Identifying novel SMYD3 interactors on the trail of cancer hallmarks

SMYD3 overexpression in several human cancers highlights its crucial role in carcinogenesis. Nonetheless, SMYD3 specific activity in cancer development and progression is currently under debate. Taking advantage of a library of rare tripeptides, which we first tested for their in vitro binding affinity to SMYD3 and then used as in silico probes, we recently identified BRCA2, ATM, and CHK2 as direct SMYD3 interactors. To gain insight into novel SMYD3 cancer-related roles, here we performed a comprehensive in silico analysis to cluster all potential SMYD3-interacting proteins identified by screening the human proteome for the previously tested tripeptides, based on their involvement in cancer hallmarks. Remarkably, we identified mTOR, BLM, MET, AMPK, and p130 as new SMYD3 interactors implicated in cancer processes. Further studies are needed to characterize the functional mechanisms underlying these interactions. Still, these findings could be useful to devise novel therapeutic strategies based on the combined inhibition of SMYD3 and its newly identified molecular partners. Of note, our in silico methodology may be useful to search for unidentified interactors of other proteins of interest.

Design and synthesis of heterocyclic azole based bioactive compounds: Molecular structures, quantum simulation, and mechanistic studies through docking as multi-target inhibitors of SARS-CoV-2 and cytotoxicity

Two heterocyclic azole compounds, 3-(2,3-dihydrobenzo[d]thiazol-2-yl)-4H-chromen-4-one (SVS1) and 5-(1H-indol-3-yl)-4-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (SVS2) were obtained unexpectedly from 2-aminothiophenol and 4-oxo-4H-chromene-3-carbaldehyde (for SVS1), and (E)-2-((1H-indol-3-yl)methylene)-N-methylhydrazine-1-carbothioamide in the presence of anhydrous FeCl₃ (for SVS2), respectively. The compounds were well characterized by analytical and spectroscopic tools. The molecular structures of both the compounds were determined by single crystal X-ray diffraction (XRD) study. The results obtained from density functional theory (DFT) study revealed the molecular geometry and electron distribution of the compounds, which were correlated well with the three-dimensional structures obtained from the single crystal XRD. DMol³ was used to calculate quantum chemical parameters [chemical potential (µ), global hardness (η), global softness (σ), absolute electronegativity (χ) and electrophilicity index (ω)] of SVS1 and SVS2. Molecular docking study was performed to elucidate the binding ability of SVS1 and SVS2 with SARS-CoV-2 main protease and human angiotensin-converting enzyme-2 (ACE-2) molecular targets. Interestingly, the binding efficiency of the compounds with the molecular targets was comparable with that of remdesivir (SARS-CoV-2), chloroquine and hydroxychloroquine. SVS1 showed better docking energy than SVS2. The molecular docking study was complemented by molecular dynamics simulation study of SARS-CoV-2 main protease-SVS1 complex, which further exemplified the binding ability of SVS1 with the target. In addition, SVS1, SVS2 and cisplatin were assessed for their cytotoxicity against a panel of three human cancer cells such as HepG-2 (hepatic carcinoma), T24 (bladder) and EA.hy926 (endothelial), as well as Vero (kidney epithelial cells extracted from an African green monkey) normal cells using MTT assay. The results showed that SVS2 has significant cytotoxicity against HepG-2 and EA.hy926 cells with the IC₅₀ values of 33.8 μM (IC₅₀ = 49.9 μM-cisplatin and 8.6 μM-doxorubicin) and 29.2 (IC₅₀ = 26.6 μM-cisplatin and 3.8 μM-doxorubicin), respectively.

Photoredox-Catalyzed Cascade of o-Hydroxyarylenaminones to Access 3-Aminated Chromones

Reported herein is a photoredox-catalyzed amination of o-hydroxyarylenaminones with tert-butyl ((perfluoropyridin-4-yl)oxy)carbamate, a versatile amidyl-radical precursor developed in our laboratory. This work establishes a new cascade pathway for the assembly of a range of 3-aminochromones under mild conditions. Downstream transformations of the obtained 3-aminochromones to construct diverse amino pyrimidines greatly broaden the applications of this photocatalyzed protocol.

NHC-catalyzed green synthesis of functionalized chromones: DFT mechanistic insights and in vitro activities in cancer cells

A simple green protocol for the synthesis of 3-aminochromone derivatives using a NHC catalyzed intramolecular hydroacylation reaction was developed. Further functional 3-aminochromes were evaluated for their anticancer activity.

Copper-Catalyzed Diversity-Oriented Synthesis (DOS) of 4-Amino-2H-chromen-2-imines: Application of Kemp Elimination toward O-Heterocycles

We report herein a copper-catalyzed sequential multicomponent reaction of benzo[d]isoxazoles with terminal alkynes and sulfonyl azides, which produced divergent 4-amino-2H-chromen-2-imines with excellent chemical selectivity. The reaction tolerated a broad range of functional groups, and released only N₂ as the sole byproduct. The sulfonyl imino group could be removed to give biologically active free 4-amino-2H-chromenone in good yield.

Identification of a specific peptide binding to colon cancer cells from a phage-displayed peptide library

BACKGROUND

New molecular probes are essential for early colon cancer diagnosis. A phage-display screening was performed to select novel binding peptides for early colon cancer imaging detection.

METHODS

A human colon cancer cell line (COLO320HSR) and a normal human intestinal epithelial cell line (NCM460) were used for subtractive screening with a phage peptide library. The positive peptides were identified, and their binding capacities were confirmed by confocal immunofluorescence both in human colon cancer cells and in biopsy specimens. The sequences were further analysed for homology and the existing mimotopes by the BLAST algorithm and the MimoDB database.

RESULTS

A peptide termed as CBP-DWS, which was demonstrated to be capable of binding to a panel of human colon cancer cell lines and tissues, was identified; it had virtually no binding to normal human intestinal epithelial cell line NCM460 and normal surrounding colon tissues. Bioinformatics analyses suggest that CBP-DWS targets human Glypican-3, which may be involved in important cellular functions in multiple cancer types.

CONCLUSIONS

These studies suggest that the selected peptide CBP-DWS may be a candidate to serve as a novel probe for colon cancer imaging.

Protein/peptide secondary structural mimics: design, characterization, and modulation of protein–protein interactions

This review discusses general aspects of novel artificial peptide secondary structure mimics for modulation of PPIs, their therapeutic applications and future prospects.