AKT- a key molecular regulator of PI-3K signaling pathway, is somatically mutated in diverse solid cancer types, and aberrant AKT activation promotes altered cancer cell growth, survival, and ...metabolism
. The most common of AKT mutations (AKT1 E17K) sensitizes affected solid tumors to AKT inhibitor therapy
. However, the pathway dependence and inhibitor sensitivity of the long tail of potentially activating mutations in AKT is poorly understood, limiting our ability to act clinically in prospectively characterized cancer patients. Here we show, through population-scale driver mutation discovery combined with functional, biological, and therapeutic studies that some but not all missense mutations activate downstream AKT effector pathways in a growth factor-independent manner and sensitize tumor cells to diverse AKT inhibitors. A distinct class of small in-frame duplications paralogous across AKT isoforms induce structural changes different than those of activating missense mutations, leading to a greater degree of membrane affinity, AKT activation, and cell proliferation as well as pathway dependence and hyper-sensitivity to ATP-competitive, but not allosteric AKT inhibitors. Assessing these mutations clinically, we conducted a phase II clinical trial testing the AKT inhibitor capivasertib (AZD5363) in patients with solid tumors harboring AKT alterations (NCT03310541). Twelve patients were enrolled, out of which six harbored AKT1-3 non-E17K mutations. The median progression free survival (PFS) of capivasertib therapy was 84 days (95% CI 50-not reached) with an objective response rate of 25% (n = 3 of 12) and clinical benefit rate of 42% (n = 5 of 12). Collectively, our data indicate that the degree and mechanism of activation of oncogenic AKT mutants vary, thereby dictating allele-specific pharmacological sensitivities to AKT inhibition.
Despite significant advances in cancer precision medicine, a significant hurdle to its broader adoption remains the multitude of variants of unknown significance identified by clinical tumor ...sequencing and the lack of biologically validated methods to distinguish between functional and benign variants. Here we used functional data on
and
mutations generated in real-time within a co-clinical trial framework to benchmark the predictive value of a three-part
methodology. Our computational approach to variant classification incorporated hotspot analysis, three-dimensional molecular dynamics simulation, and sequence paralogy.
prediction accurately distinguished functional from benign
and
mutants, yet drug sensitivity varied widely among activating mutant alleles. These results suggest that multifaceted
modeling can inform patient accrual to MEK/ERK inhibitor clinical trials, but computational methods need to be paired with laboratory- and clinic-based efforts designed to unravel variabilities in drug response. SIGNIFICANCE: Leveraging prospective functional characterization of MEK1/2 mutants, it was found that hotspot analysis, molecular dynamics simulation, and sequence paralogy are complementary tools that can robustly prioritize variants for biologic, therapeutic, and clinical validation.
.
mutations define a subset of metastatic breast cancers with a unique mechanism of oncogenic addiction to HER2 signaling. We explored activity of the irreversible pan-HER kinase inhibitor neratinib, ...alone or with fulvestrant, in 81 patients with
-mutant metastatic breast cancer. Overall response rate was similar with or without estrogen receptor (ER) blockade. By comparison, progression-free survival and duration of response appeared longer in ER
patients receiving combination therapy, although the study was not designed for direct comparison. Preexistent concurrent activating
or
alterations were associated with poor treatment outcome. Similarly, acquisition of multiple
-activating events, as well as gatekeeper alterations, were observed at disease progression in a high proportion of patients deriving clinical benefit from neratinib. Collectively, these data define
mutations as a therapeutic target in breast cancer and suggest that coexistence of additional HER signaling alterations may promote both
and acquired resistance to neratinib. SIGNIFICANCE:
mutations define a targetable breast cancer subset, although sensitivity to irreversible HER kinase inhibition appears to be modified by the presence of concurrent activating genomic events in the pathway. These findings have implications for potential future combinatorial approaches and broader therapeutic development for this genomically defined subset of breast cancer.
.
Altered expression of XPO1, the main nuclear export receptor in eukaryotic cells, has been observed in cancer, and XPO1 has been a focus of anticancer drug development. However, mechanistic evidence ...for cancer-specific alterations in XPO1 function is lacking. Here, genomic analysis of 42,793 cancers identified recurrent and previously unrecognized mutational hotspots in
XPO1 mutations exhibited striking lineage specificity, with enrichment in a variety of B-cell malignancies, and introduction of single amino acid substitutions in XPO1 initiated clonal, B-cell malignancy
. Proteomic characterization identified that mutant XPO1 altered the nucleocytoplasmic distribution of hundreds of proteins in a sequence-specific manner that promoted oncogenesis. XPO1 mutations preferentially sensitized cells to inhibitors of nuclear export, providing a biomarker of response to this family of drugs. These data reveal a new class of oncogenic alteration based on change-of-function mutations in nuclear export signal recognition and identify therapeutic targets based on altered nucleocytoplasmic trafficking. SIGNIFICANCE: Here, we identify that heterozygous mutations in the main nuclear exporter in eukaryotic cells, XPO1, are positively selected in cancer and promote the initiation of clonal B-cell malignancies. XPO1 mutations alter nuclear export signal recognition in a sequence-specific manner and sensitize cells to compounds in clinical development inhibiting XPO1 function.
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•Screen-printed carbon electrodes were modified for detecting bacterial endotoxins.•Molecular imprinting was used to prepare the modified interfaces.•Biosensors specifically detected ...lipopolysaccharides from Pseudomonas Aeruginosa.•Lipopolysaccharides retention switched on the electrochemical behavior of the biosensors.
