Identification of Candidate Growth Promoting Genes in Ovarian Cancer through Integrated Copy Number and Expression Analysis

Ovarian cancer is a disease characterised by complex genomic rearrangements but the majority of the genes that are the target of these alterations remain unidentified. Cataloguing these target genes will provide useful insights into the disease etiology and may provide an opportunity to develop novel diagnostic and therapeutic interventions. High resolution genome wide copy number and matching expression data from 68 primary epithelial ovarian carcinomas of various histotypes was integrated to identify genes in regions of most frequent amplification with the strongest correlation with expression and copy number. Regions on chromosomes 3, 7, 8, and 20 were most frequently increased in copy number (>40% of samples). Within these regions, 703/1370 (51%) unique gene expression probesets were differentially expressed when samples with gain were compared to samples without gain. 30% of these differentially expressed probesets also showed a strong positive correlation (r≥0.6) between expression and copy number. We also identified 21 regions of high amplitude copy number gain, in which 32 known protein coding genes showed a strong positive correlation between expression and copy number. Overall, our data validates previously known ovarian cancer genes, such as ERBB2, and also identified novel potential drivers such as MYNN, PUF60 and TPX2

Histidine-Rich Cationic Cell-Penetrating Peptides for Plasmid DNA and siRNA Delivery

International audienceAmphipathic, pH-responsive, membrane-active peptides such as LAH4 and derivatives thereof have the ability to effectively deliver genes and small interfering RNA (siRNA) into mammalian cells. Their ability to bind and protect nucleic acids and then disrupt membranes when activated at low pH enables them to harness the endocytic machinery to deliver cargo efficiently and with low associated toxicity. This chapter describes protocols for the chemical synthesis of transfection peptides of the LAH4 family, complex formation with nucleic acids, and their use for the in vitro delivery of either plasmid DNA or siRNA into mammalian cell lines

The Paleocene–Eocene Thermal Maximum: Plants as Paleothermometers, Rain Gauges, and Monitors

We travel back in time through this chapter and take a field trip to western North America during the Paleocene– Eocene Thermal Maximum (PETM), some 56 million years ago. Here, plant-and-animal fossils were discovered in the warmest interval of the last 500 million years, a condition that lasted only 200,000 years. We provide a brief review of what may have caused a massive influx of atmospheric carbon detected during the PETM. We contrast the PETM to similar ongoing thermal events that began during the Industrial Revolution and persist today. We discuss the tools that paleobotanists have devised to interpret climate from fossil leaf, pollen, and wood records and present a brief overview of floral changes that occurred in western North America before, during, and right after this thermal maximum. Lastly, we explore how fossil data can be incorporated with ecological and systematic information into biogeographical models to predict how Cenozoic plants respond to climate change

Lipid interactions of LAH4, a peptide with antimicrobial and nucleic acid transfection activities

The cationic amphipathic designer peptide LAH4 exhibits potent antimicrobial, nucleic acid transfection and cell penetration activities. Closely related derivatives have been developed to enhance viral transduction for gene therapeutic assays. LAH4 contains four histidines and, consequently, its overall charge and membrane topology in lipid bilayers are strongly pH dependent. In order to better understand the differential interactions of this amphipathic peptide with negatively-charged membranes its interactions, topologies, and penetration depth were investigated in the presence of lipid bilayers as a function of pH, buffer, phospholipid head group, and fatty acyl chain composition using a combination of oriented synchrotron radiation circular dichroism spectroscopy as well as oriented and non-oriented solid-state NMR spectroscopy. This combination of methods indicates that in the presence of lipids with phosphatidylglycerol head groups, the topological equilibria of LAH4 is shifted towards more in-plane configurations even at neutral pH. In contrast, a transmembrane alignment is promoted when LAH4 interacts with membranes made of dimyristoyl phospholipids rather than palmitoyl-oleoyl-phospholipids. Finally, the addition of citrate buffer favours LAH4 transmembrane alignments, even at low pH, probably by complex formation with the cationic charges of the peptide. In summary, this study has revealed that the membrane topology of this peptide is readily modulated by the environmental conditions