. Fatty acid metabolism (FAM) is associated with the development and treatment of HCC. This study aimed to build a FAM-related gene model to assess the prognosis of HCC and provide guidance for individual treatment. RNA-sequencing data of patients with HCC from The Cancer Genome Atlas and Gene Expression Omnibus database (GSE14520) were extracted as the training and validation sets, respectively. A FAM-related gene predictive signature was built, and the performance of prognostic model was assessed. The immune infiltration and drug sensitivity were also evaluated. Quantitative real-time polymerase chain reaction and western blot were performed to evaluate the levels of the model genes. A 12-gene FAM-related risk signature was constructed; patients with a higher risk score had poorer prognosis than those with a lower risk score. Risk score was shown as an independent risk factor for overall survival of HCC, and the signature was further confirmed as an effective and accurate model. A nomogram was constructed, and it exhibited the good performance in the prognostic prediction. In addition, the immune cell infiltration and sensitivity to chemotherapy drugs were correlated with different risk levels. Finally, quantitative real-time polymerase chain reaction and western blot proved the changes of above genes. Differential expression of FAM-related genes can be used to predict response to immunotherapy and chemotherapy, and improve the clinical prognosis evaluation of patients with HCC, which provides new clues for further experimental exploration and verification on FAM-related genes in HCC.

Targeting SLP2-mediated lipid metabolism reprograming restricts proliferation and metastasis of hepatocellular carcinoma and promotes sensitivity to Lenvatinib

SLP2, a protein located on mitochondrial, has been shown to be associated with mitochondrial biosynthesis. Here we explored the potential mechanisms by which SLP2 regulates the development of hepatocellular carcinoma. SLP2 could bind to the c-terminal of JNK2 to affect the ubiquitinated proteasomal degradation pathway of JNK2 and maintain the protein stability of JNK2. The increase of JNK2 markedly increases SREBP1 activity, promoting SREBP1 translocation into the nucleus to promote de novo lipogenesis. Alteration of the JNK2 C-terminal disables SLP2 from mediating SLP2-enhanced de novo lipogenesis. YTHDF1 interacts with SLP2 mRNA in a METTL3/m⁶A-dependent manner. In a spontaneous HCC animal model, SLP2/c-Myc/sgP53 increases the incidence rate of spontaneous HCC, tumor volume, and tumor number. Importantly, statistical analyses show that levels of SLP2 correlate with tumor sizes, tumor metastasis, overall survival, and disease-free survival of the patients. Targeting the SLP2/SREBP1 pathway effectively inhibits proliferation and metastasis of HCC tumors with high SLP2 expression in vivo combined with lenvatinib. These results illustrate a direct lipogenesis-promoting role of the pro-oncogenic SLP2, providing a mechanistic link between de novo lipogenesis and HCC.

Unraveling the Sweet Secrets of HCC: Glucometabolic Rewiring in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the primary form of liver cancer. It causes ∼ 800 000 deaths per year, which is expected to increase due to increasing rates of obesity and metabolic dysfunction associated steatotic liver disease (MASLD). Current therapies include immune checkpoint inhibitors, tyrosine kinase inhibitors, and monoclonal antibodies, but these therapies are not satisfactorily effective and often come with multiple side effects and recurrences. Metabolic reprogramming plays a significant role in HCC progression and is often conserved between tumor types. Thus, targeting rewired metabolic pathways could provide an attractive option for targeting tumor cells alone or in conjunction with existing treatments. Therefore, there is an urgent need to identify novel targets involved in cancer-mediated metabolic reprogramming in HCC. In this review, we provide an overview of molecular rewiring and metabolic reprogramming of glucose metabolism in HCC to understand better the concepts that might widen the therapeutic window against this deadly cancer.

ACC2 is under-expressed in lung adenocarcinoma and predicts poor clinical outcomes

PURPOSE

Acetyl-CoA Carboxylases (ACCs) are key fatty acid metabolic enzymes responsible for catalyzing the carboxylation of acetyl-CoA to malonyl-CoA. The role of ACC1 has been associated with tumor biology, but the role of ACC2 in cancer remains largely uncharacterized.

