40 Consistently, drug-treated Flvcr1a-null mice showed a significantly higher induction of HO1 and reduction in the expression and activity of ALAS1 and CYPs compared with wild-type animals, indicating that heme accumulation resulting from Flvcr1a deletion resembles what occurs after hemin administration. In conclusion, the block of

heme export PLX3397 ic50 due to Flvcr1a deletion promotes the expansion of the cytosolic heme pool, thus leading to ALAS inhibition and HO induction. We propose that the lack of FLVCR1a causes a reduction in the newly synthesized heme, impairing both CYP expression and activity ( Figure 7F). It appears that in the hepatocytes, heme is formed in slight excess over its metabolic needs 28 and its levels are maintained adequate

by a combination of synthetic, degradative, and export mechanisms, suggesting that they are equipped with a “sensing” system to monitor changes in the size of “uncommitted” heme pool. We can speculate that FLVCR1a is part of this sensing system and that, by sensing heme levels and exporting heme excess out of the cell, it controls the size of the cytosolic heme ZD1839 pool, playing a crucial regulatory role in cell metabolism and in the maintenance of a proper oxidative status. We expect that mutations in Flvcr1a and/or pathologic situations that affect its expression can result in a reduced CYP activity, altering drug metabolism, in particular in individuals that routinely assume drugs for therapeutic purposes. The authors thank Ligia Goncalves and Laura Braccini for hepatocyte culture, Paolo Provero for statistical analysis, Sonia Levi for the gift of anti-ferritin antibodies, and Rolf Sprengel for mice carrying the FLP recombinase under the control of the actin promoter. “
“Pancreatic ductal adenocarcinoma (PDAC) has a median survival of 6 months and a 5-year survival rate of <5%.1 Ninety percent of patients have surgically unresectable disease at diagnosis and the majority of patients who undergo

resection for localized lesions develop recurrent or metastatic disease.2 Consequently, Tolmetin the development of more effective strategies to combat metastasis is of paramount importance. Human PDAC arises from pancreatic intraepithelial neoplasias (PanINs) frequently driven by activating mutations in KRas,3 followed by loss or mutation of tumor suppressors, such as p53. Pdx1-Cre−driven expression of KRasG12D and Trp53R172H in murine pancreas mimics the human disease and importantly the histopathology.4 Disease progression and sites of metastases also mirror the human disease, providing a good model for human PDAC.5 Slug is a snail family transcription factor that orchestrates the epithelial to mesenchymal transition (EMT) during developmental programs, including in the mouse pancreas.6 The snail family transcription factors repress epithelial-specific genes and enhance mesenchymal-associated genes.7 Snail proteins bind to specific E-box sequences in promoters or introns and regulate gene expression.