Xiaolin Ge1, Fuxi Zhen2, Baixia Yang3, Xi Yang1, Jing Cai3, Chi Zhang1, Sheng Zhang1, Yuandong Cao1, Jianxin Ma4, Hongyan Cheng5, Xinchen Sun6. 1. Department of Radiotherapy, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China. 2. Department of Cardiothoracic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China. 3. Nantong Tumour Hospital, Nantong, Jiangsu Province, China. 4. Department of Radiotherapy, Second People's Hospital of Lianyungang, Lianyungang, Jiangsu Province, China. 5. Department of Synthetic Internal Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China. 6. Department of Radiotherapy, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China sunxinchen2012@163.com.
Abstract
OBJECTIVE: To determine if the pretreatment of hypoxic human oesophageal carcinoma cell lines (EC109, TE1 and KYSE170) with ginsenoside Rg3 (Rg3) increases their radiosensitivity to X-rays. METHODS: The growth inhibitory effect of different Rg3 concentrations was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. Radiation sensitivity was measured using a clone formation assay and flow cytometry was used to measure the effects of Rg3 on radiation-induced apoptosis. Western blot analysis was used to measure the effects of Rg3 on the levels of hypoxia inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF). RESULTS: Rg3 inhibited EC109, TE1 and KYSE170 cell growth in a dose- and time-dependent manner. Pretreatment with 10 µmol/ml Rg3 increased EC109, TE1 and KYSE170 radiosensitivity. Rg3 plus radiation significantly increased the apoptosis rate compared with radiation alone. Rg3 also decreased VEGF and HIF-1α protein levels in EC109 cells in a dose-dependent manner. The combination of Rg3 and radiation increased the fragmentation of double-stranded DNA. CONCLUSION: Rg3 enhanced the radiosensitivity of human oesophageal carcinoma cell lines cultured under hypoxic conditions possibly by downregulating VEGF and HIF-1α protein levels.
OBJECTIVE: To determine if the pretreatment of hypoxic human oesophageal carcinoma cell lines (EC109, TE1 and KYSE170) with ginsenoside Rg3 (Rg3) increases their radiosensitivity to X-rays. METHODS: The growth inhibitory effect of different Rg3 concentrations was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. Radiation sensitivity was measured using a clone formation assay and flow cytometry was used to measure the effects of Rg3 on radiation-induced apoptosis. Western blot analysis was used to measure the effects of Rg3 on the levels of hypoxia inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF). RESULTS: Rg3 inhibited EC109, TE1 and KYSE170 cell growth in a dose- and time-dependent manner. Pretreatment with 10 µmol/ml Rg3 increased EC109, TE1 and KYSE170 radiosensitivity. Rg3 plus radiation significantly increased the apoptosis rate compared with radiation alone. Rg3 also decreased VEGF and HIF-1α protein levels in EC109 cells in a dose-dependent manner. The combination of Rg3 and radiation increased the fragmentation of double-stranded DNA. CONCLUSION: Rg3 enhanced the radiosensitivity of humanoesophageal carcinoma cell lines cultured under hypoxic conditions possibly by downregulating VEGF and HIF-1α protein levels.