Design, Synthesis and Molecular Modeling of Pyrazolo[1,5-a]pyrimidine Derivatives as Dual Inhibitors of CDK2 and TRKA...

The increasing prevalence of drug resistance in cancer therapy underscores the urgent need for novel therapeutic approaches. Dual enzyme inhibitors, targeting critical kinases such as CDK2 and TRKA, represent a promising strategy. The goal of this investigation was to design, synthesize, and evaluate a set of pyrazolo[1,5-a]pyrimidine derivatives for their dual inhibition potential toward CDK2 and TRKA kinases, along with their potential antiproliferative against cancer cell lines.

A set of pyrazolo[1,5-a]pyrimidine derivatives (6a-t, 11a-g, and 12) was synthesized and subjected to in vitro enzymatic assays to determine their inhibitory activity against CDK2 and TRKA kinases. Selected compounds were further assessed for antiproliferative effects across the set of 60 cell lines from the NCI, representing various human cancer types. Additionally, simulations of molecular docking were conducted to explore the modes of binding for the whole active compounds and compare them with known inhibitors.

Compounds 6t and 6s exhibited potent dual inhibitory activity, showing an IC₅₀ = 0.09 µM and 0.23 µM against CDK2, and 0.45 µM against TRKA, respectively. These results were comparable to reference inhibitors ribociclib (CDK2, IC₅₀ = 0.07 µM) and larotrectinib (TRKA, IC₅₀ = 0.07 µM). Among the studied derivatives, compound 6n displayed a notable broad-spectrum anticancer activity, achieving a mean growth inhibition (GI%) of 43.9% across 56 cell lines. Molecular docking simulations revealed that the synthesized compounds adopt modes of binding similar to those of the lead inhibitors. Conclusions: In this study, prepared pyrazolo[1,5-a]pyrimidine derivatives demonstrated significant potential as dual CDK2/TRKA inhibitors, and showed potent anticancer activity toward diverse cancer cell lines. These findings highlight their potential as key compounds for the design of novel anticancer therapeutics.