Discovery of novel and potent PARP/PI3K dual inhibitors for the treatment of cancer.

PARP inhibitors have achieved great success in cancers with BRCA mutations, but only a small portion of patients carry BRCA mutations, which results in their narrow indication spectrum. Recently, emerging evidence has demonstrated that combinations of PARP and PI3K inhibitors could evoke unanticipated synergistic effects in various cancers, even including BRCA-proficient ones. In this work, a series of PARP/PI3K dual inhibitors were designed, synthesized, and evaluated for their biological activities. It was found that compounds 9a and 23a exhibited excellent inhibitory activities against PARP-1 (9a: IC50 = 1.57 nM, 23a: IC50 = 0.91 nM) and PI3Kα (9a: IC50 = 2.0 nM, 23a: IC50 = 1.5 nM), and showed promising antiproliferative activities against both BRCA-deficient (HCT-116, HCC-1937) and BRCA-proficient (SW620, MDA-MB-231/468) tumor cells. 9a and 23a also exhibited considerable in vivo antitumor efficacy in an MDA-MB-468 xenograft mouse model, with TGI values of 56.39% and 48.77%, respectively. Additionally, 23a possessed promising profiles including high kinase selectivity and low cardiotoxicity. Overall, this work indicates 9a and 23a might be potential PARP/PI3K dual inhibitors for cancer therapy and deserve further research.

Discovery of Novel Dual Extracellular Regulated Protein Kinases (ERK) and Phosphoinositide 3-Kinase (PI3K) Inhibitors as a Promising Strategy for Cancer Therapy.

Concomitant inhibition of MAPK and PI3K signaling pathways has been recognized as a promising strategy for cancer therapy, which effectively overcomes the drug resistance of MAPK signaling pathway-related inhibitors. Herein, we report the scaffold-hopping generation of a series of 1H-pyrazolo[3,4-d]pyrimidine dual ERK/PI3K inhibitors. Compound 32d was the most promising candidate, with potent inhibitory activities against both ERK2 and PI3Kα which displays superior anti-proliferative profiles against HCT116 and HEC1B cancer cells. Meanwhile, compound 32d possessed acceptable pharmacokinetic profiles and showed more efficacious anti-tumor activity than GDDC-0980 and the corresponding drug combination (BVD-523 + GDDC-0980) in HCT-116 xenograft model, with a tumor growth inhibitory rate of 51% without causing observable toxic effects. All the results indicated that 32d was a highly effective anticancer compound and provided a promising basis for further optimization towards dual ERK/PI3K inhibitors.