IL-24 Inhibits lung cancer cell migration and invasion by disrupting the SDF-1/CXCR4 signaling axis

© 2015 Panneerselvam et al. Background The stromal cell derived factor (SDF)-1/chemokine receptor (CXCR)-4 signaling pathway plays a key role in lung cancer metastasis and is molecular target for therapy. In the present study we investigated whether interleukin (IL)-24 can inhibit the SDF-1/CXCR4 axis and suppress lung cancer cell migration and invasion in vitro. Further, the efficacy of IL-24 in combination with CXCR4 antagonists was investigated. Methods Human H1299, A549, H460 and HCC827 lung cancer cell lines were used in the present study. The H1299 lung cancer cell line was stably transfected with doxycycline-inducible plasmid expression vector carrying the human IL-24 cDNA and used in the present study to determine the inhibitory effects of IL-24 on SDF-1/CXCR4 axis. H1299 and A549 cell lines w ere used in transient transfection studies. The inhibitory effects of IL-24 on SDF1/CXCR4 and its downstream targets were analyzed by quantitative RT-PCR, western blot, luciferase reporter assay, flow cytometry and immunocytochemistry. Functional studies included cell migration and invasion assays. Principal Findings Endogenous CXCR4 protein expression levels varied among the four human lung cancer cell lines. Doxycycline-induced IL-24 expression in the H1299-IL24 cell line resulted in reduced CXCR4 mRNA and protein expression. IL-24 post-transcriptionally regulated CXCR4 mRNA expression by decreasing the half-life of CXCR4 mRNA ( > 40%). Functional studies showed IL-24 inhibited tumor cell migration and invasion concomitant with reduction in CXCR4 and its downstream targets (pAKTS 473 , pmTORS 2448 , pPRAS40 T246 and HIF-1α). Additionally, IL-24 inhibited tumor cell migration both in the presence and absence of the CXCR4 agonist, SDF-1. Finally, IL-24 when combined with CXCR4 inhibitors (AMD3100, SJA5) or with CXCR4 siRNA demonstrated enhanced inhibitory activity on tumor cell migration. Conclusions IL-24 disrupts the SDF-1/CXCR4 signaling pathway and inhibits lung tumor cell migration and invasion. Additionally, IL-24, when combined with CXCR4 inhibitors exhibited enhanced anti-metastatic activity and is an attractive therapeutic strategy for lung metastasi

The Structural Diversity of Carbohydrate Antigens of Selected Gram-Negative Marine Bacteria

Marine microorganisms have evolved for millions of years to survive in the environments characterized by one or more extreme physical or chemical parameters, e.g., high pressure, low temperature or high salinity. Marine bacteria have the ability to produce a range of biologically active molecules, such as antibiotics, toxins and antitoxins, antitumor and antimicrobial agents, and as a result, they have been a topic of research interest for many years. Among these biologically active molecules, the carbohydrate antigens, lipopolysaccharides (LPSs, O-antigens) found in cell walls of Gram-negative marine bacteria, show great potential as candidates in the development of drugs to prevent septic shock due to their low virulence. The structural diversity of LPSs is thought to be a reflection of the ability for these bacteria to adapt to an array of habitats, protecting the cell from being compromised by exposure to harsh environmental stress factors. Over the last few years, the variety of structures of core oligosaccharides and O-specific polysaccharides from LPSs of marine microrganisms has been discovered. In this review, we discuss the most recently encountered structures that have been identified from bacteria belonging to the genera Aeromonas, Alteromonas, Idiomarina, Microbulbifer, Pseudoalteromonas, Plesiomonas and Shewanella of the Gammaproteobacteria phylum; Sulfitobacter and Loktanella of the Alphaproteobactera phylum and to the genera Arenibacter, Cellulophaga, Chryseobacterium, Flavobacterium, Flexibacter of the Cytophaga-Flavobacterium-Bacteroides phylum. Particular attention is paid to the particular chemical features of the LPSs, such as the monosaccharide type, non-sugar substituents and phosphate groups, together with some of the typifying traits of LPSs obtained from marine bacteria. A possible correlation is then made between such features and the environmental adaptations undertaken by marine bacteria

Suppression of BCL6 Function by HDAC Inhibitor Mediated Acetylation and Chromatin Modification Enhances BET Inhibitor Effects in B-cell Lymphoma Cells

Multiple genetic aberrations in the regulation of BCL6, including in acetyltransferase genes, occur in clinically aggressive B-cell lymphomas and lead to higher expression levels and activity of this transcriptional repressor. BCL6 is, therefore, an attractive target for therapy in aggressive lymphomas. In this study romidepsin, a potent histone deacetylase inhibitor (HDACi), induced apoptosis and cell cycle arrest in Burkitt and diffuse large B-cell lymphoma cell lines, which are model cells for studying the mechanism of action of BCL6. Romidepsin caused BCL6 acetylation at early timepoints inhibiting its function, while at later timepoints BCL6 expression was reduced and target gene expression increased due to chromatin modification. MYC contributes to poor prognosis in aggressive lymphoma. MYC function is reduced by inhibition of chromatin readers of the bromodomain and extra-terminal repeat (BET) family, which includes BRD4. The novel combination of romidepsin and JQ1, a BRD4 inhibitor was investigated and showed synergy. Collectively we suggest that the combination of HDACi and BRD4i should be pursued in further pre-clinical testing.Funding: The work was supported by grants SAF2014-53526-R and SAF2017-88026-R from MINECO, Spanish Government, to M.D.D. and J.L. (partially funded by FEDER program from European Union). M.G.C. was recipient of a “Marcos Fernández” fellowship from Leukemia and Lymphoma foundation. L.G.G. was recipient of a FPI fellowship from Spanish Government

The lipid A of Burkholderia multivorans C1576 smooth-type lipopolysaccharide and its pro-inflammatory activity in a cystic fibrosis airways model.

11Cystic fibrosis is an autosomal recessive disorder and it is characterised by chronic bacterial airway infection which leads to progressive lung deterioration, sometimes with fatal outcome. Burkholderia multivorans and Burkholderia cenocepacia are the species responsible for most of the infections of cystic fibrosis patients. Lipopolysaccharide endotoxins (LPSs) are among the foremost factors of pathogenesis of Gram-negative infection and, in particular, lipid A is the endotoxic portion of LPS responsible for eliciting host innate immune response. In this work, the complete primary structure of the lipid A from B. multivorans C1576 has been defined and, further, its pro-inflammatory activity in a cystic fibrosis airways model is shown. The structure of B. multivorans lipid A was attained by chemical, mass spectrometry and nuclear magnetic resonance analyses whereas its biological activity was assessed on the intestinal epithelial cell line CACO-2 cells, on the airway epithelial IB3-1 cells, carrying the ΔF508/W1282X CFTR mutation and on an ex vivo model of culture explants of nasal polyps.nonemixedIeranò T.; Cescutti P.; Leone M.R.; Luciani A.; Rizzo R.; Raia V.; Lanzetta R.; Parrilli M.; Maiuri L.; Silipo A.; Molinaro A.Ieranò, T.; Cescutti, Paola; Leone, M. R.; Luciani, A.; Rizzo, Roberto; Raia, V.; Lanzetta, R.; Parrilli, M.; Maiuri, L.; Silipo, A.; Molinaro, A