Search

We previously showed that [Pt(O,O’-acac)(γ-acac)(DMS)] ([Pt(acac)2(DMS)]) exerted substantial cytotoxic effects in SH-SY5Y neuroblastoma cells, and decreased metalloproteases (MMPs) production and cells migration in MCF-7 breast cancer cells. The ubiquitously distributed sodium-hydrogen antiporter 1 (NHE1) is involved in motility and invasion of many solid tumours. The present study focuses on the effects of [Pt(acac)2(DMS)] in SH-SY5Y cell migration and also on the possibility that NHE1 may be involved in such effect. After sublethal [Pt(acac)2(DMS)] treatment cell migration was examined by wounding assay and cell invasion by transwell assay. NHE1 activity was measured in BCECF-loaded SH-SY5Y as the rate of Na+-dependent intracellular pH recovery in response to an acute acid pulse. Gelatin zymography for MMP-2/9 activities, Western blottings of MMPs, MAPKs, mTOR, S6 and PKCs and small interfering RNAs to PKC-ε/-δ mRNA were performed. Sublethal concentrations of [Pt(acac)2(DMS)] decreases NHE1 activity, inhibites cell migration and invasion and decreases expression and activity of MMP-2 and -9. [Pt(acac)2(DMS)] administered to SH-SY5Y cells provokes the increment of ROS, generated by NADPH oxidase, responsible for the PKC-ε and PKC-δ activation. Whilst PKC-δ activates p38/MAPK, responsible for the inhibition of MMP-2 and -9 secretion, PKC-ε activates a pathway made of ERK1/2, mTOR and S6K responsible for the inhibition of NHE1 activity and cell migration. In conclusion, we have shown a drastic impairment in tumour cell metastatization in response to inhibition of NHE1 and MMPs activities by [Pt(acac)2(DMS)] occurring through a novel mechanism mediated by PKC-δ/-ε activation. [ABSTRACT FROM AUTHOR]

Scope: High intakes of n-3 fatty acids exert anti-inflammatory effects and cardiovascular protection, but the underlying molecular basis is incompletely defined. By genome-wide analysis we searched for novel effects of docosahexaenoic acid (DHA) on gene expression and pathways in human vascular endothelium under pro-inflammatory conditions., Methods and Results: Human umbilical vein endothelial cells were treated with DHA and then stimulated with interleukin(IL)-1β. Total RNA was extracted, and gene expression examined by DNA microarray. DHA alone altered the expression of 188 genes, decreasing 92 and increasing 96. IL-1β changed the expression of 2031 genes, decreasing 997 and increasing 1034. Treatment with DHA before stimulation significantly affected the expression of 116 IL-1β-deregulated genes, counter-regulating the expression of 55 genes among those decreased and of 61 among those increased. Functional and network analyses identified immunological, inflammatory and metabolic pathways as the most affected. Newly identified DHA-regulated genes are involved in stemness, cellular growth, cardiovascular system function and cancer, and included cytochrome p450 4F2(CYP4F2), transforming growth factor(TGF)-β2, Cluster of Differentiation (CD)47, caspase recruitment domain(CARD)11 and phosphodiesterase(PDE)5α., Conclusions: Endothelial exposure to DHA regulates novel genes and related pathways. Such unbiased identification should increase our understanding of mechanisms by which n-3 fatty acids affect human diseases.