4-Chlorobenzoyl berbamine, a novel berbamine derivative, induces apoptosis in multiple myeloma cells through the IL-6 signal transduction pathway and increases FOXO3a-Bim expression.

Multiple myeloma (MM) is an incurable hematopoietic malignancy, although many novel therapeutic agents have been explored. In the present study, we showed that 4-chlorobenzoyl berbamine (BBD9), a novel derivative of berbamine, inhibited the growth of 4 MM cell lines (U266, RPMI 8226, MM1.R and MM1.S). After a 24-h treatment with BBD9, the half maximal inhibitory concentration (IC(50)) values were 1.8, 2.3, 1.5 and 2.4 µg/ml, respectively, using MTT assays. In BBD9-treated U266 and RPMI 8226 cells, Annexin V (AV)-propidium iodide (PI) staining and FACS analysis demonstrated that apoptosis was involved in this inhibition. This was confirmed by western blot analysis indicating activation and cleavage of caspase-3, -8, -9 and PARP. BBD9 also induced G2/M phase cell cycle arrest in these cells. To investigate the mechanisms responsible for BBD9-induced apoptosis, U266 cells were incubated with 0, 1 or 2 µg/ml of BBD9 combined with 0 or 150 ng/ml of interleukin (IL)-6. MTT assays showed that IL-6 partially abrogated the BBD9-induced cell growth inhibition. Furthermore, BBD9 inhibited autocrine IL-6 production, and downregulated membrane IL-6 receptor (IL-6R) expression. Crucial proteins downstream of the IL-6 signaling pathway, including AKT and STAT3, were inactivated in BBD9-treated U266 cells, although exogenous IL-6 did not abrogate this effect. Forkhead transcription factor class 3a (FOXO3a), a nuclear transcription factor downstream from AKT, was upregulated in the nuclei of BBD9-treated U266 cells. Bim, the target gene of FOXO3a, was upregulated at both the protein and mRNA levels, as shown by western blot analysis and quantitative PCR. These results suggest that BBD9 induces apoptosis in MM cells through the inhibition of the IL-6 signaling pathway, leading to FOXO3a activation and upregulation of pro-apoptotic Bim.

4-Chlorobenzoyl berbamine induces apoptosis and G2/M cell cycle arrest through the PI3K/Akt and NF-kappaB signal pathway in lymphoma cells.

Berbamine is an herbal compound derived from Berberis amurensis, which is used in Chinese traditional medicine. However, few studies have investigated this anti-tumor effect or the underlying mechanisms of berbamine on lymphoma cells. We investigate the effect, as well as the mechanism of action, of 4-chlorobenzoyl berbamine (BBD9) on Raji, L428, Namalwa and Jurkat lymphoma cells lines. Our findings show that BBD9 inhibits cell proliferation and induces cell apoptosis in lymphoma cell lines as well as G2/M cell cycle arrest through PI3K/Akt and NF-kappaB signaling pathways in a caspase-dependent manner. These results may provide new insights into the treatment of lymphoma.

Interleukin-6-independent expression of glucocorticoid receptor is upregulated by triptolide in multiple myeloma.

Glucocorticoids are widely used chemotherapeutic agents for multiple myeloma. Drug resistance to steroid therapies is associated with the downregulation or loss of glucocorticoid receptor expression in malignant plasma cells. In this study, we examined the constitutive expression of glucocorticoid receptor in dexamethasone-sensitive and dexamethasone-resistant multiple myeloma cell lines. We found that triptolide increased the amount of the phosphorylated glucocorticoid receptor and enhanced the growth inhibitory effect of dexamethasone. Notably, these effects could not be blocked by interleukin-6, one of the most important growth factors in multiple myeloma.

Casticin induces leukemic cell death through apoptosis and mitotic catastrophe.

Casticin, a component from Vitex rotundifolia, widely used as an anti-inflammatory agent in Chinese traditional medicine, was reported to have anti-tumor activities. This study aims to examine the anti-leukemic activity of casticin on leukemia cells and its molecular mechanism. Cell viability was measured by MTT method; apoptosis and cell cycle arrest were determined by flow cytometry, AV-PI assay, and DNA fragmentation assay. Western blot were performed to measure the protein expression level. The cell morphology alteration was detected with immunofluorescent analysis and DAPI nuclear staining. Our results showed that the proliferation of leukemia cells, including K562, Kasumi-1, and HL-60, were inhibited by casticin in a time- and dose-dependent manner. The IC50, determined after 48 h incubation, was 5.95 microM, 4.82 microM, and 15.56 microM for K562, HL-60, and Kasumi-1, respectively. The cell cycle analysis demonstrated casticin treatment resulted in a significant G2/M accumulation, concomitant with upregulation of P21waf1 and P27kip1. The percentage of cells in G2/M increased with time of exposure and reached to its climax (75.3%) at 12 h after casticin treatment, and subsequently declined to 27% at 48 h. We found that casticin treatment induced remarkable apoptosis, evidenced by increased percentage of AV-positive PI-negative cells as well as the cleavage of PARP and caspase 3. In addition, DNA fragmentation assay showed the typical apoptotic DNA ladder in casticin-treated K562 cells. Mitotic catastrophe and decreased polymeric tubulin can also be observed in casticin-treated K562 cells. In addition, we found that PI3K/AKT pathway was activated; Ly294002, a PI3K/AKT specific inhibitor, can enhance the anti-leukemic effect of casticin. Taken together, these results demonstrated that casticin induced leukemic cell death via apoptosis and mitotic catastrophe, and could synergize with PI3K/AKT inhibitor, suggesting that casticin could be a promising therapeutic agent against leukemia.

Polymyositis/dermatomyositis associated with acute myelocytic leukemia.

Polymyositis (PM) and dermatomyositis (DM) are inflammatory myopathic diseases that often accompany cancers. However, the relationship between PM/DM and acute myelocytic leukemia (AML) has not been elucidated. We present a case of PM that developed AML 12 months after initial diagnosis. We reviewed the cases in English literature and analyzed the association between PM/DM and AML. We conclude that PM/DM is a paraneoplastic syndrome of AML.