Dataset Information

Significant alterations of sphingolipid metabolism in GC discovered by lipidome pseudotargeted metabolomics

ABSTRACT: Purpose: Increasing evidence has elucidated the significance of lipid metabolism in predicting outcomes and therapeutic efficacy. However, no studies have reported a systematic analysis of lipid metabolism characterizations in gastric cancer (GC). Experimental design: In this study, we comprehensively estimated the lipid metabolism characteristics of 367 GC patients and systematically correlated lipid metabolism with genomic characteristics, clinicopathologic features, and clinical outcomes of GC using two proposed computational algorithms (TGGA-STAD and GSE84437). Differentially expressed genes (DEGs) were identified based on the lipid metabolism cluster. At the same time, we applied single-factor Cox regression and random forest to screen signature genes to construct a prognostic model, namely, the lipid metabolism score (LMscore). Next, we deeply explored the predictive value of the LMscore as a biomarker for GC. Finally, a total of 90 serum as well as 30 tumor tissues and adjacent tissues were for pseudotargeted metabolomics analysis via UHPLC-Q-TOF/MS to determine the lipid metabolism characteristics of the GC patients. Results: A total of 3104 DEGs were determined, among which five lipid metabolism signature genes were identified. The high LMscore subgroup had a positive correlation with the progression of GC, which indicated that the LMscore could be a prognosticator for survival in different clinicopathological GC cohorts. As well, the LMscore was identified as a predictive biomarker for responses to immunotherapy and chemotherapeutic agents. Additionally, significant alterations of sphingolipid metabolism and sphingolipid molecules were discovered in cancer tissue by pseudotargeted metabolomics. Conclusions: In conclusion, multivariate analysis revealed that the LMscore was an independent prognostic biomarker of patient survival and therapeutic responses in GC. Depicting a comprehensive landscape of the lipid metabolism characteristics of GC may, therefore, help to provide insights into the pathogenesis of GC and interpret the responses of gastric tumors to therapies, which might be helpful to achieve better outcomes in the treatment of GC.

ORGANISM(S): Homo Sapiens

SUBMITTER: Jiawei Zeng

PROVIDER: PXD034233 | iProX | Wed Jun 01 00:00:00 BST 2022

REPOSITORIES: iProX

ACCESS DATA

Similar Datasets

Project description:A better understanding of the molecular mechanisms underlying the development and progression of diabetic neuropathy (DN) is essential for the design of mechanism-based therapies. We examined changes in global gene expression to define pathways regulated by diabetes in peripheral nerve. Microarray data for 24 week-old BKS db/db and db/+ mouse sciatic nerve were analyzed to define significantly differentially expressed genes (DEGs); DEGs were further used for functional enrichment analysis and network analysis to identify biological processes and pathways differentially regulated in the db/db nerve. Expression profile clustering was performed to identify co-expressed DEGs. A set of co-expressed lipid metabolism genes was used for promoter sequence analysis.We identified 4,017 DEGs; 2,122 genes were up-regulated and 1,895 genes were down-regulated in the db/db relative to the db+ samples. Over-represented biological processes identified by the functional enrichment analysis include cell cycle, lipid metabolic process, lipid transport, carbohydrate metabolic process, response to stress, apoptosis, axonogenesis and cell adhesion. Pathways regulated in the db/db nerve include lipid metabolism, carbohydrate metabolism, energy metabolism, PPAR signaling, apoptosis, and axon guidance. The majority of DEGs in the glycolysis, TCA cycle, oxidative phosphorylation, fatty acid metabolism, glycerolipid metabolism, mitochondrial fatty acid elongation, lipid transport, adipocytokine signaling, PPAR signaling, and apoptosis pathways are up-regulated, whereas most of the axonogenesis-related genes are down-regulated in db/db nerve. A network of DEGs based on their co-citation in literature identified regulatory relationship between Tnf-α and key genes from the regulated pathways. Promoter sequence analysis identified over-represented transcription factor binding site (TFBS) motifs in the promoter regions of twenty two co-expressed lipid metabolism-related genes suggesting coordinated regulation of these genes by multiple transcription factors (TF). Furthermore, TF binding to these TFBS and differentially regulated in our data are annotated with nervous system development and immune response suggesting possible co-regulation of lipid metabolism, nervous system development and stress response genes. Gene expression changes in our data are consistent with pathological characteristics observed in DN including axon degeneration and demyelination, and support existing hypotheses regarding hyperglycemia mediated nerve damage in DN. Our findings support the role of hyperglycemia-induced oxidative stress and ischemia in nerve injury. Our results also support the hypothesis of oxidized lipid-mediated nerve injury and increased mitochondrial oxidative stress in dyslipidemia. Moreover, our analyses revealed a possible co-regulation mechanism connecting hyperlipidemia, stress response and axonal degeneration. Microarray data for 24 week-old BKS db/db and db/+ mouse sciatic nerve were analyzed to define significantly differentially expressed genes

Project description:METTL3-mediated RNA N6-methyladenosine (m6A) is the most prevalent modification participates in tumor initiation and progression via regulating expression of their target genes in cancers. However, its role in tumor cell metabolism remains poorly appreciated. In this study, we conducted a multi-omics analysis including m6A microarray and quantitative proteomics to explore the potential effect and mechanism of METTL3 on the metabolism in gastric cancer cells. Our results found that significant alterations in the protein and m6A modification profile which induced by METTL3 overexpression in GC cells. Gene Ontology (GO) enrichment results showed that down-regulated proteins were significantly enriched in intracellular mitochondrial oxidative phosphorylation (OXPHOS), and the Protein-Protein Interaction (PPI) network analysis found that these differentially expressed proteins were significantly associated with OXPHOS. Subsequently, a prognostic model constructed based on the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and the high-risk group showed a worse prognosis in GC patients. Meanwhile, the Gene Set Enrichment Analysis (GSEA) showed a significant enrichment in the energy metabolism signaling pathway. Then, combined with the results of the m6A microarray analysis, the intersection molecules of DEPs and differential methylation genes (DMGs) were significantly correlated with the genes involved in OXPHOS. Besides, there were also significant differences in prognosis and GSEA enrichment between the two clusters of GC patients classified according to consensus clustering algorithm. Finally, we focused on highly expressed, highly methylated molecules regulated by METTL3 and identified three (AVEN, DAZAP2, DNAJB1) genes that were significantly associated with poor prognosis in patients with GC. These results indicated that METTL3-regulated DEPs in GC cells were significantly associated with OXPHOS. After combined with m6A microarray analysis, the results suggested that these proteins might be involved in cell energy metabolism through m6A modifications thus influencing the prognosis of GC patients. Overall, our study revealed that METTL3 involved in cell metabolism through an m6A-dependent mechanism in GC cells, and indicated a potential biomarker for prognostic prediction in GC.

Dataset Information

Significant alterations of sphingolipid metabolism in GC discovered by lipidome pseudotargeted metabolomics

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure