Roles and therapeutic targeting of ceramide metabolism in cancer

Interactions between radiotherapy resistance mechanisms and the tumor microenvironment

BACKGROUND

Resistance to radiotherapy (RT) presents a significant clinical challenge in management of cancer. Recent evidence points to specific mechanisms of resistance within the tumor microenvironment (TME), which we aim to discuss, with the aim of overcoming the clinical challenge.

METHODS

We performed the narrative review using PubMed and Web of Science databases to identify studies that reported the regulative network and treatments of RT resistance from TME perspectives.

RESULTS

RT significantly changes the immune TME of cancers, which is closely appearing to play a key role in RT resistance (RTR) by modulating immune cell infiltration and function. Various phenotypes are involved in the development of RTR, such as autophagy, senescence, oxidative stress, cell polarization, ceramide metabolism, and angiogenesis in the TME. Key genes and pathways are also implicated in RTR, including immune and inflammatory cytokines, TGF-β, P53, the NF-κB pathway, the cGAS/STING pathway, the ERK and AKT pathway, and the STAT pathway. Based on the mechanism of RTR in the TME, many proposed routes to overcome RTR, several specifically target the TME including targeting fibroblast activation protein, exosomes management, nanomedicine, and immunotherapy. Many challenges in RT resistance still need to be further explored with emerging investigative methods, such as artificial intelligence, genetic technologies, and bioengineering.

CONCLUSIONS

The complex interactions between RT and TME significantly affect the efficiency of RT. Novel approaches to overcome this clinical difficulty are promising, which needs future work to further explore and identify better treatment strategies.

Roles of plasma proteins in mediating the causal effect of the lipid species on gastric cancer: Insights from proteomic and two-step Mendelian randomization

The change of plasma lipid species has close contacts with gastric cancer (GC). However, the specific mechanism still needs to be explored further. We aim to utilize plasma proteins to decipher the association between lipid species and GC, and seek possible drug targets for GC. We performed a two-step Mendelian randomization (MR) analysis to investigate causal relationships among 179 lipid species, 4907 plasma proteins, and GC. Using summary-data-based MR and colocalization, we first examined protein-GC associations in discovery (N = 35,559) and validation (N = 54,219) cohorts. Subsequent MR analyses assessed lipid-GC and lipid-protein relationships, followed by mediation analysis using error propagation methods. Finally, macromolecular docking of prioritized proteins identified potential therapeutic ligands. Our MR analysis revealed causal relationships between 12 lipid species and GC, as well as 3 plasma proteins and GC. Importantly, mediation analysis demonstrated that CCDC80 protein mediates 2.90% (95% CI: 0.30-5.5%) of the protective effect of diacylglycerol (16:1_18:1) against GC. Based on these findings, we identified valproic acid as a promising therapeutic candidate targeting CCDC80 for GC treatment. Our study demonstrates that reduced CCDC80 expression mediates the tumor-promoting effects of diacylglycerol (16:1_18:1) in GC pathogenesis. Molecular docking confirms valproic acid binds stably to CCDC80, suggesting its therapeutic potential. These findings advance GC etiology understanding and provide a new drug development direction.

Differential Effects of Sphingolipids on Cell Death and Antioxidant Defenses in Type 1 and Type 2 Endometrial Cancer Cells

Endometrial cancer (EC) is classified into two main subtypes with distinct molecular profiles. Sphingolipids, particularly ceramide and sphingosine-1-phosphate (S1P), are crucial regulators of cell survival, apoptosis, and oxidative stress. This study examined the impact of sphingolipid metabolism in Ishikawa (type 1) and HEC-1A (type 2) EC cells following the silencing of Sptlc1 and Sptlc2, which encode subunits of serine palmitoyltransferase (SPT), a key enzyme in de novo sphingolipid synthesis. Gene silencing was confirmed by RT-PCR and Western blot, while sphingolipid levels were quantified using UHPLC/MS/MS and the sphingolipid rheostat (S1P/ceramide ratio) was calculated. Cell viability (MTT assay), cell death, ROS levels (ELISA), total antioxidant capacity (TAC), catalase and caspase-3 activity, and mitochondrial membrane potential were also assessed. The obtained data showed higher ceramide levels in Ishikawa(CON) cells and higher S1P levels in HEC-1A(CON) cells, resulting in a higher sphingolipid rheostat in HEC-1A cells. SPT knockdown reduced sphingolipid levels, increased cell viability, elevated ROS levels, and decreased cell death, particularly in Ishikawa cells. Furthermore, after gene silencing, these cells exhibited reduced catalase activity and diminished TAC, indicating an impaired redox balance. These findings reveal subtype-specific responses to disrupted sphingolipid synthesis and highlight the importance of sphingolipid homeostasis in the behavior of EC cells.

