PB1970: AS2O3 INDUCE IMMUNOGENIC CELL DEATH IN MULTIPLE MYELOMA VIA NLRP3/CASPASE SIGNALING PATHWAY

Abstract

Background: Multiple myeloma (MM) is a common plasma cell malignant disease, the clonal evolution of myeloma cells and the immune escape caused by it are an important mechanism of refractory drug resistance. Aims: To explored the relationship between NLRP3 / Caspase signaling pathway and immunogenic cell death (ICD) in the intervention of As2O3 on MM cell (a human myeloma-derived KM3 cell line), and explained the inhibitory effect of As2O3 on the proliferation of myeloma cells. Methods: The inhibitory and apoptotic effect of As2O3 on human MM cells was monitored by a CCK-8 method. Meanwhile, the effects of different concentrations of As2O3 on MM cell apoptosis were detected was further determined by flow cytometry. Moreover, the expression of BCL-2, BAX, PARP, HSP70/90, MHC-I, and NLRP3 at mRNA was determined by using quantitative PCR (Q-PCR). The effects of different concentrations of As2O3 on the expression of apoptosis related proteins Bcl-2, Bax, Caspas-3 and PARP were detected by ELISA. Moreover, the expression of ICD related HSP70/90 and MHC-I proteins, as well as the expression of NLRP3 and caspase-1 proteins were explored. Results: The results indicated that As2O3 could significantly inhibit human MM cell proliferation and cell death in a time- and dose-dependent manner in vitro. Meanwhile, the results also showed that As2O3 could effectively increase the expression of Bax, PARP, HSP70/90, MHC-I, and NLRP3 mRNA levels, and decrease the Bcl-2 mRNA level in human MM cells. Moreover, As2O3 could also significantly elevate the expression of NLRP3, caspase-1 proteins and ICD related proteins, leading to increase the expression of apoptosis related proteins Bax, Caspas-3, PARP. Summary/Conclusion: As2O3 can significantly induce human MM cell death in a time- and dose-dependent manner in vitro, and activate NLRP3 / caspase signaling pathway in human MM cells. As2O3 can also increase the expression level of ICD related molecules and apoptosis related molecules Bax, Caspas-3, PARP, and initiate MM cell apoptosis, indicating that As2O3 induce immunogenic cell death in multiple myeloma via NLRP3/Caspase signaling pathway. Overall, As2O3 may be a potential agent in treating human multiple myeloma in clinical practice.