Emerging role of lipid metabolism alterations in Cancer stem cells

Perfluorooctanesulfonic acid exposure leads to downregulation of 3-hydroxy-3-methylglutaryl-CoA synthase 2 expression and upregulation of markers associated with intestinal carcinogenesis in mouse intestinal tissues

Perfluorooctanesulfonic acid (PFOS) is a widely recognized environment pollutant known for its high bioaccumulation potential and a long elimination half-life. Several studies have shown that PFOS can alter multiple biological pathways and negatively affect human health. Considering the direct exposure to the gastrointestinal (GI) tract to environmental pollutants, PFOS can potentially disrupt intestinal homeostasis. However, there is limited knowledge about the effect of PFOS exposure on normal intestinal tissues, and its contribution to GI-associated diseases remains to be determined. In this study, we examined the effect of PFOS exposure on the gene expression profile of intestinal tissues of C57BL/6 mice using RNAseq analysis. We found that PFOS exposure in drinking water significantly downregulates mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), a rate-limiting ketogenic enzyme, in intestinal tissues of mice. We found that diets containing the soluble fibers inulin and pectin, which are known to be protective against PFOS exposure, were ineffective in reversing the downregulation of HMGCS2 expression in vivo. Analysis of intestinal tissues also demonstrated that PFOS exposure leads to upregulation of proteins implicated in colorectal carcinogenesis, including β-catenin, c-MYC, mTOR and FASN. Consistent with the in vivo results, PFOS exposure leads to downregulation of HMGCS2 in mouse and human normal intestinal organoids in vitro. Furthermore, we show that shRNA-mediated knockdown of HMGCS2 in a human normal intestinal cell line resulted in increased cell proliferation and upregulation of key proliferation-associated proteins such as cyclin D, survivin, ERK1/2 and AKT, along with an increase in lipid accumulation. In summary, our results suggest that PFOS exposure may contribute to pathological changes in normal intestinal cells via downregulation of HMGCS2 expression and upregulation of pro-carcinogenic signaling pathways that may increase the risk of colorectal cancer development.

Co-morbid intersections of cancer and cardiovascular disease and targets for natural drug action: Reprogramming of lipid metabolism

Cancer and cardiovascular diseases are major contributors to global morbidity and mortality, and their seemingly separate pathologies are intricately intertwined. In the context of cancer, the cardiovascular disease encompasses not only the side effects arising from anti-tumor treatments but also the metabolic shifts induced by oncological conditions. A growing body of research indicates that lipid metabolic reprogramming serves as a distinctive hallmark of tumors. Furthermore, anomalies in lipid metabolism play a significant role in the development of cardiovascular disease. This study delves into the cardiac implications of lipid metabolic reprogramming within the cancer context, closely examining abnormalities in lipid metabolism present in tumors, cardiac tissue, and immune cells within the microenvironment. Additionally, we examined risk factors such as obesity and anti-tumor therapy. Despite progress, a gap remains in the availability of drugs targeting lipid metabolism modulation for treating tumors and mitigating cardiac risk, with limited advancement seen in prior studies. Here, we present a review of previous research on natural drugs that exhibit both shared and distinct therapeutic effects on tumors and cardiac health by modulating lipid metabolism. Our aim is to provide insights for potential drug development.

Prediction of prognosis and immunotherapy efficacy based on metabolic landscape in lung adenocarcinoma by bulk, single-cell RNA sequencing and Mendelian randomization analyses

Immunotherapy has been a remarkable clinical advancement in cancer treatment, but only a few patients benefit from it. Metabolic reprogramming is tightly associated with immunotherapy efficacy and clinical outcomes. However, comprehensively analyzing their relationship is still lacking in lung adenocarcinoma (LUAD). Herein, we evaluated 84 metabolic pathways in TCGA-LUAD by ssGSEA. A matrix of metabolic pathway pairs was generated and a metabolic pathway-pair score (MPPS) model was established by univariable, LASSO, multivariable Cox regression analyses. The differences of metabolic reprogramming, tumor microenvironment (TME), tumor mutation burden and drug sensitivity in different MPPS groups were further explored. WGCNA and 117 machine learning algorithms were performed to identify MPPS-related genes. Single-cell RNA sequencing and in vitro experiments were used to explore the role of C1QTNF6 on TME. The results showed MPPS model accurately predicted prognosis and immunotherapy efficacy of LUAD patients regardless of sequencing platforms. High-MPPS group had worse prognosis, immunotherapy efficacy and lower immune cells infiltration, immune-related genes expression and cancer-immunity cycle scores than low-MPPS group. Seven MPPS-related genes were identified, of which C1QTNF6 was mainly expressed in fibroblasts. High C1QTNF6 expression in fibroblasts was associated with more infiltration of M2 macrophage, Treg cells and less infiltration of NK cells, memory CD8+ T cells. In vitro experiments validated silencing C1QTNF6 in fibroblasts could inhibit M2 macrophage polarization and migration. The study depicted the metabolic landscape of LUAD and constructed a MPPS model to accurately predict prognosis and immunotherapy efficacy. C1QTNF6 was a promising target to regulate M2 macrophage polarization and migration.

Anticancer Mechanism of Astragalus Polysaccharide and Its Application in Cancer Immunotherapy

Astragalus polysaccharide (APS) derived from A. membranaceus plays a crucial role in traditional Chinese medicine. These polysaccharides have shown antitumor effects and are considered safe. Thus, they have become increasingly important in cancer immunotherapy. APS can limit the spread of cancer by influencing immune cells, promoting cell death, triggering cancer cell autophagy, and impacting the tumor microenvironment. When used in combination with other therapies, APS can enhance treatment outcomes and reduce toxicity and side effects. APS combined with immune checkpoint inhibitors, relay cellular immunotherapy, and cancer vaccines have broadened the application of cancer immunotherapy and enhanced treatment effectiveness. By summarizing the research on APS in cancer immunotherapy over the past two decades, this review elaborates on the anticancer mechanism of APS and its use in cancer immunotherapy and clinical trials. Considering the multiple roles of APS, this review emphasizes the importance of using APS as an adjunct to cancer immunotherapy and compares other polysaccharides with APS. This discussion provides insights into the specific mechanism of action of APS, reveals the molecular targets of APS for developing effective clinical strategies, and highlights the wide application of APS in clinical cancer therapy in the future.

SAA1-dependent reprogramming of adipocytes by tumor cells is associated with triple negative breast cancer aggressiveness

Triple negative breast cancers (TNBC) are characterized by a poor prognosis and a lack of targeted treatments. Their progression depends on tumor cell intrinsic factors, the tumor microenvironment and host characteristics. Although adipocytes, the primary stromal cells of the breast, have been determined to be plastic in physiology and cancer, the tumor-derived molecular mediators of tumor-adipocyte crosstalk have not been identified yet. In this study, we report that the crosstalk between TNBC cells and adipocytes in vitro beyond adipocyte dedifferentiation, induces a unique transcriptional profile that is characterized by inflammation and pathways that are related to interaction with the tumor microenvironment. Accordingly, increased cancer stem-like features and recruitment of pro-tumorigenic immune cells are induced by this crosstalk through CXCL5 and IL-8 production. We identified serum amyloid A1 (SAA1) as a regulator of the adipocyte reprogramming through CD36 and P2XR7 signaling. In human TNBC, SAA1 expression was associated with cancer-associated adipocyte infiltration, inflammation, stimulated lipolysis, stem-like properties, and a distinct tumor immune microenvironment. Our findings constitute evidence that the interaction between tumor cells and adipocytes through the release of SAA1 is relevant to the aggressiveness of TNBC.

Enhanced lipid biosynthesis in oral squamous cell carcinoma cancer-associated fibroblasts contributes to tumor progression: Role of IL8/AKT/p-ACLY axis

Lipid metabolic reprogramming of tumor cells has been proven to play a critical role in tumor initiation and development. However, lipid metabolism in cancer-associated fibroblasts (CAFs) has rarely been studied, particularly in CAFs of oral squamous cell carcinoma (OSCC). Additionally, the molecular mechanism by which tumor cells regulate lipid metabolism in fibroblasts is unclear. In this study, we found that phosphorylated ATP citrate lyase (p-ACLY), a key lipid metabolic enzyme, was upregulated in OSCC CAFs. Compared to paracancerous normal fibroblasts, CAFs showed enhanced lipid synthesis, such as elevated cytosolic acetyl-CoA level and accumulation of lipid droplets. Conversely, reduction of p-ACLY level blocked this biological process. In addition, blocking lipid synthesis in CAFs or inhibiting fatty acid uptake by OSCC cells reduced the promotive effects of CAFs on OSCC cell proliferation, invasion, and migration. These findings suggested that CAFs are one of lipid sources required for OSCC progression. Mechanistically, AKT signaling activation was involved in the upregulation of p-ACLY level and lipid synthesis in CAFs. Interleukin-8 (IL8), an exocrine cytokine of OSCC cells, could activate AKT and then phosphorylate ACLY in fibroblasts. This study suggested that the IL8/AKT/p-ACLY axis could be considered as a potential target for OSCC treatment.

