Designing polymersomes with inhomogeneous membranes by co-assembly of block copolymers for controlled morphological reversibility.

Polymersomes with inhomogeneous membranes in composition and structure have generated widespread interest for the preparation of functionalized nanocarriers. We propose a simple but versatile strategy to manipulate inhomogeneous subdomains on polymersome membranes by the co-assembly of block copolymer blends with varied molecular architectures and chemistries. Both binary and ternary copolymer blends are considered to construct polymersomes, and the subdomains of the membranes are formed by controlling the difference in the flexibility and rigidity of different blocks. This difference contributes to the formation of disk-like domains (by rigid blocks) and soft domains (by flexible blocks) on the membrane. An interesting effect of this structure is that in response to external stimuli, the soft membrane domain becomes worm-like or porous to "open" the polymersome for matter exchange, while the rigid domain stays undecomposed and acts like an anchor binding all flexible copolymers. Once the external stimuli disappear, all flexible copolymers can be pulled back to restore the original polymersome morphology (i.e., "close" the polymersome). The specific morphological reversibility of hybrid polymersomes holds great potential for practical applications where changeable membrane permeability or shape under environmental stimuli is highly needed.

Increased expression of TIGIT on CD4+ T cells ameliorates immune-mediated bone marrow failure of aplastic anemia.

Aplastic anemia (AA) is an autoimmune disease in which T cell activation is suspected to play an important role. T cell immunoglobulin and ITIM (immunoreceptor tyrosine-based inhibition motif) domain (TIGIT) is an inhibitory receptor, which exhibits inhibitory functions on the immune response. However, its role in AA has not been clearly determined. In the current study, we showed that the frequency of TIGIT-positive CD4(+) T cells was reduced in the vast majority of AA patients (85%, 17/20). In TIGIT-silenced human CD4(+) T cells, stimulation of agonistic anti-TIGIT monoclonal antibody significantly facilitated cell proliferation, increased production of IL-2 and IFN-γ, and inhibited production of IL-10. However, in TIGIT-overexpressed human CD4(+) T cells, cell proliferation and the production of IL-2, IFN-γ, and TNF-α were significantly hindered; in contrast, the secretion of IL-10 was improved. RT-PCR and Western blotting showed that T-bet expression in human CD4(+) T cells was significantly decreased by TIGIT overexpression, but only slightly altered by TIGIT knockdown. In mouse models, lentivirus-mediated TIGIT-overexpressed CD4(+) T cell transfer significantly rescued the decreased red blood cell count, attenuated the increase in serum INF-γ and TNF-α levels, and lengthened the median survival time. The mRNA levels of CD34, stem cell factor (SCF), and granulocyte/macrophage-colony-stimulating factor (GM-CSF) in bone marrow mononuclear cells were also up-regulated. In conclusion, increased expression of TIGIT could inhibit the function of CD4(+) T cells in vitro and ameliorate immune-mediated bone marrow failure of AA in vivo providing a new potential strategy for the treatment of AA.

Increased 14-3-3ζ expression in the multidrug-resistant leukemia cell line HL-60/VCR as compared to the parental line mediates cell growth and apoptosis in part through modification of gene expression.

BACKGROUND: Acute myeloid leukemia (AML) recurrence is largely a result of multidrug resistance (MDR). We aimed to examine the role of 14-3-3ζ in AML chemosensitivity using HL-60 and vincristine-resistant HL-60/VCR cells. METHODS: The effects of 14-3-3ζ siRNA on the growth and cell cycle progression of HL-60 and HL-60/VCR cells were determined. The effect of 14-3-3ζ siRNA on topotecan (TPT)-induced apoptosis was evaluated by several assays. RESULTS: Compared to HL-60 cells, HL-60/VCR cells had increased 14-3-3ζ mRNA and protein expression. Increased mdr-1 mRNA as well as mdr-1, Bcl-2 and Mcl-1 protein expression were observed in HL-60/VCR cells. In both HL-60 and HL-60/VCR cells, 14-3-3ζ was observed in the cytoplasm and nuclear compartments. 14-3-3ζ siRNA significantly reduced HL-60 and HL-60/VCR cell growth after 48 h and increased the proportion of cells in the G0/G1 phase. Moreover, 14-3-3ζ siRNA significantly increased the sensitivity of both HL-60 and HL-60/VCR cells to TPT, possibly through the inhibition of Bcl-2, Mcl-1 and mdr-1 protein expression. CONCLUSIONS: Silencing of 14-3-3ζ increased the sensitivity of both sensitive and resistant HL-60 cells to TPT-induced apoptosis, possibly through altering the expression of apoptosis-associated proteins, suggesting that it may be a potential target for MDR AML.

