Targeting the SphK1/S1P/PFKFB3 axis suppresses hepatocellular carcinoma progression by disrupting glycolytic energy supply that drives tumor angiogenesis.

BACKGROUND: Hepatocellular carcinoma (HCC) remains a leading life-threatening health challenge worldwide, with pressing needs for novel therapeutic strategies. Sphingosine kinase 1 (SphK1), a well-established pro-cancer enzyme, is aberrantly overexpressed in a multitude of malignancies, including HCC. Our previous research has shown that genetic ablation of Sphk1 mitigates HCC progression in mice. Therefore, the development of PF-543, a highly selective SphK1 inhibitor, opens a new avenue for HCC treatment. However, the anti-cancer efficacy of PF-543 has not yet been investigated in primary cancer models in vivo, thereby limiting its further translation. METHODS: Building upon the identification of the active form of SphK1 as a viable therapeutic target in human HCC specimens, we assessed the capacity of PF-543 in suppressing tumor progression using a diethylnitrosamine-induced mouse model of primary HCC. We further delineated its underlying mechanisms in both HCC and endothelial cells. Key findings were validated in Sphk1 knockout mice and lentiviral-mediated SphK1 knockdown cells. RESULTS: SphK1 activity was found to be elevated in human HCC tissues. Administration of PF-543 effectively abrogated hepatic SphK1 activity and significantly suppressed HCC progression in diethylnitrosamine-treated mice. The primary mechanism of action was through the inhibition of tumor neovascularization, as PF-543 disrupted endothelial cell angiogenesis even in a pro-angiogenic milieu. Mechanistically, PF-543 induced proteasomal degradation of the critical glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3, thus restricting the energy supply essential for tumor angiogenesis. These effects of PF-543 could be reversed upon S1P supplementation in an S1P receptor-dependent manner. CONCLUSIONS: This study provides the first in vivo evidence supporting the potential of PF-543 as an effective anti-HCC agent. It also uncovers previously undescribed links between the pro-cancer, pro-angiogenic and pro-glycolytic roles of the SphK1/S1P/S1P receptor axis. Importantly, unlike conventional anti-HCC drugs that target individual pro-angiogenic drivers, PF-543 impairs the PFKFB3-dictated glycolytic energy engine that fuels tumor angiogenesis, representing a novel and potentially safer therapeutic strategy for HCC.

Independent risk factors of left ventricular hypertrophy in non-diabetic individuals in Sierra Leone - a cross-sectional study.

BACKGROUND: Left ventricular hypertrophy (LVH) is a critical factor in heart failure and cardiovascular event-related mortality. While the prevalence of LVH in diabetic patients is well-documented, its occurrence and risk factors in non-diabetic populations remain largely unexplored. This study addresses this issue by investigating the independent risk factors of LVH in non-diabetic individuals. METHODS: This cross-sectional study, conducted meticulously, utilized data from a robust and comprehensive source, DATADRYAD, in the Sierra Leone database, collected between October 2019 and October 2021, including LVH and various variables. All variables were described and screened using univariate analysis, Spearman correlation, and principal component analysis (PCA). The lipid profile, including total cholesterols (TC), triglycerides (TG), high-density lipoprotein (HDL-C), non-high-density lipoprotein (Non-HDL-C), and low-density lipoprotein cholesterol (LDL-C), TC/HDL-C ratio, TG/HDL-C ratio, Non-HDL-C /HDL-C ratio and LDL-C/HDL-C ratio, which quartiles were treated as categorical variables, with the lowest quartile serving as the reference category. Three adjusted models were constructed to mitigate the influence of other variables. To ensure the robustness of the model, receiver operating characteristic (ROC) curves were used to calculate the cutoff values by analyzing the ROC curves. A sensitivity analysis was performed to validate the findings further. RESULTS: The dataset encompasses information from 2092 individuals. After adjusting for potential factors that could influence the results, we found that TC (OR = 2.773, 95%CI: 1.805-4.26), Non-HDL-C (OR = 2.74, 95%CI: 1.7723-4.236), TC/HDL-C ratio (OR = 2.237, 95%CI: 1.445-3.463), Non-HDL-C/HDL-C ratio (OR = 2.357, 95%CI: 1.548-3.588), TG/HDL-C ratio (OR = 1.513, 95%CI: 1.02-2.245) acts as independent risk factors of LVH. ROC curve analysis revealed the predictive ability of blood lipids for LVH, with Non-HDL-C exhibiting area under the curve (AUC = 0.6109), followed by TC (AUC = 0.6084). CONCLUSIONS: TC, non-HDL-C, TC/HDL-C ratio, Non-HDL-C/HDL-C ratio, and TG/HDL-C ratio were independent risk factors of LVH in non-diabetic people. Non-HDL-C and TC were found to be essential indicators for predicting the prevalence of LVH.

Deep serum lipidomics identifies evaluative and predictive biomarkers for individualized glycemic responses following low-energy diet-induced weight loss: a PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World (PREVIEW) substudy.

BACKGROUND: Weight loss through lifestyle interventions, notably low-energy diets, offers glycemic benefits in populations with overweight-associated prediabetes. However, >50% of these individuals fail to achieve normoglycemia after weight loss. Circulating lipids hold potential for evaluating dietary impacts and predicting diabetes risk. OBJECTIVES: This study sought to identify serum lipids that could serve as evaluative or predictive biomarkers for individual glycemic changes following diet-induced weight loss. METHODS: We studied 104 participants with overweight-associated prediabetes, who lost ≥8% weight via a low-energy diet over 8 wk. High-coverage lipidomics was conducted in serum samples before and after the dietary intervention. The lipidomic recalibration was assessed using differential lipid abundance comparisons and partial least squares discriminant analyses. Associations between lipid changes and clinical characteristics were determined by Spearman correlation and Bootstrap Forest of ensemble machine learning model. Baseline lipids, predictive of glycemic parameters changes postweight loss, were assessed using Bootstrap Forest analyses. RESULTS: We quantified 439 serum lipid species and 9 related organic acids. Dietary intervention significantly reduced diacylglycerols, ceramides, lysophospholipids, and ether-linked phosphatidylethanolamine. In contrast, acylcarnitines, short-chain fatty acids, organic acids, and ether-linked phosphatidylcholine increased significantly. Changes in certain lipid species (e.g., saturated and monounsaturated fatty acid-containing glycerolipids, sphingadienine-based very long-chain sphingolipids, and organic acids) were closely associated with clinical glycemic parameters. Six baseline bioactive sphingolipids primarily predicted changes in fasting plasma glucose. In addition, a number of baseline lipid species, mainly diacylglycerols and triglycerides, were predictive of clinical changes in hemoglobin A1c, insulin and homeostasis model assessment of insulin resistance. CONCLUSIONS: Newly discovered serum lipidomic alterations and the associated changes in lipid-clinical variables suggest broad metabolic reprogramming related to diet-mediated glycemic control. Novel lipid predictors of glycemic outcomes could facilitate early stratification of individuals with prediabetes who are metabolically less responsive to weight loss, enabling more tailored intervention strategies beyond 1-size-fits-all lifestyle modification advice. The PREVIEW lifestyle intervention study was registered at clinicaltrials.gov as NCT01777893 (https://clinicaltrials.gov/study/NCT01777893).