METHODS

We conducted a transcriptomic analysis using GEPIA and Oncomine to study the expression of ACC2 in different cancers. Immunohistochemistry was used to examine the expression of ACC2 in lung cancer tissue microarray, and the correlation between ACC2 expression and clinical parameters was analyzed. Following ACC2 knockdown by RNA interference in A549 and HCC827 cells, Cell Counting Kit‑8 and transwell assays were used to detect cell proliferation and migration. Real-time PCR was used to detect cell cycle-related genes in A549 cells. GEO dataset and KM-plotter database were used to analyze the relationship between ACC2 expression and the prognosis in lung cancer patients.

RESULTS

We found that ACC2 is under-expressed in cancerous tissue and the expression of ACC2 is negatively correlated with tumor size, regional lymph-node metastases, and clinical stage of lung adenocarcinoma patients. In addition, knocking down ACC2 in A549 cells and HCC827 cells can promote cell proliferation and migration, and cell cycle-related genes MAD2L1 and CCNB2 were up-regulated after ACC2 was knockdown in A549 cells. Finally, we found that lung adenocarcinoma patients with under-expressed ACC2 have a worse prognosis.

CONCLUSIONS

Our results suggest that ACC2 is a potential diagnostic and prognostic marker that negatively correlated with clinical outcomes in lung adenocarcinoma.

The role of liver kinase B1 in tumor progression through regulation of lipid metabolism

The somatic mutation of liver kinase B1 (LKB1) has been implicated in various tumors, which is reflected in the survival, proliferation, and metastasis of tumor cells. However, the regulation of LKB1 in lipid metabolism, a process that is involved in tumor progression is not completely clear. We conclude that LKB1 deficiency results in abnormal expression and activation of multiple molecules related to lipid metabolism which locate downstream of AMP-activated protein kinase (AMPK) or salt-induced kinase (SIK). Abnormal lipid metabolism induced by LKB1 deficiency contributes to the proliferation and metastasis of tumor cells through energy regulation.

The role of lipid metabolism in tumor immune microenvironment and potential therapeutic strategies

Aberrant lipid metabolism is nonnegligible for tumor cells to adapt to the tumor microenvironment (TME). It plays a significant role in the amount and function of immune cells, including tumor-associated macrophages, T cells, dendritic cells and marrow-derived suppressor cells. It is well-known that the immune response in TME is suppressed and lipid metabolism is closely involved in this process. Immunotherapy, containing anti-PD1/PDL1 therapy and adoptive T cell therapy, is a crucial clinical cancer therapeutic strategy nowadays, but they display a low-sensibility in certain cancers. In this review, we mainly discussed the importance of lipid metabolism in the formation of immunosuppressive TME, and explored the effectiveness and sensitivity of immunotherapy treatment by regulating the lipid metabolism.

Epigallocatechin gallate triggers apoptosis by suppressing de novo lipogenesis in colorectal carcinoma cells

The de novo lipogenesis (DNL) pathway has been identified as a regulator of cancer progression and aggressiveness. Downregulation of key lipogenesis enzymes has been shown to activate apoptosis in cancerous cells. Epigallocatechin gallate (EGCG) inhibits cancer cell proliferation without causing cytotoxicity in healthy cells. The present study aimed to investigate the effects of EGCG on the promotion of apoptosis associated with the DNL pathway inhibition in cancer cells, both in vitro and in vivo. We observed that two colorectal cancer cell lines (HCT116 and HT-29) had a higher cytotoxic response to EGCG treatment than hepatocellular carcinoma cells, including HepG2 and HuH-7. EGCG treatment decreased cell viability and increased mitochondrial damage-triggered apoptosis in both HCT116 and HT-29 cancer cells. Additionally, we treated mice transplanted with HCT116 cells with 30 or 50 mg·kg-1 EGCG for 7 days to evaluate the apoptotic effects of EGCG treatment in a xenograft mouse model of cancer. We observed a decrease in intracellular fatty acid levels, which suggested that EGCG-induced apoptosis was associated with a decrease in fatty acid levels in cancer. Suppression of ATP synthesis by EGCG indicated that cell death induction in cancer cells could be mediated by shared components of the DNL and energy metabolism pathways. In addition, EGCG-induced apoptosis suppressed the expression of the phosphorylation protein kinase B and extracellular signal-regulated kinase 1/2 signaling proteins in tumors from xenografted mice. Cytotoxic effects in unaffected organs and tissues of the mouse xenograft model were absent upon EGCG treatment.

