The In Vitro Killing Effect And Molecular Mechanisms Of HZX-02-059-01 Against Multiple Myeloma Cells

Multiple myeloma(MM)is the second prevalent hematologic malignancy characterized by clonal expansion of malignant plasma cells and production of large amounts of monoclonal immunoglobulin.As the application of emerging drugs and therapies such as proteasome inhibitors,immunomodulators,monoclonal antibody,chimeric antigen receptor T cell(CAR-T),the survival of MM patients has been significantly improved.However,MM remains incurable due to intrinsic or acquired resistance to the existing regimens,and nearly all MM patients will eventually relapse and finally die.Methuosis is a unique form of nonapoptotic cell death.HZX-02-059-01,developed by professor Deng Xianming from school of life sciences in Xiamen university,can target both PIKfyve and tubulin and induce methuosis.In this study we aim to investigate whether HZX-02-059-01 could induce MM cells death and explored its underlying molecular mechanism.Our results showed that HZX-02-059-01 inhibited the proliferation of three MM cell lines,MM1S,RPMI-8226 and NCI-H929,with a dose-dependent manner.The effects of HZX-02-059-01 on MM cells were attributed to induction of the methuosis and blockade of cell cycle progression,rather than initiating traditional apoptotic cell death.RNA sequencing combined with bioinformatics analysis identified multiple mechanisms involved in HZX-02-059-01-induced cytotoxicity against MM cells.Firstly,HZX-02-059-01 up-regulated a variety of genes associated with autophagosome,lysosome and endosome through transcription factor TFEB,leading to the destruction of intracellular vesicle homeostasis,and ultimately promoted the occurrence of methuosis in myeloma cells.Secondly,HZX-02-059-01 inhibited numerous genes participating the process of RNA splicing,transfer and translation,implying a pivotal role of RNA processing and translation for the action of HZX-02-059-01 to antagonize MM cells.In addition,Proviral integration Moloney virus(Pim)kinases play important roles in MM pathogenesis and drug resistance.Surprisingly,Pim-1 and Pim-2 were the most significant downregulated genes upon HZX-02-059-01 administration in MM cells,highlighting targeting Pim kinases as a potential role for HZX-02-059-01 to suppress MM cells growth.In summary,HZX-02-059-01 inhibits MM cells growth and induces cell death through multiple mechanisms.Our data unraveled novel mechanisms for antitumor action of HZX-02-059-01 and also preliminarily assessed its potential application value in MM,thus providing a new insight and strategy for the treatment of MM.