Elucidating stroke etiology through lipidomics of thrombi and plasma in acute ischemic stroke patients undergoing endovascular thrombectomy

Acute ischemic stroke (AIS) requires detailed etiology information to guide optimal management. Given the pivotal role of lipids in AIS, we conducted a comprehensive lipidomics analysis of paired thrombi and plasma from AIS patients, correlating the findings with stroke etiology. Patients were recruited across four etiologies: cardioembolism (CE), large artery atherosclerosis (LAA), active cancer (Cancer), and undetermined. Plasma and thrombi were collected before and during endovascular thrombectomy and analyzed using in-house targeted lipidomics. Among 51 patients (37 CE, 7 LAA, 4 Cancer, and 3 undetermined), we identified 37 and 70 lipid species significantly different between thrombi in CE and LAA, and CE and Cancer, respectively (FDR-corrected P < 0.05). No significant differences were observed in plasma. Notably, 21 diacylglycerols and 11 polyunsaturated triacylglycerols were depleted (2.5 to 12 folds) in LAA compared to CE, while 10 ceramides and 57 glycerophospholipids were elevated in Cancer. With 80% validation accuracy, 29 and 59 lipids distinguished LAA and Cancer from CE, respectively. A neural network model using these lipids effectively classified undetermined patients. This study emphasizes the significance of thrombus lipids in distinguishing between LAA, CE, and Cancer etiologies in AIS, enhancing our understanding of stroke pathophysiology and informing future clinical managements.

Machine Learning-Based Radiomics in Malignancy Prediction of Pancreatic Cystic Lesions: Evidence from Cyst Fluid Multi-Omics

The malignant potential of pancreatic cystic lesions (PCLs) varies dramatically, leading to difficulties when making clinical decisions. This study aimed to develop noninvasive clinical-radiomic models using preoperative CT images to predict the malignant potential of PCLs. It also investigates the biological mechanisms underlying these models. Patients from two retrospective and one prospective cohort, all undergoing surgical resection for PCLs, are divided into four datasets: training, internal test, external test, and prospective application sets. Eleven machine learning classifiers are employed to construct radiomic models based on selected features. Cyst fluid from the prospective cohort is collected for proteomic and lipidomic analysis. The radiomic models demonstrated high accuracy, with area under the receiver operating characteristic curves (AUCs) > 0.93 across the training (n = 262), internal test (n = 50), and external test (n = 50) sets. AUCs ranged from 0.92 to 0.96 for the prospective cohort (n = 34). Meanwhile, differentially-expressed proteins and lipid molecules, along with their associated signaling pathways, are identified between high and low groups of clinical-radiomic scores. This models can effectively and accurately predict the malignant potential of PCLs, with multi-omics evidence suggesting the biological mechanisms involving secretion function and lipid metabolism underlying clinical-radiomic models.

SMPD3 as a Potential Biomarker and Therapeutic Target in Hepatocellular Carcinoma

Background and Aims: Hepatocellular carcinoma (HCC) is a prevalent and aggressive liver cancer with high mortality rates. Sphingomyelin phosphodiesterase 3 (SMPD3) has recently been suggested to play an antitumor role in several cancers. This study is aimed at investigating the role of SMPD3 in HCC and its potential as a prognostic marker and therapeutic target. Methods: A retrospective cohort study of HCC patients was conducted using clinical data from our hospital. Survival analyses, including Kaplan-Meier and multivariate Cox regression, were performed to assess the impact of SMPD3 expression on survival. Further analyses were carried out using data from The Cancer Genome Atlas (TCGA) HCC cohort. In vitro and in vivo experiments were conducted to evaluate the effects of SMPD3 overexpression on HCC cell lines and tumor growth in mice. Results: High SMPD3 expression level was associated with improved survival in both our cohort and TCGA cohort. Multivariate Cox regression analysis confirmed high SMPD3 expression level as an independent predictor of better survival outcomes. In vitro and in vivo experiments demonstrated that SMPD3 overexpression significantly decreased HCC cell proliferation, migration, and invasion and inhibited tumor growth in a nude mouse model. Conclusions: SMPD3 plays a protective role in HCC by inhibiting tumor growth and progression. Its high expression is associated with better survival outcomes and may serve as a promising prognostic marker and potential therapeutic target in HCC. Further research into the molecular mechanisms of SMPD3's antitumor effects could lead to novel therapeutic strategies for HCC.

