Tuning spacer length improves the functionality of the nanobody-based VEGFR2 CAR T cell.

BACKGROUND: The chimeric antigen receptor-expressing T (CAR-T) cells for cancer immunotherapy have obtained considerable clinical importance. CAR T cells need an optimized intracellular signaling domain to get appropriately activated and also for the proper antigen recognition, the length and composition of the extracellular spacer are critical factors. RESULTS: We constructed two third-generation nanobody-based VEGFR2-CARs containing either IgG1 hinge-CH2-CH3 region or hinge-only as long or short extracellular spacers, respectively. Both CARs also contained intracellular activating domains of CD28, OX40, and CD3ζ. The T cells from healthy individuals were transduced efficiently with the two CARs, and showed increased secretion of IL-2 and IFN-γ cytokines, and also CD69 and CD25 activation markers along with cytolytic activity after encountering VEGFR2+ cells. The VEGFR2-CAR T cells harboring the long spacer showed higher cytokine release and CD69 and CD25 expression in addition to a more efficient cytolytic effect on VEGFR2+ target cells. CONCLUSIONS: The results demonstrated that the third-generation anti-VEGFR2 nanobody-based CAR T cell with a long spacer had a superior function and potentially could be a better candidate for solid tumor treatment.

Interleukin-1 receptor accessory protein (IL-1RAP): A magic bullet candidate for immunotherapy of human malignancies.

IL-1, plays a role in some pathological inflammatory conditions. This pro-inflammatory cytokine also has a crucial role in tumorigenesis and immune responses in the tumor microenvironment (TME). IL-1 receptor accessory protein (IL-1RAP), combined with IL-1 receptor-1, provides a functional complex for binding and signaling. In addition to the direct role of IL-1, some studies demonstrated that IL1-RAP has essential roles in the progression, angiogenesis, and metastasis of solid tumors such as gastrointestinal tumors, lung carcinoma, glioma, breast and cervical cancers. This molecule also interacts with FLT-3 and c-Kit tyrosine kinases and is involved in the pathogenesis of hematological malignancies such as acute myeloid lymphoma. Additionally, IL-1RAP interacts with solute carrier family 3 member 2 (SLC3A2) and thereby increasing the resistance to anoikis and metastasis in Ewing sarcoma. This review summarizes the role of IL-1RAP in different types of cancers and discusses its targeting as a novel therapeutic approach for malignancies.

Antitumor activities of a novel fluorinated small molecule (A1) in CT26 colorectal cancer cells: molecular docking and in vitro studies.

Chemotherapeutic treatment of colorectal cancer (CRC) has not been satisfactory until now; therefore, the discovery of more efficient medications is of great significance. Based on available knowledge, the CXCL12/CXCR4 axis plays a significant role in tumorigenesis, and inhibition of CXCR4 chemokine receptor with AMD3100 is one of the most known therapeutic modalities in cancer therapy. Herein, N, N''-thiocarbonylbis(N'-(3,4-dimethylphenyl)-2,2,2-trifluoroacetimidamide) (A1) was synthesized as a potent CXCR4 inhibitor. A1 inhibitory activity was first evaluated employing Molecular Docking simulations in comparison with the most potent CXCR4 inhibitors. Then, the antiproliferative and cytotoxic effect of A1 on CT26 mouse CRC cells was investigated by MTT assay technique and compared with those of the control molecule, AMD3100. The impact of the target compounds IC50 on apoptosis, cell cycle arrest, and CXCR4 expression was determined by flow cytometry technique. Our finding demonstrated that A1 induces a cytotoxic effect on CT26 cells at 60 µg/mL concentration within 72 h and provokes cell apoptosis and G2/M cell cycle arrest in comparison with the untreated cells, while AMD3100 did not show a cytotoxic effect up to 800 µg/mL dose. The obtained results show that A1 (at a concentration of 40 µg/mL) significantly reduced the proliferation of CT26 cells treated with 100 ng/mL of CXCL12 in 72 h. Moreover, treatment with 60 µg/mL of A1 and 100 ng/mL of CXCL12 for 72 h significantly decreased the number of cells expressing the CXCR4 receptor compared to the control group treated with CXCL12. Eventually, the obtained results indicate that A1, as a dual-function fluorinated small molecule, may benefit CRC treatment through inhibition of CXCR4 and exert a cytotoxic effect on tumor cells.Communicated by Ramaswamy H. Sarma.

Human IL-2Rɑ subunit binding modulation of IL-2 through a decline in electrostatic interactions: A computational and experimental approach.