The role of DGAT1 and DGAT2 in regulating tumor cell growth and their potential clinical implications

Lipid metabolism is widely reprogrammed in tumor cells. Lipid droplet is a common organelle existing in most mammal cells, and its complex and dynamic functions in maintaining redox and metabolic balance, regulating endoplasmic reticulum stress, modulating chemoresistance, and providing essential biomolecules and ATP have been well established in tumor cells. The balance between lipid droplet formation and catabolism is critical to maintaining energy metabolism in tumor cells, while the process of energy metabolism affects various functions essential for tumor growth. The imbalance of synthesis and catabolism of fatty acids in tumor cells leads to the alteration of lipid droplet content in tumor cells. Diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2, the enzymes that catalyze the final step of triglyceride synthesis, participate in the formation of lipid droplets in tumor cells and in the regulation of cell proliferation, migration and invasion, chemoresistance, and prognosis in tumor. Several diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2 inhibitors have been developed over the past decade and have shown anti-tumor effects in preclinical tumor models and improvement of metabolism in clinical trials. In this review, we highlight key features of fatty acid metabolism and different paradigms of diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2 activities on cell proliferation, migration, chemoresistance, and prognosis in tumor, with the hope that these scientific findings will have potential clinical implications.

Advances in research on the anti-tumor mechanism of Astragalus polysaccharides

The dry root of the soybean plant Astragalus membranaceus (Fisch) Bge. var. mongholicus (Bge) Hsiao or A. membranaceus (Fisch) Bge, Astragali Radix (AR) has a long medicinal history. Astragalus polysaccharide (APS), the natural macromolecule that exhibits immune regulatory, anti-inflammatory, anti-tumor, and other pharmacological activities, is an important active ingredient extracted from AR. Recently, APS has been increasingly used in cancer therapy owing to its anti-tumor ability as it prevents the progression of prostate, liver, cervical, ovarian, and non-small-cell lung cancer by suppressing tumor cell growth and invasion and enhancing apoptosis. In addition, APS enhances the sensitivity of tumors to antineoplastic agents and improves the body's immunity. This macromolecule has prospects for broad application in tumor therapy through various pathways. In this article, we present the latest progress in the research on the anti-tumor effects of APS and its underlying mechanisms, aiming to provide novel theoretical support and reference for its use in cancer therapy.

Unveiling the STAT3-ACC1 axis: a key driver of lipid metabolism and tumor progression in non-small cell lung cancer

Background and Objective: Lung cancer is a prevalent global malignancy, and investigating the metabolic reprogramming of tumor cells has significant therapeutic implications. This study aims to explore the molecular mechanism driving the progression of non-small cell lung cancer (NSCLC), with a specific emphasis on the STAT3-ACC1-FAS axis involved in fatty acid synthesis. Methods: The levels of Signal transducer and activator of transcription 3 (STAT3) and acetyl-CoA carboxylase 1 (ACC1) were determined in mouse NSCLC specimens and cell lines using Western blot and qPCR methods. Various assays such as CCK-8, colony formation, EDU, wound-healing, and transwell migration were employed to assess cancer cell proliferation, migration, and invasion. Additionally, a nude mouse xenograft model was utilized for in vivo tumor growth analysis. The interaction between STAT3 and ACC1 was examined through chromatin immunoprecipitation and dual-luciferase assays. Results: The study observed upregulation of STAT3 and ACC1 in NSCLC tissues. Notably, the suppression of STAT3 and ACC1 inhibited the in vitro progression and lipid synthesis of NSCLC cells. Furthermore, STAT3 enhanced lipid synthesis by upregulating ACC1 expression. Mechanistic assays revealed that this process occurred through direct activation of ACC1 transcription by STAT3. STAT3 played a vital role in regulating lipid metabolism and supporting NSCLC progression. Conclusion: The findings of this study underscore the significance of the STAT3-ACC1-FAS axis in NSCLC. The activation of ACC1 through STAT3-mediated transcription serves as a crucial mechanism for stimulating the progression of NSCLC tumors and promoting lipid synthesis. Consequently, targeting the STAT3-ACC1 axis may present a promising avenue for the diagnosis and treatment of NSCLC patients.

The multivisceral landscape of colorectal cancer metastasis: implications for targeted therapies

Colorectal cancer (CRC) is among the most common cancer types and the second deadliest malignancy for both sexes. Metastatic disease poses substantial therapeutic challenges, and peritoneal spread, in particular, reduces quality of life and has a dismal outcome. In this issue of the JCI, Berlin and authors have made considerable advancements in understanding the cellular and molecular composition of multivisceral CRC metastasis in a sophisticated murine orthotopic organoid model and in humans. The study provides unprecedented insights into the complex biology of the disease and points toward the development of compartmentalized immune-therapeutic strategies.

Fatty acid synthase (FASN) signalome: A molecular guide for precision oncology

The initial excitement generated more than two decades ago by the discovery of drugs targeting fatty acid synthase (FASN)-catalyzed de novo lipogenesis for cancer therapy was short-lived. However, the advent of the first clinical-grade FASN inhibitor (TVB-2640; denifanstat), which is currently being studied in various phase II trials, and the exciting advances in understanding the FASN signalome are fueling a renewed interest in FASN-targeted strategies for the treatment and prevention of cancer. Here, we provide a detailed overview of how FASN can drive phenotypic plasticity and cell fate decisions, mitochondrial regulation of cell death, immune escape and organ-specific metastatic potential. We then present a variety of FASN-targeted therapeutic approaches that address the major challenges facing FASN therapy. These include limitations of current FASN inhibitors and the lack of precision tools to maximize the therapeutic potential of FASN inhibitors in the clinic. Rethinking the role of FASN as a signal transducer in cancer pathogenesis may provide molecularly driven strategies to optimize FASN as a long-awaited target for cancer therapeutics.

Cancer metabolism and carcinogenesis

Metabolic reprogramming is an emerging hallmark of cancer cells, enabling them to meet increased nutrient and energy demands while withstanding the challenging microenvironment. Cancer cells can switch their metabolic pathways, allowing them to adapt to different microenvironments and therapeutic interventions. This refers to metabolic heterogeneity, in which different cell populations use different metabolic pathways to sustain their survival and proliferation and impact their response to conventional cancer therapies. Thus, targeting cancer metabolic heterogeneity represents an innovative therapeutic avenue with the potential to overcome treatment resistance and improve therapeutic outcomes. This review discusses the metabolic patterns of different cancer cell populations and developmental stages, summarizes the molecular mechanisms involved in the intricate interactions within cancer metabolism, and highlights the clinical potential of targeting metabolic vulnerabilities as a promising therapeutic regimen. We aim to unravel the complex of metabolic characteristics and develop personalized treatment approaches to address distinct metabolic traits, ultimately enhancing patient outcomes.

A novel lung cancer stem cell extracellular vesicles lncRNA ROLLCSC modulate non-stemness cancer cell plasticity through miR-5623-3p and miR-217-5p targeting lipid metabolism

BACKGROUND

The high mortality rate of lung cancer is largely attributed to metastasis. Lung cancer stem cells (CSC) are conducive to cancer heterogeneity. Long noncoding RNAs are known to participate in various biological processes regulating the development of lung cancer. However, characterization of the role and mechanisms of lncRNA in lung cancer metastasis remains a challenge.

RESULTS

We demonstrate that ROLLCSC, a highly expressed lncRNA in LLC-SDs, promotes the metastasis of the low metastatic LLCs both in vitro and in vivo. ROLLCSC can be transferred from LLC-SD to LLC through encapsulation in extracellular vesicles (EVs), ultimately leading to the enhancement of the metastatic phenotype of LLCs. Mechanistically, we demonstrate that the pro-metastatic activity of ROLLCSC is achieved through its function as a competing endogenous RNA (ceRNA) of miR-5623-3p and miR-217-5p to stimulate lipid metabolism.

CONCLUSION

In this study, we have characterized ROLLCSC, a novel lncRNA, as a pivotal regulator in the metastasis of lung cancer, highlighting its potential as a therapeutic target. Specifically, we show that ROLLCSC is encapsulated by the EVs of LLC-SDs and transmitted to the LLCs, where it acts as a ceRNA of miR-5623-3p and miR-217-5p to stimulate lipid metabolism and ultimately augments metastatic colonization of LLCs.

