Preparation of silymarin nanosuspension with glycyrrhizic acid as stabilizer and study of its stabilization mechanism / 中草药

Objective: To prepare silymarin nanosuspension (SM-NS) with glycyrrhizic acid as stabilizer, and investigate the in vitro release characteristics and charge stabilization mechanism. Methods: SM-NS was prepared by high-speed shear-high pressure homogenization method. SM-NS lyophilized powder were prepared by freeze-drying method and characterized by physical and chemical characterization and in vitro release. The stability mechanism of SM-NS was studied from the ionic strength and pH value. Results: The dosage of glycyrrhizic acid (GA) was 0.15%. The preparation process was shear rate of 19 000 r/min, shear time of 4 min, homogenization pressure of 100 MPa, homogenization times of 12 times, and lyoprotectant was mannitol 3%, the average particle size of SM-NS lyophilized powder was (516.4 ± 10.4) nm, PDI was (0.260 ± 0.046); The in vitro release results showed that the dissolution rate and solubility of SM-NS lyophilized powder were significantly higher than the physical mixture; The study of charge stability mechanism showed that licorice acid can provide good charge stabilization and strong resistance to environmental impact. Conclusion: SM-NS is a potential and new nano-drug with high safety, which is formed by the charge stability of GA to significantly improve the solubility and stability of silymarin.

Valproic Acid Represses Autophagy and Enhances the Anti-myeloma Activity of DNA-damaging Drugs / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of valproic acid(VPA) on anti-myeloma activity of Doxorubicin(DOX) or Melphalan(MEL) and its related mechanism.</p><p><b>METHODS</b>Human multiple myeloma(MM) cells were treated with VPA of non-toxic dose in absence and presence of DOX or MEL at different concentrations (ie. IC10, IC20, IC40). The cell proliferation was detected by MTT method. Western blot was used to detect the expression levels of autophagy-related proteins (LC3, ATG5, ATG7) and acetylated histone H4K16ac.</p><p><b>RESULTS</b>Cell proliferation inhibition markedly increased in VPA plus DOX or MEL as compared with DOX or MEL alone (P<0.05). Both LC3 and H4K16ac expression levels in co-treatment were between VPA and DOX or MEL treated alone. Importantly, VPA of non-toxic dose not only augmented the anti-myeloma activity of DOX or MEL, but also down-regulated the autophagy-related protein expression and increases H4K16ac protein levels.</p><p><b>CONCLUSION</b>H4K16ac can inhibit the transcription of autophagy-related genes, The VPA enhance the anti-myeloma activity of DNA-damaging drugs, at least in part, via H4K16ac-mediated suppression of cytoprotective autophagy.</p>

Influence of CD117 Expression on Response of Multiple Myeloma Patients to Chemotherapy / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the influence of CD117 expression on response of multiple myeloma patients to chemo-therapy.</p><p><b>METHODS</b>A total of 65 cases of newly diagnosed multiple myeloma in our hospital from 2011 to 2013 were enrolled in this study. Cytogenetic abnormalities and immunophenotype were detected by using fluorescence in situ hybridization and flow cytometry before chemotherapy. The therapeutic efficacy of patients was evaluated after 4 cycles of PAD or TAD regimen.</p><p><b>RESULTS</b>The positive rates of 1q21 amplification, RB1: 13q14 deletion, D13S319: 13q14.3 deletion, IgH: 14q32 rearrangement and p53: 17p13 deletion were 32.2%, 40%, 40%, 20% and 3.1% respectively; the positive rates of CD38, CD138, CD56, CD117, CD20 were respectively 100%, 100%, 60%, 20%, 10.8%; the positive rates of CD19 and CD10 were 4.6% and 4.6% respectively; the positive CD22, CD7, CD5, CD103 did not found in any patients. The therapeutic efficacy of CD117⁻ patients was better than that of CD117⁺ patients (P < 0.05), there was no correlation of the remaining indicators with efficacy; the proportion of CD117⁺ patients with β2-microglobulin ≥ 5.5 mg/L was significantly higher than that of CD117⁻ patients (P < 0.05); the rest of baseline data had no significant difference (P > 0.05).</p><p><b>CONCLUSION</b>CD117 can be used as an indicator for evaluating efficacy of patients with newly diagnosed multiple myeloma.</p>

Inducing effect of chidamide on apoptosis of multiple myeloma cells and its relerance to DNA damage response / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was aimed to explore the effect of a novel histone deacetylase inhibitor Chidamide on apoptosis of human multiple myeloma(MM) cells and its relevance to DNA damage response(DDR).</p><p><b>METHODS</b>The cell proliferation was detected by MTT method, apoptosis and cell cycle distribution were analyzed by flow cytometry, the expression levels of targeted proteins were detected by Western blot, the DNA damage response was blocked by ATM kinase inhibitor KU-55933.</p><p><b>RESULTS</b>Chidamide inhibited RPMI 8226 cell proliferation in dose- and time-dependent manner and its IC50 values of 24,48,72 h were 9.6, 6 and 2.8 µmol/L respectively. Chidamide induced cell cycle arrest of RPMI 8226 cells in G0/G1 phase by upregulating the expression of P21. Chidamide triggered caspase-3 dependent apoptosis and upregulated expression of DDR-related proteins including γH2AX, pATM in RPMI 8226 cells. Pretreatment with ATM kinase inhibitor KU-55933 down-regulated expression of DDR related proteins induced by chidamide, thereby inhibiting DNA damage response and finally resulting in suppression of apoptotic cell death.</p><p><b>CONCLUSION</b>Proliferative inhibtion, cell cycle arrest and apoptosis of multiple myeloma cells induced by chidamide involve DDR.</p>