Increased demand for FAD synthesis in differentiated and stem pancreatic cancer cells is accomplished by modulating FLAD1 gene expression: the inhibitory effect of Chicago Sky Blue

Nutrigenetics and Omega-3 and Gamma-Linolenic Acid Intake and Status in Patients with Cancer: A PRISMA Scoping Review of Research Trends and Challenges

Epidemiological studies report inconsistent findings regarding the association between dietary polyunsaturated fatty acid (PUFA) intake and cancer risk. Genetic variations-particularly single-nucleotide polymorphisms (SNPs) in the FADS1 and FADS2 genes-affect PUFA metabolism, linking circulating PUFA levels to the risk of several cancers, including breast, colorectal, prostate, and pancreatic cancers. This review aimed to investigate the relationship between FADS1 and FADS2 gene variants and dietary intake, supplementation, or intervention with omega-3 fatty acids, gamma-linolenic acid (GLA), or their combination in cancer patients. A secondary objective was to examine genetically determined fatty acid profiles-shaped by FADS1 and FADS2 polymorphisms-in cancer patients without intervention and their potential association with PUFA-related cancer risk. A systematic search of the Scopus, PubMed, and Web of Science databases (up to 2024) identified 11 eligible studies out of 298 initial records. Analysis of the available literature suggests that specific FADS genotypes influence long-chain PUFA (LC-PUFA) concentrations in blood and tissues and that altered LC-PUFA levels may contribute to cancer development. The most consistent association identified is between the rs174537 variant and altered PUFA metabolism in prostate and breast cancer. However, conclusive evidence is lacking on the impact of dietary patterns on FADS desaturase activity or expression. Only one study has examined omega-3 supplementation in relation to FADS gene variants in prostate cancer patients, while the effects of GLA supplementation remain unexplored. Given the relative novelty of this research area and the limited number of studies, future investigations should integrate dietary PUFA intake, genetic variation in PUFA-metabolizing enzymes, and potential gene-nutrient interactions involving FADS gene polymorphisms and PUFAs to clarify their role in cancer risk.

Identification of DAP3 as candidate prognosis marker and potential therapeutic target for hepatocellular carcinoma

Background

Among malignant tumors, hepatocellular carcinoma (HCC) is both prevalent and highly lethal. Most patients with advanced-stage liver cancer have a poor prognosis. Death-associated protein 3 (DAP3) is reportedly related to tumors and may hold great promise for the future.

Methods

DAP3 transcriptome data along with related clinical information were obtained from The Cancer Genome Atlas (TCGA), GEO, and ICGC databases. We assessed its prognostic value, clinical relevance, associated pathways, immune infiltration, gene mutations, and sensitivity to chemotherapeutics. A prognostic risk model was subsequently developed and evaluated using receiver operating characteristic (ROC) curves and Kaplan-Meier (KM) plots. Additionally, a nomogram was created and validated through calibration and decision curve analysis (DCA). Furthermore, quantitative real-time PCR (qRT-PCR), Western blot, and immunohistochemical (IHC) staining were performed to examine the expression of DAP3 in HCC. Finally, gene knockdown and overexpression experiments, along with cell counting kit-8 (CCK-8) assays, colony formation assays, and tests for cell apoptosis, migration, and invasion, were conducted to investigate the role of DAP3 in HCC.

Results

The study discovered that DAP3 expression was linked to HCC subtypes, and its high expression was linked to a poor prognosis. There were significant differences in immune infiltration level, mutation level, prognostic value and chemotherapeutic efficacy. Subsequently, we constructed a prognostic model and demonstrated that high risk score was significantly related to a poor survival rate. A predictive nomogram demonstrated that the nomogram model was effective prediction tool that can accurately predict the survival rate of patients with different clinical characteristics. Additionally, DAP3 expression significantly increased in both tissue samples and cell lines. Elevated levels of DAP3 were correlated with larger tumor size and higher alpha-fetoprotein (AFP) levels, and Cox analysis confirmed that DAP3 was a clinically independent prognostic marker. Finally, cell assays revealed that the knockdown of DAP3 significantly impeded cell proliferation and metabolic activity and induced apoptosis. Conversely, the overexpression of DAP3 had opposite effects on these cellular processes.

Conclusions

Our study on DAP3 can provide a reference for HCC diagnosis, treatment and prognosis assessment.

Supplying LSD1 with FAD in pancreatic cancer: A matter of protein-protein interaction?

