MYC regulates metabolism through vesicular transfer of glycolytic kinases

Spliceosomal vulnerability of MYCN-amplified neuroblastoma is contingent on PRMT5-mediated regulation of epitranscriptomic and metabolomic pathways

Approximately 50% of poor prognosis neuroblastomas arise due to MYCN over-expression. We previously demonstrated that MYCN and PRMT5 proteins interact and PRMT5 knockdown led to apoptosis of MYCN amplified (MNA) neuroblastoma. Here we evaluate the highly selective first-in-class PRMT5 inhibitor GSK3203591 and its in vivo analogue GSK3326593 as targeted therapeutics for MNA neuroblastoma. Cell-line analyses show MYCN-dependent growth inhibition and apoptosis, with approximately 200-fold greater sensitivity of MNA neuroblastoma lines. RNA sequencing of three MNA neuroblastoma lines treated with GSK3203591 reveal deregulated MYCN transcriptional programmes and altered mRNA splicing, converging on key regulatory pathways such as DNA damage response, epitranscriptomics and cellular metabolism. Stable isotope labelling experiments in the same cell lines demonstrate that glutamine metabolism is impeded following GSK3203591 treatment, linking with disruption of the MLX/Mondo nutrient sensors via intron retention of MLX mRNA. Interestingly, glutaminase (GLS) protein decreases after GSK3203591 treatment despite unchanged transcript levels. We demonstrate that the RNA methyltransferase METTL3 and cognate reader YTHDF3 proteins are lowered following their mRNAs undergoing GSK3203591-induced splicing alterations, indicating epitranscriptomic regulation of GLS; accordingly, we observe decreases of GLS mRNA m6A methylation following GSK3203591 treatment, and decreased GLS protein following YTHDF3 knockdown. In vivo efficacy of GSK3326593 is confirmed by increased survival of Th-MYCN mice, with drug treatment triggering splicing events and protein decreases consistent with in vitro data. Together our study demonstrates the PRMT5-dependent spliceosomal vulnerability of MNA neuroblastoma and identifies the epitranscriptome and glutamine metabolism as critical determinants of this sensitivity.

Extracellular vesicles mediated gastric cancer immune response: tumor cell death or immune escape?

Gastric cancer (GC) is a major global health issue, being the fifth most prevalent cancer and the third highest contributor to cancer-related deaths. Although treatment strategies for GC have diversified, the prognosis for advanced GC remains poor. Hence, there is a critical need to explore new directions for GC treatment to enhance diagnosis, treatment, and patient prognosis. Extracellular vesicles (EVs) have emerged as key players in tumor development and progression. Different sources of EVs carry different molecules, resulting in distinct biological functions. For instance, tumor-derived EVs can promote tumor cell proliferation, alter the tumor microenvironment and immune response, while EVs derived from immune cells carry molecules that regulate immune function and possess tumor-killing capabilities. Numerous studies have demonstrated the crucial role of EVs in the development, immune escape, and immune microenvironment remodeling in GC. In this review, we discuss the role of GC-derived EVs in immune microenvironment remodeling and EVs derived from immune cells in GC development. Furthermore, we provide an overview of the potential uses of EVs in immunotherapy for GC.

Extracellular vesicles in neuroblastoma: role in progression, resistance to therapy and diagnostics

Neuroblastoma (NB) is the most common extracranial solid pediatric cancer, and is one of the leading causes of cancer-related deaths in children. Despite the current multi-modal treatment regimens, majority of patients with advanced-stage NBs develop therapeutic resistance and relapse, leading to poor disease outcomes. There is a large body of knowledge on pathophysiological role of small extracellular vesicles (EVs) in progression and metastasis of multiple cancer types, however, the importance of EVs in NB was until recently not well understood. Studies emerging in the last few years have demonstrated the involvement of EVs in various aspects of NB pathogenesis. In this review we summarize these recent findings and advances on the role EVs play in NB progression, such as tumor growth, metastasis and therapeutic resistance, that could be helpful for future investigations in NB EV research. We also discuss different strategies for therapeutic targeting of NB-EVs as well as utilization of NB-EVs as potential biomarkers.

