MicroRNA Alterations and Associated Aberrant DNA Methylation Patterns across Multiple Sample Types in Oral Squamous Cell Carcinoma

Background: MicroRNA (miRNA) expression is broadly altered in cancer, but few studies have investigated miRNA deregulation in oral squamous cell carcinoma (OSCC). Epigenetic mechanisms are involved in the regulation of .30 miRNA genes in a range of tissues, and we aimed to investigate this further in OSCC. Methods: TaqManH qRT-PCR arrays and individual assays were used to profile miRNA expression in a panel of 25 tumors with matched adjacent tissues from patients with OSCC, and 8 control paired oral stroma and epithelium from healthy volunteers. Associated DNA methylation changes of candidate epigenetically deregulated miRNA genes were measured in the same samples using the MassArrayH mass spectrometry platform. MiRNA expression and DNA methylation changes were also investigated in FACS sorted CD44high oral cancer stem cells from primary tumor samples (CSCs), and in oral rinse and saliva from 15 OSCC patients and 7 healthy volunteers. Results: MiRNA expression patterns were consistent in healthy oral epithelium and stroma, but broadly altered in both tumor and adjacent tissue from OSCC patients. MiR-375 is repressed and miR-127 activated in OSCC, and we confirm previous reports of miR-137 hypermethylation in oral cancer. The miR-200 s/miR-205 were epigenetically activated in tumors vs normal tissues, but repressed in the absence of DNA hypermethylation specifically in CD44high oral CSCs. Aberrant miR-375 and miR-200a expression and miR-200c-141 methylation could be detected in and distinguish OSCC patient oral rinse and saliva from healthy volunteers, suggesting a potential clinical application for OSCC specific miRNA signatures in oral fluids. Conclusions: MiRNA expression and DNA methylation changes are a common event in OSCC, and we suggest miR-375, miR- 127, miR-137, the miR-200 family and miR-205 as promising candidates for future investigations. Although overall activated in OSCC, miR-200/miR-205 suppression in oral CSCs indicate that cell specific silencing of these miRNAs may drive tumor expansion and progression

Total Synthesis and Full Histone Deacetylase Inhibitory Profiling of Azumamides A–E as Well as β²- <i>epi</i>-Azumamide E and β³-<i>epi</i>-Azumamide E

Cyclic tetrapeptide and depsipeptide natural products have proven useful as biological probes and drug candidates due to their potent activities as histone deacetylase (HDAC) inhibitors. Here, we present the syntheses of a class of cyclic tetrapeptide HDAC inhibitors, the azumamides, by a concise route in which the key step in preparation of the noncanonical disubstituted β-amino acid building block was an Ellman-type Mannich reaction. By tweaking the reaction conditions during this transformation, we gained access to the natural products as well as two epimeric homologues. Thus, the first total syntheses of azumamides B–D corroborated the originally assigned structures, and the synthetic efforts enabled the first full profiling of HDAC inhibitory properties of the entire selection of azumamides A–E. This revealed unexpected differences in the relative potencies within the class and showed that azumamides C and E are both potent inhibitors of HDAC10 and HDAC11

Game-angling tourism: Connecting people, places and natures

Freshwater game-angling is a growing tourism phenomenon creating modern, increasingly global, spaces of consumption where performances are acted out in varied destinations. These performances uphold sporting traditions dating from fifteenth century England, cemented in the Victorian era. This paper demonstrates how and why freshwater angling has grown to become one of the largest leisure activities. It questions whether game-angling tourism has become a profound ecotourism, drawing insights from sociology and geography to explore how game-angling tourism traverses the society/nature dualism. It finds that angling tourism is a compelling, relatively undiscovered, vehicle for understanding our passion for consuming the natural world

Methyl Effect in Azumamides Provides Insight Into Histone Deacetylase Inhibition by Macrocycles

Natural, nonribosomal cyclotetrapeptides have traditionally been a rich source of inspiration for design of potent histone deacetylase (HDAC) inhibitors. We recently disclosed the total synthesis and full HDAC profiling of the naturally occurring azumamides (J. Med. Chem. 2013, 56, 6512). In this work, we investigate the structural requirements for potent HDAC inhibition by macrocyclic peptides using the azumamides along with a series of unnatural analogues obtained through chemical synthesis. By solving solution NMR structures of selected macrocycles and combining these findings with molecular modeling, we pinpoint crucial enzyme–ligand interactions required for potent inhibition of HDAC3. Docking of additional natural products confirmed these features to be generally important. Combined with the structural conservation across HDACs 1–3, this suggests that while cyclotetrapeptides have provided potent and class-selective HDAC inhibitors, it will be challenging to distinguish between the three major class I deacetylases using these chemotypes

Methyl Effect in Azumamides Provides Insight Into Histone Deacetylase Inhibition by Macrocycles

Natural, nonribosomal cyclotetrapeptides have traditionally been a rich source of inspiration for design of potent histone deacetylase (HDAC) inhibitors. We recently disclosed the total synthesis and full HDAC pro fi ling of the naturally occurring azumamides ( J. Med. Chem. 2013 , 56 , 6512). In this work, we investigate the structural requirements for potent HDAC inhibition by macrocyclic peptides using the azumamides along with a series of unnatural analogues obtained through chemical synthesis. By solving solution NMR structures of selected macrocycles and combining these fi ndings with molecular modeling, we pinpoint crucial enzyme − ligand interactions required for potent inhibition of HDAC3. Docking of additional natural products con fi rmed these features to be generally important. Combined with the structural conservation across HDACs 1 − 3, this suggests that while cyclotetrapeptides have provided potent and class-selective HDAC inhibitors, it will be challenging to distinguish between the three major class I deacetylases using these chemotypes