Hong-Tao Gu

Fourth Military Medical University, Xi’an, Liaoning, China

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Publications (13)2.17 Total impact

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    ABSTRACT: 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. © 2014 S. Karger AG, Basel.
    Acta Haematologica 01/2014; 132(2):177-86. · 0.89 Impact Factor
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    ABSTRACT: To compare the efficacy and safety of standard or reduced doses of bortezomib combined with adriamycin and dexamethasone (PAD) in patients with multiple myeloma (MM). Eighty-two newly diagnosed or refractory/relapsed patients received bortezomib [either 1.2-1.3 mg/m² (standard dose) or 1.0-1.1 mg/m² (reduced dose) on day 1, 4, 8 and 11], and adriamycin (10 mg/m²) plus dexamethasone (40 mg/m²) on day 1-4 at 3-week intervals for 1 to 6 courses. The International Myeloma Working Group Criteria were used to evaluate the response. Adverse events were graded according to the National Cancer Institute Common Toxicity Criteria (Version 3.0). Two courses of standard dose of PAD resulted in a similar response rate of partial and very good partial complete remissions (PR) compared with reduced dose (80.0% vs 80.8%, P=0.728). Grade III- Ⅳ neutropenia and thrombocytopenia were higher with standard dose than that with reduced doses of PAD (21.1% vs11.1%, P=0.270; 10.5% vs 6.3%, P=0.619, respectively). Grade III-Ⅳbortezomib-induced peripheral neuropathy, herpes zoster, fatigue or abdominal distention were significantly higher with standard dose than that with reduced dose of PAD (15.8% vs 1.6%, P=0.037; 26.3% vs 6.3%, P=0.028; 36.8% vs 14.3%, P=0.046; 15.8% vs 1.6%, P=0.037, respectively). Reduced dose of PAD appears to result in a similar overall response rate, but a better tolerance and safety compared with standard dose.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 07/2013; 34(7):622-625.
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    ABSTRACT: This study was purposed to investigate the effect of triptolide on bortezomib-induced apoptosis in multiple myeloma cell line NCI-H929(H929). MTT assay was applied to detect the inhibitory effects of triptolide and bortezomib alone or combined at different concentrations on H929 cells, the cell apoptosis was assayed by flow cytometry with Annexin V-FITC/PI staining. The results showed that both triptolide (10 - 100 ng/ml) and bortezomib (10 - 100 nmol/L) alone or combination inhibited the proliferation of MM cell line H929 in a concentration-dependent manner. The apoptotic rate of H929 cells in group of triptolide combined with bortezomib was much higher than that in groups of single drug or control; moreover, the apoptotic rate of H929 cells treated by non-inhibitory concentration of triptolide (10 ng/ml) combined with bortezomib (40 nmol/L) for 24 h was significantly higher than that by bortezomib alone (P < 0.05). It is concluded that triptolide can significantly enhance the pro-apoptotic activity of bortezomib in MM cells.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 03/2012; 20(2):335-8.
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    ABSTRACT: 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.
    Asian Pacific journal of cancer prevention: APJCP 01/2011; 12(7):1807-11. · 1.27 Impact Factor
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    ABSTRACT: 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.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 10/2010; 18(5):1177-80.
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    ABSTRACT: To investigate the expression of mDia1 (mammalian diaphanous 1)in platelet and the role of mDia1 or phosphatidylinositol 3-kinase (PI3K) in the process of thrombin-induced platelet aggregation. The extent of platelet aggregation was measured by a platelet aggregation system and the expression of mDia1 and its relation with F-actin in quiescent, spreading or aggregated platelets by Western blot. There was no significant difference in mDia1 expression level between quiescent and activated platelets. mDia1 moved from a Triton-X100-soluble cytosolic fraction to insoluble cytoskeleton fraction after thrombin induced platelets aggregation. Anti-mDia1 antibody could inhibit this aggregation. PI3K inhibitor Wortmannin or Ly294002 inhibited the thrombin induced platelet aggregation and the above mentioned mDia1 translocation. PI3-kinase mediates the thrombin-induced platelet aggregation through mDia1 pathway.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 03/2010; 31(3):176-80.
