Discovery of Novel Isatin-Based p53 Inducers

Abstract

A series of isatin Schiff base derivatives were identified during in silico screening of the small molecule library for novel activators of p53. The compounds selected based on molecular docking results were further validated by a high-content screening assay using U2OS human osteosarcoma cells with an integrated EGFP-expressing p53-dependent reporter. The hit compounds activated and stabilized p53, as shown by Western blotting, at higher rates than the well-known positive control Nutlin-3. Thus, the p53-activating compounds identified by this approach represent useful molecular probes for various cancer studies.KEYWORDS: in silico, isatin Mannich and Schiff bases, p53 activators, in vivo assay, protein−protein interactions, MDM2

Novel isatin-derived molecules activate p53 via interference with Mdm2 to promote apoptosis

“…In the previous study [42] we reported an identification of a number of isatin-like p53-activating compounds (Fig. S1).…”

“…Recently, by means of molecular docking followed by in cellulo screening we uncovered that Isatin Schiff and Mannich based derivatives (ISMBDs) were able to activate p53 [42]. In line with this, Rana and colleagues have shown that isatin-derived spirocyclic a-methylene-g-butyrolactone can be used as a novel anticancer agent [43].…”

“…Isatin Mannich and Schiff Based derivatives were identified using virtual screening approach as described in our previous paper [42]. The Schrodinger Glide package was used for SM molecular docking studies in extra precision mode.…”

“…For the screening of small molecules U2-OS-pLV (p53+ and p53-) reporter cell lines were generated [42]. Briefly, episomal EBNA1-based vector that contains minimal HSP70 promoter with three minimal p53 binding sites inserted upstream of the start site ( Supplementary Fig.…”

“…All of them, despite their different structural properties, mimic the amino-terminal alpha-helix of p53 that binds Mdm2. Using this pharmacophore hypothesis (Figure 1(a)) we carried out a molecular docking of the in-house library of 38,000 compounds available from St. Petersburg Technological Institute combined with 1800 molecules from the diversity library set obtained from Interbioscreen (Chernogolovka, Russia) for novel molecules that bind the Mdm2 cleft [42].…”