Benzimidazole derivatives as tubulin polymerization inhibitors: Design, synthesis and in vitro cytotoxicity studies.

A new class of benzimidazole derivatives as tubulin polymerization inhibitors has been designed and synthesized in this study. The in vitro anticancer profile of the developed molecules was reconnoitred on selected human cancer cells. The highest cytotoxicity was illustrated by compounds 7n and 7u with IC50 values ranging from 2.55 to 17.89 µM with specificity toward SK-Mel-28 cells. They displayed 5-fold less cytotoxicity towards normal rat kidney epithelial NRK52E cells, which implies that they are not harmful to normal, healthy cells. The cellular staining procedures like AO/EB, DCFDA, and DAPI were applied to comprehend the inherent mechanism of apoptosis which displayed nuclear and morphological alterations. The Annexin V binding and JC-1 studies were executed to evaluate the extent of apoptosis and the decline in mitochondrial transmembrane potential in SK-Mel-28 cell lines. Compound 7n dose-dependently arrested the G2/M phase of the cell cycle and the target-based outcomes proposed tubulin polymerization inhibition by 7n (IC50 of 5.05±0.13 µM). Computational studies were also conducted on the tubulin protein (PDB ID: 3E22) to investigate the stabilized binding interactions of compounds 7n and 7u with tubulin, respectively.

Unravelling KDM4 histone demethylase inhibitors for cancer therapy.

Epigenetic enzyme-targeted therapy is a promising new development in the field of drug discovery. To date, histone deacetylases and DNA methyltransferases have been investigated as druggable epigenetic enzyme targets in cancer therapeutics. Histone methyltransferases and lysine demethylase inhibitors are the latest groups of epi-drugs being actively studied in clinical trials. KDM4s are JmjC domain-containing histone H3 lysine 9/36 demethylase enzymes, belonging to the 2-OG-dependent oxygenases, which are upregulated in multiple malignancies. In the recent years, these enzymes have captured much attention as a novel target in cancer therapy. Herein, we traverse the discovery path and current challenges in designing potent KDM4 inhibitors as potential anticancer agents. We discuss the considerable efforts and proposed future strategies to develop selective small molecule inhibitors of KDM4s, highlighting scaffold candidates and cyclic skeletons for which activity data, selectivity profiles and structure-activity relationships (SARs) have been studied.