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Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin's lymphoma. R-CHOP is currently the standard therapy for DLBCL, but the prognosis of refractory or recurrent patients remains poor. In this study, we synthesized a new water-soluble antimalarial drug artemisinin derivative, SM1044. The treatment of DLBCL cell lines with SM1044 induces autophagy-dependent apoptosis, which is directed by an accelerated degradation of the antiapoptosis protein Survivin, via its acetylation-dependent interaction with the autophagy-related protein LC3-II. Additionally, SM1044 also stimulates the de novo synthesis of ceramide, which in turn activates the CaMKK2-AMPK-ULK1 axis, leading to the initiation of autophagy. Our findings not only elucidate the mechanism of autophagy-dependent apoptosis in DLBCL cells, but also suggest that SM1044 is a promising therapeutic molecule for the treatment of DLBCL, along with R-CHOP regimen., (© 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

The aim of this study was to investigate the apoptosis-inducing effect of artemisinin derivative SM1044 on Kasumi-1 cells and its possible mechanism. Kasumi-1 cells were treated with different concentrations of SM1044, the cell viability was evaluated by MTT assay. Cell apoptosis and cell cycle progression were assessed by using flow cytometry with Annexin-V/PI double staining and flow cytometry with PI staining respectively. The expression of apoptosis-related proteins caspase 3, PARP and the fusion protein AML1-ETO were detected by Western blot. The results indicated that SM1044 inhibited cell growth of Kasumi-1 cells in time- and dose-dependent manners. After exposure of Kasumi-1 cells to 1 µmol/L SM1044 for 24 hours, the cell viability was decreased to 50%. IC(50) of SM1044 to Kasumi-1 cells at 48 hours was 0.17 ± 0.067 µmol/L. SM1044 induced cell apoptosis in a caspase-dependent manner, and the apoptotic rate of Kasumi-1 cells increased as SM1044 concentration increased. Flow cytometry with PI staining revealed that SM1044 induced cell cycle arrest, and the proportion of cells in G(0)/G(1) phase increased from 58.33 ± 4.46% to 71.75 ± 2.24% after exposure to 5 µmol/L SM1044 for 24 hours. Western blot showed that SM1044 increased the expression of apoptosis-related proteins cPARP and cleaved caspase 3 and also degraded the AML1-ETO fusion protein. It is concluded that SM1044 can inhibit the proliferation of Kasumi-1 cells, induce cell apoptosis which may be related to the increased level of cleaved PARP and cleaved caspase 3. SM1044 can also induce cell arrest in G(0)/G(1) phase. As the fusion protein AML1-ETO degrades obviously, it can be the potential target of SM1044 in Kasumi-1 cells.

This study was aimed to explore the effect of arsenic trioxide (ATO) on proliferation and apoptosis of mantle cell lymphoma (MCL) cell lines and the underlying mechanisms of the apoptosis. MCL cell lines (jeko-1, mino, JVM-2) were treated with different concentrations of ATO, then growth profile of these cells were detected by MTT. Apoptosis of ATO-treated jeko-1 cells were detected by flow cytometry with Annexin V-FITC/PI double staining. The loss of mitochondrial membrane potential of ATO-treated jeko-1 cells were detected by FCM with DiOC₆(3) staining. The expressions of cyclin D1 and apoptosis related proteins MCL-1, BCL-2, PUMA, NOXA, cCaspase-3 (cleaved caspase-3), cCaspase-9 (cleaved caspase-9), cPARP (cleaved PARP) were detected by Western blot. The results indicated that ATO inhibited cell growth, induced apoptosis of MCL cells and disrupted mitochondrial membrane potential. ATO could decrease expressions of MCL-1, PUMA and cyclin D1, increase expressions of cPARP, cCaspase-3, cCaspase-9 and the expressions of BLC-2 and NOXA were not changed. It is concluded that ATO can induce cell growth arrest and apoptosis of MCL cells. The mitochondrial pathway plays a very important role in cell apoptosis.

Although most of the mantle cell lymphoma (MCL) patients initially responded well to bortezomib (BTZ), the dose-dependent toxicities have greatly limited the application of BTZ to MCL. To investigate the efficacy and mechanism of arsenic trioxide (ATO) with BTZ in inducing apoptosis of MCL cells, two MCL cell lines, along with primary cells from MCL patients (n = 4), were used. Additionally, the NOD-SCID mice xenograft model of Jeko-1 cells was established to study the anti-MCL mechanisms in an in vivo setting. ATO treatment highly improved BTZ capacity to inhibit proliferation and induce apoptosis of MCL cells. Furthermore, the interaction of Noxa and Mcl-1 leads Bak to release from Mcl-1 or from Bcl-xl, which could further activate Bak and Bax and then induce cell apoptosis. We also found that when lower doses of BTZ were used in combination with ATO, more effective proapoptotic effects in both the cell lines and the primary cells were obtained compared to the effects of BTZ used alone at higher doses. Simultaneously, the combination of these two drugs delayed the tumor growth in mice more effectively than BTZ alone. The cooperative anti-MCL effects of this combination therapy both in vitro and in vivo strongly provided a new strategy to the clinical treatment of MCL. [ABSTRACT FROM AUTHOR]