Discovery of Potent and Selective Phosphatidylinositol 3-Phosphate 5-Kinase (PIKfyve) Inhibitors as Methuosis Inducers.

Cytoplasmic vacuolation-associated cell death, known as methuosis, offers a promising nonapoptotic approach for cancer treatment. In this study, we outline the synthesis and evaluation of potent methuosis-inducing compounds. These compounds selectively induce cell death, characterized by extensive cytoplasmic vacuolation in HeLa and MDA-MB-231 cells. Notably, compound exhibited a remarkable interaction with PIKfyve kinase, boasting a value of 0.47 nM, surpassing the positive controls D-13 and MOMIPP in potency. Furthermore, it is important to highlight that cell death induced by compound is unequivocally attributed to methuosis as it differs from apoptosis, necrosis, or autophagy. Importantly, when administered orally, effectively inhibited tumor growth in a HeLa xenograft model without any apparent signs of toxicity. These results underscore the potential of as a valuable tool for in-depth investigations into the mechanisms of methuosis and as a promising lead compound to guide structural optimization.