A validated LC-MS/MS assay for the quantitative determination of curdione in rabbit plasma and its application to a pharmacokinetic study after administration of zedoary turmeric oil and bioavailability of the oil.

A selective and sensitive liquid chromatography tandem mass spectrometry method was developed for the first time for the identification and quantification of curdione in rabbit plasma after vaginal drug administration and intravenous administration of zedoary turmeric oil (ZTO) solution (10 mg/kg). The analysis was performed on a triple-quadrupole tandem mass spectrometer with multiple reaction monitoring mode via electrospray ionization source in positive ionization mode. After mixing with internal standard diazepam, plasma samples were extracted with ethyl ether-acetic ether (1:1, v/v). Chromatographic separation was carried out on a C18 column with gradient elution using a mixture of water and acetonitrile (both containing 0.1% formic acid) as mobile phases. Linearity ranged over 1.06-106 and 10.6-530 ng/mL (r ≥ 0.995) with the lower limit of quantfication 1.06 ng/mL. The intra- and inter-day precision relative standard deviation values were <12% and the accuracy relative error was from -10.6 to -6.1% at all quality control sample levels. The method was applied to a study of the pharmacokinetics of curdione after vaginal drug administration and intravenous administration of ZTO.

K-doped Li2ZnTi3O8/C as an efficient anode material with high performance for Li-ion batteries.

Li2ZnTi3O8/C and Li1.9K0.1ZnTi3O8/C were successfully synthesized using the sol-gel method. Doping K apparently yielded a wider tunnel, helpful for increasing the rate of transport of lithium ions, and furthermore yielded excellent electrochemical properties. The first discharge capacity for Li1.9K0.1ZnTi3O8/C was 352.9 mA h g-1 at a current density of 200 mA g-1. Li1.9K0.1ZnTi3O8/C also performed stably, retaining a capacity of 323.7 mA h g-1 at the 100th cycle, indicative of its excellent cycling properties. In the rate performance test, Li1.9K0.1ZnTi3O8/C showed at the first cycle a high discharge capacity of 379.5 mA h g-1 for a current density of 50 mA g-1 and a capacity of 258.9 mA h g-1 at 1000 mA g-1. The results indicated that K-doping should be considered a useful method for improving electrochemical performances.

Bile-derived exosome noncoding RNAs as potential diagnostic and prognostic biomarkers for cholangiocarcinoma.