Let-7a-5p abrogates progression of papillary thyroid carcinoma cells by decreasing nuclear receptor subfamily 6 group a member 1-mediated lipogenesis

Increasing evidence shows that microRNAs (miRNAs) contribute vital roles in papillary thyroid carcinoma (PTC) carcinogenesis, proliferation, invasion, and so on. As the most common endocrine malignancy, there still have largely unknown molecular events. First, our analysis and open access database information indicates that the downregulation of let-7a-5p accelerates PTC progression. Next, lentivirus mediates the overexpression of let-7a-5p PTC cells, and found let-7a-5p suppressed cancer cells proliferation and invasion. Interestingly, bioinformatics analysis hints NR6A1 is the potential target gene of let-7a-5p. The regulation was validated by luciferase and quantitative reverse transcription polymerase chain reaction (qRT-PCR) in PTC tissue and the clinic tumors. Moreover, let-7a-5p regulated NR6A1 involved in PTC cells lipogensis in vitro and in vivo. Finally, let-7a-5p abrogates PCT xenograft tumors growth, NR6A1 expression and lipogenesis. Taken together, our data indicates that let-7a-5p suppresses PCT progression through decreased lipogenesis, the related let-7a-5p/NR6A1axis might be promising candidate targets for PTC treatment.

Discovery of a novel lipid metabolism-related gene signature to predict outcomes and the tumor immune microenvironment in gastric cancer by integrated analysis of single-cell and bulk RNA sequencing

Gastric cancer (GC) is a pressing global clinical issue, with few treatment options and a poor prognosis. The onset and spread of stomach cancer are significantly influenced by changes in lipid metabolism-related pathways. This study aimed to discover a predictive signature for GC using lipid metabolism-related genes (LMRGs) and examine its correlation with the tumor immune microenvironment (TIME). Transcriptome data and clinical information from patients with GC were collected from the TCGA and GEO databases. Data from GC samples were analyzed using both bulk RNA-seq and single-cell sequencing of RNA (scRNA-seq). To identify survival-related differentially expressed LMRGs (DE-LMRGs), differential expression and prognosis studies were carried out. We built a predictive signature using LASSO regression and tested it on the TCGA and GSE84437 datasets. In addition, the correlation of the prognostic signature with the TIME was comprehensively analyzed. In this study, we identified 258 DE-LMRGs in GC and further screened seven survival-related DE-LMRGs. The results of scRNA-seq identified 688 differentially expressed genes (DEGs) between the three branches. Two critical genes (GPX3 and NNMT) were identified using the above two gene groups. In addition, a predictive risk score that relies on GPX3 and NNMT was developed. Survival studies in both the TCGA and GEO datasets revealed that patients categorized to be at low danger had a significantly greater prognosis than those identified to be at high danger. Additionally, by employing calibration plots based on TCGA data, the study demonstrated the substantial predictive capacity of a prognostic nomogram, which incorporated a risk score along with various clinical factors. Within the high-risk group, there was a noticeable abundance of active natural killer (NK) cells, quiescent monocytes, macrophages, mast cells, and activated CD4 + T cells. In summary, a two-gene signature and a predictive nomogram have been developed, offering accurate prognostic predictions for general survival in GC patients. These findings have the potential to assist healthcare professionals in making informed medical decisions and providing personalized treatment approaches.

Screening of Lipid Metabolism-Related Genes as Diagnostic Indicators in Chronic Obstructive Pulmonary Disease

Objective

It has been observed that local and systemic disorders of lipid metabolism occur during the development of chronic obstructive pulmonary disease (COPD), but no specific mechanism has yet been identified.

Methods

The mRNA microarray dataset GSE76925 of COPD patients was downloaded from the Gene Expression Omnibus database and screened for differentially expressed genes (DEGs). Lipid metabolism-related genes (LMRGs) were extracted from the Kyoto Encyclopedia of Genes and Genomes database and Molecular Signature Database. The DEGs were intersected with LMRGs to obtain differentially expressed lipid metabolism-related genes (DeLMRGs). GO enrichment analysis and KEGG pathway analysis were performed on DeLMRGs, and protein-protein interaction networks were constructed and screened to identify hub genes. The GSE8581 validation set and further ELISA experiments were used to validate key DeLMRG expression.

Results

Differential analysis of dataset GSE76925 identified 587 DEGs, of which 62 genes were up-regulated and 525 were down-regulated. Taking the intersection of 587 DEGs with 1102 LMRGs, 20 DeLMRGs were obtained, including 1 up-regulated gene and 19 down-regulated genes. 10 hub genes were screened by cytohubba plugin, including 9 down-regulated genes PLA2G4A, HPGDS, LEP, PTGES3, LEPR, PLA2G2D, MED21, SPTLC1 and BCHE, as well as the only up-regulated gene PLA2G7. Validation of the identified 10 DeLMRGs using the validation set GSE8581 revealed that BCHE and PLA2G7 expression levels differed between the two groups. We further constructed the ceRNA network of BCHE and PLA2G7. Cell experiments also showed that PLA2G7 expression was up-regulated and BCHE expression was down-regulated in CSE-treated RAW264.7 and THP-1 cells.

Conclusion

Based on a comprehensive bioinformatic analysis of lipid metabolism genes, we identified BCHE and PLA2G7 as potentially significant biomarkers of COPD. These biomarkers may represent promising targets for COPD diagnosis and treatment.

Cancer stem cells: advances in the glucose, lipid and amino acid metabolism

Cancer stem cells (CSCs) are a class of cells with self-renewal and multi-directional differentiation potential, which are present in most tumors, particularly in aggressive tumors, and perform a pivotal role in recurrence and metastasis and are expected to be one of the important targets for tumor therapy. Studies of tumor metabolism in recent years have found that the metabolic characteristics of CSCs are distinct from those of differentiated tumor cells, which are unique to CSCs and contribute to the maintenance of the stemness characteristics of CSCs. Moreover, these altered metabolic profiles can drive the transformation between CSCs and non-CSCs, implying that these metabolic alterations are important markers for CSCs to play their biological roles. The identification of metabolic changes in CSCs and their metabolic plasticity mechanisms may provide some new opportunities for tumor therapy. In this paper, we review the metabolism-related mechanisms of CSCs in order to provide a theoretical basis for their potential application in tumor therapy.

Jian Yun Qing Hua Decoction inhibits malignant behaviors of gastric carcinoma cells via COL12A1 mediated ferroptosis signal pathway

BACKGROUND

Jian Yun Qing Hua Decoction (JYQHD), a traditional Chinese medicine decoction, which has been applied in the treatment of gastric cancer (GC). We attempt to confirm the anti-gastric cancer effect of JYQHD and explore the mechanism of JYQHD.

METHODS

Acute toxicity test was used to understand the toxicity of JYQHD. We studied the expression and prognostic outcome of COL12A1 within GC tissues through the network databases. Using several web-based databases, we analyzed the major components and targets of JYQHD, as well as known therapeutic targets in gastric cancer. The Venn diagram was utilized to obtain the overlapped genes. Lentiviral vector, shRNAs and plasmids, were used to transfect GC cells. Cell counting kit-8 (CCK8), sphere formation, malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), Fe2+, transmission electron microscopy (TEM), quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), Western-Blot (WB), and immunohistochemical (IHC) assays were employed to investigate the role and mechanism of COL12A1 and JYQHD in GC.

RESULTS

The results showed that JYQHD was non-toxic and safe. JYQHD inhibited growth and sphere formation ability through inducing the ferroptosis of GC cells, and suppressed the GC cells induced subcutaneous xenograft tumor growth. COL12A1 was highly expressed in gastric cancer tissues, indicating poor prognosis. COL12A1 specifically enhanced GC cell progression and stemness via suppressing ferroptosis. JYQHD down-regulated COL12A1 in order to suppress the stemness of GC cells via inducing ferroptosis.

CONCLUSION

COL12A1 inhibited ferroptosis and enhanced stemness in GC cells. JYQHD inhibited the development of GC cells by inhibiting cancer cell stemness via the ferroptosis pathway mediated by COL12A1.

Lipid metabolic reprogramming in tumor microenvironment: from mechanisms to therapeutics

Lipid metabolic reprogramming is an emerging hallmark of cancer. In order to sustain uncontrolled proliferation and survive in unfavorable environments that lack oxygen and nutrients, tumor cells undergo metabolic transformations to exploit various ways of acquiring lipid and increasing lipid oxidation. In addition, stromal cells and immune cells in the tumor microenvironment also undergo lipid metabolic reprogramming, which further affects tumor functional phenotypes and immune responses. Given that lipid metabolism plays a critical role in supporting cancer progression and remodeling the tumor microenvironment, targeting the lipid metabolism pathway could provide a novel approach to cancer treatment. This review seeks to: (1) clarify the overall landscape and mechanisms of lipid metabolic reprogramming in cancer, (2) summarize the lipid metabolic landscapes within stromal cells and immune cells in the tumor microenvironment, and clarify their roles in tumor progression, and (3) summarize potential therapeutic targets for lipid metabolism, and highlight the potential for combining such approaches with other anti-tumor therapies to provide new therapeutic opportunities for cancer patients.

