Mull, M. | Search bioRxiv

bioRxiv2024

The biotoxin BMAA promotes mesenchymal transition in neuroblastoma cells

Mesenchymal-like cancer cells are an indicator of malignant tumors as they exhibit tumorigenic properties including downregulation of differentiation markers, and increased colony-forming potential, motility, and chemoresistance. We have previously demonstrated that the cyanobacterial biotoxin beta-methylamino-L-alanine (BMAA) is capable of influencing neural cell differentiation state through mechanisms involving the Wnt signaling pathway, suggesting the possibility that BMAA may play a role in influencing other Wnt related differentiation processes including mesenchymal transition. In this study we present evidence characterizing the effects of BMAA on mesenchymal transition in a human neuroblastoma cell line and provide support for the hypothesis that the biotoxin can promote this process in these cells by altering differentiation state, inducing changes in gene expression, and changing cellular function in manners consistent with cellular mesenchymal transition. Results of this study indicate that BMAA exposure may promote carcinogenesis through its effects on cell differentiation state in certain contexts. These results suggest that exposure to the biotoxin BMAA may be an influencing factor in chemotherapy resistance and cancer relapse in neuroblastoma.

molecular biology↗

bioRxiv2018

Aberrant DEGS1 sphingolipid metabolism impairs central and peripheral nervous system function in humans

Sphingolipids including ceramides are important components of cellular membranes and functionally associated with fundamental processes such as cell differentiation, neuronal signaling and myelin sheath formation. Defects in the synthesis or degradation of sphingolipids are associated with various neurological pathologies, however, the entire spectrum of disorders affecting sphingolipid metabolism remains elusive. By whole-exome sequencing in a patient with a multisystem neurological disorder of both the central and peripheral nervous system, we identified a homozygous variant p.(Ala280Val) in DEGS1, encoding an enzyme of the ceramide synthesis pathway. The blood sphingolipid profile and patient-derived fibroblasts both showed a significant shift from the unsaturated to the dihydro-forms of sphingolipids. Moreover, an atypical and potentially toxic sphingolipid metabolite is formed as consequence of the altered synthesis pathway. The changes in the sphingolipid profile were recapitulated in a CRISPR/Cas-based DEGS1 knockout HAP1-cell model and by chemical inhibition of DEGS1, suggesting a loss of DEGS1 function in the disease. DEGS1 insufficiency is thus a novel cause for a multisystem neurological disorder. A sphingolipid-rich diet may correct the metabolic profile and improve the clinical outcome of affected individuals and suggests that this heritable condition might be treatable.\n\nAbbreviations

genetics↗