Background: Cholangiocarcinoma (CCA) is one of the most aggressive malignancies, lacking novel diagnostic and prognostic biomarkers. Exosome noncoding RNAs (ncRNA) were previously proposed as a potential source of biomarkers in several cancers. This study aimed to interpret the value of specific bile-derived ncRNA as predictors for early diagnosis and prognosis of CCA. Methods: We recruited 100 patients who received endoscopic retrograde cholangiopancreatography at our hospital for bile duct obstruction due to CCA (n = 50) and biliary stone (n = 50). They were further divided into training set and validation set (3:2). A panel of CCA-specific ncRNAs including 5 miRNAs (PMID: 30165035) and 2 lncRNAs (PMID: 29050258) were detected in both serum and bile exosomes. The diagnostic accuracy was assessed using the area under the receiver operating characteristic curve. Logistic analysis was used to classify the potential predictors of CCA and further establish the diagnostic model. And the prognostic value of the ncRNAs was also assessed. Results: Exosomes were successfully collected from bile and serum. Exosomal miR-141-3p, miR-200a-3p, miR-200c-3p in serum and bile, as well as miR-200b-3p and ENST00000588480.1 in bile showed AUCs of >0.70 in the diagnosis of CCA. Bile exosomal miR-200c-3p displayed the best diagnostic value with the AUC of 0.87. The combination of serum CA19-9 into the model could increase the AUC to 0.906. Bile exosomal miR-200a-3p and miR-200c-3p were found to be independent predictors of CCA. Among exosomal ncRNAs in human bile and blood, 3 (serum and bile exosomal miR-200c-3p, bile exosomal miR-200a-3p) showed significant value in predicting cancer recurrence and 1 (serum exosomal miR-200c-3p) had great predictive ability of cancer death. High levels of serum exosomal miR-200c-3p showed unfavorable tumor-free survival and overall survival. Conclusion: The bile exosomal miR-200 family, particularly miR-200c-3p, was verified to be a potential biomarker for the early detection of CCA. The diagnostic ability of exosomal ncRNAs in human bile is better than that in blood. Moreover, high levels of bile exosomal miR-200a-3p, miR-200c-3p, and serum exosomal miR-200c-3p represented adverse clinical outcomes.

ZrO2 coated Li1.9K0.1ZnTi3O8 as an anode material for high-performance lithium-ion batteries.

The Li1.9K0.1ZnTi3O8@ZrO2 (1 wt%, 3 wt%, and 5 wt%) anode material was synthesized by doping Li2ZnTi3O8 with potassium and coating ZrO2, where the ZrO2 coating layer was prepared by citric acid and zirconium acetate, and the potassium source was KCl. When the added ZrO2 amount is 3%, the material has the most uniform size, reduced polarization, and reduced charge transfer resistance, and the specific capacity of LKZTO@ZrO2 (3 w%) was 361.5 mA h g-1 at 200 mA g-1 at the 100th cycle, which is higher than that of LKZTO, of 311.3 mA h g-1. The specific capacities of LKZTO@ZrO2 (3 w%) at 50, 100, 200, 500, and 1000 mA g-1 after 10 cycles were 424.9, 410.7, 394.1, 337.6 and 270.6 mA h g-1, indicating that LKZTO@ZrO2 (3 w%) has excellent electrochemical performance.

[New method for wave-plate orientation determination based on the shape of the modulated spectrum].

A new method for the determination of fast axis of wave-plate is introduced. Based on the principle of electro-optic phase compensation in the wave-plate phase measuring method, the relation between the polarization extinction system out-put signal and the modulating signal can be acquired through the composition of frequency fixed alternating voltage modulation signal. Through the analysis of this process with Jones matrix, the out-put signal was usually found to be the composition of fundamental frequency and second harmonic frequency, the composition signal reflects the axis information as well as the phase information of the wave-plate, and this phenomenon has never been noticed before. Through the analysis of this phenomenon, the transformation trends of the composed wave-form by rotating of wave-plates with different orientations were deduced, and through the observation of the transformation trend, one can easily distinguish the fast and slow axes of wave-plates with phase retardation > pi as well as those with phase retardation < pi, and their phenomena are reverse to each other.

Risk factors and prognosis analysis of acute myeloid leukemia in children.