Regulation of iron metabolism and ferroptosis in cancer stem cells

The ability of cancer stem cells (CSCs) to self-renew, differentiate, and generate new tumors is a significant contributor to drug resistance, relapse, and metastasis. Therefore, the targeting of CSCs for treatment is particularly important. Recent studies have demonstrated that CSCs are more susceptible to ferroptosis than non-CSCs, indicating that this could be an effective strategy for treating tumors. Ferroptosis is a type of programmed cell death that results from the accumulation of lipid peroxides caused by intracellular iron-mediated processes. CSCs exhibit different molecular characteristics related to iron and lipid metabolism. This study reviews the alterations in iron metabolism, lipid peroxidation, and lipid peroxide scavenging in CSCs, their impact on ferroptosis, and the regulatory mechanisms underlying iron metabolism and ferroptosis. Potential treatment strategies and novel compounds targeting CSC by inducing ferroptosis are also discussed.

Mitochondria in Cancer Stem Cells: From an Innocent Bystander to a Central Player in Therapy Resistance

Cancer continues to rank among the world's leading causes of mortality despite advancements in treatment. Cancer stem cells, which can self-renew, are present in low abundance and contribute significantly to tumor recurrence, tumorigenicity, and drug resistance to various therapies. The drug resistance observed in cancer stem cells is attributed to several factors, such as cellular quiescence, dormancy, elevated aldehyde dehydrogenase activity, apoptosis evasion mechanisms, high expression of drug efflux pumps, protective vascular niche, enhanced DNA damage response, scavenging of reactive oxygen species, hypoxic stability, and stemness-related signaling pathways. Multiple studies have shown that mitochondria play a pivotal role in conferring drug resistance to cancer stem cells, through mitochondrial biogenesis, metabolism, and dynamics. A better understanding of how mitochondria contribute to tumorigenesis, heterogeneity, and drug resistance could lead to the development of innovative cancer treatments.

Parabacteroides distasonis uses dietary inulin to suppress NASH via its metabolite pentadecanoic acid

Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary interventions, such as fibre, have been shown to alleviate this metabolic disorder in mice via the gut microbiota. Here, we investigated the mechanistic role of the gut microbiota in ameliorating NASH via dietary fibre in mice. Soluble fibre inulin was found to be more effective than insoluble fibre cellulose to suppress NASH progression in mice, as shown by reduced hepatic steatosis, necro-inflammation, ballooning and fibrosis. We employed stable isotope probing to trace the incorporation of 13C-inulin into gut bacterial genomes and metabolites during NASH progression. Shotgun metagenome sequencing revealed that the commensal Parabacteroides distasonis was enriched by 13C-inulin. Integration of 13C-inulin metagenomes and metabolomes suggested that P. distasonis used inulin to produce pentadecanoic acid, an odd-chain fatty acid, which was confirmed in vitro and in germ-free mice. P. distasonis or pentadecanoic acid was protective against NASH in mice. Mechanistically, inulin, P. distasonis or pentadecanoic acid restored gut barrier function in NASH models, which reduced serum lipopolysaccharide and liver pro-inflammatory cytokine expression. Overall this shows that gut microbiota members can use dietary fibre to generate beneficial metabolites to suppress metabolic disease.

Loss of SPRY2 contributes to cancer-associated fibroblasts activation and promotes breast cancer development

The communication between tumor cells and tumor microenvironment plays a critical role in cancer development. Cancer-associated fibroblasts (CAFs) are the major components of the tumor microenvironment and take part in breast cancer formation and progression. Here, by comparing the gene expression patterns in CAFs and normal fibroblasts, we found SPRY2 expression was significantly decreased in CAFs and decreased SPRY2 expression was correlated with worse prognosis in breast cancer patients. SPRY2 knockdown in fibroblasts promoted tumor growth and distant metastasis of breast cancer in mice. Loss of stromal SPRY2 expression promoted CAF activation dependent on glycolytic metabolism. Mechanically, SPRY2 suppressed Y10 phosphorylation of LDHA and LDHA activity by interfering with the interaction between LDHA and SRC. Functionally, SPRY2 knockdown in fibroblasts enhanced the stemness of tumor cell dependent on glycolysis in fibroblasts. Collectively, this work identified SPRY2 as a negative regulator of CAF activation, and SPRY2 in CAFs may potentially be therapeutically targeted in breast cancer treatment.

Advances on the anti-tumor mechanisms of the carotenoid Crocin

Saffron is located in the upper part of the crocus stigma of iridaceae, which has a long history of medicinal use. Crocin (molecular formula C44H64O24) is a natural floral glycoside ester compound extracted from saffron, which is a type carotenoid. Modern pharmacological studies have shown that crocin has multiple therapeutic effects including anti-inflammatory, anti-oxidant, anti-hyperlipidemic and anti-stone effects. In recent years, crocin has been widely noticed due to its considerable anti-tumor effects manifested by the induction of tumor cell apoptosis, inhibition of tumor cell proliferation, inhibition of tumor cell invasion and metastasis, enhancement of chemotherapy sensitivity and improvement of immune status. The anti-tumor effects have been shown in various malignant tumors such as gastric cancer, liver cancer, cervical cancer, breast cancer and colorectal cancer. In this review, we compiled recent studies on the anti-tumor effects of crocin and summarized its anti-tumor mechanism for developing ideas of treating malignancies and exploring anti-tumor drugs.

ARF1 maintains intestinal homeostasis by modulating gut microbiota and stem cell function

AIMS

The small GTPase protein ARF1 has been shown to be involved in the lipolysis pathway and to selectively kill stem cells in Drosophila melanogaster. However, the role of ARF1 in mammalian intestinal homeostasis remains elusive. This study aimed to explore the role of ARF1 in intestinal epithelial cells (IECs) and reveal the possible mechanism.

MATERIALS AND METHODS

IEC-specific ARF1 deletion mouse model was used to evaluate the role of ARF1 in intestine. Immunohistochemistry and immunofluorescence analyses were performed to detect specific cell type markers, and intestinal organoids were cultured to assess intestinal stem cell (ISC) proliferation and differentiation. Fluorescence in situ hybridization, 16S rRNA-Seq analysis, and antibiotic treatments were conducted to elucidate the role of gut microbes in ARF1-mediated intestinal function and the underlying mechanism. Colitis was induced in control and ARF1-deficient mice by dextran sulfate sodium (DSS). RNA-seq was performed to elucidate the transcriptomic changes after ARF1 deletion.

KEY FINDINGS

ARF1 was essential for ISC proliferation and differentiation. Loss of ARF1 increased susceptibility to DSS-induced colitis and gut microbial dysbiosis. Gut microbiota depletion by antibiotics could rescue the intestinal abnormalities to a certain extent. Furthermore, RNA-Seq analysis revealed alterations in multiple metabolic pathways.

SIGNIFICANCE

This work is the first to elucidate the essential role of ARF1 in regulating gut homeostasis, and provides novel insights into the pathogenesis of intestinal diseases and potential therapeutic targets.

"DEPHENCE" system-a novel regimen of therapy that is urgently needed in the high-grade serous ovarian cancer-a focus on anti-cancer stem cell and anti-tumor microenvironment targeted therapies

Ovarian cancer, especially high-grade serous type, is the most lethal gynecological malignancy. The lack of screening programs and the scarcity of symptomatology result in the late diagnosis in about 75% of affected women. Despite very demanding and aggressive surgical treatment, multiple-line chemotherapy regimens and both approved and clinically tested targeted therapies, the overall survival of patients is still unsatisfactory and disappointing. Research studies have recently brought some more understanding of the molecular diversity of the ovarian cancer, its unique intraperitoneal biology, the role of cancer stem cells, and the complexity of tumor microenvironment. There is a growing body of evidence that individualization of the treatment adjusted to the molecular and biochemical signature of the tumor as well as to the medical status of the patient should replace or supplement the foregoing therapy. In this review, we have proposed the principles of the novel regimen of the therapy that we called the "DEPHENCE" system, and we have extensively discussed the results of the studies focused on the ovarian cancer stem cells, other components of cancer metastatic niche, and, finally, clinical trials targeting these two environments. Through this, we have tried to present the evolving landscape of treatment options and put flesh on the experimental approach to attack the high-grade serous ovarian cancer multidirectionally, corresponding to the "DEPHENCE" system postulates.

Stearoyl-CoA Desaturase 1 as a Therapeutic Biomarker: Focusing on Cancer Stem Cells

The dysregulation of lipid metabolism and alterations in the ratio of monounsaturated fatty acids (MUFAs) to saturated fatty acids (SFAs) have been implicated in cancer progression and stemness. Stearoyl-CoA desaturase 1 (SCD1), an enzyme involved in lipid desaturation, is crucial in regulating this ratio and has been identified as an important regulator of cancer cell survival and progression. SCD1 converts SFAs into MUFAs and is important for maintaining membrane fluidity, cellular signaling, and gene expression. Many malignancies, including cancer stem cells, have been reported to exhibit high expression of SCD1. Therefore, targeting SCD1 may provide a novel therapeutic strategy for cancer treatment. In addition, the involvement of SCD1 in cancer stem cells has been observed in various types of cancer. Some natural products have the potential to inhibit SCD1 expression/activity, thereby suppressing cancer cell survival and self-renewal activity.