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    ABSTRACT: The aim of this study was to investigate the role of RhoA/mDia1 pathway in the process of thrombin-induced platelet aggregation and regulatory effect of PI3K inhibitor on this process. The human platelets were isolated from peripheral blood, the activation of RhoA, Rac1 and Cdc42 in the platelet aggregation was detected by GST pull-down assay and immune co-precipitation, the interaction of RhoA, Rac1 and Cdc42 with mDia1 and the formation of complex in the process of platelet aggregation were determined by immune coprecipitation, and the effect of PI3K inhibitor (wortmannin) on above-mentioned process was assayed. The results showed that thrombin elevated the activity of RhoA and the binding capability of RhoA with mDia1 during thrombin-induced platelet aggregation and spreading on Fg coated coverslips. Wortmannin inhibited the rising of RhoA activity and the binding level of RhoA with mDia1 induced by thrombin. Thrombin elevated the activity of Rac1 and Cdc42 during thrombin-induced platelet aggregation, but could not induce binding of Rac1 or Cdc42 with mDia1. Wortmannin could not inhibit the rising of Rac1 and Cdc42 activity induced by thrombin. It is concluded that the PI3-kinase regulates the thrombin-induced actin cytoskeleton reconstitution in platelets by RhoA-mDia1 pathway.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 12/2009; 17(6):1555-9.
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    ABSTRACT: To investigate the efficacy and safety of PAD [bortezomib (PS-341), doxorubicin and dexamethasone] regimen for relapsed or refractory multiple myeloma (MM). Seventeen patients with relapsed or refractory MM received two to four 21-day cycles of PAD: an intravenous bolus of bortezomib (1.3 mg/m2) on days 1, 4, 8, and 11; doxorubicin 10 mg per day on days 1 to 4, and dexamethasone 40 mg on days 1-4. Response was evaluated according to International Myeloma Working Group Criteria (IMWG 2006), toxicity was graded according to NCI CTCAE (common terminology criteria for adverse events) v 3.0. After 2-4 courses of PAD, 14 patients (82.4%) response, including complete response (CR) in 4 (23.5%), very good partial response (VGPR) in 4 (23.5%), partial response (PR) in 6 (35.3%) and stable disease (SD) in 3 (17.6%). Median time to progression was 9.5 months. The median course to response was 1.6 (1-3). All of 5 patients with extramedullary plasmacytoma achieved at least PR after the first cycle therapy; the plasmacytoma disappeared after 1-2 cycles of PAD. The efficacy was independent of other prognostic factors such as beta2-MG. Adverse events included thrombocytopenia in 9 patients (52.9%), leukopenia in 4 (23.5%), peripheral neuropathy in 4 (23.5%), varicella herpes zoster in 3 (17.6%), fatigue in 6 (35.3%) and diarrhea in 2 (11.7%). All of these adverse reactions could be controlled with routine supportive treatment, only one patient died from respiratory failure during his fifth PAD cycle. PAD regimen should be considered as an appropriate treatment for relapsed or refractory MM, especially for MM with extramedullary plasmacytoma. Its efficacy is independent of traditional prognostic factors. The side effects are usually manageable.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 05/2009; 30(4):260-3.
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    ABSTRACT: 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.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 03/2009; 17(1):107-10.
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    ABSTRACT: Cytomegalovirus (CMV) infection is a dangerous complication in patients with chronic graft versus host disease (cGVHD). CMV-specific immunity depends on the activity of T cells. This study was aimed to investigate the effect of CMV pp65 gene modified dendritic cells (DCs) on activation of autologous T cells. Lentivirus system was utilized to introduce the CMV full-length pp65 gene into mouse DCs; CpG-DNA was used to induce mature DCs; flow cytometry and immunofluorescence were used to determine the expression of antigen and IFNgamma in T lymphocytes. The results showed that the DCs were infected with lentivirus at a multiplicity of infection (MOI) of 50 with optimal infectious efficiency of 30%-40%; mature DCs expressing pp65 gene could stimulate autologous naive T cells to express CD69 specifically; mature DCs expressing PP65 could stimulate autologous CD4+ or CD8+ T cells to produce IFNgamma. It is concluded that CMV pp65-modified and CpG-DNA-induced mature DCs can activate CMV-specific T lymphocytes in vitro.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 05/2008; 16(2):397-400.