PURPOSE: To explore the efficacy and related prognostic factors of acute myeloid leukemia (AML) in children except acute promyelocytic leukemia (APL). METHODS: The clinical data of 89 non-APL children with AML treated in our hospital were retrospectively analyzed. The remission status was analyzed after chemotherapy, the long-term survival was evaluated using the Kaplan-Meier method, and the influencing factors for the prognosis were detected using univariate and multivariate Cox regression analyses. RESULTS: Complete remission (CR) was realized in 71 cases (79.8%) after the first course of treatment, 13 cases (14.6%) after the second course of treatment, and 5 cases (5.6%) after the third course of treatment. The 5-year event-free survival (EFS) rate and overall survival (OS) rate were 53.9% and 66.3%, respectively. The children were divided into low-risk group (n=31), middle-risk group (n=36) and high-risk group (n=22). In the three groups, the 5-year OS rate was 74.2%, 72.2% and 45.5%, respectively, while the 5-year EFS rate was 67.7%, 55.6% and 31.8%, respectively. Extramedullary infiltration at the time of initial diagnosis [HR=3.313 (95% CI: 1.748-13.664)], CD56+ [HR=1.592 (95% CI: 1.172-2.255)] and recurrence time <1 year [HR=3.040 (95% CI: 1.087-5.508)] were independent risk factors affecting the prognosis, and CR achieved after the first course [HR=0.786 (95% CI: 0.228-0.803)] was an independent factor improving the prognosis of patients. CONCLUSIONS: The prognosis is poor in non-APL children with AML who have extramedullary infiltration at the time of initial diagnosis, CD56+ and recurrence time <1 year, and CR achieved after the first course is an independent factor improving the prognosis of patients. The long-term EFS rate is significantly lower in high-risk group than that in low- and middle-risk groups. Intensive chemotherapy or early hematopoietic stem cell transplantation should be performed for high-risk patients.

Cr-Doped Li2ZnTi3O8 as a High Performance Anode Material for Lithium-Ion Batteries.

Li2ZnTi2.9Cr0.1O8 and Li2ZnTi3O8 were synthesized by the liquid phase method and then studied comparatively using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), galvanostatic charge-discharge testing, cyclic stability testing, rate performance testing, and electrochemical impedance spectroscopy (EIS). The results showed that Cr-doped Li2ZnTi3O8 exhibited much improved cycle performance and rate performance compared with Li2ZnTi3O8. Li2ZnTi2.9Cr0.1O8 exhibited a discharge ability of 156.7 and 107.5 mA h g-1 at current densities of 2 and 5 A g-1, respectively. In addition, even at a current density of 1 A g-1, a reversible capacity of 162.2 mA h g-1 was maintained after 200 cycles. The improved electrochemical properties of Li2ZnTi2.9Cr0.1O8 are due to its increased electrical conductivity.

Research Progress on Na3V2(PO4)3 Cathode Material of Sodium Ion Battery.

Sodium ion batteries (SIBs) are one of the most potential alternative rechargeable batteries because of their low cost, high energy density, high thermal stability, and good structure stability. The cathode materials play a crucial role in the cycling life and safety of SIBs. Among reported cathode candidates, Na3V2(PO4)3 (NVP), a representative electrode material for sodium super ion conductor, has good application prospects due to its good structural stability, high ion conductivity and high platform voltage (~3.4 V). However, its practical applications are still restricted by comparatively low electronic conductivity. In this review, recent progresses of Na3V2(PO4)3 are well summarized and discussed, including preparation and modification methods, electrochemical properties. Meanwhile, the future research and further development of Na3V2(PO4)3 cathode are also discussed.

CDK5 inhibition in vitro and in vivo induces cell death in myeloma and overcomes the obstacle of bortezomib resistance.

The emergence of new drugs is a major feature of the treatment history of multiple myeloma (MM), which also reflects the current incurability of MM. As a unique member of cyclin dependent kinase (CDK) family, CDK5 participates in numerous tumorigenic or non­tumorigenic processes. The aim of this study is to investigate the effects of CDK5 on the viability of MM cells and bortezomib resistance using western blotting, immunohistochemistry, transient transfection, MTT assays, cell cycle analysis, apoptosis assays and a myeloma xenograft mouse model. The present study found that MM patients with high CDK5 expression in the bone marrow do not respond well to bortezomib, have higher DS stage and worse prognosis. Genetic and pharmacological (dinaciclib) inhibition of CDK5 triggers MM cell viability inhibition. Dinaciclib induces G2/M arrest and apoptosis of MM cells. In vivo experiments with myeloma xenograft mice indicate that dinaciclib significantly reduces the volume of tumors with good tolerance. Dinaciclib combined with bortezomib exerts a synergistic anti­myeloma activity accompanied by inhibiting the activation of the nuclear factor­κB pathway. This study demonstrates the important role of CDK5 in the pathogenesis, viability, prognosis and resistance to bortezomib of MM, laying a solid theoretical foundation for further clinical use of CDK5 inhibitors.

