PIK3CA hotspot mutations p. H1047R and p. H1047L sensitize breast cancer cells to thymoquinone treatment by regulating the PI3K/Akt1 pathway

Background

Nigella sativa (N. sativa) exhibits anti-inflammatory, antioxidant, antidiabetic, antimetastatic and antinociceptive effects and has been used to treat dozens of diseases. Thymoquinone (TQ) is an important and active component isolated from N. sativa seeds. Inhibition of cancer-associated activating PIK3CA mutations is a new prospective targeted therapy in personalized metastatic breast cancer (MBC). TQ is reported to be an effective inhibitor of the PI3K/Akt1 pathway in MBC. This study aimed to evaluate the in vitro antitumor effect of TQ in the context of two PIK3CA hotspot mutations, p. H1047R and p. H1047L.

Methods and results

Molecular dynamics, free energy landscapes and principal component analyses were also used to survey the mechanistic effects of the p. H1047R and p. H1047L mutations on the PI3K/Akt1 pathway. Our findings clearly confirmed that the p. H1047R and p. H1047L mutants could reduce the inhibitory effect of ΔNp63α on the kinase domain of PIK3CA, resulting in increased activity of PI3K downstream signals. Structurally, the partial disruption of the interaction between the ΔNp63α DNA binding domain and the PIK3CA kinase domain at residues 114–359 and 797–1068 destabilizes the conformation of the activation loop and modifies the PIK3CA/ΔNp63α complex. Alongside these structural changes, we found that TQ treatment resulted in high PI3K/Akt1 pathway inhibition in p. H1047R and p. H1047L-expressing cells versus wild-type cells.

Conclusions

These two PIK3CA hotspot mutations therefore not only contribute to tumor progression in patients with MBC but may also serve as targets for the development of novel small molecule therapeutic strategies.

     

OCC-1D regulates Wnt signaling pathway: potential role of long noncoding RNA in colorectal cancer

Molecular Biology Reports - Aberrant activation of the Wnt signaling pathway is observed in most colorectal cancers (CRC). OCC-1D is a splice variant of OCC-1 gene which is considered as a long...     

Copper (II) complexes with N,S donor pyrazole-based ligands as anticancer agents

BioMetals - A group of bidentate nitrogen and sulfur donor pyrazole derivative ligands abbreviated as Na[RNCS(Pz)], Na[RNCS(PzMe2)], Na[RNCS(PzMe3)], Na[RNCS(PzPhMe)], Na[RNCS(PzPh2)], where...     

Techno-economical study of ethanol and biogas from spruce wood by NMMO-pretreatment and rapid fermentation and digestion

Given that N-methylmorpholine-N-oxide (NMMO) is a promising alternative for the pretreatment of lignocelluloses, a novel process for ethanol and biogas production from wood was developed. The solvent, NMMO, is concentrated by multistage evaporation, and the wood is pretreated with the concentrated NMMO. Thereafter, ethanol is produced by the non-isothermal simultaneous saccharification and fermentation (NSSF) method, which is a rapid and efficient process. The wastewater is treated by upflow anaerobic sludge blanket (UASB) digester for rapid production of biogas. The process was simulated by Aspen plus®. Using mechanical vapor recompression for evaporators in the pretreatment and multi-pressure distillation columns, the energy requirements for the process were minimized. The economical feasibility of the developed biorefinery for five different plant capacities was studied by Aspen Icarus Process Evaluator. The base case was designed to utilize 200,000 tons of spruce wood per year and required M€ 58.3 as the total capital investment, while the production cost of ethanol is calculated to be €/l 0.44.     

Evaluation of epithelial mesenchymal transition in patients with chronic obstructive pulmonary disease

Background

The reticular basement membrane (Rbm) in smokers and especially smokers with COPD is fragmented with "clefts" containing cells staining for the collagenase matrix-metalloproteinase-9 (MMP-9) and fibroblast protein, S100A4. These cells are also present in the basal epithelium. Such changes are likely hallmarks of epithelial mesenchymal transition (EMT). We aimed to confirm the epithelial origin of these Rbm cells, and to exclude potential confounding by infiltrating inflammatory cells.

