Publisher Correction: Compartmentalized activities of the pyruvate dehydrogenase complex sustain lipogenesis in prostate cancer

Comprehensive analysis of cuproptosis-related prognostic gene signature and tumor immune microenvironment in HCC

Background: Copper is an indispensable mineral element involved in many physiological metabolic processes. Cuproptosis is associated with a variety of cancer such as hepatocellular carcinoma (HCC). The objective of this study was to examine the relationships between the expression of cuproptosis-related genes (CRGs) and tumor characteristics, including prognosis and microenvironment of HCC. Methods: The differentially expressed genes (DEGs) between high and low CRGs expression groups in HCC samples were identified, and further were analyzed for functional enrichment analysis. Then, CRGs signature of HCC was constructed and analyzed utilizing LASSO and univariate and multivariate Cox regression analysis. Prognostic values of CRGs signature were evaluated by Kaplan-Meier analysis, independent prognostic analysis and nomograph. The expression of prognostic CRGs was verified by Real-time quantitative PCR (RT-qPCR) in HCC cell lines. In addition, the relationships between prognostic CRGs expression and the immune infiltration, tumor microenvironment, antitumor drugs response and m6A modifications were further explored using a series of algorithms in HCC. Finally, ceRNA regulatory network based on prognostic CRGs was constructed. Results: The DEGs between high and low CRG expression groups in HCC were mainly enriched in focal adhesion and extracellular matrix organization. Besides, we constructed a prognostic model that consists of CDKN2A, DLAT, DLST, GLS, and PDHA1 CRGs for predicting the survival likelihood of HCC patients. And the elevated expression of these five prognostic CRGs was substantially in HCC cell lines and associated with poor prognosis. Moreover, immune score and m6A gene expression were higher in the high CRG expression group of HCC patients. Furthermore, prognostic CRGs have higher mutation rates in HCC, and are significantly correlated with immune cell infiltration, tumor mutational burden, microsatellite instability, and anti-tumor drug sensitivity. Then, eight lncRNA-miRNA-mRNA regulatory axes that affected the progression of HCC were predicted. Conclusion: This study demonstrated that the CRGs signature could effectively evaluate prognosis, tumor immune microenvironment, immunotherapy response and predict lncRNA-miRNA-mRNA regulatory axes in HCC. These findings extend our knowledge of cuproptosis in HCC and may inform novel therapeutic strategies for HCC.

Abnormal lipid droplets accumulation induced cognitive deficits in obstructive sleep apnea syndrome mice via JNK/SREBP/ACC pathway but not through PDP1/PDC pathway

The mechanisms of chronic intermittent hypoxia (CIH)-induced cognitive deficits remain unclear. Here, our study found that about 3 months CIH treatment induced lipid droplets (LDs) accumulation in hippocampal nerve and glia cells of C57BL/6 mice, and caused severe neuro damage including neuron lesions, neuroblast (NB) apoptosis and abnormal glial activation. Studies have shown that the neuronal metabolism disorders might contribute to the CIH induced-hippocampal impairment. Mechanistically, the results showed that pyruvate dehydrogenase complex E1ɑ subunit (PDHA1) and the pyruvate dehydrogenase complex (PDC) activator pyruvate dehydrogenase phosphatase 1 (PDP1) did not noticeable change after intermittent hypoxia. Consistent with those results, the level of Acetyl-CoA in hippocampus did not significantly change after CIH exposure. Interestingly, we found that CIH produced large quantities of ROS, which activated the JNK/SREBP/ACC pathway in nerve and glia cells. ACC catalyzed the carboxylation of Acetyl-CoA to malonyl-CoA and then more lipid acids were synthesized, which finally caused aberrant LDs accumulation. Therefore, the JNK/SREBP/ACC pathway played a crucial role in the cognitive deficits caused by LDs accumulation after CIH exposure. Additionally, LDs were peroxidized by the high level of ROS under CIH conditions. Together, lipid metabolic disorders contributed to nerve and glia cells damage, which ultimately caused behavioral dysfunction. An active component of Salvia miltiorrhiza, SMND-309, dramatically alleviated these injuries and improved cognitive deficits of CIH mice.

The Interplay Between Prostate Cancer Genomics, Metabolism, and the Epigenome: Perspectives and Future Prospects

Prostate cancer is a high-incidence cancer, often detected late in life. The prostate gland is an accessory gland that secretes citrate; an impaired citrate secretion reflects imbalances in the activity of enzymes in the TCA Cycle in mitochondria. Profiling studies on prostate tumours have identified significant metabolite, proteomic, and transcriptional modulations with an increased mitochondrial metabolic activity associated with localised prostate cancer. Here, we focus on the androgen receptor, c-Myc, phosphatase and tensin Homolog deleted on chromosome 10 (PTEN), and p53 as amongst the best-characterised genomic drivers of prostate cancer implicated in metabolic dysregulation and prostate cancer progression. We outline their impact on metabolic function before discussing how this may affect metabolite pools and in turn chromatin structure and the epigenome. We reflect on some recent literature indicating that mitochondrial mutations and OGlcNAcylation may also contribute to this crosstalk. Finally, we discuss the technological challenges of assessing crosstalk given the significant differences in the spatial sensitivity and throughput of genomic and metabolomic profiling approaches.

Effect of PTEN loss on metabolic reprogramming in prostate cancer cells

The tumor suppressor gene PTEN is one of the most often deleted genes in human prostate cancer. Loss of PTEN is an important event in prostate carcinogenesis. Metabolic reprogramming induced by PTEN loss fuels malignant growth and proliferation of prostate cancer cells. Targeted metabolomics analysis was used to investigate the effects of PTEN loss on intracellular metabolic pathways in prostate cancer cells. DU-145 cells were transfected with PTEN siRNAs (siRNA-1 and siRNA-2) for 48 h, and endogenous PTEN expression was monitored by western blotting. Changes in intracellular metabolites were determined by liquid chromatography-tandem mass chromatography (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS). Most intracellular metabolites involved in glycolysis and glutaminolysis were increased in PTEN knockdown prostate cancer cells. In addition, most intracellular metabolites involved in fatty acid de novo synthesis, fatty acid beta oxidation and branched chain amino acid catabolism were also increased in PTEN knockdown prostate cancer cells. These results revealed that PTEN loss induced the metabolic reprogramming of prostate cancer cells and promoted the malignant proliferation of prostate cancer cells. The present metabolomics analysis indicates that tumor suppressor gene PTEN mutation or deletion can induce metabolic reprogramming in prostate cancer cells and tumorigenesis by altering the metabolic flux of glycolysis, glutaminolysis, fatty acid metabolism and branched chain amino acid catabolism pathways. Metabolic reprogramming is one of the contributors to PTEN-loss driven prostate cancer.