NRAS Mutant Dictates AHCYL1-Governed ER Calcium Homeostasis for Melanoma Tumor Growth.

Calcium homeostasis is critical for cell proliferation, and emerging evidence shows that cancer cells exhibit altered calcium signals to fulfill their need for proliferation. However, it remains unclear whether there are oncogene-specific calcium homeostasis regulations that can expose novel therapeutic targets. Here, from RNAi screen, we report that adenosylhomocysteinase like protein 1 (AHCYL1), a suppressor of the endoplasmic reticulum (ER) calcium channel protein inositol trisphosphate receptor (IP3R), is selectively upregulated and critical for cell proliferation and tumor growth potential of human NRAS-mutated melanoma, but not for melanoma expressing BRAF V600E. Mechanistically, AHCYL1 deficiency results in decreased ER calcium levels, activates the unfolded protein response (UPR), and triggers downstream apoptosis. In addition, we show that AHCYL1 transcription is regulated by activating transcription factor 2 (ATF2) in NRAS-mutated melanoma. Our work provides evidence for oncogene-specific calcium regulations and suggests AHCYL1 as a novel therapeutic target for RAS mutant-expressing human cancers, including melanoma. IMPLICATIONS: Our findings suggest that targeting the AHCYL1-IP3R axis presents a novel therapeutic approach for NRAS-mutated melanomas, with potential applicability to all cancers harboring RAS mutations, such as KRAS-mutated human colorectal cancers.

Discovery of Potent Antiallergic Agents Based on an o-Aminopyridinyl Alkynyl Scaffold.

Effective therapeutic agents are highly desired for immune-mediated allergic diseases. Herein, we report the design, synthesis, and structure-activity relationship of an o-aminopyridinyl alkyne series as novel orally bioavailable antiallergic agents, which was identified through phenotypic screening. Compound optimization yielded a highly potent compound 36, which effectively suppressed mast cell degranulation in a dose-dependent manner (IC50, 2.54 nM for RBL-2H3 cells; 48.28 nM for peritoneal mast cells (PMCs)) with a good therapeutic index. It also regulated the activation of FcεRI-mediated downstream signaling proteins in IgE/Ag-stimulated RBL-2H3 cells. In addition, 36 exhibited excellent in vivo pharmacokinetic properties and antiallergic efficacy in both passive systemic anaphylaxis (PSA) and house dust mite (HDM)-induced murine models of pulmonary allergic inflammation. Furthermore, preliminary analysis of the kinases profile identified Src-family kinases as potential targets for 36. Compound 36 may serve as a new valuable lead compound for future antiallergic drug discovery.

Discovery of selective HDAC/BRD4 dual inhibitors as epigenetic probes.

According to the binding mode of ABBV-744 with bromodomains and the cape space of HDAC, the novel selective HDAC/BRD4 dual inhibitors were designed and synthesized by the pharmacophore fusion strategy. Evaluating the biomolecular activities through SARs exploration identified three kinds of selective dual inhibitors 41c (HDAC1/BRD4), 43a (pan-HDAC/BRD4) and 43d (HDAC6/BRD4(BD2)), whose target-related cellular activities in MV-4-11 cells were also confirmed. Significantly, the selective dual inhibitor 41c (HDAC1/BRD4) exhibited synergistic effects against MV-4-11 cells, which strongly induced G0/G1 cell cycle arrest and apoptosis, and the first HDAC6/BRD4(BD2) dual inhibitor was found. This study provides support for selective HDAC/BRD4 dual inhibitors as epigenetic probes based on pyrrolopyridone core for the future biological evaluation in different cancer cell lines.

Adsorption and Gas Sensing Properties of the Pt3-MoSe2 Monolayer to SOF2 and SO2F2.

SF6 acts as an insulation gas in gas-insulated switchgear (GIS), which inevitably decomposes under partial discharge caused by insulation defects. This work is devoted to finding a new gas-sensing material for detecting two characteristic SF6 decomposition products: SOF2 and SO2F2. The platinum-cluster-modified molybdenum diselenide (Pt3-MoSe2) monolayer has been proposed as a gas sensing material. Based on first-principles calculations, the adsorption properties and the mechanism were studied by analyzing the adsorption structures, adsorption energy, charge transfer, density of states, and molecular orbitals. The adsorption ability of Pt3-MoSe2 to SO2F2 is stronger than that to SOF2 due to its chemisorption property. The obvious change of conductivity of the adsorption system during the gas adsorption process shows that Pt3-MoSe2 is sensitive to both of the gas molecules. In addition, the modest adsorption energy signifies that the gas adsorption process can be reversible, which confirms the feasibility of Pt3-MoSe2-based gas sensors. Our calculation suggests that Pt3-MoSe2-based gas sensors can be employed in GIS for partial discharge detection.

Novel Class of Colony-Stimulating Factor 1 Receptor Kinase Inhibitors Based on an o-Aminopyridyl Alkynyl Scaffold as Potential Treatment for Inflammatory Disorders.

Colony-stimulating factor 1 receptor (CSF-1R) is involved in inflammatory disorders as well as in many types of cancer. Based on high-throughput screening and docking results, we performed a detailed structure-activity-relationship study, leading to the discovery of a new series of compounds with nanomolar IC50 values against CSF-1R without the inhibition of fibroblast growth factor receptors. One of the most promising hits, compound 29, potently inhibited CSF-1R kinase with an IC50 value of 0.7 nM, while it showed no inhibition to the same family member FMS-like tyrosine kinase 3. Compound 29 displayed excellent anti-inflammatory effects against RAW264.7 macrophages indicated by significant inhibition against the activation of the CSF-1R pathway with low cytotoxicity. In addition, compound 29 exhibited strong in vivo anti-inflammatory efficacy alongside favorable drug characteristics. This novel compound 29 may serve as a new drug candidate with promising applications in inflammatory disorders.

S-oxiracetam ameliorates ischemic stroke induced neuronal apoptosis through up-regulating α7 nAChR and PI3K / Akt / GSK3ß signal pathway in rats.

Ischemic stroke, the main reason for severe disabilities in the world, is associated with a high incidence of sensorimotor and cognitive dysfunction. In this study, we use the middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and oxygen glucose deprivation/reoxygenation (OGD/R) model in fetal rat primary cortical neurons to investigate whether and how S-oxiracetam (S-ORC) protect brain injury from ischemic stroke. The results revealed that S-ORC reduced brain infarct size and lessened neurological dysfunction after stroke. Further study demonstrated that S-ORC diminished TUNEL positive cells, increased cell viability, decreased LDH activity, and inhibited cell apoptotic rate. Furthermore, S-ORC inhibited neuronal apoptosis by activating the PI3K/Akt/GSK3ß signaling pathway via α7 nAChR, which was evidenced by α7 nAChR siRNA. In conclusion, our findings strongly suggest that S-ORC could be used as an effective neuroprotective agent for ischemic stroke due to its effect in preventing neuronal apoptosis.