The KRAS-regulated kinome identifies WEE1 and ERK coinhibition as a potential therapeutic strategy in KRAS-mutant pancreatic cancer

Oncogenic KRAS drives cancer growth by activating diverse signaling networks, not all of which have been fully delineated. We set out to establish a system-wide profile of the KRAS-regulated kinase signaling network (kinome) in KRAS-mutant pancreatic ductal adenocarcinoma (PDAC). We knocked down KRAS expression in a panel of six cell lines and then applied multiplexed inhibitor bead/MS to monitor changes in kinase activity and/or expression. We hypothesized that depletion of KRAS would result in downregulation of kinases required for KRAS-mediated transformation and in upregulation of other kinases that could potentially compensate for the deleterious consequences of the loss of KRAS. We identified 15 upregulated and 13 downregulated kinases in common across the panel of cell lines. In agreement with our hypothesis, all 15 of the upregulated kinases have established roles as cancer drivers (e.g., SRC, TGF-β1, ILK), and pharmacological inhibition of one of these upregulated kinases, DDR1, suppressed PDAC growth. Interestingly, 11 of the 13 downregulated kinases have established driver roles in cell cycle progression, particularly in mitosis (e.g., WEE1, Aurora A, PLK1). Consistent with a crucial role for the downregulated kinases in promoting KRAS-driven proliferation, we found that pharmacological inhibition of WEE1 also suppressed PDAC growth. The unexpected paradoxical activation of ERK upon WEE1 inhibition led us to inhibit both WEE1 and ERK concurrently, which caused further potent growth suppression and enhanced apoptotic death compared with WEE1 inhibition alone. We conclude that system-wide delineation of the KRAS-regulated kinome can identify potential therapeutic targets for KRAS-mutant pancreatic cancer.     

Differential detection of genetic Loci underlying stem and root lignin content in Populus

In this study, we established a comprehensive genetic map with a large number of progeny from a three-generation hybrid Populus intercross, and phenotyped the lignin content, S/G ratio and 28 cell wall subcomponents both in stems and roots for the mapping individuals. Phenotypic analysis revealed that lignin content and syringyl-to-guaiacyl (S/G) ratio using pyrolysis molecular beam mass spectroscopy (pyMBMS) varied among mapping individuals. Phenotypic analysis revealed that stem lignin content is significantly higher than that in root and the quantified traits can be classified into four distinct groups, with strong correlations observed among components within organs. Altogether, 179 coordinating QTLs were detected, and they were co-localized into 49 genetic loci, 27 of which appear to be pleiotropic. Many of the detected genetic loci were detected differentially in stem and root. This is the first report of separate genetic loci controlling cell wall phenotypes above and below ground. These results suggest that it may be possible to modify lignin content and composition via breed and/or engineer as a means of simultaneously improving Populus for cellulosic ethanol production and carbon sequestration.     

Antiapoptotic effects of vitamins C and E against cypermethrin‐induced oxidative stress and spermatogonial germ cell apoptosis

Toxicological studies have demonstrated the relation between use of agrochemicals and fertility issues within males. Thus, the present study aimed to elucidate the propensity of cypermethrin (CYP) in bringing testicular germ cell apoptosis and effective attenuation by vitamins C and E in caprines. Reproductive toxicity of CYP was evaluated using histomorphological, cytological, and biochemical changes in the testicular germ cells in dose‐dependent (1, 5, 10 μg/mL) and time‐dependent (4, 6, 8 h) manner. Histological and ethidium bromide/acridine orange fluorescence staining exhibited that vitamins C and E (0.5 and 1.0 mM) successfully diminished the CYP‐induced testicular germ cells apoptosis. CYP exposure along with vitamins C and E supplementation also resulted in significantly increased ferric reducing antioxidant power activity along with the antioxidant enzymes, namely catalase, superoxide dismutase, and glutathione‐s‐transferase, and decreased lipid peroxidation in testicular germ cells. Thus, vitamins C and E ameliorated CYP‐induced testicular germ cell apoptosis, thereby preventing spermatogonial cells degeneration and male infertility.     

