Recent Advances in Therapeutic Applications of Bisbenzimidazoles

Cancer-testis antigen CEP55 serves as a prognostic biomarker and is correlated with immune infiltration and immunotherapy efficacy in pan-cancer

Background: Centrosomal Protein 55 (CEP55) was initially described as a main participant in the final stage of cytokinesis. Further research identified CEP55 as a cancer-testis antigen (CTA) that is aberrantly expressed in different malignancies and a cancer vaccination candidate. The current study aimed to disclose the complete expression of CEP55, its effect on various malignancy prognoses, and its role in the tumor microenvironment. Methods: Transcriptional information regarding tumor and normal tissues, as well as externally validated and protein expression data were gathered from the Cancer Genome Atlas, Genotype-Tissue Expression project, Gene Expression Omnibus, and Human Protein Atlas. We examined the effect of CEP55 on tumor prognosis using Kaplan-Meier (KM) and univariate Cox regression analyses. In addition, we investigated the connections between CEP55 expression and hallmark cancer pathways, immune cell infiltration, and immune regulator expression across malignancies. We constructed and validated a CEP55-related risk model for hepatocellular carcinoma (HCC) and explored the correlations between CEP55 expression and HCC molecular subtypes. Finally, we investigated putative small-molecule drugs targeting CEP55 using a connectivity map (CMap) database and validated them using molecular docking analysis. Findings: CEP55 was aberrantly expressed in most cancers and revealed a prognostic value for several malignancies. Cancers with high CEP55 expression showed significantly enhanced cell cycle, proliferation, and immune-related pathways. For most malignancies, elevated CEP55 expression was associated with the infiltration of myeloid-derived suppressor cells (MDSCs) and Th2 cells. In addition, CEP55 expression was linked to immunomodulators and the potential prediction of immune checkpoint inhibitor (ICI) responses, and strongly associated with distinct molecular HCC subtypes, whereby the CEP55-based nomogram performed well in predicting short- and long-term HCC survival. Finally, we used connectivity map (CMap) and molecular docking analyses to discover three candidate small-molecule drugs that could directly bind to CEP55. Conclusion: CEP55 affected the occurrence and development of various cancers and possibly the regulation of the tumor immune microenvironment. Our findings suggest that CEP55 is a potential biomarker for prognosis and a powerful biomarker for ICI efficacy prediction.

Homo- and hetero-dinuclear Pt(II)/Pd(II) complexes: studies of hydrolysis, nucleophilic substitution reactions, DNA/BSA interactions, DFT calculations, molecular docking and cytotoxic activity

Three dinuclear complexes [Pd2(tpbd)Cl2]Cl2 (PP1), [Pt2(tpbd)Cl2]Cl2 (PP2) and [PdPt(tpbd)Cl2]Cl2 (PP3) (tpbd = N,N,N',N'-tetrakis(2-pyridylmethyl)benzene-1,4-diamine) have been synthesized and characterized and the protonation constants of their corresponding diaqua analogues have been determined. Also, in water solution, the aqua analogues of these complexes exist as mono-hydroxo, di-hydroxo and dimer μ-hydroxo complexes in the pH between 3.0 and 11.0. Substitution reactions with sulfur- and nitrogen-donor nucleophiles, such as thiourea (Tu), l-methionine (l-Met), glutathione (GSH) and guanosine-5'-monophosphate (5'-GMP), were studied at pH 7.2 by conventional and stopped-flow UV-Vis spectrophotometry and the observed reactivity follows the order: Tu > l-Met > GSH > 5'-GMP. Also, the interactions with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were investigated. Competitive studies with DNA were performed in the presence of ethidium bromide and Hoechst dye 33258 as well. The complexes possess the strong ability to react with CT-DNA exhibiting intercalation and more preferable minor groove binding. Nevertheless, all complexes showed a good binding affinity toward BSA with relatively high binding constants. The nature of the binding forces between complexes and biomolecules has been identified as hydrophobic. Experimental results were compared with the molecular docking results, while the relative stability and thermodynamic properties of dinuclear complexes were compared with their mononuclear units by DFT calculations. Among three tested complexes, PP2 showed the most powerful cytotoxic effect on HTB140 and H460 cancer cell lines after 48 h of treatment and exerted a strong long-term influence on the proliferation potential of both tested cell lines. PP2 induced the inhibition of autophagy, G2/M cell cycle arrest and mitotic catastrophe.

