18β-甘草次酸抑制胃癌过程中相关miRNAs表达的研究

发布时间：2018-10-08 12:55

【摘要】：研究背景:胃癌是常见的消化道恶性肿瘤,发病率与死亡率均较高。目前对胃癌化学预防的研究主要集中在根除幽门螺杆菌、抗氧化剂、叶酸、选择性环氧合酶抑制剂上。由于幽门螺杆菌耐药能力的增强,除菌药的效率降低。因此,开发新药、寻找药物靶点尤为重要。甘草次酸是甘草的主要活性成分之一,具有多种生理活性,包括抗炎、抗溃疡、抗病毒、抗肿瘤及调节免疫功能等。甘草次酸在体内外实验中具有潜在抑制肿瘤的作用,因此有可能成为新型胃癌化学预防的药物。转基因胃肿瘤鼠模型K19-C2m E能够在胃近端自发的出现隆起型肿瘤,且其所生长的胃肿瘤形态特征与人自发的肿瘤很相似,可作为理想的胃癌模型供实验研究。Micro RNA是一类长约20-22个核苷酸的非编码单链RNA。这类RNA能够调节癌基因或抑癌基因的表达,将来癌基因mi RNA抑制剂或抑癌基因mi RNA的替代品将可能成为肿瘤治疗的新手段。目的:探讨甘草次酸能否降低K19-C2m E转基因鼠胃肿瘤的发病率,是否影响转基因鼠胃肿瘤中的mi RNAs表达。并进一步研究相关mi RNA对人胃癌细胞增殖、凋亡和细胞周期的影响。方法:建立K19-C2m E转基因胃肿瘤小鼠模型。设立对照组和甘草次酸投药组。对小鼠胃癌组织进行mi RNA芯片分析,同时用甘草次酸处理胃癌细胞系MKN-1和BGC-823分析相关mi RNA的表达,并通过细胞转染改变相关mi RNA的表达对胃癌细胞的影响。利用统计学分析软件,分析甘草次酸组和对照组转基因小鼠胃癌组织和胃癌细胞中mi RNA的变化。结果:18β-甘草次酸能显著降低胃肿瘤的发生率(P=0.002),其中对照组小鼠肿瘤发生率是77.8%(28/36),甘草次酸组小鼠胃肿瘤发生率为33.3%(13/39);mi RNA芯片分析发现甘草次酸处理后小鼠肿瘤中的38种mi RNAs的表达发生改变(fd≥2或fd≤0.5,P0.01);其中变化差异最大的是mi R-149-3P,与对照组相比其表达量上调了3.8倍;甘草次酸处理胃癌细胞系BGC-823和MKN-1后可使mi R-149-3p上调,并呈浓度和时间依赖性;mi R-149-3p能够抑制胃癌细胞系MKN-1和BGC-823增殖,促进细胞凋亡。
[Abstract]:Background: gastric cancer is a common malignant tumor of digestive tract with high morbidity and mortality. Current studies on chemical prevention of gastric cancer have focused on the eradication of Helicobacter pylori, antioxidants, folic acid and selective cyclooxygenase inhibitors. Because of the enhancement of drug resistance of Helicobacter pylori, the efficiency of sterilizing agents was decreased. Therefore, it is very important to develop new drugs and find drug targets. Glycyrrhetinic acid is one of the main active components of licorice. It has many physiological activities, including anti-inflammation, anti-ulcer, anti-virus, anti-tumor and regulating immune function. Glycyrrhetinic acid has the potential to inhibit tumor in vitro and in vivo, so it may become a new chemoprevention drug for gastric cancer. K19-C2m E, a transgenic gastric tumor model, was able to spontaneously present protruding tumors at the proximal end of the stomach, and the morphological characteristics of the gastric tumors were similar to those of human spontaneous tumors. It can be used as an ideal gastric cancer model for experimental research. Micro RNA is a class of uncoded single-stranded RNA. with about 20-22 nucleotides in length. This kind of RNA can regulate the expression of oncogene or tumor suppressor gene. In the future, mi RNA inhibitor or mi RNA replacement of oncogene may become a new method of tumor therapy. Aim: to investigate whether glycyrrhetinic acid can reduce the incidence of gastric neoplasms in K19-C2m E transgenic mice and whether it affects the expression of mi RNAs in gastric neoplasms of transgenic mice. Furthermore, the effects of mi RNA on proliferation, apoptosis and cell cycle of human gastric cancer cells were studied. Methods: K19-C2m E transgenic gastric tumor model was established in mice. Control group and glycyrrhetinic acid group were established. The expression of related mi RNA in gastric cancer cell line MKN-1 and BGC-823 was analyzed by mi RNA microarray, and the expression of related mi RNA was changed by cell transfection. The changes of mi RNA in gastric cancer tissues and gastric cancer cells of Glycyrrhetinic acid group and control group were analyzed by statistical analysis software. Results 1: 18 尾 -glycyrrhetinic acid could significantly reduce the incidence of gastric neoplasms (P0. 002). The incidence of gastric neoplasms in the control group was 77.8% (28 / 36), and the incidence of gastric tumors in the glycyrrhetinic acid group was 33. 3% (13 / 39). The results of RNA microarray analysis showed that 38 of the tumors were treated with glycyrrhetinic acid. The expression of mi RNAs was changed (fd 鈮，

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