USP22 regulates lipidome accumulation by stabilizing PPARγ in hepatocellular carcinoma

Elevated de novo lipogenesis is considered to be a crucial factor in hepatocellular carcinoma (HCC) development. Herein, we identify ubiquitin-specific protease 22 (USP22) as a key regulator for de novo fatty acid synthesis, which directly interacts with deubiquitinates and stabilizes peroxisome proliferator-activated receptor gamma (PPARγ) through K48-linked deubiquitination, and in turn, this stabilization increases acetyl-CoA carboxylase (ACC) and ATP citrate lyase (ACLY) expressions. In addition, we find that USP22 promotes de novo fatty acid synthesis and contributes to HCC tumorigenesis, however, this tumorigenicity is suppressed by inhibiting the expression of PPARγ, ACLY, or ACC in in vivo tumorigenesis experiments. In HCC, high expression of USP22 positively correlates with PPARγ, ACLY or ACC expression, and associates with a poor prognosis. Taken together, we identify a USP22-regulated lipogenesis mechanism that involves the PPARγ-ACLY/ACC axis in HCC tumorigenesis and provide a rationale for therapeutic targeting of lipogenesis via USP22 inhibition.

Different deubiquitinases are associated to cancer development. Here, the authors show that PPARgamma is stabilized by USP22-mediated deubiquitination leading to lipid accumulation and promoting hepatocellular carcinoma.

Acetyl-CoA Carboxylases and Diseases

Acetyl-CoA carboxylases (ACCs) are enzymes that catalyze the carboxylation of acetyl-CoA to produce malonyl-CoA. In mammals, ACC1 and ACC2 are two members of ACCs. ACC1 localizes in the cytosol and acts as the first and rate-limiting enzyme in the de novo fatty acid synthesis pathway. ACC2 localizes on the outer membrane of mitochondria and produces malonyl-CoA to regulate the activity of carnitine palmitoyltransferase 1 (CPT1) that involves in the β-oxidation of fatty acid. Fatty acid synthesis is central in a myriad of physiological and pathological conditions. ACC1 is the major member of ACCs in mammalian, mountains of documents record the roles of ACC1 in various diseases, such as cancer, diabetes, obesity. Besides, acetyl-CoA and malonyl-CoA are cofactors in protein acetylation and malonylation, respectively, so that the manipulation of acetyl-CoA and malonyl-CoA by ACC1 can also markedly influence the profile of protein post-translational modifications, resulting in alternated biological processes in mammalian cells. In the review, we summarize our understandings of ACCs, including their structural features, regulatory mechanisms, and roles in diseases. ACC1 has emerged as a promising target for diseases treatment, so that the specific inhibitors of ACC1 for diseases treatment are also discussed.

Lipid alterations in chronic liver disease and liver cancer

Lipids are a complex and diverse group of molecules with crucial roles in many physiological processes, as well as in the onset, progression, and maintenance of cancers. Fatty acids and cholesterol are the building blocks of lipids, orchestrating these crucial metabolic processes. In the liver, lipid alterations are prevalent as a cause and consequence of chronic hepatitis B and C virus infections, alcoholic hepatitis, and non-alcoholic fatty liver disease and steatohepatitis. Recent developments in lipidomics have also revealed that dynamic changes in triacylglycerols, phospholipids, sphingolipids, ceramides, fatty acids, and cholesterol are involved in the development and progression of primary liver cancer. Accordingly, the transcriptional landscape of lipid metabolism suggests a carcinogenic role of increasing fatty acids and sterol synthesis. However, limited mechanistic insights into the complex nature of the hepatic lipidome have so far hindered the development of effective therapies.