Sodium salicylate-triggered apoptosis in HL-60 cells depends on caspase-8 activation.

For investigation of the killing and proapoptotic effects of sodium salicylate (Na-Sal) on HL-60 cells, the cytotoxic activity of Na-Sal was measured by means of MTT assay. Apoptosis was identified and analyzed with the help of transmission electron microscopy, annexin V staining, and DNA gel electrophoresis, and the association of caspase-8 activation with apoptosis was determined with the specific protease inhibitor IETD-fmk. After exposure of HL-60 cells to increasing concentrations of Na-Sal (0.5, 1, 3, 5, and 7 mmol/L) for 24 hours, the mean cell viability gradually dropped to 92%, 83%, 68%, 50%, and 42%. With treatment of target cells with 5-mmol/L (IC50) Na-Sal for 6, 12, 24, or 36 hours, the mean cell survival tapered to 91%, 81%, 48% (P <.05 versus control), and 14% (P <.05 versus control). Again incubated with 5-mmol/L Na-Sal for 12 or 24 hours, HL-60 cells displayed clear early or late signs of apoptosis, including (1) notable enhancement of phosphatidylserine externalization, (2) cell shrinkage, membrane blebbing, and eventual disintegration into numerous apoptotic bodies, and (3) formation of ladder DNA. The viability of HL-60 cells increased significantly during 24 or 36 hours of coculture with 100-micromol/L IETD-fmk in combination with 5-mmol/L Na-Sal compared with the viability when 5-mmol/L Na-Sal was used alone (P < .05). Moreover, the target cells showed a considerable decrease in phosphatidylserine exposure and DNA fragmentation after coincubation for 12 or 24 hours performed as described above. The findings presented herein strongly suggest that Na-Sal can exert potent killing and proapoptotic activity against HL-60 cells, and this effect appears to depend on caspase-8 activation.

[Application of support vector machines to classification of blood cells].

The support vector machine (SVM) is a new learning technique based on the statistical learning theory. It was originally developed for two-class classification. In this paper, the SVM approach is extended to multi-class classification problems, a hierarchical SVM is applied to classify blood cells in different maturation stages from bone marrow. Based on stepwise decomposition, a hierarchical clustering method is presented to construct the architecture of the hierarchical (tree-like) SVM, then the optimal control parameters of SVM are determined by some criterion for each discriminant step. To verify the performances of classifiers, the SVM method is compared with three classical classifiers using 3-fold cross validation. The preliminary results indicate that the proposed method avoids the curse of dimensionality and has greater generalization. Thus, the method can improve the classification correctness for blood cells from bone marrow.

[Inhibitory effect of 14-3-3ζ on the proliferation of HL-60 cells and HL-60/VCR cells].

