Synergistic effect of Hsp90 inhibitor ginkgolic acids C15 ꞉1 combined with paclitaxel on nasopharyngeal carcinoma / 中南大学学报(医学版)

OBJECTIVES@#Nasopharyngeal cracinoma is a kind of head and neck malignant tumor with high incidence and high mortality. Due to the characteristics of local recurrence, distant metastasis, and drug resistance, the survival rate of patients after treatment is not high. Paclitaxel (PTX) is used as a chemotherapy drug in treating nasopharyngeal carcinoma, but nasopharyngeal carcinoma cells are easy to develop resistance to PTX. Inhibition of heat shock protein 90 (Hsp90) can overcome common signal redundancy and resistance in many cancers. This study aims to investigate the anti-tumor effect of ginkgolic acids C15꞉1 (C15:1) combined with PTX on nasopharyngeal carcinoma CNE-2Z cells and the mechanisms.@*METHODS@#This experiment was divided into a control group (without drug), a C15:1 group (10, 30, 50, 70 μmol/L), a PTX group (5, 10, 20, 40 nmol/L), and a combination group. CNE-2Z cells were treated with the corresponding drugs in each group. The proliferation of CNE-2Z cells was evaluated by methyl thiazolyl tetrazolium (MTT). Wound-healing assay and transwell chamber assay were used to determine the migration of CNE-2Z cells. Transwell chamber was applied to the impact of CNE-2Z cell invasion. Annexin V-FITC/PI staining was used to observe the effect on apoptosis of CNE-2Z cells. The changes of proteins involved in cell invasion, migration, and apoptosis after the combination of C15꞉1 and PTX treatment were analyzed by Western blotting.@*RESULTS@#Compared with the control group, the C15꞉1 group and the PTX group could inhibit the proliferation of CNE-2Z cells (all P<0.05). The cell survival rates of the C15꞉1 50 μmol/L combined with 5, 10, 20, or 40 nmol/L PTX group were lower than those of the single PTX group (all P<0.05), the combination index (CI) value was less than 1, suggesting that the combined treatment group had a synergistic effect. Compared with the 50 μmol/L C15꞉1 group and the 10 nmol/L PTX group, the combination group significantly inhibited the invasion and migration of CNE-2Z cells (all P<0.05). The results of Western blotting demonstrated that the combination group could significantly down-regulate Hsp90 client protein matrix metalloproteinase (MMP)-2 and MMP-9. The results of double staining showed that compared with the 50 μmol/L C15꞉1 group and the 10 nmol/L PTX group, the apoptosis ratio of CNE-2Z cells in the combination group was higher (both P<0.05). The results of Western blotting suggested that the combination group could decrease the Hsp90 client proteins [Akt and B-cell lymphoma-2 (Bcl-2)] and increase the Bcl-2-associated X protein (Bax).@*CONCLUSIONS@#The combination of C15꞉1 and PTX has a synergistic effect which can inhibit cell proliferation, invasion, and migration, and induce cell apoptosis. This effect may be related to the inhibition of Hsp90 activity by C15꞉1.

Effect of methanol-ethyl acetate partitioned fractions from on proliferation and apoptosis of human non-small cell lung cancer H1975 cells / 南方医科大学学报

OBJECTIVE@#To investigate the effects of methanol-ethyl acetate partitioned fractions from (MEDS) on the proliferation and apoptosis of human non-small cell lung cancer H1975 cells.@*METHODS@#The systemic solvent extraction method was used to preliminary separation of the effective fractions in the methanol extract of . The cytotoxicity of each extract (5, 10, 20, 40, and 80 μg/mL) was tested using MTT assay. Colony cloning method was used to assess the effect of different concentrations of methanol-ethyl acetate partitioned fractions from MEDS (5, 10, 20, 40, and 80 μg/ mL) on the proliferation of H1975 cells. Flow cytometric analysis with Annexin V-FITC/PI staining was performed to detect the apoptosis of the cells after treatment with different concentrations of MEDS fractions (10, 20, and 40 μg/mL). Western blotting was used to evaluate the effects of MEDS fractions on the expressions of apoptosis-related proteins Akt, Bax, and Bcl-2. The anti-tumor activity of 100 mg/kg MEDS fractions was tested in a nude mouse model bearing H1975 cell xenografts.@*RESULTS@#MTT assay and colony forming experiment showed that MEDS fractions significantly inhibited the proliferation of H1975 cells in a dose-and time-dependent manner ( < 0.05). The results of flow cytometry showed that MEDS fractions induced obvious apoptosis of H1975 cells in a concentration-dependent manner ( < 0.05). MEDS fractions also significantly decreased the expressions of Bcl-2 and Akt protein and increased the protein expression of Bax ( < 0.05). In the tumor-bearing nude mouse model, MEDS fractions showed potent anti-tumor effects with a low toxicity to affect the body weight and organs of the mice.@*CONCLUSIONS@#The methanol-ethyl acetate partitioned fractions from MEDS show potent anti-tumor activity both and , suggesting their value as promising therapeutic agents against lung cancer.