Lysine-specific demethylase 1 (LSD1) is a key regulator in cancer epigenetic, and its activity is reliant on flavin adenine dinucleotide (FAD) as a cofactor. In this study, we investigated the correlation between LSD1 and FAD synthase isoform 2 (FADS2) protein levels in pancreatic ductal adenocarcinoma (PDAC) cell lines. We first assessed LSD1 protein and mRNA levels in mutant p53-expressing PANC-1 and MiaPaCa2 cells and p53-null AsPc-1 cells, compared to human pancreatic ductal epithelial (HPDE) controls. Our results confirmed elevated LSD1 protein levels in PANC-1 and MiaPaCa2, but not in AsPc-1, despite mRNA overexpression across all cell lines. Similarly, FADS2 levels were significantly upregulated in PANC-1 and MiaPaCa2, but not in AsPc-1, highlighting a possible link between FADS2 expression and p53 gain-of-function mutations. These results prompted us to better investigate the functional relationship between FADS2 and LSD1 by performing in cellulo protein-protein interaction analyses. Our results indicate a direct interaction between LSD1 and FADS2, while no significant interaction was observed between LSD1 and FADS1. These findings reinforce the role of FAD synthesis and its delivery to LSD1 as critical events in cancer progression and shed light on potential implications of FADS2-LSD1 dynamics as targeted therapies in cancer.

Copy number amplification of FLAD1 promotes the progression of triple-negative breast cancer through lipid metabolism

Triple-negative breast cancer (TNBC) is known for frequent copy number alterations (CNAs) and metabolic reprogramming. However, the mechanism by which CNAs of metabolic genes drive distinct metabolic reprogramming and affect disease progression remains unclear. Through an integrated analysis of our TNBC multiomic dataset (n = 465) and subsequent experimental validation, we identify copy number amplification of the metabolic gene flavin-adenine dinucleotide synthetase 1 (FLAD1) as a crucial genetic event that drives TNBC progression. Mechanistically, FLAD1, but not its enzymatically inactive mutant, upregulates the enzymatic activity of FAD-dependent lysine-specific demethylase 1 (LSD1). LSD1 subsequently promotes the expression of sterol regulatory element-binding protein 1 (SREBP1) by demethylating dimethyl histone H3 lysine 9 (H3K9me2). The upregulation of SREBP1 enhances the expression of lipid biosynthesis genes, ultimately facilitating the progression of TNBC. Clinically, pharmacological inhibition of the FLAD1/LSD1/SREBP1 axis effectively suppresses FLAD1-induced tumor progression. Moreover, LSD1 inhibitor enhances the therapeutic effect of doxorubicin and sacituzumab govitecan (SG). In conclusion, our findings reveal the CNA-derived oncogenic signalling axis of FLAD1/LSD1/SREBP1 and present a promising treatment strategy for TNBC.

Exploring the impact of flavin homeostasis on cancer cell metabolism

Flavins and their associated proteins have recently emerged as compelling players in the landscape of cancer biology. Flavins, encompassing flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), serve as coenzymes in a multitude of cellular processes, such as metabolism, apoptosis, and cell proliferation. Their involvement in oxidative phosphorylation, redox homeostasis, and enzymatic reactions has long been recognized. However, recent research has unveiled an extended role for flavins in the context of cancer. In parallel, riboflavin transporters (RFVTs), FAD synthase (FADS), and riboflavin kinase (RFK) have gained prominence in cancer research. These proteins, responsible for riboflavin uptake, FAD biosynthesis, and FMN generation, are integral components of the cellular machinery that governs flavin homeostasis. Dysregulation in the expression/function of these proteins has been associated with various cancers, underscoring their potential as diagnostic markers, therapeutic targets, and key determinants of cancer cell behavior. This review embarks on a comprehensive exploration of the multifaceted role of flavins and of the flavoproteins involved in nucleus-mitochondria crosstalk in cancer. We journey through the influence of flavins on cancer cell energetics, the modulation of RFVTs in malignant transformation, the diagnostic and prognostic significance of FADS, and the implications of RFK in drug resistance and apoptosis. This review also underscores the potential of these molecules and processes as targets for novel diagnostic and therapeutic strategies, offering new avenues for the battle against this relentless disease.

Structural insights into the bifunctional enzyme human FAD synthase

Human flavin adenine dinucleotide synthase (hFADS) is a bifunctional, multi-domain enzyme that exhibits both flavin mononucleotide adenylyltransferase and pyrophosphatase activities. Here we report the crystal structure of full-length hFADS2 and its C-terminal PAPS domain in complex with flavin adenine dinucleotide (FAD), and dissect the structural determinants underlying the contribution of each individual domain, within isoforms 1 and 2, to each of the two enzymatic activities. Structural and functional characterization performed on complete or truncated constructs confirmed that the C-terminal domain tightly binds FAD and catalyzes its synthesis, while the combination of the N-terminal molybdopterin-binding and KH domains is the minimal essential substructure required for the hydrolysis of FAD and other ADP-containing dinucleotides. hFADS2 associates in a stable C2-symmetric dimer, in which the packing of the KH domain of one protomer against the N-terminal domain of the other creates the adenosine-specific active site responsible for the hydrolytic activity.