Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Chin Med J (Engl). 2013;126(11):2168-73.
Infection with Helicobacter pylori (H. pylori) may lead to chronic inflammation of the stomach epithelium, mucosal atrophy, imbalance of proliferation and apoptosis of epithelial cells; resulting in chronic gastritis, peptic ulcer, gastric cancer, and many other clinical outcomes. Why and how H. pylorus leads to gastric cancer is not clear yet. Through in vitro experiments, this study evaluated the effects of broth culture filtrate protein (BCF-P) from the supernatant of liquid culture media of H. pylori on proliferation and apoptosis of immortalized human gastric epithelial cell lines (GES-1) and gastric cancer cell lines (AGS).
For the study, GES-1 and AGS cell lines mix with BCF-P and epidermal growth factor (EGF). MTT assay and flow cytometry (FCM) determined the levels of proliferation and apoptosis. Detected expression levels of cyclooxygenase-2 (COX-2) and Fas mRNA by reverse transcription (RT)-PCR. Also did analysis of the effects of BCF-P on epidermal growth factor receptor (EGFR) tyrosine kinase activity of GES-1 and AGS cells by non-radioactive enzyme-linked assay. The Student's t test and one-way analysis of variance (ANOVA) were used for statistical analysis.
BCF-P inhibited proliferation of GES-1 and AGS cells in a concentration-dependent manner. The inhibition rates are respectively 68.7% in AGS and 61.4% in GES-1. With the same dose and time for inhibiting the proliferation, BCF-P failed to induce apoptosis of GES-1 and AGS cells. Effects of BCF-P reduced the expression of Fas mRNA of GES-1 and AGS cells (P < 0.05). This is consistent with the effects of EGF. BCF-P reduced the expression of COX-2 mRNA of AGS cells (P < 0.05). This is opposite to the effects of EGF (P < 0.05). Effects of BCF-P improved more than three times the EGFR tyrosine kinase activity of GES-1 and AGS cells.
BCF-P inhibited the proliferation of AGS and GES-1 cells in vitro, unrelated to apoptosis. Effects of BCF-P on gastric epithelial cells in vitro are not equivalent to that of EGF.
幽门螺杆菌（H. pylori）感染可导致胃上皮细胞的慢性炎症、黏膜萎缩、上皮细胞增殖和凋亡失衡，进而导致慢性胃炎、消化性溃疡、胃癌等多种临床结局。然而，H. pylori 导致胃癌的原因和机制尚不清楚。本体外实验通过研究 H. pylori 液体培养基上清液的肉汤培养滤液蛋白（BCF-P）对永生化人胃上皮细胞系（GES-1）和胃癌细胞系（AGS）增殖和凋亡的影响，探讨 H. pylori 感染导致胃癌的可能机制。
将 GES-1 和 AGS 细胞系与 BCF-P 和表皮生长因子（EGF）混合，采用 MTT 法和流式细胞术（FCM）检测细胞增殖和凋亡，逆转录（RT）-PCR 检测环氧合酶-2（COX-2）和 Fas mRNA 的表达水平，非放射性酶联免疫吸附试验分析 BCF-P 对 GES-1 和 AGS 细胞表皮生长因子受体（EGFR）酪氨酸激酶活性的影响。采用 Student's t 检验和单因素方差分析（ANOVA）进行统计学分析。
BCF-P 呈浓度依赖性抑制 GES-1 和 AGS 细胞的增殖，在 AGS 细胞中的抑制率为 68.7%，在 GES-1 细胞中的抑制率为 61.4%。在相同剂量和时间抑制细胞增殖时，BCF-P 未能诱导 GES-1 和 AGS 细胞发生凋亡。BCF-P 降低了 GES-1 和 AGS 细胞 Fas mRNA 的表达（P<0.05），与 EGF 的作用一致。BCF-P 降低了 AGS 细胞 COX-2 mRNA 的表达（P<0.05），与 EGF 的作用相反（P<0.05）。BCF-P 使 GES-1 和 AGS 细胞的 EGFR 酪氨酸激酶活性提高了 3 倍以上。
BCF-P 体外抑制 AGS 和 GES-1 细胞的增殖，与细胞凋亡无关。BCF-P 对体外胃上皮细胞的作用与 EGF 不同。