Although high-dose IL-2 has clear antitumor effects, severe side effects like severe toxicity and activation of Tregs by binding of IL-2 to high-affinity IL-2R, hypotension, and vascular leak syndrome limit its applications as a therapeutic antitumor agent. Here in this study, a rational computational approach was employed to develop and design novel triple-mutant IL-2 variants with the aim of improving IL-2-based immunotherapy. The affinity of the mutants towards IL-2Rα was further computed with the aid of molecular dynamic simulations and umbrella sampling techniques and the obtained results were compared to those of wild-type IL-2. In vitro experiments by flow cytometry showed that the anti-CD25 mAb was able to bind to PBMC cells even after mutant 2 preincubation, however, the binding strength of the mutant to α-subunit was less than of wtIL-2. Additionally, reduction of IL-2Rα subunit affinity did not significantly disturb IL-2/IL2Rßγc subunits interactions.

Identification of a New Isoindole-2-yl Scaffold as a Qo and Qi Dual Inhibitor of Cytochrome bc 1 Complex: Virtual Screening, Synthesis, and Biochemical Assay.

Respiratory chain ubiquinol-cytochrome (cyt) c oxidoreductase (cyt bc 1 or complex III) has been demonstrated as a promising target for numerous antibiotics and fungicide applications. In this study, a virtual screening of NCI diversity database was carried out in order to find novel Qo/Qi cyt bc 1 complex inhibitors. Structure-based virtual screening and molecular docking methodology were employed to further screen compounds with inhibition activity against cyt bc 1 complex after extensive reliability validation protocol with cross-docking method and identification of the best score functions. Subsequently, the application of rational filtering procedure over the target database resulted in the elucidation of a novel class of cyt bc 1 complex potent inhibitors with comparable binding energies and biological activities to those of the standard inhibitor, antimycin.

Structure-Based Virtual Screening for Defeating Drug Resistant Form of EGFR Protein.

Epidermal growth factor receptor (EGFR) is a tyrosine kinase with a key role in cell proliferation, death and differentiation. Mutations in EGFR, including substitution of Thr790 by methionine and Leu858 by arginine (T790M/L858R), lead to a lung cancer that is resistant against first generation inhibitors. In fact, second generation inhibitors were developed, but they proved to have had severe side effects because of the significant potency to suppress the wild type protein just as much. To resolve the problem, a step-by-step rational virtual screening was employed over almost sixty million compounds of PubChem Compound Database to filter out selective inhibitor(s) of T790M/L858R subtype. Consequently, the compound CID 133077 was observed, an active metabolite of Axitirome and also a cholesterol lowering prodrug. Selecting this compound can be explained by the oxamic acid part of molecule. Hence, administration of Axitirome or other compounds which contain oxamic acid is suggested in cases with EGFR T790M/L858R drug resistance.

Molecular perception of interactions between bis(7)tacrine and cystamine-tacrine dimer with cholinesterases as the promising proposed agents for the treatment of Alzheimer's disease.

The infamous chronic neurodegenerative disease, Alzheimer's, that starts with short-term memory loss and eventually leads to gradual bodily function decline which has been attributed to the deficiency in brain neurotransmitters, acetylcholine, and butylcholine. As a matter of fact, design of compounds that can inhibit cholinesterases activities (acetylcholinesterase and butylcholinesterase) has been introduced as an efficient method to treat Alzheimer's. Among proposed compounds, bis(7)tacrine (B7T) is recognized as a noteworthy suppressor for Alzheimer's disease. Recently a new analog of B7T, cystamine-tacrine dimer is offered as an agent to detain Alzheimer's complications, even better than the parent compound. In this study, classical molecular dynamic simulations have been employed to take a closer look into the modes of interactions between the mentioned ligands and both cholinesterase enzymes. According to our obtained results, the structural differences in the target enzymes active sites result in different modes of interactions and inhibition potencies of the ligands against both enzymes. The obtained information can help to investigate those favorable fragments in the studied ligands skeletons that have raised the potency of the analog in comparison with the parent compound to design more potent multi target ligands to heal Alzheimer's disease.

Potent Human Telomerase Inhibitors: Molecular Dynamic Simulations, Multiple Pharmacophore-Based Virtual Screening, and Biochemical Assays.

