BackgroundPancreatic ductal adenocarcinoma (PDAC) is a common malignancy with dismal prognosis. Metastatic spread and therapeutic resistance, the main causes of PDAC-related mortalities, are both partially underlined by the epithelial-mesenchymal transition (EMT) of PDAC cells. While the role of Warburg metabolism has been recognized in supporting rapid cellular growth and proliferation in many cancer types, less is known about the metabolic changes occurring during EMT, particularly in the context of PDAC.ResultsIn the current study, experimental models of EMT were established in the Panc-1 cell line of human PDAC via exposure to two physiologically relevant EMT inducers (tumor necrosis factor-α and transforming growth factor-β) and the metabolic consequences examined. The two EMT models displayed similar alterations in the general metabolic profile including augmented glucose uptake and lactate secretion as well as the lack of change in oxidative metabolism. Examination of molecular markers revealed differences in the pathways underlying the metabolic rewiring. 13C-Glucose tracer data confirmed that a major portion of accumulated lactate was derived from glucose, but subsequent flux analysis suggested involvement of non-canonical pathways towards lactate production.ConclusionsOur results characterize the metabolic reprogramming occurring during PDAC cell EMT and highlight the common changes of increased glucose uptake and lactate secretion under different EMT conditions. Such insight is urgently required for designing metabolic strategies to selectively target cells undergoing EMT in PDAC.Electronic supplementary materialThe online version of this article (doi:10.1186/s40170-016-0160-x) contains supplementary material, which is available to authorized users.

+) is a ubiquitous metabolite that serves an essential role in the catabolism of nutrients. Recently, there has been a surge of interest in NAD + biology, with the recognition that NAD + influences many biological processes beyond metabolism, including transcription, signalling and cell survival.There are a multitude of pathways involved in the synthesis and breakdown of ).This redox cycling of NAD + is a key process across numerous metabolic pathways (eg, glycolysis, oxidative phosphorylation).By contrast to its redox role where the levels of NAD + stay essentially constant, NAD + has more recently gained attention following recognition that it also functions as a co-substrate for a range of different enzymes, including sirtuins, poly(ADP-ribose) polymerases (PARPs) and cyclic ADP-ribose synthases, where NAD + is actively degraded during the enzymatic processes catalysed by these proteins.Because of the breadth of cellular processes regulated by these en- | NAD + HOMEOSTASISThe 11The main pathways involved in the biosynthesis of NAD + are the Preiss-Handler pathway, the de novo biosynthesis pathway and

Background: Insulin regulates metabolism via the PI3K/Akt pathway. Results: A kinome siRNA screen identified PFKFB3, a glycolysis regulator, as a modulator of insulin action. Manipulation of PFKFB3 activity or glycolysis affected insulin signaling. Conclusion: Intracellular metabolism modulates important signal transduction pathways. Significance: The novel link between glycolysis and growth factor signaling has important implications for the treatment of metabolic diseases.

The zinc finger transcription factor Snail is a known effector of epithelial-to-mesenchymal transition (EMT), a process that underlies the enhanced invasiveness and chemoresistance of common to cancerous cells. Induction of Snail-driven EMT has also been shown to drive a range of pro-survival metabolic adaptations in different cancers. In the present study, we sought to determine the specific role that Snail has in driving EMT and adaptive metabolic programming in pancreatic ductal adenocarcinoma (PDAC) by overexpressing Snail in a PDAC cell line, Panc1, and in immortalized, non-tumorigenic human pancreatic ductal epithelial (HPDE) cells. Snail overexpression was able to induce EMT in both pancreatic cell lines through suppression of epithelial markers and upregulation of mesenchymal markers alongside changes in cell morphology and enhanced migratory capacity. Snail-overexpressed pancreatic cells additionally displayed increased glucose uptake and lactate production with concomitant reduction in oxidative metabolism measurements. Snail overexpression reduced maximal respiration in both Panc1 and HPDE cells, with further reductions seen in ATP production, spare respiratory capacity and non-mitochondrial respiration in Snail overexpressing Panc1 cells. Accordingly, lower expression of mitochondrial electron transport chain proteins was observed with Snail overexpression, particularly within Panc1 cells. Modelling of 13C metabolite flux within both cell lines revealed decreased carbon flux from glucose in the TCA cycle in snai1-overexpressing Panc1 cells only. This work further highlights the role that Snail plays in EMT and demonstrates its specific effects on metabolic reprogramming of glucose metabolism in PDAC.

Highlights d Invasive tumor borders and cells proximal to vessels show upregulated Rac1 activity d Rac1 inhibition enhances tumor cell vulnerability during fluidflow shear stress d Live in vivo imaging of Rac1 activity guides optimal disease progression targeting d Rac1 inhibition reduces intratumoral movement and lung metastasis