Sex-specific adipose tissue's dynamic role in metabolic and inflammatory response following peripheral nerve injury

Epidemiological data and research highlight increased neuropathy and chronic pain prevalence among females, spanning metabolic and normometabolic contexts, including murine models. Prior findings demonstrated diverse immune and neuroimmune responses between genders in neuropathic pain (NeP), alongside distinct protein expression in sciatic nerves. This study unveils adipose tissue's (AT) role in sex-specific NeP responses after peripheral nerve injury. Metabolic assessments, metabolomics, energy expenditure evaluations, AT proteomic analyses, and adipokine mobilization depict distinct AT reactions to nerve damage. Females exhibit altered lipolysis, fatty acid oxidation, heightened energy expenditure, and augmented steroids secretion affecting glucose and insulin metabolism. Conversely, male neuropathy prompts glycolysis, reduced energy expenditure, and lowered unsaturated fatty acid levels. Males' AT promotes regenerative molecules, oxidative stress defense, and stimulates peroxisome proliferator-activated receptors (PPAR-γ) and adiponectin. This study underscores AT's pivotal role in regulating gender-specific inflammatory and metabolic responses to nerve injuries, shedding light on female NeP susceptibility determinants.

Deregulated transcription factors in cancer cell metabolisms and reprogramming

Metabolic reprogramming is an important cancer hallmark that plays a key role in cancer malignancies and therapy resistance. Cancer cells reprogram the metabolic pathways to generate not only energy and building blocks but also produce numerous key signaling metabolites to impact signaling and epigenetic/transcriptional regulation for cancer cell proliferation and survival. A deeper understanding of the mechanisms by which metabolic reprogramming is regulated in cancer may provide potential new strategies for cancer targeting. Recent studies suggest that deregulated transcription factors have been observed in various human cancers and significantly impact metabolism and signaling in cancer. In this review, we highlight the key transcription factors that are involved in metabolic control, dissect the crosstalk between signaling and transcription factors in metabolic reprogramming, and offer therapeutic strategies targeting deregulated transcription factors for cancer treatment.

Tumoral heterogeneity in neuroblastoma

Neuroblastoma is a solid, neuroendocrine tumor with divergent clinical behavior ranging from asymptomatic to fatal. The diverse clinical presentations of neuroblastoma are directly linked to the high intra- and inter-tumoral heterogeneity it presents. This heterogeneity is strongly associated with therapeutic resistance and continuous relapses, often leading to fatal outcomes. The development of successful risk assessment and tailored treatment strategies lies in evaluating the extent of heterogeneity via the accurate genetic and epigenetic profiling of distinct cell subpopulations present in the tumor. Recent studies have focused on understanding the molecular mechanisms that drive tumoral heterogeneity in pursuing better therapeutic and diagnostic approaches. This review describes the cellular, genetic, and epigenetic aspects of neuroblastoma heterogeneity. In addition, we summarize the recent findings on three crucial factors that can lead to heterogeneity in solid tumors: the inherent diversity of the progenitor cells, the presence of cancer stem cells, and the influence of the tumor microenvironment.

The Glyoxalase System Is a Novel Cargo of Amniotic Fluid Stem-Cell-Derived Extracellular Vesicles

The glyoxalase system is a ubiquitous cellular metabolic pathway whose main physiological role is the removal of methylglyoxal (MG). MG, a glycolysis byproduct formed by the spontaneous degradation of triosephosphates glyceraldehyde-3-phosphate (GA3P) and dihydroxyacetonephosphate (DHAP), is an arginine-directed glycating agent and precursor of the major advanced glycation end product arginine-derived, hydroimidazolone (MG-H1). Extracellular vesicles (EVs) are a heterogeneous family of lipid-bilayer-vesicular structures released by virtually all living cells, involved in cell-to-cell communication, specifically by transporting biomolecules to recipient cells, driving distinct biological responses. Emerging evidence suggests that included in the EVs cargo there are different metabolic enzymes. Specifically, recent research has pointed out that EVs derived from human amniotic fluid stem cell (HASC-EVs) contain glycolytic pay-off phase enzymes, such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Since GAPDH catalyzes the sixth step of glycolysis using as a substrate GA3P, from which MG spontaneously origins, we wanted to investigate whether MG-derived MG-H1, as well as glyoxalases, could be novel molecule cargo in these EVs. By using immunoassays and spectrophotometric methods, we found, for the first time ever, that HASC-EVs contain functional glyoxalases and MG-H1, pioneering research to novel and exciting roles of these eclectic proteins, bringing them to the limelight once more.