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    ABSTRACT: To explore the mechanisms of suppression growth and induction apoptosis of curcumin on human multiple myeloma cell line RPMI8226, the suppressive effect of curcumin on RPMI8226 was examined by MTT assay; the induction apoptosis and cell cycle arrest of curcumin on RPMI8226 were determined by flow cytometry (FCM); the changes of survivin, Bcl-2, Bax mRNA levels were detected by RT-PCR. The results showed that curcumin obviously suppressed the proliferation of RPMI8226 in both time- and dose-dependent manners, and the IC(50) were 12.15 micromol/L, 4.9 micromol/L for 24 and 48 hours respectively. FCM indicated that the apoptosis ratio rose from 10.6% of untreated cells up to 36.9% of treated cells (p < 0.05), and curcumin arrested cell cycle of RPMI8226 at G(2)/M phase. RT-PCR showed that RPMI8226 cells expressed survivin, Bcl-2 strongly and Bax slightly; while RPMI8226 cells were treated with curcumin 10 micromol/L for 24 hours, the expressions of survivin, Bcl-2 mRNA were apparently down-regulated, and the expression of Bax mRNA was markedly up-regulated. It is concluded that curcumin can suppress the proliferation of human multiple myeloma cell line RPMI8226, and induce their apoptosis. The mechanism of antitumous effect of curcumin may be related to down-regulation of survivin, Bcl-2 mRNA and up-regulation of Bax mRNA.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 09/2007; 15(4):762-6.
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    ABSTRACT: To study the effect of platelet factor 4 (PF4) on murine bone marrow cell apoptosis after irradiation with 5.0 Gy (60)COgamma and explore its potential mechanism. 30 male BALB/c mice were randomly divided into three groups: namely normal control group (n = 6), PF4 treatment group (n=12) and irradiation (IR) group (n = 12). The mice in PF4 treatment group were administrated intraperitoneally PF4 40 microg/kg at 26 h and 20 h respectively before total-body irradiation with 5.0 Gy (60)COgamma ray. At 4 h and 20 h after irradiation the apoptosis of bone marrow cells were detected by flow cytometry (FCM) and the expression of Bax protein was identified by Western blot. At 4 h and 20 h after irradiation the apoptosis of bone marrow cells in PF4 treatment group was significantly lower than that in IR group (P < 0.01), the expression of Bax protein in the PF4 group was lower than that in the IR group (P < 0.05). PF4 can protect bone marrow cells from radiation-induced apoptosis, which is partly due to the down-regulation of proapoptotic protein Bax expression.
    Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 09/2007; 23(9):813-5.
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    ABSTRACT: To study the effects of tyrosine-kinase inhibitor STI571 on the adhesion of RPMI8226 cells to fibronectin (FN), cell adhesion mediated adriamycin-resistance and the Rac1 mRNA expression, the adhesion of RPMI8226 cells to fibronectin and drug resistance mediated by cell adhesion were determined by means of crystal violet staining and MTT assays respectively, Rac1 mRNA levels in RPMI8226 cells were examined by semi-quantitative RT-PCR. The results showed that STI571 could inhibit the adhesion of RPMI8226 cells to fibronectin. When RPMI8226 cells had been adhered to FN or BSA-coated wells for 1, 6 and 12 hours, the adhesion rates were (43.71 +/- 2.18)%, (55.63 +/- 1.56)%, and (63.42 +/- 2.46)% respectively. After treatment with STI571 20 micromol/L, the adhesion rates decreased to (15.12 +/- 1.04)%, (17.58 +/- 1.32)% and (17.24 +/- 1.59)% respectively (P < 0.05). The experiment revealed that growth of RPMI8226 cells adhered to FN-coated plates had a significant advantage over growth on BSA-coated plates when exposed to adriamycin (Adr) for 1 hour followed by a 24-hour culture period, and the mean IC(50) value for FN-adhered cells was (1.46 +/- 0.04) micromol/L while mean IC(50) value for BSA control was (0.78 +/- 0.03) micromol/L (P < 0.05). Following treatment with 20 micromol/L STI571, the mean IC50 values for FN and BSA adhered cells were (0.81 +/- 0.05) micromol/L, (0.74 +/- 0.02) micromol/L respectively, there was no significant difference between them (P > 0.05). RT-PCR demonstrated that the relative Rac1 mRNA level (Rac1/GAPDH) in RPMI8226 cells was downregulated following being treated with 20 micromol/L STI571. It is concluded that STI571 can inhibit the adhesion of RPMI8226 cells to fibronectin, reverse cell adhesion mediated adriamycin-resistance, and downregulate Rac1 mRNA level.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 04/2006; 14(2):267-70.