Ceramide as a Promising Tool for Diagnosis and Treatment of Clinical Diseases: A Review of Recent Advances

Background/Objectives: Ceramide, a sphingolipid metabolite, has emerged as a key player in various physiological and pathological processes. Changes in ceramide levels are associated with the occurrence and development of various diseases, highlighting its potential as a biomarker of various clinical diseases. Methods: The biosynthesis and metabolism of ceramide are discussed, along with its functions in cell signaling, apoptosis, and inflammation. This study further examines the potential of ceramide as a biomarker for disease diagnosis and treatment. Results: This article highlights the involvement of ceramide in several diseases, including cardiovascular diseases, dermatosis, cancer, neurodegenerative disorders and metabolic syndromes. For each disease, the potential of ceramide as a biomarker for disease diagnosis and prognosis is explored, and the feasibility of therapeutic strategies targeting ceramide metabolism are reviewed. Additionally, the challenges and future directions in the field of ceramide research are addressed. Conclusions: This review article provides an overview of the recent advances in understanding the role of ceramide in clinical diseases and its potential as a diagnostic and therapeutic tool.

Untargeted Lipidomic Biomarkers for Liver Cancer Diagnosis: A Tree-Based Machine Learning Model Enhanced by Explainable Artificial Intelligence

Background and Objectives: Liver cancer ranks among the leading causes of cancer-related mortality, necessitating the development of novel diagnostic methods. Deregulated lipid metabolism, a hallmark of hepatocarcinogenesis, offers compelling prospects for biomarker identification. This study aims to employ explainable artificial intelligence (XAI) to identify lipidomic biomarkers for liver cancer and to develop a robust predictive model for early diagnosis. Materials and Methods: This study included 219 patients diagnosed with liver cancer and 219 healthy controls. Serum samples underwent untargeted lipidomic analysis with LC-QTOF-MS. Lipidomic data underwent univariate and multivariate analyses, including fold change (FC), t-tests, PLS-DA, and Elastic Network feature selection, to identify significant biomarker candidate lipids. Machine learning models (AdaBoost, Random Forest, Gradient Boosting) were developed and evaluated utilizing these biomarkers to differentiate liver cancer. The AUC metric was employed to identify the optimal predictive model, whereas SHAP was utilized to achieve interpretability of the model's predictive decisions. Results: Notable alterations in lipid profiles were observed: decreased sphingomyelins (SM d39:2, SM d41:2) and increased fatty acids (FA 14:1, FA 22:2) and phosphatidylcholines (PC 34:1, PC 32:1). AdaBoost exhibited a superior classification performance, achieving an AUC of 0.875. SHAP identified PC 40:4 as the most efficacious lipid for model predictions. The SM d41:2 and SM d36:3 lipids were specifically associated with an increased risk of low-onset cancer and elevated levels of the PC 40:4 lipid. Conclusions: This study demonstrates that untargeted lipidomics, in conjunction with explainable artificial intelligence (XAI) and machine learning, may effectively identify biomarkers for the early detection of liver cancer. The results suggest that alterations in lipid metabolism are crucial to the progression of liver cancer and provide valuable insights for incorporating lipidomics into precision oncology.