Effect of anacardic acid, a Hsp90 inhibitor, on proliferation, invasion and migration of breast cancer MDA-MB-231 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of the Hsp90 inhibitor anacardic acid on cell proliferation, invasion and migration of breast cancer MDA-MB-231 cells.</p><p><b>METHODS</b>The inhibitory effect of anacardic acid on Hsp90 was assessed with in vitro ATPase inhibition assay and ATP-sepharose binding assay. MTT assay was used to detect the growth inhibition induced by anacardic acid in MDA-MB-231 cells. Transwell assays were used to evaluate MDA-MB-231 cell invasion and migration. Western blotting was performed to assess the effect of anacardic acid in triggering the degradation of MMP-9, TIMP-1, Hsp90, and Hsp70.</p><p><b>RESULTS</b>Anacardic acid exhibited a modest activity of ATPase inhibition with an IC50 value of 82.5 µmol/L. Anacardic acid significantly suppressed the proliferation of MDA-MB-231 cells in a dose-dependent manner (IC50 value of 29.3 µmol/L). Treatment with 12.5, 25, and 50 µmol/L anacardic acid for 36 h caused inhibition of cell invasion by 23.6%, 56.6%, and 67.0% in MDA-MB-231 cells, respectively (P<0.05), and anacardic acid treatment for 24 h inhibited the cell migration by 30.0%, 45.5%, and 77.5%, respectively (P<0.05). Anacardic acid dose-dependently induced MMP-9 degradation, but did not obviously affect Hsp90 or Hsp70 expressions.</p><p><b>CONCLUSION</b>Anacardic acid can significantly inhibit the proliferation, invasion, and migration of MDA-MB-231 cells, the mechanism of which may involve the inhibition of Hsp90 ATPse activity and down-regulation of MMP-9 expression.</p>

Transglycosylation of neolignans by enzymatic synthesis and evaluation of their antitumor activity / 南方医科大学学报

<p><b>OBJECTIVE</b>To improve the water solubility and biological activity of neoligans (magnolol and honokiol) and test the antitumor activity of the modified compounds.</p><p><b>METHODS</b>The glycosylated products of magnolol and honokiol were obtained by enzymatic synthesis using a UDP-glycosyltransferase (YjiC) from Bacillus. The products were characterized by high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR) analysis. MTT assay was used to detect the growth inhibition of 4 human cancer cell lines induced by the compounds.</p><p><b>RESULTS</b>We obtained two glucosides of neolignans (magnolol and honokiol) for the first time by enzymatic synthesis using a UDP-glycosyltransferase. Based on the spectroscopic data, the glucosides were identified as magnolol-2- O-β-D-glucopyranoside (1) and honokiol-4'-O-β-D-glucopyranoside (2). Compounds 1-4 exhibited moderate anti-proliferative activities against the 4 human cancer cell lines, with IC50 values ranging from 9.41 to 111.21 µmol/L.</p><p><b>CONCLUSION</b>The glycoslated products show enhanced water solubility and drug sensitivity against SMMC7721 cells, suggesting their value as potential therapeutic drugs.</p>

3-bromopyruvate enhances cisplatin sensitivity of hepatocellular carcinoma cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of 3-bromopyruvate (3-BP) in sensitizing hepatocellular carcinoma cells to cisplatin-induced apoptosis and its possible mechanism.</p><p><b>METHODS</b>The growth inhibition of HepG2 and SMMC7721 cells following exposures to different concentrations of 3-BP and cisplatin was measured by MTT assay. The apoptosis of cells treated with 100 µmol/L 3-BP with or without 8 µmol/L cisplatin was assessed using flow cytometry with PI staining, and the activity of caspase-3 and intracellular ATP level were detected using commercial detection kits; the expression of XIAP and PARP was analyzed using Western blotting.</p><p><b>RESULTS</b>3-BP produced obvious inhibitory effects on HepG2 and SMMC7721 cells at the concentrations of 50-400 µmol/L with IC50 values of 238.9∓13.9 µmol/L and 278.7∓11.7 µmol/L for a 48-h treatment, respectively. Cisplatin also inhibited the growth of HepG2 and SMMC7721 cells at the concentrations of 2-32 µmol/L, with IC50 values of 16.4∓0.9 µmol/L and 20.9∓1.8 µmol/L after a 48-h treatment, respectively. Treatment with 100 µmol/L 3-BP combined with 8 µmol/L cisplatin for 48 h resulted in a growth inhibition rate of (60.6∓2.2)% in HepG2 cells and (56.8∓2.3)% in SMMC7721 cells, which were significantly higher than those in cells treated with 3-BP or cisplatin alone. The combined treatment for 48 h induced an apoptotic rate of (51.1∓4.3)% in HepG2 cells and (46.5∓3.9)% in SMMC7721 cells, which were also markedly higher than those in cells with 3-BP or cisplatin treatment alone.</p><p><b>CONCLUSION</b>3-BP can sensitize HepG2 and SMMC7721 cells to cisplatin-induced apoptosis possibly by causing intracellular ATP deficiency, down-regulating XIAP, and increasing caspase-3 activity.</p>