Discovery of Pyrimidinediamine Derivatives as Potent Methuosis Inducers for the Treatment of Triple-Negative Breast Cancer

Abstract

Triple-negative breast cancer (TNBC) is a leading malignancy among women that currently lack effective targeted therapeutic agents, and the limitations of treatment have prompted the emergence of new strategies. Methuosis is a novel vacuolepresenting cell death modality that promotes tumor cell death. Hence, a series of pyrimidinediamine derivatives were designed and synthesized through evaluation of their abilities that inhibit proliferation as well as induce methuosis against TNBC cells. Among them, JH530 showed excellent anti-proliferative activities and vacuolization capacity in TNBC. The mechanism research indicated that JH530 caused cell death through inducing methuosis of cancer cells. Furthermore, JH530 inhibited tumor growth remarkably in the HCC1806 xenograft model without an apparent decrease in body weight. Overall, JH530 is a methuosis inducer that displayed remarkable suppression of TNBC growth in vitro and in vivo, which provides a basis for the future progress of more small molecules for TNBC treatment.

Progress in the discovery and development of small molecule methuosis inducers

“…DZ-514 also exhibits methuosis-inducing activity in a TNBC mouse xenograft model. Very recently, the same authors have also reported another analogue named JH530 which significantly induced methuosis in HCC1806, HCC1937 and MDA-MB-468 breast cancer cells, 69 and the detailed molecular mechanism of JH530, though not mentioned in the new publication, should be the same as that of its congener, DZ-514, due to their high structural similarity.…”

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

“…Apilimod, the first-in-class PIKfyve inhibitor with a K d of 75 nM, exhibits broad antitumor activities against various subtypes of B-cell non-Hodgkin lymphoma and is currently undergoing a clinical trial for the treatment of COVID-19 (NCT04446377) . Several reported compounds also induce methuosis, such as vacquinol-1, ursolic acid derivative, JH530, and YM201636 . Vacuolin-1 induces homotypic fusion of endosomes or lysosomes, resulting in the formation of large vacuoles. , Ursolic acid derivatives and JH530 trigger large vacuoles through hyperstimulation of micropinocytosis. ,, YM201636, a potent PIKfyve inhibitor with an IC 50 value of 33 nM, leads to marked enlargement of vacuoles in the cytoplasm .…”

“…Several reported compounds also induce methuosis, such as vacquinol-1, ursolic acid derivative, JH530, and YM201636 . Vacuolin-1 induces homotypic fusion of endosomes or lysosomes, resulting in the formation of large vacuoles. , Ursolic acid derivatives and JH530 trigger large vacuoles through hyperstimulation of micropinocytosis. ,, YM201636, a potent PIKfyve inhibitor with an IC 50 value of 33 nM, leads to marked enlargement of vacuoles in the cytoplasm . However, the activity of inducing methuosis and K d value against PIKfyve of these compounds still needs to be improved.…”