Cancer stem cells (CSCs) represent a small subpopulation of self-renewing oncogenic cells. As in many other stem cells, metabolic reprogramming has been implicated to be a key characteristic of CSCs. However, little is known about how the metabolic features of cancer cells are controlled to orchestrate their CSC-like properties. We recently demonstrated that hyaluronan (HA) overproduction allowed plastic cancer cells to revert to stem cell states. Here, we adopted stable isotope-assisted tracing and mass spectrometry profiling to elucidate the metabolic features of HA-overproducing breast cancer cells. These integrated approaches disclosed an acceleration of metabolic flux in the hexosamine biosynthetic pathway (HBP). A metabolic shift toward glycolysis was also evident by quantitative targeted metabolomics, which was validated by the expression profiles of key glycolytic enzymes. Forced expression of glutamine:fructose-6-phosphate amidotransferase 1 (GFAT1), an HBP rate-limiting enzyme, resembled the results of HA overproduction with regard to HIF-1α accumulation and glycolytic program, whereas GFAT1 inhibition significantly decreased HIF-1α protein level in HA-overproducing cancer cells. Moreover, inhibition of the HBP-HIF-1 axis abrogated HA-driven glycolytic enhancement and reduced the CSC-like subpopulation. Taken together, our results provide compelling evidence that HA production regulates the metabolic and CSC-like properties of breast cancer cells via HBP-coupled HIF-1 signaling.

BackgroundRheumatoid arthritis (RA) is an autoimmune disease that causes chronic synovitis, cartilage degradation and bone deformities. Synovitis is the term for inflammation of the synovial membrane, an early stage of RA. The pathogenesis of the disease occurs through cytokine induction. The major cytokine that increases the severity of RA is TNF-α. Thus, inhibition of the TNF-α cascade is an effective way to diminish the progression of the disease. We are interested in investigating the difference between primary human synovial fibroblast (hSF) cells and SW982 as synovitis models induced by TNF-α and in monitoring their responses to sesamin as an anti-inflammatory phytochemical.MethodThe designed experiments were performed in hSF cells or the SW982 cell line treated with 10 ng/ml TNF-α with or without 0.25, 0.5 or 1 μM sesamin. Subsequently, pro-inflammatory cytokine genes and proteins were measured in parallel with a study of associated signalling transduction involved in inflammatory processes, including NF-κB and MAPK pathways.ResultsThe results demonstrated that although hSF and SW982 cells responded to TNF-α induction in the same fashion, they reacted at different levels. TNF-α could induce IL-6, IL-8 and IL-1β in both cell types, but the levels in SW982 cells were much higher than in hSF cells. This characteristic was due to the different induction of MAPKs in each cell type. Both cell types reacted to sesamin in almost the same fashion. However, hSF cells were more sensitive to sesamin than SW982 cells in terms of the anti-RA effect.ConclusionsThe responses of TNF-α-induced hSF and SW982 were different at the signal transduction level. However, the two cell types showed almost the same reaction to sesamin treatment in terms of the end point of the response.Electronic supplementary materialThe online version of this article (10.1186/s12906-017-2035-2) contains supplementary material, which is available to authorized users.

BackgroundRheumatoid arthritis (RA) is an autoimmune disease associated with chronic inflammatory arthritis. TNF-α and OSM are pro-inflammatory cytokines that play a key role in RA progression. Thus, reducing the effects of both cytokines is practical in order to relieve the progression of the disease. This current study is interested in sesamin, an active compound in sesame seeds. Sesamin has been shown to be a chondroprotective agent in osteoarthritis models. Here, we have evaluated a porcine cartilage explant as a cartilage degradation model related to RA induced by TNF-α and/or OSM in order to investigate the effects of sesamin on TNF-α and OSM in the cartilage degradation model.MethodsA porcine cartilage explant was induced with a combination of TNF-α and OSM (test group) or IL-1β and OSM (control group) followed by a co-treatment of sesamin over a long-term period (35 days). After which, the tested explants were analyzed for indications of both the remaining and the degradation aspects using glycosaminoglycan and collagen as an indicator.ResultsThe combination of TNF-α and OSM promoted cartilage degradation more than either TNF-α or OSM alone and was comparable with the combination of IL-1β and OSM. Sesamin could be offering protection against cartilage degradation by reducing GAGs and collagen turnover in the generated model.ConclusionsSesamin might be a promising agent as an alternative treatment for RA patients. Furthermore, the generated model revealed itself to be an impressive test model for the analysis of phytochemical substances against the cartilage degradation model for RA. The model could be used to test for the prevention of cartilage degradation in other biological agents induced with TNF-α and OSM as well.