In the context of global issues concerning pathogen contamination of surface and ground waters, this pioneering study describes the fabrication of screen-printed carbon electrodes modified with polymers molecularly imprinted with lipopolysaccharide in an attempt to detect endotoxins derived from specific Gram-negative bacteria. The biosensors detected lipopolysaccharides derived from Pseudomonas Aeruginosa with high specificity, relative to control sensors, while the response to the same endotoxin derived from Escherichia coli was quite different.
In this study, ligand-free nanogels (LFNGs) as potential antivenom mimics were developed with the aim of preventing hypersensitivity and other side effects following massive bee attacks. For this ...purpose, poly (ethylene glycol) diacrylate was chosen as a main synthetic biocompatible matrix to prepare the experimental LFNGs. The overall concept uses inverse mini-emulsion polymerization as the main route to deliver nanogel caps with complementary cavities for phospholipase A2 (PLA2) from bee venom, created artificially with the use of molecular imprinting (MI) technologies. The morphology and the hydrodynamic features of the nanogels were confirmed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis. The following rebinding experiments evidenced the specificity of molecularly imprinted LFNG for PLA2, with rebinding capacities up to 8-fold higher compared to the reference non-imprinted nanogel, while the in vitro binding assays of PLA2 from commercial bee venom indicated that such synthetic nanogels are able to recognize and retain the targeted PLA2 enzyme. The results were finally collaborated with in vitro cell-viability experiments and resulted in a strong belief that such LFNG may actually be used for future therapies against bee envenomation.
This study presents the formulation and application of strippable coatings for the entrapment and removal of heavy metals (HMs) and radio nuclides (RNs). The “green” formulations involve the use of a ...water-based solution consisting of a synthetic biodegradable polymer, polyvinyl alcohol (PVA), together with a natural polymer (sodium alginate) as the polymer matrix and bentonite as the reinforcing agent with cation exchange capacity. Four chelating agents comprising two classical chelating agents (ethylenediaminetetraacetic acid (EDTA), diethylenetriamine-pentaacetic acid (DPTA)) and two “green” chelating agents (iminodisuccinic acid (IDS), 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC)) were used to evaluate the capacity to remove Cu, Sb, Zn, Sr, Pb, Co, and Hg from the contaminated surfaces. This decontamination method leads to the formation of a solid waste, thus eliminating the need for wastewater treatment. Atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), and ultraviolet-visible (UV–Vis) spectroscopy were used to comparatively evaluate the decontamination efficacy. EDX elemental mapping confirmed the entrapment of the contaminants inside the polymeric matrix.
Cross-linguistic influence (CLI) refers to the linguistic influence of one of a bilingual's languages while processing the other. Researchers have debated whether CLI is better explained by the ...structure of bilinguals' two languages or by a combination of processing demands and structure. In this study, we test if Welsh–English bilingual children manifest CLI when producing adjectival constructions. Welsh adjectives typically appear postnominally, English adjectives typically appear prenominally. Since these structures do not overlap, there may be no CLI. If, however, CLI is a result of competition between languages, children's adjectival constructions may be reversed in both languages. We elicited adjectival constructions from Welsh–English bilingual children and English monolingual children between three and six years of age. The bilingual children produced more reversals than monolinguals and equivalent rates of reversals in both languages. In other words, the results support an interpretation of CLI resulting, at least in part, from processing demands.
Skin infections are frequently treated via intravenous or oral administration of antibiotics, which can lead to serious adverse effects and may sometimes contribute to the proliferation of resistant ...bacterial strains. Skin represents a convenient pathway for delivering therapeutic compounds, ensured by the high number of blood vessels and amount of lymphatic fluids in the cutaneous tissues, which are systematically connected to the rest of the body. This study provides a novel, straightforward method to obtain nafcillin-loaded photocrosslinkable nanocomposite hydrogels and demonstrates their performance as drug carriers and antimicrobial efficacy against Gram-positive bacteria. The novel formulations obtained, based on polyvinylpyrrolidone, tri(ethylene glycol) divinyl ether crosslinker, hydrophilic bentonite nanoclay, and/or two types of photoactive (TiO
and ZnO) nanofillers, were characterized using various analytical methods (transmission electron microscopy (TEM), scanning electron microscopy-energy-dispersive X-ray analysis (SEM-EDX), mechanical tests (tension, compression, and shear), ultraviolet-visible spectroscopy (UV-Vis), swelling investigations, and via specific microbiological assays ("agar disc diffusion method" and "time-kill test"). The results reveal that the nanocomposite hydrogel possessed high mechanical resistance, good swelling abilities, and good antimicrobial activity, demonstrating a decrease in the bacteria growth between 3log
and 2log
after one hour of direct contact with
In this work, hybrid hydrogels based on bacterial cellulose (BC) and poly (ethylene glycol) diacrylate (PEGDA) were synthesized by a radical polymerization reaction using a redox initiator system. ...The proposed interpenetrating networks (IPNs) were intended for developing a controlled release micro-vesicular system for wound therapy, through micro-colloidal architectures of hydrogels based on bacterial cellulose. Therefore, the hybrid hydrogels were first characterized to determine the influence of the BC concentration on the swelling degree and their mechanical stability. Further on, infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA/DTG), and scanning electron microscopy (SEM) were implemented to investigate their structure, composition, thermal stability, and morphology. The controlled release assay of cephalexin (CEX) was performed in buffer solution at pH 7.4 and 37 °C using CEX-loaded hydrogels and the release profiles were deciphered with the aid of UV–Visible spectroscopy. Cytotoxicity tests performed on simple and CEX-loaded samples indicated that the BC-PEGDA hydrogels containing the drug of interest were relatively non-toxic when exposed to murine fibroblasts, representing thus a potential candidate for materials used for wound treatment.
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