Mitochondria in colorectal cancer stem cells - a target in drug resistance

Colorectal cancer (CRC) is the third most diagnosed cancer and the second most deadly type of cancer worldwide. In late diagnosis, CRC can resist therapy regimens in which cancer stem cells (CSCs) are intimately related. CSCs are a subpopulation of tumor cells responsible for tumor initiation and maintenance, metastasis, and resistance to conventional treatments. In this scenario, colorectal cancer stem cells (CCSCs) are considered an important key for therapeutic failure and resistance. In its turn, mitochondria is an organelle involved in many mechanisms in cancer, including chemoresistance of cytotoxic drugs due to alterations in mitochondrial metabolism, apoptosis, dynamics, and mitophagy. Therefore, it is crucial to understand the mitochondrial role in CCSCs regarding CRC drug resistance. It has been shown that enhanced anti-apoptotic protein expression, mitophagy rate, and addiction to oxidative phosphorylation are the major strategies developed by CCSCs to avoid drug insults. Thus, new mitochondria-targeted drug approaches must be explored to mitigate CRC chemoresistance via the ablation of CCSCs.

Obesity and cancer stem cells: Roles in cancer initiation, progression and therapy resistance

Obesity, the global pandemic since industrialization, is the number one lifestyle-related risk factor for premature death, which increases the incidence and mortality of various diseases and conditions, including cancer. In recent years, the theory of cancer stem cells (CSCs), which have the capacity for self-renewal, metastasis and treatment resistance, has been bolstered by increasing evidence. However, research on how obesity affects CSCs to facilitate cancer initiation, progression and therapy resistance is still in its infancy, although evidence has already begun to accumulate. Regarding the ever-increasing burden of obesity and obesity-related cancer, it is pertinent to summarize evidence about the effects of obesity on CSCs, as elucidating these effects will contribute to the improvement in the management of obesity-related cancers. In this review, we discuss the association between obesity and CSCs, with a particular focus on how obesity promotes cancer initiation, progression and therapy resistance through CSCs and the mechanisms underlying these effects. In addition, the prospect of preventing cancer and targeting the mechanisms linking obesity and CSCs to reduce cancer risk or to improve the survival of patients with cancer is considered.

Targeting autophagy and lipid metabolism in cancer stem cells

Cancer stem cells (CSCs) are a subset of cancer cells with self-renewal ability and tumor initiating properties. Unlike the other non-stem cancer cells, CSCs resist traditional therapy and remain a major cause of disease relapse. With the recent advances in metabolomics, various studies have demonstrated that CSCs have distinct metabolic properties. Metabolic reprogramming in CSCs contributes to self-renewal and maintenance of stemness. Accumulating evidence suggests that rewiring of energy metabolism is a key player that enables to meet energy demands, maintains stemness, and sustains cancer growth and invasion. CSCs use various mechanisms such as increased glycolysis, redox signaling and autophagy modulation to overcome nutritional deficiency and sustain cell survival. The alterations in lipid metabolism acquired by the CSCs support biomass production through increased dependence on fatty acid synthesis and β-oxidation and contribute to oncogenic signaling pathways. This review summarizes our current understanding of lipid metabolism in CSCs and how pharmacological regulation of autophagy and lipid metabolism influences CSC phenotype. Increased dependence on lipid metabolism appears as an attractive strategy to eliminate CSCs using therapeutic agents that specifically target CSCs based on their modulation of lipid metabolism.

HOXB9 a miR-122-5p regulated gene, suppressed the anticancer effects of brassaol by upregulating SCD1 expression in melanoma

Brusatol (Bru), a Chinese medicine Brucea javanica extract, has a variety of antitumour effects. However, its role and underlying mechanism in melanoma have not been fully elucidated. In this study, we found that brusatol inhibited melanoma cell proliferation and migration and promoted cell apoptosis in vitro, in addition to suppressing melanoma cell tumorigenesis in vivo. Further studies on the mechanism revealed that brusatol significantly downregulated the expression of stearoyl-CoA desaturase 1 (SCD1). Increased SCD1 expression could impair the antitumour effects of brusatol on melanoma cells. Subsequently, we found that HOXB9, an important transcription factor, was directly bound to the promoter of SCD1, facilitating its transcription. Overexpression of HOXB9 inhibited brusatol-induced SCD1 reduction and promoted cell survival. Furthermore, our results revealed that miR-122-5p was significantly increased in response to brusatol treatment and led to a decrease in HOXB9 in melanoma. Collectively, our data suggested that the miR-122-5p/HOXB9/SCD1 axis might play an important role in the antitumour effects of brusatol and that brusatol might have potential clinical implications in melanoma therapy.

Lipogenesis promotes mitochondrial fusion and maintains cancer stemness in human NSCLC

Cancer stem-like cells (CSCs) are critically involved in cancer metastasis and chemoresistance, acting as one major obstacle in clinical practice. While accumulating studies have implicated the metabolic reprogramming of CSCs, mitochondrial dynamics in such cells remain poorly understood. Here we pinpointed OPA1hi with mitochondrial fusion as a metabolic feature of human lung CSCs, licensing their stem-like properties. Specifically, human lung CSCs exerted enhanced lipogenesis, inducing OPA1 expression via transcription factor SAM Pointed Domain containing ETS transcription Factor (SPDEF). In consequence, OPA1hi promoted mitochondrial fusion and stemness of CSCs. Such lipogenesishi, SPDEFhi, and OPA1hi metabolic adaptions were verified with primary CSCs from lung cancer patients. Accordingly, blocking lipogenesis and mitochondrial fusion efficiently impeded CSC expansion and growth of organoids derived from patients with lung cancer. Together, lipogenesis regulates mitochondrial dynamics via OPA1 for controlling CSCs in human lung cancer.

ALDOC- and ENO2- driven glucose metabolism sustains 3D tumor spheroids growth regardless of nutrient environmental conditions: a multi-omics analysis

BACKGROUND

Metastases are the major cause of cancer-related morbidity and mortality. By the time cancer cells detach from their primary site to eventually spread to distant sites, they need to acquire the ability to survive in non-adherent conditions and to proliferate within a new microenvironment in spite of stressing conditions that may severely constrain the metastatic process. In this study, we gained insight into the molecular mechanisms allowing cancer cells to survive and proliferate in an anchorage-independent manner, regardless of both tumor-intrinsic variables and nutrient culture conditions.

METHODS

3D spheroids derived from lung adenocarcinoma (LUAD) and breast cancer cells were cultured in either nutrient-rich or -restricted culture conditions. A multi-omics approach, including transcriptomics, proteomics, and metabolomics, was used to explore the molecular changes underlying the transition from 2 to 3D cultures. Small interfering RNA-mediated loss of function assays were used to validate the role of the identified differentially expressed genes and proteins in H460 and HCC827 LUAD as well as in MCF7 and T47D breast cancer cell lines.

RESULTS

We found that the transition from 2 to 3D cultures of H460 and MCF7 cells is associated with significant changes in the expression of genes and proteins involved in metabolic reprogramming. In particular, we observed that 3D tumor spheroid growth implies the overexpression of ALDOC and ENO2 glycolytic enzymes concomitant with the enhanced consumption of glucose and fructose and the enhanced production of lactate. Transfection with siRNA against both ALDOC and ENO2 determined a significant reduction in lactate production, viability and size of 3D tumor spheroids produced by H460, HCC827, MCF7, and T47D cell lines.

CONCLUSIONS

Our results show that anchorage-independent survival and growth of cancer cells are supported by changes in genes and proteins that drive glucose metabolism towards an enhanced lactate production. Notably, this finding is valid for all lung and breast cancer cell lines we have analyzed in different nutrient environmental conditions. broader Validation of this mechanism in other cancer cells of different origin will be necessary to broaden the role of ALDOC and ENO2 to other tumor types. Future in vivo studies will be necessary to assess the role of ALDOC and ENO2 in cancer metastasis.

Epigenetic effects of high-fat diet on intestinal tumorigenesis in C57BL/6J-Apc Min/+ mice

Aim

Obesity and obesogenic diets might partly accelerate cancer development through epigenetic mechanisms. To determine these early effects, we investigated the impact of three days of a high-fat diet on epigenomic and transcriptomic changes in Apc ^Min/+ murine intestinal epithelia.

Method

ChIP-Seq and RNA-Seq were performed on small intestinal epithelia of WT and Apc ^Min/+ male mice fed high-fat diet (HFD) or low-fat diet (LFD) for three days to identify genomic regions associated with differential H3K27ac levels as a marker of variant enhancer loci (VELs) as well as differentially expressed genes (DEGs).