Sparstolonin B Suppresses Proliferation and Modulates Toll-like Receptor Signaling and Inflammatory Pathways in Human Colorectal Cancer Cells

Background: Sparstolonin B (SsnB), a natural compound with anti-inflammatory and anti-proliferative properties, was investigated for its effects on cell viability, apoptosis, and inflammatory pathways in human colorectal cancer cells (HCT-116) and healthy human fibroblasts (BJ). Phorbol 12-myristate 13-acetate (PMA), a tumor promoter and inflammatory activator, was used to stimulate proliferation and inflammatory pathways. Methods: HCT-116 and BJ cells were treated with SsnB (3.125-50 μM) or PMA (1-10 nM) for 12-18 h. Cell viability was assessed using MTT analysis, while apoptosis was evaluated through cleaved caspase-3 staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry. Proliferation was analyzed through proliferating cell nuclear antigen (PCNA) staining. Toll-like receptor (TLR) signaling, cytokine expression, and sphingolipid levels were measured using immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and mass spectrometry, respectively. Results: SsnB reduced HCT-116 cell viability in a dose- and time-dependent manner with minimal effects on BJ cells. SsnB (25 μM, 12 h) decreased HCT-116 viability 0.6-fold, while PMA (10 nM, 12 h) increased it 2-fold (p < 0.01). No significant change was observed in BJ cells. PCNA fluorescence staining increased 2-fold with PMA and decreased 0.4-fold with SsnB (p < 0.001). PMA upregulated TLR2 and TLR4 mRNA and protein levels, with MyD88, p-ERK, and pNF-κB fluorescence increasing 2.1-, 1.5-, and 1.7-fold, respectively (p < 0.001). PMA elevated TNF-α, IL-1β, and IL-6 levels (p < 0.01). SsnB suppressed PMA-induced effects and promoted apoptosis, increasing cleaved caspase-3 levels by 1.5-fold and TUNEL staining by 1.9-fold (p < 0.01). Flow cytometry confirmed a significant increase in early and late apoptotic cells in the SsnB group. SsnB also increased ceramide (C18, C20, C22, and C24) levels (1.3- to 2.5-fold, p < 0.01) while reducing PMA-induced S1P and C1P increases (p < 0.01). Conclusions: SsnB selectively inhibits proliferation, induces apoptosis, and modulates inflammatory and sphingolipid pathways in colorectal cancer cells, with minimal toxicity to healthy fibroblasts, supporting its potential as a targeted therapeutic agent.

Identification of Lipid Species Signatures in FOLFOXIRI-Resistant Colorectal Cancer Cells

Chronic drug treatment can alter the lipidome of cancer cells, potentially leading to significant biological changes, such as drug resistance or increased tumor aggressiveness. This study examines the lipidome profiles of four human colorectal cancer (CRC) cell lines, comparing treatment-naïve cells with the same cells after chronic exposure to a clinically used combination therapy (FOLFOXIRI: folinic acid, 5-fluorouracil, oxaliplatin, and irinotecan). Lipidomic profiling was obtained with untargeted liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS). For data deconvolution and to interpret the multifactorial dataset generated, Analysis of Variance Multiblock Orthogonal Partial Least Squares (AMOPLS) was used. Our results indicate specific shifts in triglycerides (TGs), sphingolipids, and phospholipids in CRC cells resistant to FOLFOXIRI. The overall shift in TGs, phosphatidylcholine, and cholesteryl ester species was notably linked to FOLFOXIRI resistance (-R) in SW620 cells, whereas an increased abundance of phospholipids, mainly hexosylceramide and sphingomyelin, was present in the signatures of HCT116-R, LS174T-R, and DLD1-R cells. These altered lipid species may serve as potential prognostic markers in CRC following chemotherapy. Furthermore, lipid-targeting therapies aimed at reprogramming the lipid profiles of drug-resistant cells could play a crucial role in restoring drug sensitivity and improving patient survival.

Role of dietary and nutritional interventions in ceramide-associated diseases

Ceramides are important intermediates in sphingolipid metabolism and serve as signaling molecules with independent biological significance. Elevated cellular and circulating ceramide levels are consistently associated with pathological conditions including cardiometabolic diseases, neurological diseases, autoimmune diseases, and cancers. Although pharmacological inhibition of ceramide formation often protects against these diseases in animal models, pharmacological modulation of ceramides in humans remains impractical. Dietary interventions including the Mediterranean diet, lacto-ovo-vegetarian diet, calorie-restricted diet, restriction of dairy product consumption, and dietary supplementation with polyunsaturated fatty acids, dietary fibers, and polyphenols, all have beneficial effects on modulating ceramide levels. Mechanistic insights into these interventions are discussed. This article reviews the relationships between ceramides and disease pathogenesis, with a focus on dietary intervention as a viable strategy for lowering the concentration of circulating ceramides.

