Trifluoperazine Synergistically Potentiates Bortezomib-Induced Anti-Cancer Effect in Multiple Myeloma via Inhibiting P38 MAPK/NUPR1.

Multiple myeloma (MM) is a common hematological malignancy. Bortezomib (BTZ) is a traditional medicine for MM treatment, but there are limitations for current treatment methods. Trifluoperazine (TFP) is a clinical drug for acute and chronic psychosis therapy. Lately, researchers have found that TFP can suppress tumor growth in many cancers. We attempted to study the effects of BTZ and TFP on MM in vivo and in vitro. We concentrated on the individual and combined impact of BTZ and TFP on the proliferation and apoptosis of MM cells via Cell Counting kit-8 assay, EdU assay, western blot, and flow cytometry. We found that combination therapy has a strong synergistic impact on MM cells. Combination therapy could induce cell arrest during G2/M phase and induce apoptosis in MM cells. Meanwhile, BTZ combined with TFP could play a better role in the anti-MM effect in vivo through MM.1s xenograft tumor models. Furthermore, we explored the mechanism of TFP-induced apoptosis in MM, and we noticed that TFP might induce MM apoptosis by inhibiting p-P38 MAPK/NUPR1. In summary, our findings suggest that TFP could synergistically enhance the BTZ-induced anti-cancer effect in multiple myeloma, which might be a promising therapeutic strategy for MM treatment.

microRNA-637 promotes apoptosis and suppresses proliferation and autophagy in multiple myeloma cell lines via NUPR1.

Multiple myeloma (MM) is a heterogeneous disease with poor prognosis. Increasing evidence has revealed that microRNAs (miRNAs) are strongly associated with the pathogenesis and progression of MM. Here, we investigated the role of microRNA-637 (miR-637) in MM to identify potential therapeutic targets. We measured the expression of miR-637 in bone marrow samples of MM patients and MM cell lines by quantitative real-time PCR and western blot. The effect of miR-637 on proliferation and apoptosis of MM primary cells was also investigated. Analyses of four bioinformatics databases showed that miR-637 is associated with nuclear protein 1 (NUPR1) in MM cells, which was confirmed by luciferase reporter assay. We found that the overexpression of miR-637 suppressed the development of MM. miR-637 mimics increased the levels of Bax, cleaved caspase 3, and P62, and decreased the levels of Bcl2 and LC3. Additionally, luciferase reporter assays were performed to demonstrate that NUPR1 is the main target of miR-637 in MM cells. Overexpression of NUPR1 reversed the effects of miR-637 mimics in MM cells. Our results suggest that miR-637 inhibits cell proliferation and autophagy, and promotes apoptosis in MM cells by targeting NUPR1. Our findings also suggest that miR-637 may have potential as a novel molecular therapeutic target for MM treatment.

Trifluoperazine induces cellular apoptosis by inhibiting autophagy and targeting NUPR1 in multiple myeloma.

Multiple myeloma (MM) is the second most common hematologic malignancy of immunoglobulin-secreting plasma cells. Recent modern combination therapies have improved survival rates, but many patients develop resistance to novel drugs, leading to relapse. Trifluoperazine (TFP), a typical antipsychotic drug, has been reported to exert antitumor effects by targeting various pathways. Thus far, the role of TFP in MM has not been elucidated. In the current study, we demonstrated that TFP inhibited cell growth and autophagy activity but induced apoptosis of U266 and RPMI 8226 MM cells. Furthermore, cotreatment of these cell lines with TFP and rapamycin, a potent autophagy inducer, reduced cell apoptosis compared with TFP treatment alone. We also found that TFP inhibited nuclear protein 1 (NUPR1) expression. In the presence of TFP, cells stably overexpressing NUPR1 showed a higher viability than cells treated with the nonspecific control. Autophagy suppression and apoptosis induction caused by TFP were also reversed in MM cells upon NUPR1 overexpression. Overall, our results indicate that in the context of MM, TFP targets NUPR1, inhibiting cell growth and inducing apoptosis by autophagy inhibition. Our results could contribute toward efforts for the development of more effective therapies for MM to be tested in future clinical trials.