ERCC6L is a biomarker and therapeutic target for non-small cell lung adenocarcinoma

BACKGROUND

Non-small cell lung carcinoma (NSCLC) accounts for the majority of lung cancer which is one of the most common cancer types and results in high percentage of cancer-related deaths. Although NSCLC patients have been benefiting from the existing standard treatments, more candidate biomarkers for effective diagnosis and targets for therapy are still required to be uncovered. The expression pattern and biological function of Excision repair cross-complementation group 6 like (ERCC6L) in NSCLC are ill-investigated.

METHODS

We performed bioinformatic analyses in NSCLC patients with lung adenocarcinoma (LUAD) or lung squamous cell carcinoma (LUSC), respectively. Patient survival determination and meta-analysis were carried out to check the clinical significance of ERCC6L. Datamining was also performed to evaluate the ERCC6L mRNA and protein expression levels in patients with LUAD and the correlation with immune cell infiltration. In silico prediction indicated the potential interacting proteins and correlated pathways of ERCC6L in LUAD. Loss-of-function studies were performed to determine the role of ERCC6L in LUAD cells.

RESULTS

Here, we found that ERCC6L is upregulated in patients with LUAD and LUSC and is strongly associated with poor outcomes of LUAD, but not LUSC, patients. In addition, ERCC6L mRNA and protein were shown to be more expressed in patients with advanced stages of LUAD. Finally, functional analyses reveal the promoting effects of ERCC6L on LUAD cell survival, migration and invasion.

CONCLUSIONS

Cohort data analysis and experimental validation shed light on the promising prognostic and therapeutic application of ERCC6L in LUAD, but maybe not LUSC, patients.

Interplay between Dysbiosis of Gut Microbiome, Lipid Metabolism, and Tumorigenesis: Can Gut Dysbiosis Stand as a Prognostic Marker in Cancer?

The gut bacterial community is involved in the metabolism of bile acids and short-chain fatty acids (SCFAs). Bile acids are involved in the absorption of fat and the regulation of lipid homeostasis through emulsification and are transformed into unconjugated bile acids by the gut microbiota. The gut microbiota is actively involved in the production of bile acid metabolites, such as deoxycholic acid, lithocholic acid, choline, and SCFAs such as acetate, butyrate, and propionate. Metabolites derived from the gut microbiota or modified gut microbiota metabolites contribute significantly to host pathophysiology. Gut bacterial metabolites, such as deoxycholic acid, contribute to the development of hepatocellular carcinoma and colon cancer by factors such as inflammation and oxidative DNA damage. Butyrate, which is derived from gut bacteria such as Megasphaera, Roseburia, Faecalibacterium, and Clostridium, is associated with the activation of Treg cell differentiation in the intestine through histone acetylation. Butyrate averts the action of class I histone deacetylases (HDAC), such as HDAC1 and HDAC3, which are responsible for the transcription of genes such as p21/Cip1, and cyclin D3 through hyperacetylation of histones, which orchestrates G1 cell cycle arrest. It is essential to identify the interaction between the gut microbiota and bile acid and SCFA metabolism to understand their role in gastrointestinal carcinogenesis including colon, gastric, and liver cancer. Metagenomic approaches with bioinformatic analyses are used to identify the bacterial species in the metabolism of bile acids and SCFAs. This review provides an overview of the current knowledge of gut microbiota-derived bile acid metabolism in tumor development and whether it can stand as a marker for carcinogenesis. Additionally, this review assesses the evidence of gut microbiota-derived short-chain fatty acids including butyric acid in antitumor activity. Future research is required to identify the beneficial commensal gut bacteria and their metabolites which will be considered to be therapeutic targets in inflammation-mediated gastrointestinal cancers.

Aberrant lipid metabolism reprogramming and immune microenvironment for gastric cancer: a literature review

Objective

We summarize the aberrant lipid metabolism disorders associated with enzyme activity and expression changes and related immune microenvironment for gastric cancer.