A facile approach synthesis of benzoylaryl benzimidazole as potential α-amylase and α-glucosidase inhibitor with antioxidant activity

Synthetic routes to a series of benzoylarylbenzimidazol 3a-h have been derived from 3,4-diaminobenzophenone and an appropriate arylaldehyde in the presence of ammonium chloride or a mixture of ammonium chloride and sodium metabisulfite as catalyst. The antioxidant activity of targeted compounds 3a-h has been measured by four different methods and the overall antioxidant evaluation of the compounds indicated the significant MCA, FRAP, and (DPPH-SA) of the compounds except for the compound 3h. In vitro antidiabetic assay of α-amylase and α-glucosidase suggest a good to excellent activity for most tested compounds. The target benzimidazole 3f containing hydroxyl motif at para-position of phenyl revealed an important activity inhibitor against α- amylase (IC₅₀ = 12.09 ± 0.38 µM) and α-glucosidase (IC₅₀ = 11.02 ± 0.04 µM) comparable to the reference drug acarbose. The results of the anti hyperglycemic activity were supported by means of in silico molecular docking calculations showing strong binding affinity of compounds 3a-h with human pancreatic α-amylase (HPA) and human lysosomal acid-α-glucosidase (HLAG) active sites that confirm a good to excellent activity for most of tested compounds.

Novel Bis- and Mono-Pyrrolo[2,3-d]pyrimidine and Purine Derivatives: Synthesis, Computational Analysis and Antiproliferative Evaluation

Novel symmetrical bis-pyrrolo[2,3-d]pyrimidines and bis-purines and their monomers were synthesized and evaluated for their antiproliferative activity in human lung adenocarcinoma (A549), cervical carcinoma (HeLa), ductal pancreatic adenocarcinoma (CFPAC-1) and metastatic colorectal adenocarcinoma (SW620) cells. The use of ultrasound irradiation as alternative energy input in Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) shortened the reaction time, increased the reaction efficiency and led to the formation of exclusively symmetric bis-heterocycles. DFT calculations showed that triazole formation is exceedingly exergonic and confirmed that the presence of Cu(I) ions is required to overcome high kinetic requirements and allow the reaction to proceed. The influence of various linkers and 6-substituted purine and regioisomeric 7-deazapurine on their cytostatic activity was revealed. Among all the evaluated compounds, the 4-chloropyrrolo[2,3-d]pyrimidine monomer 5f with 4,4′-bis(oxymethylene)biphenyl had the most pronounced, although not selective, growth-inhibitory effect on pancreatic adenocarcinoma (CFPAC-1) cells (IC₅₀ = 0.79 µM). Annexin V assay results revealed that its strong growth inhibitory activity against CFPAC-1 cells could be associated with induction of apoptosis and primary necrosis. Further structural optimization of bis-chloropyrrolo[2,3-d]pyrimidine with aromatic linker is required to develop novel efficient and non-toxic agent against pancreatic cancer.

Effects on anti-inflammatory, DNA binding and molecular docking properties of 2-chloroquinolin-3-yl-methylene-pyridine/pyrazole derivatives and their palladium(II) complexes

Two new sets of Schiff bases 2-chloroquinolin-3-yl-methylene-pyridin-2-amine (CMPA) and 2-chloroquinolin-3-yl-methylene-pyrazole-5-amine-3-thole (CMPT) and their respective palladium (II) complexes have been synthesised and characterized with the aid of elemental analysis, IR, ¹H &¹³C NMR, UV-Vis., and electrochemical studies. The surface morphology of palladium complexes were examined by Scanning Electron Microscopic image. The binding affinities of complexes with CT-DNA were carried out by absorption spectra and cyclic voltammetric studies. The observed hypochromic (~20%) and bathochromic (~30%) shifts indicates that the complexes bind with Guanine base pair of CT-DNA via intercalation. The increasing cathodic peak potential from +0.968 eV to +1.104 eV in complexes confirm the presence of intercalation. Anti-inflammatory activities of both ligands and complexes have been studied using carrageenan induced hind paw edema in Wistar rats. The change in paw volume revealed that the maximum percentage of inhibition was observed in metal complex at 5th hour with a dose of 200 mg/kg. In order to evaluate the binding affinity of ligand and metal complex, molecular interaction analysis were performed by maestro implemented in Schrodinger.