Methods

Endobronchial biopsy sections from 17 COPD current smokers, with documented Rbm splitting and cellularity were stained for neutrophil elastase (neutrophil marker), CD68 (macrophage/mature fibroblasts), CD4+/CD8+ T lymphocytes, CD19 (B-cells), CD11c (dendritic cells/inflammatory cells), and S100 (Langerhans cells). The number of cells in the Rbm and epithelium staining for these "inflammatory" cell markers were then compared to numbers staining for S100A4, "a documented EMT epitope". Slides were double stained for S100A4 and cytokeratin(s).

Results

In the basal epithelium significantly more cells stained for S100A4 compared to infiltrating macrophages, fibroblasts or immune cells: median, 26 (21.3 - 37.3) versus 0 (0 - 9.6) per mm, p < 0.003. Markedly more S100A4 staining cells were also observed in the Rbm compared to infiltrating macrophages, neutrophils, fibroblasts or immune cells or any sub-type: 58 (37.3 - 92.6) versus 0 (0 - 4.8) cells/mm Rbm, p < 0.003. Cells in the basal epithelium 26 (21.3 - 37.3) per mm) and Rbm (5.9 (2.3 - 13.8) per mm) frequently double stained for both cytokeratin and S100A4.

Conclusions

These data provide additional support for active EMT in COPD airways.     

Proteome analysis of wheat leaf rust fungus, Puccinia triticina, infection structures enriched for haustoria

Puccinia triticina (Pt) is a representative of several cereal-infecting rust fungal pathogens of major economic importance world wide. Upon entry through leaf stomata, these fungi establish intracellular haustoria, crucial feeding structures. We report the first proteome of infection structures from parasitized wheat leaves, enriched for haustoria through filtration and sucrose density centrifugation. 2-D PAGE MS/MS and gel-based LC-MS (GeLC-MS) were used to separate proteins. Generated spectra were compared with a partial proteome predicted from a preliminary Pt genome and generated ESTs, to a comprehensive genome-predicted protein complement from the related wheat stem rust fungus, Puccinia graminis f. sp. tritici (Pgt) and to various plant resources. We identified over 260 fungal proteins, 16 of which matched peptides from Pgt. Based on bioinformatic analyses and/or the presence of a signal peptide, at least 50 proteins were predicted to be secreted. Among those, six have effector protein signatures, some are related and the respective genes of several seem to belong to clusters. Many ribosomal structural proteins, proteins involved in energy, general metabolism and transport were detected. Measuring gene expression over several life cycle stages of ten representative candidates using quantitative RT-PCR, all were shown to be strongly upregulated and four expressed solely upon infection.     

Discordance in diagnosis of osteoporosis using spine and hip bone densitometry

BACKGROUND: Diagnostic discordance for osteoporosis is the observation that the T-score of an individual patient varies from one key measurement site to another, falling into two different diagnostic categories identified by the World Health Organization (WHO) classification system. This study was conducted to evaluate the presence and risk factors for this phenomenon in a large sample of Iranian population. METHODS: Demographic data, anthropometric measurements, and risk factors for osteoporosis were derived from a database on 4229 patients referred to a community-based outpatient osteoporosis testing center from 2000 to 2003. Dual-energy X-ray absorptiometry (DXA) was performed on L1-L4 lumbar spine and total hip for all cases. Minor discordance was defined as present when the difference between two sites was no more than one WHO diagnostic class. Major discordance was present when one site is osteoporotic and the other is normal. Subjects with incomplete data were excluded. RESULTS: In 4188 participants (3848 female, mean age 53.4 +/- 11.8 years), major discordance, minor discordance, and concordance of T-scores were seen in 2.7%, 38.9% and 58.3%, respectively. In multivariate logistic regression analysis, older age, menopause, obesity, and belated menopause were recognized as risk factors and hormone replacement therapy as a protective factor against T-score discordance. CONCLUSION: The high prevalence of T-score discordance may lead to problems in interpretation of the densitometry results for some patients. This phenomenon should be regarded as a real and prevalent finding and physicians should develop a particular strategy approaching to these patients.