Iron overload adversely effects bone marrow haematogenesis via SIRT-SOD2-mROS in a process ameliorated by curcumin.

BACKGROUND: Iron overload, which is common in patients with haematological disorders, is known to have a suppressive effect on haematogenesis. However, the mechanism for this effect is still unclear. The antioxidant curcumin has been reported to protect against iron overload-induced bone marrow damage through an as-yet-unknown mechanism. METHODS: We established iron overload cell and mouse models. Mitochondrial reactive oxygen species (mROS) levels, autophagy levels and the SIRT3/SOD2 pathway were examined in the models and in the bone marrow of patients with iron overload. RESULTS: Iron overload was shown to depress haematogenesis and induce mitochondrion-derived superoxide anion-dependent autophagic cell death. Iron loading decreased SIRT3 protein expression, promoted an increase in SOD2, and led to the elevation of mROS. Overexpression of SIRT3 reversed these effects. Curcumin treatment ameliorated peripheral blood cells generation, enhanced SIRT3 activity, decreased SOD2 acetylation, inhibited mROS production, and suppressed iron loading-induced autophagy. CONCLUSIONS: Our results suggest that curcumin exerts a protective effect on bone marrow by reducing mROS-stimulated autophagic cell death in a manner dependent on the SIRT3/SOD2 pathway.

Anti-DLBCL efficacy of DCZ0825 in vitro and in vivo: involvement of the PI3K‒AKT‒mTOR/JNK pathway.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, characterized by high heterogeneity. The poor outcome of a portion of patients who suffer relapsing or resistant to conventional treatment impels the development of novel agents for DLBCL. DCZ0825 is a novel compound derived from pterostilbene and osalmide, whose antitumor activities have drawn our attention. In this study, we found that DCZ0825 exhibited high cytotoxicity toward DLBCL cell lines in a dose- and time-dependent manner, as revealed by cell counting kit-8 assay. Flow cytometry and western blot analysis results showed that DCZ0825 also promoted cell apoptosis via both extrinsic and intrinsic apoptosis pathways mediated by caspase. In addition, DCZ0825 induced cell cycle arrest in the G2/M phase by downregulating Cdc25C, CDK1, and Cyclin B1, thus interfering with cell proliferation. Further investigation showed the involvement of the phosphatidylinositol 3-kinase (PI3K)‒AKT‒mTOR/JNK pathway in the efficacy of DCZ0825 against DLBCL. Remarkably, DCZ0825 also exerted notable cytotoxic effects in vivo as well, with low toxicity to important internal organs such as the liver and kidney. Our results suggest that DCZ0825 may have the potential to become a novel anti-DLBCL agent or to replenish the conventional therapeutic scheme of DLBCL.

Quercetin inhibits the proliferation of multiple myeloma cells by upregulating PTPRR expression.

Multiple myeloma (MM) is an incurable disease characterized by malignant plasma cell clonal expansion in the bone marrow; therefore, inhibiting the proliferation of plasma cells is an important approach to overcome the progression of MM. Quercetin (Que) is a promising flavonoid with broad-spectrum anti-tumor activity against various cancers, including MM; however, the underlying mechanism is not yet understood. The present study aimed to reveal the gene expression profile of Que-treated MM cells and clarify its potential mechanism. The 30% inhibitory concentration (IC30) of Que against MM cells was calculated, and the proliferation rate was significantly reduced after Que treatment. Next, 495 dysregulated genes were identified via RNA sequencing in Que-treated MM cells. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses indicated that the dysregulated genes were enriched in various apoptosis-related GO terms and amino acid metabolism-related pathways. qPCR validation showed that protein tyrosine phosphatase receptor-type R (PTPRR) had the highest verified log2 FC (abs) among the top 15 dysregulated genes. Overexpression of PTPRR increased the sensitivity of MM cells against Que, significantly inhibiting their proliferation and colony formation ability; silencing of PTPRR showed the opposite results. Furthermore, bioinformatics analyses and PPI network construction of PTPRR indicated that dephosphorylation of ERK might be the potential pathway for the PTPRR-induced inhibition of MM cell proliferation. In summary, our study identified the gene expression profile in Que-treated MM cells and demonstrated that the upregulation of PTPRR was one of the important mechanisms for the Que-induced inhibition of MM cell proliferation.

Resveratrol induces AMPK and mTOR signaling inhibition-mediated autophagy and apoptosis in multiple myeloma cells.