Differentially Expressed Peroxidases from <Emphasis Type="Italic">Artemisia annua</Emphasis> and Their Responses to Various Abiotic Stresses

Artemisia annua is well-known for producing the antimalarial phytomolecule, artemisinin. The role of peroxidases has been hypothesized in artemisinin metabolism owing to the presence of an –O–O– linkage in this sesquiterpene lactone. Earlier, using a microarray, we identified differentially expressed genes, including peroxidases, in plant growth stages having contrasting artemisinin content. Here, three peroxidases—Aa547, having higher expression in low-artemisinin stage, and Aa540 and Aa528, having higher expression in high artemisinin stage, which could be associated with trichomes on the basis of their approximate gene expression pattern inferred from EST counts in UniGene—were selected for full-length cloning, tissue-specific expression profiling, and in silico analyses. The upstream genomic region of Aa547 was cloned and various cis-regulatory elements were identified. All the three candidates were predicted to be class III plant peroxidases. Further, this study aimed to check the responsiveness of the logically selected peroxidase genes to various abiotic stress factors. Taking cues from previous reports and the regulatory elements observed in the Aa547 promoter, hydration, salinity, temperature, salicylic acid, hydrogen peroxide, and methyl jasmonate, were selected to study their effect on the expression of the peroxidase genes through qRT-PCR. The peroxidases were found to be highly sensitive to the various factors but differed in their responses. Broadly, except for responses to high temperature and salicylic acid, the response of Aa547 to various factors was distinct from that of Aa540 and Aa528, which was in line with its distinctness from the other two peroxidases, considering the in planta artemisinin content and predicted structural features.     

Predicting cross-reactive immunological material (CRIM) status in Pompe disease using GAA mutations: lessons learned from 10 years of clinical laboratory testing experience

Enzyme replacement therapy (ERT) for Pompe disease using recombinant acid alpha-glucosidase (rhGAA) has resulted in increased survival although the clinical response is variable. Cross-reactive immunological material (CRIM)-negative status has been recognized as a poor prognostic factor. CRIM-negative patients make no GAA protein and develop sustained high antibody titers to ERT that render the treatment ineffective. Antibody titers are generally low for the majority of CRIM-positive patients and there is typically a better clinical outcome. Because immunomodulation has been found to be most effective in CRIM-negative patients prior to, or shortly after, initiation of ERT, knowledge of CRIM status is important before ERT is begun. We have analyzed 243 patients with infantile Pompe disease using a Western blot method for determining CRIM status and using cultured skin fibroblasts. Sixty-one out of 243 (25.1%) patients tested from various ethnic backgrounds were found to be CRIM-negative. We then correlated the CRIM results with GAA gene mutations where available (52 CRIM-negative and 88 CRIM-positive patients). We found that, in most cases, CRIM status can be predicted from GAA mutations, potentially circumventing the need for invasive skin biopsy and time wasted in culturing cells in the future. Continued studies in this area will help to increase the power of GAA gene mutations in predicting CRIM status as well as possibly identifying CRIM-positive patients who are at risk for developing high antibody titers.     

Non-peptide calcitonin gene-related peptide receptor antagonists from a benzodiazepinone lead

High-throughput screening of the Merck sample collection identified benzodiazepinone tetralin-spirohydantoin 1 as a CGRP receptor antagonist with micromolar activity. Comparing the structure of 1 with those of earlier peptide-based antagonists such as BIBN 4096 BS, a key hydrogen bond donor-acceptor pharmacophore was hypothesized. Subsequent structure activity studies supported this hypothesis and led to benzodiazepinone piperidinyldihydroquinazolinone 7, CGRP receptor K(i)=44nM and IC(50)=38nM. Compound 7 was orally bioavailabile in rats and is a lead in the development of orally bioavailable CGRP antagonists for the treatment of migraine.     

In silico discrimination of nsSNPs in hTERT gene by means of local DNA sequence context and regularity

Understanding and predicting the significance of novel genetic variants revealed by DNA sequencing is a major challenge to integrate and interpret in medical genetics with medical practice. Recent studies have afforded significant advances in characterization and predicting the association of single nucleotide polymorphisms in human TERT with various disorders, but the results remain inconclusive. In this context, a comparative study between disease causing and novel mutations in hTERT gene was performed computationally. Out of 59 missense mutations, five variants were predicted to be less stable with the most deleterious effect on hTERT gene by in silico tools, in which two mutations (L584W and M970T) were not previously reported to be involved in any of the human disorders. To get insight into the structural and functional impact due to the mutation, docking study and interaction analysis was performed followed by 6 ns molecular dynamics simulation. These results may provide new perspectives for the targeted drug discovery in the coming future.