Results

Regarding epigenetic and transcriptomic changes, diet type (LFD vs. HFD) showed a significant impact, and genotype (WT vs.Apc ^Min/+) showed a small impact. Compared to LFD, HFD resulted in 1306 gained VELs, 230 lost VELs, 133 upregulated genes, and 127 downregulated genes in WT mice, with 1056 gained VELs, 371 lost VELs, 222 upregulated genes, and 182 downregulated genes in Apc ^Min/+ mice. Compared to the WT genotype, the Apc ^Min/+ genotype resulted in zero changed VELs for either diet type group, 21 DEGs for LFD, and 48 DEGs for HFD. Most gained VELs, and upregulated genes were associated with lipid metabolic processes. Gained VELs were also associated with Wnt signaling. Downregulated genes were associated with antigen presentation and processing.

Conclusion

Three days of HFD-induced epigenomic and transcriptomic changes involving metabolic and immunologic pathways that may promote tumor growth in the genetically predisposed murine intestine without affecting key cancer signaling pathways.

Targeting lipid metabolism with natural products: A novel strategy for gastrointestinal cancer therapy

Gastrointestinal cancer (GIC), including gastric cancer and colorectal cancer, is a common malignant tumor originating from gastrointestinal epithelial cells. Although the pathogenesis of GIC remains unclear, aberrant lipid metabolism has emerged as a hallmark of cancer. Several enzymes, proteins, and transcription factors are involved in lipid metabolism reprogramming in GIC, and their abnormal expression can promote lipid synthesis and accumulation of lipid droplets through numerous mechanisms, thereby affecting the growth, proliferation, and metastasis of GIC cells. Studies show that some natural compounds, including flavonoids, alkaloids, and saponins, can inhibit the de novo synthesis of lipids in GIC, reduce the level of lipid accumulation, and subsequently, inhibit the occurrence and development of GIC by regulating Sterol regulatory element-binding protein 1 (SREBP-1), adenosine monophosphate-activated protein kinase (AMPK), 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), phosphatidylinositol-3-kinase/Akt and the mammalian target of rapamycin PI3K/Akt/mTOR, amongst other targets and pathways. Therefore, targeting tumor lipid metabolism is the focus of anti-gastrointestinal tumor therapy. Although most natural products require further high-quality studies to firmly establish their clinical efficacy, we review the potential of natural products in the treatment of GIC and summarize the application prospect of lipid metabolism as a new target for the treatment of GIC, hoping to provide a reference for drug development for gastrointestinal tumors.

Monoacylglycerol lipase regulates macrophage polarization and cancer progression in uveal melanoma and pan-cancer

Background

Although lipid metabolism has been proven to play a key role in the development of cancer, its significance in uveal melanoma (UM) has not yet been elucidated in the available literature.

Methods

To identify the expression patterns of lipid metabolism in 80 UM patients from the TCGA database, 47 genes involved in lipid metabolism were analyzed. Consensus clustering revealed two distinct molecular groups. ESTIMATE, TIMER, and ssGSEA analyses were done to identify the differences between the two subgroups in tumor microenvironment (TME) and immune state. Using Cox regression and Lasso regression analysis, a risk model based on differentially expressed genes (DEGs) was developed. To validate the expression of monoacylglycerol lipase (MGLL) and immune infiltration in diverse malignancies, a pan-cancer cohort from the UCSC database was utilized. Next, a single-cell sequencing analysis on UM patients from the GEO data was used to characterize the lipid metabolism in TME and the role of MGLL in UM. Finally, in vitro investigations were utilized to study the involvement of MGLL in UM.

Results

Two molecular subgroups of UM patients have considerably varied survival rates. The majority of DEGs between the two subgroups were associated with immune-related pathways. Low immune scores, high tumor purity, a low number of immune infiltrating cells, and a comparatively low immunological state were associated with a more favorable prognosis. An examination of GO and KEGG data demonstrated that the risk model based on genes involved with lipid metabolism can accurately predict survival in patients with UM. It has been demonstrated that MGLL, a crucial gene in this paradigm, promotes the proliferation, invasion, and migration of UM cells. In addition, we discovered that MGLL is strongly expressed in macrophages, specifically M2 macrophages, which may play a function in the M2 polarization of macrophages and M2 macrophage activation in cancer cells.

Conclusion

This study demonstrates that the risk model based on lipid metabolism may be useful for predicting the prognosis of patients with UM. By promoting macrophage M2 polarization, MGLL contributes to the evolution of malignancy in UM, suggesting that it may be a therapeutic target for UM.

Lipid metabolism-related gene signature predicts prognosis and depicts tumor microenvironment immune landscape in gliomas

Background

Glioma is the most common primary brain tumor in adults and accounts for more than 70% of brain malignancies. Lipids are crucial components of biological membranes and other structures in cells. Accumulating evidence has supported the role of lipid metabolism in reshaping the tumor immune microenvironment (TME). However, the relationship between the immune TME of glioma and lipid metabolism remain poorly described.

Materials and methods

The RNA-seq data and clinicopathological information of primary glioma patients were downloaded from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA). An independent RNA-seq dataset from the West China Hospital (WCH) also included in the study. Univariate Cox regression and LASSO Cox regression model was first to determine the prognostic gene signature from lipid metabolism-related genes (LMRGs). Then a risk score named LMRGs-related risk score (LRS) was established and patients were stratified into high and low risk groups according to LRS. The prognostic value of the LRS was further demonstrated by construction of a glioma risk nomogram. ESTIMATE and CIBERSORTx were used to depicted the TME immune landscape. Tumor Immune Dysfunction and Exclusion (TIDE) was utilized to predict the therapeutic response of immune checkpoint blockades (ICB) among glioma patients.

Results

A total of 144 LMRGs were differentially expressed between gliomas and brain tissue. Finally, 11 prognostic LMRGs were included in the construction of LRS. The LRS was demonstrated to be an independent prognostic predictor for glioma patients, and a nomogram consisting of the LRS, IDH mutational status, WHO grade, and radiotherapy showed a C-index of 0.852. LRS values were significantly associated with stromal score, immune score, and ESTIMATE score. CIBERSORTx indicated remarkable differences in the abundance of TME immune cells between patients with high and low LRS risk levels. Based on the results of TIDE algorithm, we speculated that the high-risk group had a greater chance of benefiting from immunotherapy.

Conclusion

The risk model based upon LMRGs could effectively predict prognosis in patients with glioma. Risk score also divided glioma patients into different groups with distinct TME immune characteristics. Immunotherapy is potentially beneficial to glioma patients with certain lipid metabolism profiles.

Oleic acid from cancer-associated fibroblast promotes cancer cell stemness by stearoyl-CoA desaturase under glucose-deficient condition

BACKGROUND

Cancer-associated fibroblasts (CAFs) coordinate the malignancy of cancer cells via secretory materials. Reprogrammed lipid metabolism and signaling play critical roles in cancer biology. Oleic acid (OA) serves as a source of energy under glucose-deficient conditions, but its function in cancer progression remains unclear. The present study investigated that CAFs in xenografted tumors had higher amounts of fatty acids, particularly OA, compared to normal fibroblasts, and promoted the cancer cell stemness in lung adenocarcinoma cells under glucose-deficient condition.

METHODS

Xenografts were established in immunodeficient mice by injection of NCI-H460 (H460) cells. Lipids and fatty acids were evaluated using the BODIPY staining and fatty-acid methyl esters analysis. The expression levels of markers for lipid metabolism and cancer stemness were determined by western blot, flow cytometry, and real-time PCR. Cancer cell subclones against stearoyl-CoA desaturase (SCD) were produced by lentiviral vector and CRISPR/cas9 systems. The expression of SCD was examined immunochemically in human adenocarcinoma tissues, and its clinical relevance to survival rate in lung adenocarcinoma patients was assessed by Kaplan-Meier analysis.

RESULTS

Transferred CAF-derived OA through lipid transporter upregulated SCD in cancer cells under glucose-deficient conditions, resulting in enhanced lipid metabolism and autophagosome maturation. By OA treatment under glucose deficient condition, cancer cell stemness was significantly enhanced through sequential activation of SCD, F-actin polymerization and nuclear translocation of yes-associated protein. These findings were confirmed by experiments using chemical inhibitors, SCD-overexpressing cells and SCD-knockout (KO) cells. When xenografted, SCD-overexpressing cells produced larger tumors compared with parental cells, while SCD-KO cells generated much smaller tumors. Analysis of tumor tissue microarray from lung adenocarcinoma patients revealed that SCD expression was the marker for poor prognosis involving tumor grade, clinical stage and survival rate.

CONCLUSION

Our data indicate that CAFs-derived OA activated lipid metabolism in lung adenocarcinoma cells under glucose-deficient conditions, subsequently enhancing stemness and progression toward malignancy.

