tretinoin and cerivastatin

All-trans-retinoic acid (RA), the active metabolite of vitamin A, can reduce the malignant phenotype in some types of cancer and paradoxically also can promote cancer growth and invasion in others. For instance, it has been reported that RA induces tumor suppression in tumor xenografts of MDA-MB-468 breast cancer cells while increasing tumor growth and metastases in xenografts of MDA-MB-231 breast cancer cells. The signaling pathways involved in the pro-invasive action of retinoic acid remain mostly unknown. We show here that RA activates the pro-invasive axis Src-YAP-Interleukin 6 (Src-YAP-IL6) in triple negative MDA-MB-231 breast cancer cells, yielding to increased invasion of these cells. On the contrary, RA inhibits the Src-YAP-IL6 axis of triple-negative MDA-MB-468 cells, which results in decreased invasion phenotype. In both types of cells, inhibition of the Src-YAP-IL6 axis by the Src inhibitor PP2 drastically reduces migration and invasion. Src inhibition also downregulates the expression of a pro-invasive isoform of VEGFR1 in MDA-MB-231 breast cancer cells. Furthermore, interference of YAP nuclear translocation using the statin cerivastatin reverses the upregulation of Interleukin 6 (IL-6) and the pro-invasive effect of RA on MDA-MB-231 breast cancer cells and also decreases invasion and viability of MDA-MB-468 breast cancer cells. These results altogether suggest that RA induces pro-invasive or anti-invasive actions in two triple-negative breast cancer cell lines due to its ability to activate or inhibit the Src-YAP-IL6 axis in different cancer cells. The pro-invasive effect of RA can be reversed by the statin cerivastatin.

Topics: Biomarkers; Cell Cycle Proteins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Interleukin-6; Nuclear Proteins; Phosphorylation; Pyridines; Signal Transduction; src-Family Kinases; Transcription Factors; Tretinoin; Triple Negative Breast Neoplasms

Neural apoptosis-regulated convertase (NARC)-1 is the newest member of the proprotein convertase family implicated in the cleavage of a variety of protein precursors. The NARC-1 gene, PCSK9, has been identified recently as the third locus implicated in autosomal dominant hypercholesterolemia (ADH). The 2 other known genes implicated in ADH encode the low-density lipoprotein receptor and apolipoprotein B. As an approach toward the elucidation of the physiological role(s) of NARC-1, we studied its transcriptional regulation.. Using quantitative RT-PCR, we assessed NARC-1 regulation under conditions known to regulate genes involved in cholesterol metabolism in HepG2 cells and in human primary hepatocytes. We found that NARC-1 expression was strongly induced by statins in a dose-dependent manner and that this induction was efficiently reversed by mevalonate. NARC-1 mRNA level was increased by cholesterol depletion but insensitive to liver X receptor activation. Human, mouse, and rat PCSK9 promoters contain 2 typical conserved motifs for cholesterol regulation: a sterol regulatory element (SRE) and an Sp1 site.. PCSK9 regulation is typical of that of the genes implicated in lipoprotein metabolism. In vivo, PCSK9 is probably a target of SRE-binding protein (SREBP)-2.

Topics: Alitretinoin; Animals; Atorvastatin; Base Sequence; Cell Line; Cholesterol; Consensus Sequence; DNA-Binding Proteins; Gene Expression Regulation; Hepatocytes; Heptanoic Acids; Homeostasis; Humans; Hydroxycholesterols; Hydroxymethylglutaryl CoA Reductases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Liver X Receptors; Lovastatin; Mevalonic Acid; Mice; Orphan Nuclear Receptors; Promoter Regions, Genetic; Proprotein Convertase 9; Proprotein Convertases; Pyridines; Pyrroles; Quinolines; Rats; Receptors, Cytoplasmic and Nuclear; Regulatory Sequences, Nucleic Acid; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sequence Alignment; Sequence Homology, Nucleic Acid; Serine Endopeptidases; Simvastatin; Sp1 Transcription Factor; Species Specificity; Sterol Regulatory Element Binding Protein 2; Transcription Factors; Tretinoin