Glycosylation inhibitor 2-deoxy-D-glucose sensitizes oral cancer cells to TRAIL-induced apoptosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of 2-deoxy-D-glucose (2-DG) in enhancing the sensitivity of oral cancer cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis.</p><p><b>METHODS</b>The oral cancer cell line KB was incubated in the presence of different concentrations (0, 0.625, 1.25, 2.5, 5, and 10 mmol/L) of 2-DG with or without TRAIL (200 ng/ml). The cell viability was measured using MTT assay and cell apoptosis was detected using flow cytometry with propidium iodide (PI) staining. KB cells treated with 5 mmol/L 2-DG with or without TRAIL for 0, 6, 16, or 24 h were examined with Western blotting for protein expressions of death receptor 5 (DR5) and caspase-3.</p><p><b>RESULTS</b>Treatment of the cells with 5 mmol/L 2-DG for 24, 48 and 72 h resulted in a cell viability of 25.25%, 69.06%, and 59.19%, respectively. Combined treatment with 5 mmol/L 2-DG with TRAIL for 24 significantly enhanced the cell apoptotic rate (72.5%) as compared to the rate induced by TRAIL alone (45.3%) and by 2-DG (15.9%) alone. 2-DG treatment markedly up-regulated DR5 and caspase-3 expression and enhanced the inhibitory effect of TRAIL on cell colony formation.</p><p><b>CONCLUSION</b>2-DG sensitizes oral cancer cells to TRAIL- induced apoptosis by up-regulating DR5 and caspase-3 expressions.</p>

Small interfering RNA-mediated RIP1 knockdown enhances L-OHP sensitivity of human oral squamous carcinoma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of small interfering RNA-mediated receptor-interacting protein kinase 1 (RIP1) knockdown on the sensitivity of human oral squamous carcinoma cells to to oxaliplatin (L-OHP)-induced apoptosis and explore a new target for clinical treatment of oral squamous carcinoma.</p><p><b>METHODS</b>The viability of human oral squamous carcinoma cell line KB exposed to different concentrations (0, 0.25, 0.5, 1, 2, 4 µmol/L) of L-OHP were detected by MTT assay. PI/Annexin V staining was used to observe cell apoptosis in naive KB cells, cell and transfected with pSH1Si-RIP1 or with the empty plasmid. Western blotting was used to detect RIP1 expression in KB cells exposed to L-OHP and in cells transfected with pSH1Si-RIP1.</p><p><b>RESULTS</b>Exposure to L-OHP (1µmol/L) for 24, 48, 72 h resulted in KB cell survival rates of 67.66%, 55.17%, and 41.34%, respectively, but the cell apoptosis rate was only 9.6% following a 24-h exposure. KB cells transfected with pSH1Si-RIP1 showed an apoptotic rate of 9.4%, which increased to 29.1% following L-OHP exposure. RIP1 expression was first up-regulated and then down-regulated in KB cells treated with L-OHP, and was significantly reduced after cell transfection with pSH1Si-RIP1.</p><p><b>CONCLUSION</b>Suppression of RIP1 expression increases the apoptotic rate of human oral squamous carcinoma cells, suggesting the potential of RIP1 as a new candidate target for clinical treatment of oral squamous carcinoma.</p>

