Dual effects of 8-Br-cAMP on differentiation and apoptosis of human esophageal cancer cell line Eca-109

AIM: To investigate the effects of 8-Br-cAMP on differentiation and apoptosis of human esophageal cancer cell line Eca-109, and the related gene expression.METHODS: The cultured Eca-109 cells were divided into four groups: E1 group (co-cultured with 8-Br-cAMP for 24 h); E2 group (co-cultured with 8-Br-cAMP for 48 h); C1 group (treated without 8-Br-cAMP for 24 h); and C2 group (treated without 8-Br-cAMP for 48 h). The same concentration of cell suspension of each group was dropped separately onto the slides and nitrocellulose membranes (NCM). The biotin-labeled cDNA probes for c-myc, wild-type (wt) p53, bcl-2 and iNOS were prepared for in situ hybridization. The expressions of epidermal growth factor receptor (EGFR), p38 kinase, FAS, FasL and caspase-3 were detected using immunocytochemistry, and the NOS activity and the ratio of differentiated cells/proliferating cells were examined by cytochemistry. Immunocytochemistry, cytochemistry,and in situ hybridization were separately carried out on both slides and NCM specimens for each group. In addition, TUNEL was used to detect the cell apoptosis rate in each group.RESULTS: The apoptotic rate of E2 group was significantly higher compared to E1 group, while there was no difference in the ratio of differentiated cells/ proliferating cells between E1 and E2 groups. The signals of wt p53 and iNOS were markedly stronger, while the signals of c-myc and EGFR were obviously weaker in E1 group than those in C1 group (P＜0.05). Moreover, the signals of wt p53, iNOS, p38 kinase, caspase-3 and NOS activity were significantly stronger, whereas, the signals of bcl-2, c-myc and Fas/FasL were markedly weaker in E2 group than those in C2 group (P＜0.05). CONCLUSION: The differentiation and apoptosis of human esophageal cancer cell Eca-109 can be induced after 24- and 48-h treatment with 8-BrcAMP, respectively. Upregulation of wt p53, iNOS and downregulation of c-myc may be associated with differentiation and apoptosis of Eca-109 cells.Furthermore, upregulation of FasL, p38 kinase and caspase-3 as well as downregulation of bcl-2, and Fas may be involved in the apoptosis of Eca-109 cells.

Combined Antitumor Effect of Ursolic Acid And 5-Fluorouracil on Human Esophageal Carcinoma Cell Eca-109 In Vitro

Objective： To study the combined antitumor effect and possible mechanisms of ursolic acid with 5-fluorouracil （5-FU） on human esophageal carcinoma cell Eca-109 in vitro. Methods： Eca-109 cells were treated with ursolic acid （10-50 μmol/L） and/or 5-fluorouracil （48.0-768.8 μmol/L） for 48 h in vitro. And then cell proliferation was determined by MTT assay. Cell cycle and apoptosis rate were analyzed by flow cytometry （FCM）. The morphological changes of apoptosis were observed by fluorescent microscopy. At last the expression of P27kipl, bcl-2 and bax were detected by western blot. Results： Results： In comparison with single agent treatment, the combination of ursolic acid and 5-fluorouracil produced greater efficacy in growth inhibition, cell cycle arrest at G0/G1 phase, and apoptosis induction （P〈0.05）. Western blot analysis showed that the combination use of ursolic acid and 5-fluorouracil suppressed the expression of bcl-2 and increased the expressions of bax and P27kip1. Conclusion： Ursolic acid combined with 5-fluorouracil showed adjuvant antiproliferative effects on human esophageal carcinoma cell Eca-109 in vitro, which mainly due to the induction of cell cycle arrest as well as apoptosis.

不同浓度山豆根对Eca-109细胞株生长的抑制和杀伤作用

目的 探讨山豆根对体外培养人食管癌 (Eca - 10 9)细胞株的作用。方法 将Eca - 10 9细胞株分为对照组和实验组两组 ,测定不同浓度山豆根对两组的杀伤效应、酶活性测定及Fulgen -DNA法显示分裂指数。结果 10 0mg/ml、2 0 0mg/ml浓度对细胞的杀伤能力随药物作用时间延长而增强 ,5 0mg/ml浓度维持在 3%左右。 10 0mg/ml、2 0 0mg/ml实验在加药第 3天对细胞分裂指数抑制率接近或达到 10 0 % ,5 0mg/ml实验作用呈负相关。山豆根使谷氨酸脱氢酶、苹果酸脱氢酶和乳酸脱氢酶活性下降 ,直至阴性反应。结论 山豆根对Eca - 10 9细胞株生长有抑制和杀伤作用 ,对脱氢酶有影响作用。