Design, synthesis and biological evaluation of pteridine-7(8H)-one derivatives as potent and selective CDK4/6 inhibitors

Novel indolyl 1,2,4-triazole derivatives as potential anti-proliferative agents: in silico studies, synthesis, and biological evaluation

A new series of indolyl 1,2,4-triazole scaffolds was designed, synthesised, and biologically evaluated for their inhibitory activity against both CDK4 and CDK6. The results ranged from 0.049 μM to 3.031 μM on CDK4 and from 0.075 μM to 1.11 μM on CDK6 when compared to staurosporine, with IC50 values of 1.027 and 0.402 μM, respectively. Moreover, all compounds were tested for their cytotoxicity against two breast cancer cell lines, MCF-7 and MDA-MB-231. All of the synthesised compounds showed promising anti-proliferative activity, with two compounds Vf (IC50 = 2.91 and 1.914 μM, respectively) and Vg (IC50 = 0.891 and 3.479 μM, respectively) having potent cytotoxic activity in comparison to the reference staurosporine (IC50 = 3.144 and 4.385 μM, respectively). Vf and Vg were also found to significantly induce apoptosis to 45.33% and 37.26% (control = 1.91%) where Vf arrested the cell cycle at the S phase while Vg arrested the cycle at the G0/G1 phase. The binding mode and interactions of all compounds were studied and found to mimic those of the FDA approved CDK4/6 inhibitor palbociclib that was used as a reference throughout the study.

Recent Progress in CDK4/6 Inhibitors and PROTACs

Cell division in eukaryotes is a highly regulated process that is critical to the life of a cell. Dysregulated cell proliferation, often driven by anomalies in cell Cyclin-dependent kinase (CDK) activation, is a key pathological mechanism in cancer. Recently, selective CDK4/6 inhibitors have shown clinical success, particularly in treating advanced-stage estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. This review provides an in-depth analysis of the action mechanism and recent advancements in CDK4/6 inhibitors, categorizing them based on their structural characteristics and origins. Furthermore, it explores proteolysis targeting chimers (PROTACs) targeting CDK4/6. We hope that this review could be of benefit for further research on CDK4/6 inhibitors and PROTACs.

Quinazolinone derivatives as new potential CDK4/6 inhibitors, apoptosis inducers and radiosensitizers for breast cancer

Background: Targeting CDK4/6 has advanced breast cancer treatment. Herein, new quinazolinones were synthesized with acetamide linkers as potential anti-breast cancer agents. Methods & results: In vitro cytotoxic evaluation on human breast cancer cell lines (MCF7 and MDA-MB-231) identified 1,3-benzodioxole (5d) to be of the highest potency. It showed good inhibitory activity on CDK4/6. Compound 5d arrested the cell cycle at the G1-phase, caused induction of early and late apoptosis in an Annexin V-FITC assay, led to an increase in the level of caspase-3 and upregulated Bax expression and downregulated Bcl-2 in MCF7 cells. Compound 5d showed good radiosensitizing activity when combined with a single dose of 8-Gy γ-radiation. Conclusion: This study introduces quinazolinone scaffolds as new CDK4/6 inhibitors for breast cancer.