This study was aimed to investigate the expression and role of 14-3-3ζ in the AML cell lines: sensitive HL-60 and drug-resistant HL-60/VCR cells. Semi-quantitative RT-PCR and Western blot were respectively used to examine the expression of mdr1 mRNA and Pgp in AML cell lines to validate the results of microarray. Western blot was performed to investigate the expression of Pgp, 14-3-3ζ, and anti-apoptosis protein BCL-2, MCL-1 proteins. Immunofluorescence assay was used to detect the subcellular location of 14-3-3ζ protein in HL-60 and HL-60/VCR cells by laser scanning confocal microscopy. Transduction with siRNA was used to silence 14-3-3ζ in AML cell lines. Cell count method and flow cytometry of cell cycle were used to analyze the changes of growth of AML cells. The results found that mdr1 mRNA and Pgp did not expressed in HL-60 cells, but significantly overexpressed in HL-60/VCR cells. Except 14-3-3σ, the expression of other subtypes of 14-3-3 was higher in HL-60/VCR cells than that in HL-60 cells, especially 14-3-3ζ. The higher expression of 14-3-3ζ, BCL-2, MCL-1 protein was observed in HL-60/VCR cells than that in HL-60 cells. These results were same results from gene chip. It was also noticed that 14-3-3ζ was located in the cytoplasma and nuclei of AML cell lines, especially over-expressed in HL-60/VCR cells. Furthermore, suppression of 14-3-3ζ by RNA interference resulted in inhibition of the proliferation of AML cells with decreased protein expression of BCL-2 and MCL-1, especially in HL-60/VCR cells. It is concluded that 14-3-3ζ plays an important role in proliferation of AML cells and associates with BCL-2 and MCL-1 expression. These results suggested that development of therapy targeting 14-3-3ζ may provide novel, effective strategies for refractory and relapsed AML.

Bryostatin 5 induces apoptosis in acute monocytic leukemia cells by activating PUMA and caspases.

Acute leukemia is a malignant clonal hematopoietic stem cell disease. In the current study, we examined the effects of bryostatin 5 on acute monocytic leukemia cells in vitro and in vivo. We also explored the mechanisms and pathways underlying the increase in apoptosis induced by bryostatin 5. Bryostatin 5 inhibited the growth of primary acute monocytic leukemia cells and U937 cells in a dose- and time-dependent manners. Bryostatin 5 also induced an increase in apoptosis and a decrease in the mitochondrial membrane potential (MMP) in U937 cells. Transmission electron microscopy (TEM) revealed that bryostatin 5-treated cells displayed typical apoptotic characteristics (chromatin condensation, karyopyknosis and formation of crescents and apoptotic bodies). In addition, bryostatin 5 increased the expression of P53 upregulated modulator of apoptosis (PUMA) and slightly increased P53 expression. Bryostatin 5 also significantly decreased Bcl-XL expression and significantly increased the expression levels of Bak, Bax, cleaved caspase 9 and cleaved caspase 3. The pro-apoptotic activity of bryostatin 5 in U937 cells was inhibited by PUMA siRNA and z-LEHD-fmk (a specific caspase 9 inhibitor). In addition, the PUMA siRNA significantly affected the expression of cleaved caspase 9, whereas z-LEHD-fmk had little effect on the expression of PUMA. The results suggest that PUMA is located upstream of caspase 9 in this apoptotic signaling pathway. These novel findings provide mechanistic insight into the induction of apoptosis by bryostatin 5 and might facilitate the development of clinical strategies to enhance the therapeutic efficacy of treatments for acute monocytic leukemia.

Reduced tumor lysis syndrome with low dose chemotherapy for hyperleukocytic acute leukemia prior to induction therapy.

Patients with hyperleukocytic acute leukemia (HAL) can succumb to leukostasis. In an attempt to reduce its incidence, 45 patients with newly diagnosed HAL and hyperleukocytosis were administered half the conventional dose of etoposide and cytosine arabinoside (EA: 50 mg/m2 daily each) until WBC counts were significantly reduced and standard induction therapy was initiated. We retrospectively reviewed their outcomes and analyzed potential factors with a logistic regression model. The incidence of early mortality (<30 days) was 4.4% (2/45). Patients who achieved complete remission with induction chemotherapy had significantly lower median WBC counts (26x10(9) L-1) after low dose EA treatment than the no response patients (median WBC: 65x10(9) L-1 (P<0.05). Low dose EA treatment of HAL patients reduced WBC for both lymphoid and myeloid leukemic cells and can be considered for preemptive administration to HAL patients prior to the differential diagnosis of the acute leukemia. This approach warrants further studies as a cytoreduction therapy for HAL.