Resveratrol, a natural compound extracted from the skins of grapes, berries, or other fruits, has been shown to have anti-tumor effects against multiple myeloma (MM) via promoting apoptosis and inhibiting cell viability. In addition to apoptosis, autophagy also plays a significant role in anti-tumor effects. However, whether autophagy is involved in anti-MM activity of resveratrol remains unclear. In this study, human MM cell lines U266, RPMI-8226, and NCI-H929 were treated with resveratrol. Cell Counting Kit-8 assay and colony formation assay were used to measure cell viability. Western blot analysis was used to detect apoptosis- and autophagy-associated proteins. 3-Methyladenine (3-MA) was applied to inhibit autophagy. Results showed that resveratrol inhibited cell viability and colony formation via promoting apoptosis and autophagy in MM cell lines U266, RPMI-8226, and NCI-H929. Resveratrol promoted apoptosis-related proteins, Caspase-3 activating poly-ADP-ribose polymerase and Caspase-3 cleavage, and decreased the protein level of Survivin in a dose-dependent manner. Additionally, resveratrol upregulated the levels of LC3 and Beclin1 in a dose-dependent way, indicating that autophagy might be implicated in anti-MM effect of resveratrol. Furthermore, 3-MA relieved the cytotoxicity of resveratrol by blocking the autophagic flux. Resveratrol increased the phosphorylation of adenosine monophosphate (AMP)-activated protein kinase and decreased the phosphorylation of mammalian target of rapamycin (mTOR) and its downstream substrates p70S6K and 4EBP1 in a dose-dependent manner, leading to autophagy. Therefore, our results suggest that resveratrol exerts anti-MM effects through apoptosis and autophagy, which can be used as a new therapeutic strategy for MM in clinic.

Inhibition of autophagy enhances the antitumour activity of tigecycline in multiple myeloma.

Accumulating evidence shows that tigecycline, a first-in-class glycylcycline, has potential antitumour properties. Here, we found that tigecycline dramatically inhibited the proliferation of multiple myeloma (MM) cell lines RPMI-8226, NCI-H929 and U266 in a dose and time-dependent manner. Meanwhile, tigecycline also potently impaired the colony formation of these three cell lines. Mechanism analysis found that tigecycline led to cell cycle arrest at G0/G1 with down-regulation of p21, CDK2 and cyclin D1, rather than induced apoptosis, in MM cells. Importantly, we found that tigecycline induced autophagy and an autophagy inhibitor bafilomycin A1 further amplified the tigecycline-induced cytotoxicity, suggesting that autophagy plays a cytoprotective role in tigecycline-treated MM cells. Mechanisms modulating autophagy found that tigecycline enhanced the phosphorylation of AMPK, but did not decrease the phosphorylation of Akt, to inhibit the phosphorylation of mTOR and its two downstream effectors p70S6K1 and 4E-BP1. Tigecycline effectively inhibited tumour growth in the xenograft tumour model of RPMI-8226 cells. Autophagy also occurred in tigecycline-treated tumour xenograft, and autophagy inhibitor chloroquine and tigecycline had a synergistic effect against MM cells in vivo. Thus, our results suggest that tigecycline may be a promising candidate in the treatment of MM.

Matrine induces Akt/mTOR signalling inhibition-mediated autophagy and apoptosis in acute myeloid leukaemia cells.

Pharmacological modulation of autophagy has been referred to as a promising therapeutic strategy for cancer. Matrine, a main alkaloid extracted from Sophora flavescens Ait, has antitumour activity against acute myelocytic leukaemia (AML). Whether autophagy is involved in antileukaemia activity of matrine remains unobvious. In this study, we demonstrated that matrine inhibited cell viability and colony formation via inducing apoptosis and autophagy in AML cell lines HL-60, THP-1 and C1498 as well as primary AML cells. Matrine promoted caspase-3 and PARP cleavage dose-dependently. Matrine up-regulated the level of LC3-II and down-regulated the level of SQSTM1/p62 in a dose-dependent way, indicating that autophagy should be implicated in anti-AML effect of matrine. Furthermore, the autophagy inhibitor bafilomycin A1 relieved the cytotoxicity of matrine by blocking the autophagic flux, while the autophagy promoter rapamycin enhanced the cytotoxicity of matrine. Additionally, matrine inhibited the phosphorylation of Akt, mTOR and their downstream substrates p70S6K and 4EBP1, which led to the occurrence of autophagy. In vivo study demonstrated that autophagy was involved in antileukaemia effect of matrine in C57BL/6 mice bearing murine AML cell line C1498, and the survival curves showed that mice did benefit from treatment with matrine. Collectively, our findings indicate that matrine exerts antitumour effect through apoptosis and autophagy, and the latter one might be a potential therapeutic strategy for AML.

