9u4s
From Proteopedia
Crystal Structure of PI5P4K-gamma in complex with n40
Structural highlights
FunctionPI42C_HUMAN May play an important role in the production of Phosphatidylinositol bisphosphate (PIP2), in the endoplasmic reticulum. Publication Abstract from PubMedINTRODUCTION: Phosphatidylinositol 5-phosphate 4-kinase type II gamma (PI5P4Kgamma) has emerged as a promising therapeutic target in oncology due to its key role in cancer progression. However, currently available inhibitors targeting either the orthosteric or allosteric sites of PI5P4Kgamma suffer from limited in vitro activity and in vivo validation. OBJECTIVES: This study aimed to develop a highly potent and selective PI5P4Kgamma inhibitor capable of simultaneously engaging both the orthosteric and allosteric sites, as well as to validate their potential in therapy for non-small cell lung cancer (NSCLC) were investigated. METHODS: Through the structural modification of the propionamide side chain of the pyridine ring and the N3 substituent of the quinazolinone, the structure-activity relationship (SAR) was elucidated, leading to the identification of the target compound n40. The binding mode of n40 to PI5P4Kgamma, was elucidated by X-ray crystallography. In vitro effects were assessed through KINOMEscan Technology, cell proliferation, apoptosis, and EMT analysis. In vivo efficacy was evaluated using an HCC827 xenograft mouse model. Both single-dose (up to 400 mg/kg) and repeated-dose (20-180 mg/kg/day for 28 days) toxicity studies of n40 were conducted in mice, with comprehensive monitoring of physiological parameters and organ toxicity indices. RESULTS: Compound n40 exhibited a strong binding affinity for PI5P4Kgamma (K(d) = 6.55 nM), with 3,000-fold selectivity over other two isoforms. Additionally, it displayed sub-50 nM antiproliferative activity in NSCLC cells with higher PI5P4Kgamma levels. X-ray crystallography revealed n40 simultaneously binds to both orthosteric and a novelallosteric pocket. Functionally, n40 induced S-phase arrest, apoptosis, and EMT reversal and PI3K/AKT/mTOR signaling inhibition in a PI5P4Kgamma-dependent manner. In HCC827 xenografts, n40 achieved > 60 % tumor growth inhibition without any observed toxicity. CONCLUSION: This study establishes PI5P4Kgamma as a druggable target in NSCLC and demonstrates that dual orthosteric-allosteric targeting is a viable strategy to achieve potent and selective PI5P4Kgamma inhibitors. Orthosteric-allosteric dual inhibitors of PI5P4Kgamma with potent antitumor activity in non-small cell lung cancer.,Xiong L, Tang åç£ L, Zhao W, Wang R, Cheng C, Wang D, Xu Y, Tang æ±¤ç£ L, Fan Y J Adv Res. 2025 Sep 22:S2090-1232(25)00728-3. doi: 10.1016/j.jare.2025.09.024. PMID:40992727[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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