Diagnostics and Therapy for Malignant Tumors

Malignant tumors remain one of the most significant global health challenges and contribute to high mortality rates across various cancer types. The complex nature of these tumors requires multifaceted diagnostic and therapeutic approaches. This review explores current advancements in diagnostic methods, including molecular imaging, biomarkers, and liquid biopsies. It also delves into the evolution of therapeutic strategies, including surgery, chemotherapy, radiation therapy, and novel targeted therapies such as immunotherapy and gene therapy. Although significant progress has been made in the understanding of cancer biology, the future of oncology lies in the integration of precision medicine, improved diagnostic tools, and personalized therapeutic approaches that address tumor heterogeneity. This review aims to provide a comprehensive overview of the current state of cancer diagnostics and treatments while highlighting emerging trends and challenges that lie ahead.

Combination of plasma-based lipidomics and machine learning provides a useful diagnostic tool for ovarian cancer

Ovarian cancer (OC), the second leading cause of death among gynecological cancers, is often diagnosed at an advanced stage due to its asymptomatic nature at early stages. This study aimed to explore the diagnostic potential of plasma-based lipidomics combined with machine learning (ML) in OC. Non-targeted lipidomics analysis was conducted on plasma samples from participants with epithelial ovarian cancer (EOC), benign ovarian tumor (BOT), and healthy control (HC). The samples were randomly divided into a train set and a test set. Differential lipids between groups were selected using two-tailed Student's t-test and partial least squares discriminant analysis (PLS-DA). Both single lipid-based receiver operating characteristic (ROC) model, and multiple lipid-based ML model, were constructed to investigate the diagnostic value of the differential lipids. The results showed several lipids with significant diagnostic potential. ST 27:2;O achieved the highest prediction accuracy of 0.92 in distinguishing EOC from HC. DG 42:2 had the highest prediction accuracy of 0.96 in diagnosing BOT from HC. Cer d18:1/18:0 had the highest prediction accuracy of 0.65 in differentiating EOC from BOT. Furthermore, multiple lipid-based ML models illustrated better diagnostic performance. K-nearest neighbors (k-NN), partial least squares (PLS), and random forest (RF) models achieved the highest prediction accuracy of 0.96 in discriminating EOC from HC. The support vector machine (SVM) model reached the highest prediction accuracy both in distinguishing BOT from HC, and in differentiating EOC from BOT, with accuracies of 1.00 and 0.74, respectively. In conclusion, this study revealed that the combination of plasma-based lipidomics and ML algorithms is an effective method for diagnosing OC.

BCL2L13 Influences Autophagy and Ceramide Metabolism without Affecting Temozolomide Resistance in Glioblastoma

Temozolomide (TMZ) resistance in glioblastoma (GB) poses a significant therapeutic challenge. We developed a TMZ-resistant (TMZ-R) U251 GB model, revealing distinct differences in cell viability, apoptosis, autophagy, and lipid metabolism between TMZ-R and non-resistant (TMZ-NR) cells. TMZ-NR cells exhibited heightened sensitivity to TMZ-induced apoptosis, while TMZ-R cells-maintained viability. Autophagy flux was completely inhibited in TMZ-R cells, indicated by LC3βII and SQSTM1 accumulation. BCL2L13, which showed higher expression in TMZ-R cells, demonstrated increased interaction with Ceramide Synthase 6 (CerS6) and reduced interaction with Ceramide Synthase 2 (CerS2) in TMZ-NR cells. BCL2L13 knockdown (KD) disrupted autophagy flux, decreasing autophagosome accumulation in TMZ-R cells while increasing it in TMZ-NR cells. These changes contributed to altered ceramide profiles, where TMZ-R cells displayed elevated levels of Cer 16:0, 18:0, 20:0, 22:0, 24:0, and 24:1. Our findings highlight BCL2L13 and altered ceramide metabolism as potential therapeutic targets to overcome TMZ resistance in GB.

