Rational Design of a Novel Class of Human ClpP Agonists through a Ring-Opening Strategy with Enhanced Antileukemia Activity.

The activation of Homo sapiens Casein lysing protease P (HsClpP) by a chemical or genetic strategy has been proved to be a new potential therapy in acute myeloid leukemia (AML). However, limited efficacy has been achieved with classic agonist imipridone ONC201. Here, a novel class of HsClpP agonists is designed and synthesized using a ring-opening strategy based on the lead compound 1 reported in our previous study. Among these novel scaffold agonists, compound 7k exhibited remarkably enhanced proteolytic activity of HsClpP (EC50 = 0.79 ± 0.03 µM) and antitumor activity in vitro (IC50 = 0.038 ± 0.003 µM). Moreover, the intraperitoneal administration of compound 7k markedly suppressed tumor growth in Mv4-11 xenograft models, achieving a tumor growth inhibition rate of 88%. Concurrently, 7k displayed advantageous pharmacokinetic properties in vivo. This study underscores the promise of compound 7k as a significant HsClpP agonist and an antileukemia drug candidate, warranting further exploration for AML treatment.

Discovery of a Novel Series of Homo sapiens Caseinolytic Protease P Agonists for Colorectal Adenocarcinoma Treatment via ATF3-Dependent Integrated Stress Response.

Homo sapiens caseinolytic protease P (HsClpP) activation is a promising strategy for colon cancer treatment. In this study, CCG1423 was identified as a selective activator of HsClpP. After optimization, NCA029 emerged as the most potent compound, with an EC50 of 0.2 µM against HsClpP. Molecular dynamics revealed that the affinity of NCA029 for the YYW aromatic network is crucial for its selectivity toward HsClpP. Furthermore, NCA029 displayed favorable pharmacokinetics and safety profiles and significantly inhibited tumor growth in HCT116 xenografts, resulting in 83.6% tumor inhibition. Mechanistically, NCA029 targeted HsClpP, inducing mitochondrial dysfunction and activating the ATF3-dependent integrated stress response, ultimately causing cell death in colorectal adenocarcinoma. These findings highlight NCA029 as an effective HsClpP activator with potential for colon cancer therapy.

Discovery of a Novel Series of Imipridone Compounds as Homo sapiens Caseinolytic Protease P Agonists with Potent Antitumor Activities In Vitro and In Vivo.

Homo sapiens caseinolytic protease P (HsClpP) plays an important role in maintaining mitochondrial proteostasis. Activating HsClpP has been proved to be a potential strategy for cancer therapy. In this paper, a novel class of HsClpP agonists is designed and synthesized using a position shift strategy based on the imipridone ONC201. Among these newly synthesized imipridone derivatives, compound 16z exhibits remarkably enhanced antitumor activity (IC50 = 0.04 µM against HCT116 cells). It can improve HsClpP thermal stability and induce mitochondrial dysfunction, reactive oxygen species production, cell cycle arrest in the G0/G1 phase, and apoptosis of HCT116 cells. Moreover, compound 16z possesses excellent pharmacokinetic profiles and significantly inhibits tumor growth in HCT116 cell-inoculated xenograft nude mouse models. Our study demonstrates that 16z has potential to be an antitumor drug candidate for further development and provides insights for the design of the next generation of HsClpP agonists for cancer treatment.