ABSTRACT
<p><b>OBJECTIVE</b>To explore the synergetic effect of norcantharidin (NCTD) and adriamycin (ADR) on the proliferation and apoptosis of multiple myeloma (MM) cells.</p><p><b>METHODS</b>Human MM cell line U266 cells were treated with NCTD alone (10 µmol/L) or in combination with ADR (0.25 µmol/L). MTT and Annexin V/PI staining were used to determine cell viability and apoptosis. The protein expression of nuclear factor-κB P65 (NF-κB P65), phosphorylated NF-κB p65 (p-NF-κB p65), NF-κB P65 inhibitor IκBα, phosphorylated IκBα (p-IκBα), survivin, Bcl-2 and Bax were determined by Western blot. Immunohistochemistry was used to determine the expression of vascular endothelial growth factor (VEGF).</p><p><b>RESULTS</b>(1) NCTD potentiated the cytotoxicity and pro-apoptotic effects induced by ADR. The combination of NCTD and ADR had synergistic anti-proliferation effect. (2) Combination of ADR and NCTD downregulated the expression of nuclear NF-κB P65 and cytoplasm p-IκBα induced by ADR. The expression of nuclear NF-κB P65 and cytoplasm p-IκBα decreased from 2.08 ± 0.29 and 0.39 ± 0.07 to 0.48 ± 0.08 and 0.02 ± 0.01 respectively, while the expression of the cytoplasm NF-κB P65 and IκBα were unchanged in the ADR alone group and the combined group. (3) The expression of survivin and bcl-2 decreased from 0.31 ± 0.05 and 0.23 ± 0.05 to 0.03 ± 0.02 and 0.05 ± 0.02, while the expression of Bax increased from 0.46 ± 0.06 to 0.62 ± 0.08 respectively in ADR alone group and combined group. (4) The positive rate of VEGF in ADR group and combination group were (44.6 ± 4.4)% and (27.0 ± 2.1)% respectively, indicating that NCTD could potentiate the inhibition effect on VEGF induced by ADR.</p><p><b>CONCLUSIONS</b>The results suggest that NCTD can potentialize the chemosensitivity of multiple myeloma cells to ADR through regulating NF-κB/IκBα signaling pathway and NF-κB-regulated gene products including survivin, Bcl-2, Bax and VEGF.</p>
Subject(s)
Humans , Bridged Bicyclo Compounds, Heterocyclic , Pharmacology , Cell Line, Tumor , Cell Proliferation , Down-Regulation , Doxorubicin , Pharmacology , I-kappa B Proteins , Metabolism , Inhibitor of Apoptosis Proteins , Metabolism , Multiple Myeloma , Metabolism , NF-KappaB Inhibitor alpha , Proto-Oncogene Proteins c-bcl-2 , Metabolism , Signal Transduction , Transcription Factor RelA , Metabolism , Vascular Endothelial Growth Factor A , Metabolism , bcl-2-Associated X Protein , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To explore the role of angiogenesis in bone marrow in acute myeloid leukemia (AML).</p><p><b>METHODS</b>Bone marrow culture supernatant was assayed for vascular endothelial growth factor (VEGF) by ELISA, bone marrow biopsies from 28 newly diagnosed AML patients were assayed for microvessel density (MVD), VEGF and its receptors KDR, Flt-1 by immunohistochemical staining before and after induction chemotherapy.</p><p><b>RESULTS</b>Culture supernatant of AML bone marrow mononuclear cells showed higher amount of VEGF (425.31 ng/L) than that of control (140.12 ng/L). The VEGF and KDR expressions and MVD were significantly higher in newly diagnosed AML patients (78.6%, 78.6% and 7.1%, respectively) than that of control group (P < 0.05). There was a positive correlation between VEGF, KDR and MVD. The positive rate of VEGF, KDR and MVD reduced to normal after the patients achieved complete remission, while in non-remission patients did not. Kaplan-Meier analysis showed that the survival time was longer in VEGF negative group than in VEGF positive group. The pre-treatment MVD and VEGF had no correlation with survival time.</p><p><b>CONCLUSIONS</b>There is remarkable angiogenesis in AML and VEGF/KDR signaling pathway takes an important role in the pathological angiogenesis. VEGF could be used as a prognostic factor in AML.</p>