Design and synthesis of potent RSK inhibitors

Utilizing the already described 3,4-bi-aryl pyridine series as a starting point, incorporation of a second ring system with a hydrogen bond donor and additional hydrophobic contacts yielded the azaindole series which exhibited potent, picomolar RSK2 inhibition and the most potent in vitro target modulation seen thus far for a RSK inhibitor. In the context of the more potent core, several changes at the phenol moiety were assessed to potentially find a tool molecule appropriate for in vivo evaluation.     

Investigating spatial structure in specific tree species in ancient semi-natural woodland using remote sensing and marked point pattern analysis

Remote sensing classification has the potential to provide important information, such as tree species distribution maps, to ecologists, at a range of spatial and temporal scales. However, standard classification procedures often fail to provide the high accuracies required for many ecological applications. Previously, a modified remote sensing classification technique was used to provide very high classification accuracies for one or two classes (e.g. species) of interest. The aim of this paper was to demonstrate that the output from the method can be suitable for spatial ecological analyses, and to provide a generic simulation framework for assessing the adequacy of any given remote sensing classification for such analyses. Marked point pattern analysis (MPPA) was applied to tree species distribution data obtained for sycamore Acer pseudoplatanus and ash Fraxinus excelsior from a 400 ha ancient semi-natural woodland in southern England using the modified remote sensing classification method to test several hypotheses of ecological interest relating to the spatial distribution and interaction of these species. Monte Carlo simulation methods were then used to evaluate the data and data quality requirements of the MPPA to check that the classified tree species maps for sycamore and ash were adequate. Using the combined method the spatial distributions for sycamore and ash were found to be aggregated and inter-dependent at a range of spatial scales. Together, the remote sensing classification and simulation approaches provide the basis for exploiting more fully the potential of remote sensing to provide information of value to ecologists.     

Vasoactive intestinal polypeptide stimulates nonovarian progesterone secretion in rabbits

Recent experiments conducted in this laboratory have shown that intravenous infusions of vasoactive intestinal polypeptide (VIP) induced significant increases in plasma progesterone (P) in female rabbits. The purpose of this study was to determine the organ source of this P and to clarify the mechanisms by which it is induced. Intravenous infusions of VIP (37.5, 75, and 150 pmol/kg per min for 60 min) produced acute dose-dependent increases in plasma P in intact estrous rabbits. In ovariectomized (OVX) animals, VIP infusion (75 pmol/kg per min) produced a P increase of the same magnitude. In animals both OVX and adrenalectomized (ADX), this VIP effect was eliminated. The only significant change noted in luteotropic hormone (LH) or follicle stimulating hormone (FSH) was a decrease in FSH immediately following VIP infusion (150 pmol/kg). VIP infusion significantly increased plasma cortisol in intact and OVX animals, but not in OVX/ADX animals. It is concluded that VIP primarily stimulates the adrenal component of P secretion in the rabbit, via mechanisms independent of LH or FSH.     

Tritium labeling of thermolysin, elastase, and ribonuclease by exposure to tritium gas at low pressure

The bacterial metalloendoprotease thermolysin, bovine pancreatic ribonuclease, and porcine pancreatic elastase have been tritiated by exposure to subcurie amounts of tritium gas at pressures below 50 mTorr for periods of 1 to 6 h. Thermolysin, ribonuclease, and elastase have been purified to specific radioactivities of 15, 5, and 1 Ci/mol, respectively. Amino acid analyses of the tritiated enzymes revealed higher relative specific radioactivities for His, Pro, and Phe in all three proteins while Val and Ile were among the residues with the lowest relative specific radioactivities. The recovery of enzyme activity was always greater than 95% and the formation of tritiated decomposition products was not observed. This lowpressure gas exposure process requires less tritium gas and less time than the original method of Wilzbach to achieve equal or higher levels of tritium incorporation. In addition, the enzymes were completely active and did not show the presence of highly radioactive byproducts which have been observed in earlier studies of the Wilzbach labeling of proteins.     

Assessment of SLX4 Mutations in Hereditary Breast Cancers

Background

SLX4 encodes a DNA repair protein that regulates three structure-specific endonucleases and is necessary for resistance to DNA crosslinking agents, topoisomerase I and poly (ADP-ribose) polymerase (PARP) inhibitors. Recent studies have reported mutations in SLX4 in a new subtype of Fanconi anemia (FA), FA-P. Monoallelic defects in several FA genes are known to confer susceptibility to breast and ovarian cancers.

Methods and Results

To determine if SLX4 is involved in breast cancer susceptibility, we sequenced the entire SLX4 coding region in 738 (270 Jewish and 468 non-Jewish) breast cancer patients with 2 or more family members affected by breast cancer and no known BRCA1 or BRCA2 mutations. We found a novel nonsense (c.2469G>A, p.W823*) mutation in one patient. In addition, we also found 51 missense variants [13 novel, 23 rare (MAF<0.1%), and 15 common (MAF>1%)], of which 22 (5 novel and 17 rare) were predicted to be damaging by Polyphen2 (score = 0.65–1). We performed functional complementation studies using p.W823* and 5 SLX4 variants (4 novel and 1 rare) cDNAs in a human SLX4-null fibroblast cell line, RA3331. While wild type SLX4 and all the other variants fully rescued the sensitivity to mitomycin C (MMC), campthothecin (CPT), and PARP inhibitor (Olaparib) the p.W823* SLX4 mutant failed to do so.

Conclusion

Loss-of-function mutations in SLX4 may contribute to the development of breast cancer in very rare cases.     

Autism Linked to Increased Oncogene Mutations but Decreased Cancer Rate

Autism spectrum disorder (ASD) is one phenotypic aspect of many monogenic, hereditary cancer syndromes. Pleiotropic effects of cancer genes on the autism phenotype could lead to repurposing of oncology medications to treat this increasingly prevalent neurodevelopmental condition for which there is currently no treatment. To explore this hypothesis we sought to discover whether autistic patients more often have rare coding, single-nucleotide variants within tumor suppressor and oncogenes and whether autistic patients are more often diagnosed with neoplasms. Exome-sequencing data from the ARRA Autism Sequencing Collaboration was compared to that of a control cohort from the Exome Variant Server database revealing that rare, coding variants within oncogenes were enriched for in the ARRA ASD cohort (p<1.0x10^-8). In contrast, variants were not significantly enriched in tumor suppressor genes. Phenotypically, children and adults with ASD exhibited a protective effect against cancer, with a frequency of 1.3% vs. 3.9% (p<0.001), but the protective effect decreased with age. The odds ratio of neoplasm for those with ASD relative to controls was 0.06 (95% CI: 0.02, 0.19; p<0.0001) in the 0 to 14 age group; 0.35 (95% CI: 0.14, 0.87; p = 0.024) in the 15 to 29 age group; 0.41 (95% CI: 0.15, 1.17; p = 0.095) in the 30 to 54 age group; and 0.49 (95% CI: 0.14, 1.74; p = 0.267) in those 55 and older. Both males and females demonstrated the protective effect. These findings suggest that defects in cellular proliferation, and potentially senescence, might influence both autism and neoplasm, and already approved drugs targeting oncogenic pathways might also have therapeutic value for treating autism.