Telomere maintenance is a universal cancer hallmark, and small molecules that disrupt telomere maintenance generally have anticancer properties. Since the vast majority of cancer cells utilize telomerase activity for telomere maintenance, the enzyme has been considered as an anticancer drug target. Recently, rational design of telomerase inhibitors was made possible by the determination of high resolution structures of the catalytic telomerase subunit from a beetle and subsequent molecular modeling of the human telomerase complex. A hybrid strategy including docking, pharmacophore-based virtual screening, and molecular dynamics simulations (MDS) were used to identify new human telomerase inhibitors. Docking methodology was applied to investigate the ssDNA telomeric sequence and two well-known human telomerase inhibitors' (BIBR1532 and MST-312) modes of interactions with hTERT TEN domain. Subsequently molecular dynamic simulations were performed to monitor and compare hTERT TEN domain, TEN-ssDNA, TEN-BIBR1532, TEN-MST-312, and TEN-ssDNA-BIBR1532 behavior in a dynamic environment. Pharmacophore models were generated considering the inhibitors manner in the TEN domain anchor site. These exploratory studies identified several new potent inhibitors whose IC50 values were generated experimentally in a low micromolar range with the aid of biochemical assays, including both the direct telomerase and the telomeric repeat amplification protocol (TRAP) assays. The results suggest that the current models of human telomerase are useful templates for rational inhibitor design.

Urease Inhibitory Activities of some Commonly Consumed Herbal Medicines.

Urease enzyme has a crucial role in the persistent habitation of Helicobacter pylori (H. pylori) that induces gastrointestinal diseases, in particular gastritis, duodenal, peptic ulcer, and gastric cancer. Plants have long been utilized as the biggest source of substances with medicinal properties from natural origin and therefore result in less toxicity and adverse side effects upon usage. 15 medicinal plant extracts were examined against Jack bean urease activity by Berthelot reaction. Each herb was extracted using 80% aqueous methanol. The more effective extracts were further tested and their IC50 values were determined. Three plant extracts including Ginkgo biloba, Rhus coriaria, and Matricaria inodora were found to be the most effective ones with IC50 values of 36.17, 80.29, and 100.6 µg/mL, respectively.

Large scale screening of commonly used Iranian traditional medicinal plants against urease activity.

BACKGROUND AND PURPOSE OF THE STUDY: H. pylori infection is an important etiologic impetus usually leading to gastric disease and urease enzyme is the most crucial role is to protect the bacteria in the acidic environment of the stomach. Then urease inhibitors would increase sensitivity of the bacteria in acidic medium. METHODS: 137 Iranian traditional medicinal plants were examined against Jack bean urease activity by Berthelot reaction. Each herb was extracted using 50% aqueous methanol. The more effective extracts were further tested and their IC50 values were determined. RESULTS: 37 plants out of the 137 crude extracts revealed strong urease inhibitory activity (more than 70% inhibition against urease activity at 10 mg/ml concentration). Nine of the whole studied plants crude extracts were found as the most effective with IC50 values less than 500 µg/ml including; Rheum ribes, Sambucus ebulus, Pistachia lentiscus, Myrtus communis, Areca catechu, Citrus aurantifolia, Myristica fragrans, Cinnamomum zeylanicum and Nicotiana tabacum. CONCLUSIONS: The most potent urease inhibitory was observed for Sambucus ebulus and Rheum ribes extracts with IC50 values of 57 and 92 µg/ml, respectively.

A theoretical study on interactions between mitoxantrone as an anticancer drug and DNA: application in drug design.

This research is an effort to further understand the physicochemical interaction between the novel drug, mitoxantrone (MTX) and its biologic receptor, DNA. The ultimate goal is to design drugs that interact more with DNA. Understanding the physicochemical properties of the drug as well as the mechanism by which it interacts with DNA, it should ultimately allow the rational design of novel anti-cancer or anti-viral drugs. Molecular modelling on the complex formed between MTX and DNA presented that this complex was indeed fully capable of participating in the formation of a stable intercalation site. Furthermore, the molecular geometries of MTX and the DNA bases (adenine, guanine, cytosine and thymine) were optimized with the aid of the B3LYP/6-31G* method. The properties of the isolated intercalator and its stacking interactions with the adenine...thymine (AT) and guanine...cytosine (GC) nucleic acid base pairs were studied with the DFTB method (density functional tight-binding), an approximate version of the DFT method, that was extended to cover the London dispersion energy. The B3LYP/6-31G* stabilization energies of the intercalator...base pair complexes were found 10.06 kcal/mol and 21.64 kcal/mol for AT...MTX and GC...MTX, respectively. It was concluded that the dispersion energy and the electrostatic interaction contributed to the stability of the intercalator.DNA base pair complexes. The results concluded from the comparison of the DFTB method and the Hartree-fock method point out that these methods show close results and support each other.