The Interplay between Oxidative Stress and Sphingolipid Metabolism in Endometrial Cancer

Endometrial cancer is one of the most common malignancies in women. Sphingolipids, a group of lipids, play a key role in cancer biology. Cancer cells often exhibit abnormal redox homeostasis characterized by elevated levels of reactive oxygen species (ROS). Emerging evidence suggests that ceramides are involved in inhibiting proliferation and inducing apoptosis through ROS production. However, there is no data on the relationship between sphingolipid metabolism and oxidative status in endometrial cancer. The present study aims to assess the content of individual sphingolipids and oxidative status in healthy women and those with endometrial cancer. Sphingolipid analysis was performed using mass spectrometry. Total oxidative status (TOS) and total antioxidant capacity (TAC) were assessed colorimetrically. Our results showed a significant increase in the levels of all measured sphingolipids in cancer tissues compared to healthy endometrium. Additionally, a significant decrease in the S1P/ceramide ratio (sphingolipid rheostat) was observed in cancer patients, particularly for C14:0-Cer, C16:0-Cer, C18:1-Cer, C22:0-Cer, and C24:0-Cer. Furthermore, increased TOS and decreased TAC were found in cancer patients compared to healthy women. Significant correlations were observed between the levels of individual sphingolipids and oxidative status, with the strongest correlation noted between C22:0-Cer and TOS (r = 0.64). We conclude that endometrial cancer is characterized by profound changes in sphingolipid metabolism, contributing to oxidative dysregulation and tumor progression.

Propylene Glycol Alleviates Oxidative Stress and Enhances Immunity in Ketotic Cows through Modulating Amino Acid and Lipid Metabolism

This study investigates the impact of propylene glycol (PRG) on ketotic cows, focusing on alleviating oxidative stress and enhancing immunity through modulating amino acid and lipid metabolism. Ketosis, a prevalent metabolic disease in dairy cows, negatively affects productivity and health. PRG, known for its gluconeogenic properties, was administered to cows with ketosis daily for three days and compared to an untreated group. Serum samples were taken to measure the biochemical parameters, and metabolomic and lipidomic analyses were performed with ultra-high-performance liquid chromatography-mass spectrometry. The results showed significant reductions in serum non-esterified fatty acids, beta-hydroxybutyrate, and C-reactive protein levels, alongside increased glucose, anti-inflammatory factor interleukin-10, superoxide dismutase, and glutathione peroxidase activities. Metabolomic and lipidomic analyses revealed significant alterations, including increased levels of glucogenic amino acids like glutamate and proline, and decreased levels of ceramide species. A pathway analysis indicated that PRG affects multiple metabolic pathways, including alanine, aspartate, glutamate metabolism, and sphingolipid metabolism. These findings suggest that PRG not only mitigates oxidative stress, but also enhances immune function by restoring metabolic homeostasis. This study provides valuable insights into the biochemical mechanisms underlying PRG's therapeutic effects, offering potential strategies for the effective management and treatment of ketosis in dairy cows.

Polyamine Pathway Inhibitor DENSPM Suppresses Lipid Metabolism in Pheochromocytoma Cell Line

Pheochromocytomas (PCCs) are tumors arising from chromaffin cells in the adrenal medulla, and paragangliomas (PGLs) are tumors derived from extra-adrenal sympathetic or parasympathetic paraganglia; these tumors are collectively referred to as PPGL cancer. Treatment for PPGL primarily involves surgical removal of the tumor, and only limited options are available for treatment of the disease once it becomes metastatic. Human carriers of the heterozygous mutations in the succinate dehydrogenase subunit B (SDHB) gene are susceptible to the development of PPGL. A physiologically relevant PCC patient-derived cell line hPheo1 was developed, and SDHB_KD cells carrying a stable short hairpin knockdown of SDHB were derived from it. An untargeted metabolomic approach uncovered an overactive polyamine pathway in the SDHB_KD cells that was subsequently fully validated in a large set of human SDHB-mutant PPGL tumor samples. We previously reported that treatment with the polyamine metabolism inhibitor N1,N11-diethylnorspermine (DENSPM) drastically inhibited growth of these PCC-derived cells in culture as well as in xenograft mouse models. Here we explored the mechanisms underlying DENSPM action in hPheo1 and SDHB_KD cells. Specifically, by performing an RNAseq analysis, we have identified gene expression changes associated with DENSPM treatment that broadly interfere with all aspects of lipid metabolism, including fatty acid (FA) synthesis, desaturation, and import/uptake. Furthermore, by performing an untargeted lipidomic liquid chromatography-mass spectrometry (LC/MS)-based analysis we uncovered specific groups of lipids that are dramatically reduced as a result of DENSPM treatment. Specifically, the bulk of plasmanyl ether lipid species that have been recently reported as the major determinants of cancer cell fate are notably decreased. In summary, this work suggests an intersection between active polyamine and lipid pathways in PCC cells.

