Fluorinated isoindolinone-amino acid hybrids possessing antiproliferative and antitumor activity in vitro and in vivo.

Abstract

The limited efficacy and resistance associated with current anticancer therapies necessitate the development of novel agent, particularly for aggressive malignancies. In this study, a series of fluorine-substituted isoindolinone-amino acid conjugates was designed and evaluated for antiproliferative activity using a phenotypic screening approach. A library of 24 compounds was screened against lung, breast and skin cancer cell lines, among which 11 derivatives demonstrated promising antiproliferative activity with IC50 values ranging from 7.36 to 41.99 µM. SAR analysis revealed that incorporation of trifluoromethoxy (-OCF3) substitution with Trp, Tyr, and Phe conjugation significantly enhances activity relative to trifluoromethyl (-CF3) and mono-fluoro analogues. The lead compounds 9c, 9d, 9e, and 10c markedly inhibited cancer cell proliferation, clonogenic survival, and migration, while inducing apoptosis and a pronounced S-phase cell-cycle arrest. Network pharmacology identified CDK2 and GSK3B as key hub genes associated with cell-cycle regulation. Mechanistic studies demonstrated downregulation of CDK2 and PCNA, activation of p53-p21 signaling pathway, and increased γ-H2AX expression, indicating replicating-associated damage. Molecular docking predicted favorable interactions with the CDK2 catalytic pocket, which was further validated by an in vitro CDK2/CyclinA2 kinase inhibition and reduced CDK2 protein expression determined by western blot analysis, collectively implicating CDK2 as a key molecular target. Furthermore, compounds 9c, 9d, 9e and 10c exhibited significant tumor growth inhibition (TGI) values of 53.50%, 79.47%, 64.50% and 69.14% respectively, in the 4T1 murine breast cancer model without evident systemic toxicity. Collectively, these findings identify fluorinated isoindolinone-amino acid conjugates as promising anticancer leads targeting CDK2-associated cell-cycle signaling against triple-negative breast cancer.