CAPN1 is a novel biomaker of patients with AML based on comprehensive analysis.

Acute myeloid leukemia (AML) is a common hematologic malignancy in adults. Recent studies investigating the potential pathogenesis of AML have significantly advanced our understanding of this disease. While cytogenetics and molecular abnormalities are crucial for confirming chemotherapy response and long-term outcomes, there are additional potential therapeutic targets and prognostic factors. The CAPN1 gene, which encodes a large subunit of the ubiquitous enzyme calpain, has not been extensively studied in hematological diseases. In this study, we used data from the TCGA public database to perform a bioinformatic analysis and found that CAPN1 is differentially expressed in multiple cancers and is associated with an unfavorable prognosis in AML. We employed R software and websites such as David and STRING to conduct differential analysis, GO and KEGG analysis, and explore the correlation between CAPN1 and physiological processes and key pathways. Our findings suggest that CAPN1 is significantly associated with the structure of the extracellular matrix and receptor-ligand interactions, indicating its potential role in disease progression. Additionally, we used CYBERSORT and ssGSEA to analyze the immune environment of CAPN1 and found that it is associated with most immune components, particularly CD56 cells and neutrophils. In conclusion, CAPN1 is a key prognostic gene in AML that is significantly correlated with disease progression, clinical features, and immune invasion.

The novel HLA-DPB1*02:02:07 allele identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-DPB1*02:02:07 differs from HLA-DPB1*02:02:01:01 by one nucleotide in exon 2.

DCZ0014, a novel compound in the therapy of diffuse large B-cell lymphoma via the B cell receptor signaling pathway.

Diffuse large B cell lymphoma (DLBCL) is a clinical and genetically heterogeneous lymphoid malignancy. Although R-CHOP (rituximab plus cyclophosphamide, vincristine, doxorubicin, and prednisone) treatment can improve the survival rate of patients with DLBCL, more than 30% of patients exhibit treatment failure, relapse, or refractory disease. Therefore, novel drugs or targeted therapies are needed to improve the survival of patients with DLBCL. The compound DCZ0014 is a novel chemical similar to berberine. In this study, we found that DCZ0014 significantly inhibited the proliferation and activity of DLBCL cells, and induced cell apoptosis. Following treatment with DCZ0014, DLBCL cells accumulated in G0/G1-phase of the cell cycle and showed decreased mitochondrial membrane potential. Additionally, DCZ0014 inhibited DNA synthesis, enhanced DNA damage in DLBCL cells, as well as inhibited Lyn/Syk in B cell receptor signaling pathway. Further experiments demonstrated that DCZ0014 did not significantly affect peripheral blood mononuclear cells. Tumor xenograft model showed that DCZ0014 not only inhibited tumor growth but also extended the survival time of mice. Thus, DCZ0014 showed potential for clinical application in the treatment of patients with DLBCL.

Benzene metabolite hydroquinone induces apoptosis of bone marrow mononuclear cells through inhibition of ß-catenin signaling.

The Akt/glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin signaling pathway has been shown to play an important role in hematopoiesis, and hematopoietic cells are sensitive targets for benzene-induced hematotoxicity. We therefore hypothesized that dysregulation of the Akt/GSK-3ß/ß-catenin signaling was associated with benzene-induced hematotoxicity. Here, we showed that hydroquinone (HQ), a major metabolite of benzene in humans, significantly inhibited cell viability and colony formation while inducing apoptosis of human bone marrow mononuclear cells in vitro. Interestingly, we found that HQ inhibited the Akt affected ß-catenin signaling by activation of GSK-3ß, resulting in downregulation of ß-catenin and its targets Cyclin D1 and Survivin. HQ blocked nuclear translocation of ß-catenin and lymphoid enhancer-binding factor 1 (LEF-1), and importantly, HQ also reduced the interaction of ß-catenin and LEF-1 in the nucleus. As expected, blockage of GSK-3ß activity with a GSK-3ß inhibitor lithium chloride (LiCl) or activation of Akt signaling with an Akt agonist insulin-like growth factor-1 (IGF-1) could inhibit HQ-induced activation of GSK-3ß as well as hematotoxicity. Taken together, our results suggest that HQ-induced hematotoxicity in bone marrow mononuclear cells is associated with dysregulation of Akt/GSK-3ß/ß-catenin signaling due to the dissociation of ß-catenin/LEF-1 complex, and LiCl and IGF-1 may be two potential agents to ameliorate HQ-induced hematotoxicity.