Background

Gastric cancer is a malignant tumor of the primary digestive system with high incidence, poor prognosis characterized by extensive metastasis and poor effect with radiotherapy and chemotherapy. One of the most important metabolic characteristics of cancer cells is lipid metabolism reprogramming to adapt to the tumor micro-environment.

Methods

The focus of research in recent years has also been on lipid metabolism disorders, particularly aberrant metabolism of fatty acids (FAs) in gastric cancer cells, as well as an upregulation of the expression and activity of key enzymes in lipid metabolism. These changes remind us of the occurrence and development of gastric cancer. These metabolic changes are not unique to cancer cells. Changes in metabolic procedures also determine the function and viability of immune cells. In the immune microenvironment of gastric cancer, the metabolic competition and interaction between cancer cells and immune cells are not very clear, while a deeper understanding of the topic is critical to targeting the differential metabolic requirements of them that comprise an immune response to cancer offers an opportunity to selectively regulate immune cell function.

Conclusions

Recent research suggests that targeting metabolism is an emerging and potentially promising treatment strategy for gastric cancer patients. We need to explore it further.

Metabolic dysregulation and emerging therapeutical targets for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive human cancer with increasing incidence worldwide. Multiple efforts have been made to explore pharmaceutical therapies to treat HCC, such as targeted tyrosine kinase inhibitors, immune based therapies and combination of chemotherapy. However, limitations exist in current strategies including chemoresistance for instance. Tumor initiation and progression is driven by reprogramming of metabolism, in particular during HCC development. Recently, metabolic associated fatty liver disease (MAFLD), a reappraisal of new nomenclature for non-alcoholic fatty liver disease (NAFLD), indicates growing appreciation of metabolism in the pathogenesis of liver disease, including HCC, thereby suggesting new strategies by targeting abnormal metabolism for HCC treatment. In this review, we introduce directions by highlighting the metabolic targets in glucose, fatty acid, amino acid and glutamine metabolism, which are suitable for HCC pharmaceutical intervention. We also summarize and discuss current pharmaceutical agents and studies targeting deregulated metabolism during HCC treatment. Furthermore, opportunities and challenges in the discovery and development of HCC therapy targeting metabolism are discussed.

Role of Lipogenesis Rewiring in Hepatocellular Carcinoma

Metabolic rewiring is one of the hallmarks of cancer. Altered de novo lipogenesis is one of the pivotal metabolic events deregulated in cancers. Sterol regulatory element-binding transcription factor 1 (SREBP1) controls the transcription of major enzymes involved in de novo lipogenesis, including ACLY, ACACA, FASN, and SCD. Studies have shown the increased de novo lipogenesis in human hepatocellular carcinoma (HCC) samples. Multiple mechanisms, such as activation of the AKT/mechanistic target of rapamycin (mTOR) pathway, lead to high SREBP1 induction and the coordinated enhanced expression of ACLY, ACACA, FASN, and SCD genes. Subsequent functional analyses have unraveled these enzymes' critical role(s) and the related de novo lipogenesis in hepatocarcinogenesis. Importantly, targeting these molecules might be a promising strategy for HCC treatment. This paper comprehensively summarizes de novo lipogenesis rewiring in HCC and how this pathway might be therapeutically targeted.

Patient-derived xenograft models in hepatopancreatobiliary cancer

Animal models are crucial tools for evaluating the biological progress of human cancers and for the preclinical investigation of anticancer drugs and cancer prevention. Various animals are widely used in hepatopancreatobiliary cancer research, and mouse models are the most popular. Generally, genetic tools, graft transplantation, and chemical and physical measures are adopted to generate sundry mouse models of hepatopancreatobiliary cancer. Graft transplantation is commonly used to study tumour progression. Over the past few decades, subcutaneous or orthotopic cell-derived tumour xenograft models (CDX models) have been developed to simulate distinct tumours in patients. However, two major limitations exist in CDX models. One model poorly simulates the microenvironment of tumours in humans, such as the vascular, lymphatic and immune environments. The other model loses genetic heterogeneity compared with the corresponding primary tumour. Increased efforts have focused on developing better models for hepatopancreatobiliary cancer research. Hepatopancreatobiliary cancer is considered a tumour with high molecular heterogeneity, making precision medicine challenging in cancer treatment. Developing a new animal model that can better mimic tumour tissue and more accurately predict the efficacy of anticancer treatments is urgent. For the past several years, the patient-derived xenograft model (PDX model) has emerged as a promising tool for translational research. It can retain the genetic and histological stability of their originating tumour at limited passages and shed light on precision cancer medicine. In this review, we summarize the methodology, advantages/disadvantages and applications of PDX models in hepatopancreatobiliary cancer research.