Small interfering RNA-mediated glucose-regulated protein 78 knockdown enhances chemosensitivity of breast cancer cells to cisplatin / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of small interfering RNA-mediated glucose-regulated protein 78 (GRP78) knockdown on the chemosensitivity of breast cancer cells to cisplatin.</p><p><b>METHODS</b>Human breast cancer cell line MDA-MB-231 was exposed to different doses of cisplatin (0, 1, 2, 4, 8, and 16 µmol/L), and the changes in cell viability were detected using MTT assay. PI/Annexin V staining was used to observe the apoptosis of the cells in response to transfection with a small interfering RNA targeting GRP78 (pSH1Si-GRP78). Western blotting was employed to detect GRP78 expression in pSH1Si- GRP78-transfected cells after exposure to 8 µmol/L cisplatin for 24, 48 and 72 h.</p><p><b>RESULTS</b>Exposure of the cells to 8 µmol/L cisplatin for 24, 48 and 72 h resulted in a cell survival rate of 83.13%, 54.22% and 35.79%, respectively, but the cell apoptosis rate was only 10.8% at 24 h. Transfection of MDA-MB-231 cells with pSH1Si-GRP78 caused a cell apoptosis rate of 24.6%, which increased to 48.9% in cells with both pSH1Si-GRP78 transfection and cisplatin exposure. Cisplatin exposure caused an initial up-regulation followed then by a down-regulation of GRP78 expression in MDA-MB-231 cells, while pSH1Si-GRP78 transfection produced an obvious down-regulation of GRP78 expression.</p><p><b>CONCLUSIONS</b>Inhibition of GRP78 expression increases the apoptosis and enhance cisplatin chemosensitivity of breast cancer cells in vitro, suggesting the value of GRP78 as a potential therapeutic target in the clinical treatment of breast cancer.</p>

Effects of cisplatin combined with heparanase inhibitor on proliferation and invasion of human nasopharyngeal carcinoma cells / 药学学报

This study is to investigate the effects of cisplatin combined with heparanase inhibitor OGT2115 on proliferation, invasion and migration of human nasopharyngeal carcinoma cells CNE-2 and to provide a new target for the treatment of metastasis of nasopharyngeal carcinoma. MTT assay was used to detect the cell viability of CNE-2 after exposure to different concentrations of DDP (2, 4, 8, 16 and 32 micromol x L(-1)), different concentrations of OGT2115 (0.4, 0.8, 1.6, 3.2 and 6.4 micromol x L(-1)), and DDP combined with OGT2115. Transwell assay was applied to analyze the effects of drugs on invasion and migration of human nasopharyngeal carcinoma cells. Wound healing assay was performed to detect cell migration and heparanase activity was analyzed by ELISA. MTT results showed that DDP can inhibit the proliferation of CNE-2 cells in a time and concentration-dependent manner, with an IC50 of 24.03 micromol x L(-1) at 24 h (P < 0.05), low concentration of DDP has almost no inhibitory effect on cell invasion and migration. DDP combined with OGT2115 can significantly inhibit cell invasion and migration. Inhibition of heparanase can significantly enhance anti-invasion and anti-proliferation of DDP.

Effect of low-molecular-weight heparin combined with paclitaxel on the invasiveness and migration of nasopharyngeal carcinoma cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of low-molecular-weight heparin (LMWH) combined with paclitaxel (PTX) on the invasiveness and migration of nasopharyngeal carcinoma cells and explore the molecular mechanisms.</p><p><b>METHODS</b>MTT assay was used to detect the growth inhibition induced by LMWH and PTX in CNE1 and CNE2 cells. Wound healing assay and Transwell migration assay were employed to assess the effects of the drugs on the cell migration, and Transwell invasion assay was used to evaluate the cell invasiveness. The cellular expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were analyzed by Western blotting. ELISA was used to determine the expression of heparanase (HPA) in the culture medium of the cells.</p><p><b>RESULTS</b>MTT assay showed an obvious suppression of CNE1 and CNE2 cell proliferation in response to LMWH and PTX treatments. Treatment with 200 U·ml LMWH combined with 0.1 µmol·L PTX for 24 h resulted in the inhibition rates of migration of 66.70% and 70.53% in CNE1 and CNE2 cells, respectively significantly higher than the rates in cells with PTX treatment alone. The combined treatment with LMWH and PTX for 24 h also caused a significantly higher inhibition rate of cell invasion than LMWH and PTX alone. LMWH enhanced the down-regulation of MMP-9 and HPA induced by PTX.</p><p><b>CONCLUSION</b>LMWH can enhance the inhibitory effect of PTX on the migration and invasion of nasopharyngeal carcinoma cells, the mechanism of which may involve the down-regulation of MMP-9 and HPA expressions.</p>