Novel Inhibitors of Eukaryotic Elongation Factor 2 Kinase: In Silico, Synthesis, and in Vitro Studies

Eukaryotic elongation factor 2 kinase (eEF2K) is an unusual alpha kinase whose expression is highly upregulated in various cancers and contributes to tumor growth, metastasis, and progression. More importantly, expression of eEF2K is associated with poor clinical outcome and shorter patient survival triple negative breast cancer (TNBC). Therefore, eEF2K is an emerging molecular target for development of novel targeted therapeutics and precision medicine in solid cancers. However, currently potent, and specific inhibitors of eEF2K are not available for clinical translation. In the current study, we investigated the effects of various newly designed and synthesized a series of compounds with coumarin scaffold substitutions in inhibiting eEF2K activity using in silico approaches and in vitro studies in TNBC cells. We utilized an amide substitution at 3-position on the coumarin ring with their pharmacologically active groups containing pyrrolidine, piperidine, morpholine and piperazine groups with –(CH2)2– bridged for aliphatic amides. To evaluate substituent effects on coumarin scaffold, boronic acid pinacol ester and boronic acids on phenyl rings were investigated using in silico and in vitro analyses. Due to their ability to form covalent binding to the target enzyme, we investigated the effects of boron containing groups on functionalized coumarin ring (3 compounds) and designed novel aliphatic and aromatic derivatives of coumarin scaffolds (10 compounds) and phenyl ring with boron groups (4 compounds). In silico analysis and molecular docking studies were performed using the Glide/SP module of Maestro molecular modeling package. According to obtained results, structure activity relationship (SAR) was carried out. Among the newly designed, synthesized, and tested compounds, our in vitro findings revealed that several compounds displayed a highly effective eEF2K inhibition at submicromolar concentration in in vitro breast cancer cells. In conclusion, we identified novel eEF2K inhibitors as promising anticancer drug substance candidates which should be further evaluated by in vivo studies, preclinical and clinical studies.<br /

Antiproliferative activity of <i>Humulus lupulus</i> extracts on human hepatoma (Hep3B), colon (HT-29) cancer cells and proteases, tyrosinase, <i>β</i>-lactamase enzyme inhibition studies

<div><p></p><p>The aims of this study were to examine the antiproliferation of <i>Humulus lupulus</i> extracts on human hepatoma carcinoma (Hep3B) and human colon carcinoma (HT-29) cell lines along with enzyme inhibitory effects of the crude extracts. Potential cell cytotoxicity of six different <i>H. lupulus</i> extracts were assayed on various cancer cells using MTT assay at 24, 48 and 72 h intervals. Methanol-1 extract has inhibited the cell proliferation with doses of 0.6–1 mg/mL in a time dependent (48 and 72 hours) manner in Hep3B cells with 70% inhibition, while inhibitory effect was not seen in colon cancer cells. Acetone extract has increased the cell proliferation at low doses of 0.1 mg/mL for 72 h in Hep3B cells and 0.1–0.2 mg/mL for 48 and 72 h in HT29 cells. The inhibitory effects of the extracts were compared by relative maximum activity values (<i>V</i>_max) using proteases such as <i>α</i>-chymotrypsin, trypsin and papain, tyrosinase and <i>β</i>-lactamase (penicillinase).</p></div