Development and Clinical Validation of a Novel 5 Gene Signature Based on Fatty Acid Metabolism-Related Genes in Oral Squamous Cell Carcinoma

Background/Aim

Lipid metabolism disorders play a crucial role in tumor development and progression. The aim of the study focused on constructing a novel prognostic model of oral squamous cell carcinoma (OSCC) patients using fatty acid metabolism-related genes.

Methods

Microarray test and data from The Cancer Genome Atlas (TCGA) were used to identify differentially expressed genes related to fatty acid metabolism. The quantitative real-time polymerase chain reaction (qRT-PCR) was then used to validate the expression of targeted fatty acid metabolism genes. A risk predictive scoring model of fatty acid metabolism-related genes was generated using a multivariate Cox model. The efficacy of this model was assessed by time-dependent receiver operating characteristic curve (ROC).

Results

14 fatty acid metabolism-related genes were identified by microarray test and TCGA database analysis and then confirmed by PCR. Finally, a 5 gene signature (ACACB, FABP3, PDK4, PPARG, and PLIN5) was constructed and a RiskScore was calculated for each patient. Compared to the high RiskScore group, the low RiskScore group had better overall survival (OS) (p = 0.02). The RiskScore derived from a 5 gene signature was a prognostic factor (HR: 3.73, 95% CI: 1.38, 10.09) for OSCC patients. The predictive classification efficiencies of RiskScore were evaluated and the area under the curve (AUC) values for 1, 3, and 5 years were 0.613, 0.652, and 0.681, respectively. Then we compared the predictive performance of the prognostic model with or without the RiskScore. The 5 gene-derived RiskScore can improve the predictive performance with AUC values of 0.760, 0.803, and 0.830 for 1, 3, and 5 years OS in prognostic model including the RiskScore. While the predicted AUC values of the model without RiskScore for 1, 3, and 5 years OS were 0.699, 0.715, and 0.714, respectively.

Conclusion

We developed a predictive score model using 5 fatty acid metabolism-related genes, which could be a potential prognostic indicator in OSCC.

Characterization of fatty acid metabolism-related lncRNAs in lung adenocarcinoma identifying potential novel prognostic targets

Lung adenocarcinoma (LUAD), a malignant respiratory tumor with an extremely poor prognosis, has troubled the medical community all over the world. According to recent studies, fatty acid metabolism (FAM) and long non-coding RNAs (lncRNAs) regulation have shown exciting results in tumor therapy. In this study, the original LUAD patient data was obtained from the TCGA database, and 12 FAM-related lncRNAs (AL390755.1, AC105020.6, TMPO-AS1, AC016737.2, AC127070.2, LINC01281, AL589986.2, GAS6-DT, AC078993.1, LINC02198, AC007032.1, and AL021026.1) that were highly related to the progression of LUAD were finally identified through bioinformatics analysis, and a risk score model for clinical reference was constructed. The window explores the immunology and molecular mechanism of LUAD, aiming to shed the hoping light on LUAD treatment.

Emerging Roles of Lipophagy in Cancer Metastasis

Simple Summary

Metastasis is the main cause of death in patients with malignant tumors worldwide. Mounting evidence suggests lipid droplet metabolism is involved in the process of metastasis. As a mechanism to selectively degrade lipid droplets, the current research on lipophagy and tumor metastasis is quite limited. This review summarizes the crosstalk among lipophagy, tumor lipid metabolism and cancer metastasis, which will provide a new reference for the development of effective targeted drugs.

Abstract

Obesity is a prominent risk factor for certain types of tumor progression. Adipocytes within tumor stroma contribute to reshaping tumor microenvironment (TME) and the metabolism and metastasis of tumors through the production of cytokines and adipokines. However, the crosstalk between adipocytes and tumor cells remains a major gap in this field. Known as a subtype of selective autophagy, lipophagy is thought to contribute to lipid metabolism by breaking down intracellular lipid droplets (LDs) and generating free fatty acids (FAs). The metastatic potential of cancer cells closely correlates with the lipid degradation mechanisms, which are required for energy generation, signal transduction, and biosynthesis of membranes. Here, we discuss the recent advance in the understanding of lipophagy with tumor lipid metabolism and review current studies on the roles of lipoghagy in the metastasis of certain human malignancies. Additionally, the novel candidate drugs targeting lipophagy are integrated for effective treatment strategies.

Comprehensive analysis of fatty acid and lactate metabolism–related genes for prognosis value, immune infiltration, and therapy in osteosarcoma patients

Osteosarcoma is the most frequent bone tumor. Notwithstanding that significant medical progress has been achieved in recent years, the 5-year overall survival of osteosarcoma patients is inferior. Regulation of fatty acids and lactate plays an essential role in cancer metabolism. Therefore, our study aimed to comprehensively assess the fatty acid and lactate metabolism pattern and construct a fatty acid and lactate metabolism–related risk score system to predict prognosis in osteosarcoma patients. Clinical data and RNA expression data were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Gene Expression Omnibus (GEO) databases. We used the least absolute shrinkage and selection operator (LASSO) and Cox regression analyses to construct a prognostic risk score model. Relationships between the risk score model and age, gender, tumor microenvironment characteristics, and drug sensitivity were also explored by correlation analysis. We determined the expression levels of prognostic genes in osteosarcoma cells via Western blotting. We developed an unknown fatty acid and lactate metabolism–related risk score system based on three fatty acid and lactate metabolism–related genes (SLC7A7, MYC, and ACSS2). Survival analysis showed that osteosarcoma patients in the low-risk group were likely to have a better survival time than those in the high-risk group. The area under the curve (AUC) value shows that our risk score model performs well in predicting prognosis. Elevated fatty acids and lactate risk scores weaken immune function and the environment of the body, which causes osteosarcoma patients’ poor survival outcomes. In general, the constructed fatty acid and lactate metabolism–related risk score model can offer essential insights into subsequent mechanisms in available research. In addition, our study may provide rational treatment strategies for clinicians based on immune correlation analysis and drug sensitivity in the future.

Posttranslational control of lipogenesis in the tumor microenvironment

Metabolic reprogramming of cancer cells within the tumor microenvironment typically occurs in response to increased nutritional, translation and proliferative demands. Altered lipid metabolism is a marker of tumor progression that is frequently observed in aggressive tumors with poor prognosis. Underlying these abnormal metabolic behaviors are posttranslational modifications (PTMs) of lipid metabolism-related enzymes and other factors that can impact their activity and/or subcellular localization. This review focuses on the roles of these PTMs and specifically on how they permit the re-wiring of cancer lipid metabolism, particularly within the context of the tumor microenvironment.

Purinergic receptors are a key bottleneck in tumor metabolic reprogramming: The prime suspect in cancer therapeutic resistance

ATP and other nucleoside phosphates have specific receptors named purinergic receptors. Purinergic receptors and ectonucleotidases regulate various signaling pathways that play a role in physiological and pathological processes. Extracellular ATP in the tumor microenvironment (TME) has a higher level than in normal tissues and plays a role in cancer cell growth, survival, angiogenesis, metastasis, and drug resistance. In this review, we investigated the role of purinergic receptors in the development of resistance to therapy through changes in tumor cell metabolism. When a cell transforms to neoplasia, its metabolic processes change. The metabolic reprogramming modified metabolic feature of the TME, that can cause impeding immune surveillance and promote cancer growth. The purinergic receptors contribute to therapy resistance by modifying cancer cells' glucose, lipid, and amino acid metabolism. Limiting the energy supply of cancer cells is one approach to overcoming resistance. Glycolysis inhibitors which reduce intracellular ATP levels may make cancer cells more susceptible to anti-cancer therapies. The loss of the P2X7R through glucose intolerance and decreased fatty acid metabolism reduces therapeutic resistance. Potential metabolic blockers that can be employed in combination with other therapies will aid in the discovery of new anti-cancer immunotherapy to overcome therapy resistance. Therefore, therapeutic interventions that are considered to inhibit cancer cell metabolism and purinergic receptors simultaneously can potentially reduce resistance to treatment.

Acylglycerol kinase promotes ovarian cancer progression and regulates mitochondria function by interacting with ribosomal protein L39

Background

Epithelial ovarian cancer (EOC) is the leading cause of deaths among patients with gynecologic malignancies. In recent years, cancer stem cells (CSCs) have attracted great attention, which have been regarded as new biomarkers and targets in cancer diagnoses as well as therapies. However, therapeutic failure caused by chemotherapy resistance in late-stage EOC occurs frequently. The 5-year survival rate of patients with EOC remains at about 30%.

Methods

In this study, the expression of acylglycerol kinase (AGK) was analyzed among patients with EOC. The effect of AGK on EOC cell proliferation and tumorigenicity was studied using Western blotting, flow cytometry, EdU assay and in vivo xenotransplantation assays. Furthermore, AGK induced CSC-like properties and was resistant to cisplatin chemotherapy in the EOC cells, which were investigated through sphere formation assays and the in vivo model of chemoresistance. Finally, the relationship between AGK and RPL39 (Ribosomal protein L39) in mitochondria as well as their effect on the mitochondrial function was analyzed through methods including transmission electron microscopy, microarray, biotin identification and immunoprecipitation.