Tumor Microenvironment Acidity Triggers Lipid Accumulation in Liver Cancer via SCD1 Activation

Acidification is recognized as the predominant characteristic of the tumor microenvironment (TME) and contributes to tumor progression. However, the mechanism of extracellular acidic TME directly influences intercellular pathological responses remains unclear. Meanwhile, acidic TME is mainly ascribed to aberrant metabolism of lipids and glucose, but whether and how acidity affects metabolic reprogramming, especially for lipid metabolism, is still unknown. We found that lipid was significantly accumulated in liver cancer cells when exposed to acidic TME. Moreover, proteomic analysis showed that differentially expressed proteins were mainly clustered into fatty acid pathways. Subsequently, we found that acidification increased the expression of SCD1 by activating PI3K/AKT signaling pathway. Interestingly, we found that SCD1 directly bound to PPARα in the acidic TME, which vanished after 2-day reverse incubation in pH7.4 medium, implying extracellular acidosis might influence intercellular function by mediating the binding affinity between SCD1 and PPARα under different pH gradients. In summary, our data revealed that acidosis could significantly trigger fatty acid synthesis to promote liver tumorigenesis by upregulating SCD1 in a PI3K/AKT activation dependent manner and simultaneously promote SCD1 binding to PPARα. Our study not only provides direct mechanistic evidence to support the vital role of acidosis in lipid metabolic reprogramming, but also provides novel insights for determining the binding affinity of functional proteins as a molecular mechanism to better understand the role of the acidic TME in tumor development. Implications: The acidic TME contributes to lipid accumulation in liver cancer by activating the PI3K/AKT signaling pathway and promoting SCD1-PPARα binding.

Paired related homeobox 1 attenuates autophagy via acetyl-CoA carboxylase 1-regulated fatty acid metabolism in salivary adenoid cystic carcinoma

Autophagy can affect the invasion and metastasis of carcinoma. Our previous study has shown that invasion and epithelial‐mesenchymal transition in salivary adenoid cystic carcinoma (SACC) can be promoted by the metabolic reprogramming of free fatty acids (FFAs). However, the effect of FFA metabolism on autophagy in SACC remains unknown. In this study, we showed that overexpression of paired related homeobox 1 (PRRX1) reduced the number of autophagosomes and decreased the expression of LC3 and Beclin‐1 in SACC patients and SACC‐83 cells in vitro. Moreover, PRRX1‐mediating FFA reprogramming triggered to autophagy via regulating acetyl‐CoA carboxylase 1 (ACC1), leading to invasion and migration in SACC.

NAD kinase sustains lipogenesis and mitochondrial metabolismthrough fatty acid synthesis

Lipid storage in fat tissue is important for energy homeostasis and cellular functions. Through RNAi screening in Drosophila fat body, we found that knockdown of a Drosophila NAD kinase (NADK), which phosphorylates NAD to synthesize NADP de novo, causes lipid storage defects. NADK sustains lipogenesis by maintaining the pool of NADPH. Promoting NADPH production rescues the lipid storage defect in the fat body of NADK RNAi animals. Furthermore, NADK and fatty acid synthase 1 (FASN1) regulate mitochondrial mass and function by altering the levels of acetyl-CoA and fatty acids. Reducing the level of acetyl-CoA or increasing the synthesis of cardiolipin (CL), a mitochondrion-specific phospholipid, partially rescues the mitochondrial defects of NADK RNAi. Therefore, NADK- and FASN1-mediated fatty acid synthesis coordinates lipid storage and mitochondrial function.