Metabolomics analyses reveal the crucial role of ERK in regulating metabolic pathways associated with the proliferation of human cutaneous T-cell lymphoma cells treated with Glabridin

Cutaneous T-cell lymphomas (CTC) are a heterogeneous group of T-cell lymphoproliferative malignancies of the skin with limited treatment options, increased resistance and remission. Metabolic reprogramming is vital in orchestrating the uncontrolled growth and proliferation of cancer cells. Importantly, deregulated signalling plays a significant role in metabolic reprogramming. Considering the crucial role of metabolic reprogramming in cancer-cell growth and proliferation, target identification and the development of novel and multi-targeting agents are imperative. The present study explores the underlying mechanisms and metabolic signalling pathways associated with Glabridin mediated anti-cancer actions in CTCL. Our results show that Glabridin significantly inhibits the growth of CTCL cells through induction of programmed cell death (PCD) such as apoptosis, autophagy and necrosis. Interestingly, results further show that Glabridin induces PCD in CTCL cells by targeting MAPK signalling pathways, particularly the activation of ERK. Further, Glabridin also sensitized CTCL cells to the anti-cancer drug, bortezomib. Importantly, LC-MS-based metabolomics analyses further showed that Glabridin targeted multiple metabolites and metabolic pathways intricately involved in cancer cell growth and proliferation in an ERK-dependent fashion. Overall, our findings revealed that Glabridin induces PCD and attenuates the expression of regulatory proteins and metabolites involved in orchestrating the uncontrolled proliferation of CTCL cells through ERK activation. Therefore, Glabridin possesses important features of an ideal anti-cancer agent.

Sphingosine 1-Phosphate Stimulates ER to Golgi Ceramide Traffic to Promote Survival in T98G Glioma Cells

Glioblastoma multiforme is the most common and fatal brain tumor among human cancers. Ceramide (Cer) and Sphingosine 1-phosphate (S1P) have emerged as bioeffector molecules that control several biological processes involved in both cancer development and resistance. Cer acts as a tumor suppressor, inhibiting cancer progression, promoting apoptosis, enhancing immunotherapy and sensitizing cells to chemotherapy. In contrast, S1P functions as an onco-promoter molecule, increasing proliferation, survival, invasiveness, and resistance to drug-induced apoptosis. The pro-survival PI3K/Akt pathway is a recognized downstream target of S1P, and we have previously demonstrated that in glioma cells it also improves Cer transport and metabolism towards complex sphingolipids in glioma cells. Here, we first examined the possibility that, in T98G glioma cells, S1P may regulate Cer metabolism through PI3K/Akt signaling. Our research showed that exogenous S1P increases the rate of vesicular trafficking of Cer from the endoplasmic reticulum (ER) to the Golgi apparatus through S1P receptor-mediated activation of the PI3K/Akt pathway. Interestingly, the effect of S1P results in cell protection against toxicity arising from Cer accumulation in the ER, highlighting the role of S1P as a survival factor to escape from the Cer-generating cell death response.

ASAH1 facilitates TNBC by DUSP5 suppression-driven activation of MAP kinase pathway and represents a therapeutic vulnerability

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is prone to metastasis and therapy resistance. Owing to its aggressive nature and limited availability of targeted therapies, TNBC is associated with higher mortality as compared to other forms of breast cancer. In order to develop new therapeutic options for TNBC, we characterized the factors involved in TNBC growth and progression. Here, we demonstrate that N-acylsphingosine amidohydrolase 1 (ASAH1) is overexpressed in TNBC cells and is regulated via p53 and PI3K-AKT signaling pathways. Genetic knockdown or pharmacological inhibition of ASAH1 suppresses TNBC growth and progression. Mechanistically, ASAH1 inhibition stimulates dual-specificity phosphatase 5 (DUSP5) expression, suppressing the mitogen-activated protein kinase (MAPK) pathway. Furthermore, pharmacological cotargeting of the ASAH1 and MAPK pathways inhibits TNBC growth. Collectively, we unmasked a novel role of ASAH1 in driving TNBC and identified dual targeting of the ASAH1 and MAPK pathways as a potential new therapeutic approach for TNBC treatment.