[Clinical analysis on 28 patients with hemophagocytic lymphohistiocytosis syndrome].

In order to profoundly understand the clinical and laboratorial characteristics and inducing factors of hemophagocytic lymphohistiocytosis syndrome (HLH), 28 HLH patients received from 2004 to 2009 years in our hospital were analyzed retrospectively. The results indicated that all of the patients had a history with prolonged fever (more than 1 week), pancytopenia, hepatosplenomegaly, elevated ferritin level, hypofibrinogen, and hemophagocytosis in bone marrow. HLH was the first characteristic sign of malignant lymphoma in 9 patients; 1 patient had a clinical manifestation similar to fulminant hepatic failure; severe psycho-abnormality occurred in 1 HLH patient and pronounced hemophagocytosis were detected in his cerebrospinal fluid; 1 patient was eventually diagnosed as having HLH by the findings in a lymph node biopsy showing obvious hemophagocytosis. Additionally, the analysis of underlying factors in 28 patients with HLH indicated 11 patients with EB virus-associated HLH, 11 with lymphoma-associated HLH, 2 with Leishmania-associated HLH, and 3 with autoimmune disease-associated HLH. It is concluded that HLH disease is characterised with high heterogenicity in both clinical features and inducing factors; in addition, the patients from a pasturing area should be paid attention to parasite infection such as leishmania.

[Effects of xbp-1 gene silencing on bortezomib-induced apoptosis in human multiple myeloma cells].

This study was purposed to investigate the effect of xbp-1 gene silencing on bortezomib-induced apoptosis in multiple myeloma cell line NCI-H929 (H929). After xbp-1 gene expression was interfered by small hairpin RNA, the cell apoptosis was assayed by flow cytometry with Annexin V-FITC/PI staining, and the expression level of XBP-1 protein was detected by Western blot. The results showed that XBP-1 protein level of H929 cells was inhibited effectively by the PLL3.7 lentiviral vector mediated expression xbp-1 shRNA. The apoptosis rate was significantly higher in xbp-1 shRNA-expressing cells than in untreated control group [(10.13±0.61)% vs (2.5±0.2)%, p<0.05]. After treatment with bortezomib, the apoptosis rate of XBP-1 protein functionally deficient H929 cells was significantly higher than those in vector control group [(45.07±1)% vs (19.53±0.8)%, p<0.05]. It is concluded that xbp-1 gene silencing can significantly enhance the pro-apoptotic activity of bortezomib in multiple myeloma cells.

[Bortezomib-induced BiP expression and apoptosis in multiple myeloma cells].

This study was aimed to explore the effect of bortezomib on the apoptosis and expression of the molecular chaperone BiP in human multiple myeloma cell line NCI-H929 (H929). After treatment of H929 cells with different concentrations of bortezomib for 24 hours, cell apoptosis was assayed by flow cytometry with Annexin V-FITC/PI staining, and the expression levels of BiP mRNA and protein were detected by RT-PCR and Western blotting analysis. The results showed that bortezomib of different concentrations (20, 40 and 80 nmol/L) induced apoptosis of H929 cells in dose-dependent manner, with apoptotic rates (15.73 +/- 0.67)%, (27.83 +/- 1.26)% and (44.17 +/- 2.25)% respectively, which were significantly higher than that in control (1.21 +/- 0.07%) (p < 0.05). Bortezomib-induced up-regulation of BiP mRNA levels was almost on a parallel with BiP protein when compared with control. Under the similar apoptosis-stimulating conditions with apoptotic rates varying from 40% to 50%, expression levels of BiP mRNA and BiP protein induced by the classical endoplasmic reticulum stressor Brefeldin A (500 ng/ml, 24 h) were almost consistent with those by bortezomib (80 nmol/L, 24 h). It is concluded that bortezomib-induced apoptosis in H929 cells correlates closely with endoplasmic reticulum stress.