Results

AGK showed a markedly upregulated expression in EOC, which was significantly associated with the poor survival of patients with EOC, the expression of AGK-promoted EOC cell proliferation and tumorigenicity. AGK also induced CSC-like properties in the EOC cells and was resistant to cisplatin chemotherapy. Furthermore, the results indicated that AGK not only maintained mitochondrial cristae morphogenesis, but also increased the production of reactive oxygen species and Δψm of EOC cells in a kinase-independent manner. Finally, our results revealed that AGK played its biological function by directly interacting with RPL39.

Conclusions

We demonstrated that AGK was a novel CSC biomarker for EOC, which the stemness of EOC was promoted and chemotherapy resistance was developed through physical as well as functional interaction with RPL39.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02448-5.

Comprehensive analysis of the endoplasmic reticulum stress-related long non-coding RNA in bladder cancer

Background

Bladder cancer is ranked the second most frequent tumor among urological malignancies. The research strived to establish a prognostic model based on endoplasmic reticulum stress (ERS)-related long non-coding RNA (lncRNA) in bladder cancer.

Methods

We extracted the ERS-related genes from the published research and bladder cancer data from the Cancer Genome Atlas database. ERS-related lncRNAs with prognostic significance were screened by univariate Cox regression, least absolute shrinkage and selection operator regression analysis and Kaplan-Meier method. Multivariate Cox analysis was leveraged to establish the risk score model. Moreover, an independent dataset, GSE31684, was used to validate the model’s efficacy. The nomogram was constructed based on the risk score and clinical variables. Furthermore, the biological functions, gene mutations, and immune landscape were investigated to uncover the underlying mechanisms of the ERS-related signature. Finally, we employed external datasets (GSE55433 and GSE89006) and qRT-PCR to investigate the expression profile of these lncRNAs in bladder cancer tissues and cells.

Results

Six ERS-related lncRNAs were identified to be closely coupled with patients’ prognosis. On this foundation, a risk score model was created to generate the risk score for each patient. The ERS-related risk score was shown to be an independent prognostic factor. And the results of GSE31684 dataset also supported this conclusion. Then, a nomogram was constructed based on risk scores and clinical characteristics, and proven to have excellent predictive value. Moreover, the gene function analysis demonstrated that ERS-related lncRNAs were closely linked to fatty extracellular matrix, cytokines, cell adhesion, and tumor pathways. Further analysis revealed the association of the 6-lncRNAs signature with gene mutations and immunity in bladder cancer. Finally, the external datasets and qRT-PCR verified high expressions of the ERS-related lncRNAs in bladder cancer tissues and cells.

Conclusions

Overall, our findings indicated that ERS-related lncRNAs, which may affect tumor pathogenesis in a number of ways, might be exploited to assess the prognosis of bladder cancer patients.

Glioblastoma Stem-Like Cells (GSCs) with Mesenchymal Signature: Lipid Profiles of Mobile Lipids Obtained with MRS before and after Radio/Chemical Treatments

Glioblastoma is the most common and lethal primary malignant brain tumor in adults. Glioblastoma stem cells (GSCs) promote and are responsible for glioblastoma intratumoral heterogeneity and therapy resistance, due to their two main features: self-renewal and differentiation. Lipids have important biological and physiological functions that are critical for understanding the regulation and control of stem cell fate; lipid metabolism and related unsaturation levels play a possible role as the target of therapeutics to overcome glioblastoma radioresistance. This paper aimed at an in-depth analysis of 13 GSC mesenchymal (MES) lines, two subclones, and a stabilized glioblastoma line (T98G) by magnetic resonance spectroscopy (MRS). Particularly, 2D MRS was used to investigate lipid unsaturation behavior during growth in culture and after treatment with etomoxir and photon beams. MES lines, although belonging to the same genetic and metabolic cluster, showed metabolic heterogeneity when observed by MRS, focusing on lipid signals. Nonetheless, the observed unsaturation level stability for two representative lines after stressful treatments suggests unusual robustness of the unsaturation levels for each line, as a peculiar and intrinsic characteristic of GSCs.

m6A-related metabolism molecular classification with distinct prognosis and immunotherapy response in soft tissue sarcoma

N6-methyladenosine (m6A) methylation, one of the most crucial RNA modifications, has been proven to play a key role that affect prognosis of soft tissue sarcoma (STS). However, m6A methylation potential role in STS metabolic processes remains unknown. We comprehensively estimated the m6A metabolic molecular subtypes and corresponding survival, immunity, genomic and stemness characteristics based on 568 STS samples and m6A related metabolic pathways. Then, to quantify the m6A metabolic subtypes, machine learning algorithms were used to develop the m6A-metabolic Scores of individual patients. Finally, two distinct m6A metabolic subtypes (Cluster A and Cluster B) among the STS patients were identified. Compared to Cluster B subtype, the Cluster A subtype was mainly characterized by better survival advantages, activated anti-tumor immune microenvironment, lower gene mutation frequency and higher anti-PD-1 immunotherapy response rates. We also found that the m6A-metabolic Scores could accurately predict the molecular subtype of STS, prognosis, the abundance of immune cell infiltration, tumor metastasis status, sensitivity to chemotherapeutics and immunotherapy response. In general, this study revealed that m6A-regulated tumor metabolism processes played a key role in terms of prognosis of STS, tumor progression, and immune microenvironment. The identification of metabolic molecular subtypes and the construction of m6A-metabolic Score will help to more effectively guide immunotherapy, metabolic therapy and chemotherapy in STS.

UHPLC-HRMS–based serum lipisdomics reveals novel biomarkers to assist in the discrimination between colorectal adenoma and cancer

The development of a colorectal adenoma (CA) into carcinoma (CRC) is a long and stealthy process. There remains a lack of reliable biomarkers to distinguish CA from CRC. To effectively explore underlying molecular mechanisms and identify novel lipid biomarkers promising for early diagnosis of CRC, an ultrahigh-performance liquid chromatography tandem high-resolution mass spectrometry (UHPLC-HRMS) method was employed to comprehensively measure lipid species in human serum samples of patients with CA and CRC. Results showed significant differences in serum lipid profiles between CA and CRC groups, and 85 differential lipid species (P < 0.05 and fold change > 1.50 or < 0.67) were discovered. These significantly altered lipid species were mainly involved in fatty acid (FA), phosphatidylcholine (PC), and triacylglycerol (TAG) metabolism with the constituent ratio > 63.50%. After performance evaluation by the receiver operating characteristic (ROC) curve analysis, seven lipid species were ultimately proposed as potential biomarkers with the area under the curve (AUC) > 0.800. Of particular value, a lipid panel containing docosanamide, SM d36:0, PC 36:1e, and triheptanoin was selected as a composite candidate biomarker with excellent performance (AUC = 0.971), and the highest selected frequency to distinguish patients with CA from patients with CRC based on the support vector machine (SVM) classification model. To our knowledge, this study was the first to undertake a lipidomics profile using serum intended to identify screening lipid biomarkers to discriminate between CA and CRC. The lipid panel could potentially serve as a composite biomarker aiding the early diagnosis of CRC. Metabolic dysregulation of FAs, PCs, and TAGs seems likely involved in malignant transformation of CA, which hopefully will provide new clues to understand its underlying mechanism.

The metabolic addiction of cancer stem cells

Cancer stem cells (CSC) are the minor population of cancer originating cells that have the capacity of self-renewal, differentiation, and tumorigenicity (when transplanted into an immunocompromised animal). These low-copy number cell populations are believed to be resistant to conventional chemo and radiotherapy. It was reported that metabolic adaptation of these elusive cell populations is to a large extent responsible for their survival and distant metastasis. Warburg effect is a hallmark of most cancer in which the cancer cells prefer to metabolize glucose anaerobically, even under normoxic conditions. Warburg's aerobic glycolysis produces ATP efficiently promoting cell proliferation by reprogramming metabolism to increase glucose uptake and stimulating lactate production. This metabolic adaptation also seems to contribute to chemoresistance and immune evasion, a prerequisite for cancer cell survival and proliferation. Though we know a lot about metabolic fine-tuning in cancer, what is still in shadow is the identity of upstream regulators that orchestrates this process. Epigenetic modification of key metabolic enzymes seems to play a decisive role in this. By altering the metabolic flux, cancer cells polarize the biochemical reactions to selectively generate "onco-metabolites" that provide an added advantage for cell proliferation and survival. In this review, we explored the metabolic-epigenetic circuity in relation to cancer growth and proliferation and establish the fact how cancer cells may be addicted to specific metabolic pathways to meet their needs. Interestingly, even the immune system is re-calibrated to adapt to this altered scenario. Knowing the details is crucial for selective targeting of cancer stem cells by choking the rate-limiting stems and crucial branch points, preventing the formation of onco-metabolites.