c-fos在幽门螺杆菌诱导的蒙古沙鼠胃癌前病变中的过表达。

Overexpression of c-fos in Helicobacter pylori-induced gastric precancerosis of Mongolian gerbil.

作者信息

Yang Yong-Li, Xu Bo, Song Yu-Gang, Zhang Wan-Dai

机构信息

Institute of Gastrointestinal Diseases, Nanfang Hospital, First Military Medical University, Guang-zhou 510515, Guangdong Province, China.

出版信息

World J Gastroenterol. 2003 Mar;9(3):521-4. doi: 10.3748/wjg.v9.i3.521.

DOI:10.3748/wjg.v9.i3.521

PMID:12632510

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4621574/

Abstract

AIM

To explore dysregulation of c-fos in several human malignancies, and to further investigate the role of c-fos in Helicobacter pylori (H. pylori)-induced gastric precancerosis.

METHODS

Four-week-old male Mongolian gerbils were employed in the study. 0.5 mL 1X10(8) cfu/L suspension of H. pylori NCTC 11 637 in Brucella broth were inoculated orally into 20 Mongolian gerbils. Another 20 gerbils were inoculated with Brucella broth as controls. 10 of the infected gerbils and 10 of the non- infected control gerbils were sacrificed at 25 and 45 weeks after infection. The stomach of each gerbil was removed and opened for macroscopic observation. The expression of c-fos was analyzed by RT-PCR and immunohistochemical studies in H. pylori-induced gastric precancerosis of Mongolian gerbil. Half of each gastric antrum mucosa was dissected for RNA isolation and RT-PCR. beta-actin was used as the housekeeping gene and amplified with c-fos as contrast. PCR products of c-fos were analyzed by gel image system and the level of c-fos was reflected with the ratio of c-fos/beta-actin. The immunostaining for c-fos was conducted using monoclonal antibody of c-fos and the StreptAvidin-Biotin-enzyme Complex kit.

RESULTS

H. pylori was constantly found in all infected animals in this study. After infection of H. pylori for 25 weeks, ulcers were observed in the antral and the body of stomach of 60 % infected animals (6/10). Histological examination showed that all animals developed severe inflammation, especially in the area close to ulcers, and multifocal lymphoid follicles appeared in the lamina propria and submucosa. After infection of H. pylori for 45 weeks, severe atrophic gastritis in all infected animals, intestinal metaplasia in 80 % infected animals (8/10) and dysplasia in 60 % infected animals (6/10) could be observed. C-fos mRNA levels were significantly higher after infection of H. pylori for 25 weeks (1.84+/-0.79), and for 45 weeks (1.59+/-0.37) than those in control-animals (0.74+/-0.22, P<0.01). C-fos mRNA levels were increased 2.5-fold by 25th week (P<0.01) and 2.1-fold by 45th week (P<0.01) in precancerosis induced by H. pylori, when compared with normal gastric epithelium of Mongolian gerbil. Immunohistochemical staining revealed exclusive nuclear staining of c-fos. Furthermore, there was a sequential increase in c-fos positive cells from normal epithelium to precancerosis.

CONCLUSION

The study suggested that overexpression of c-fos occurs relatively early in gastric tumorigenesis in this precancerosis model induced by H. pylori.

摘要

目的

探讨c-fos在多种人类恶性肿瘤中的失调情况，并进一步研究c-fos在幽门螺杆菌（H. pylori）诱导的胃癌前期病变中的作用。

方法

本研究采用4周龄雄性蒙古沙鼠。将0.5 mL含1×10⁸ cfu/L幽门螺杆菌NCTC 11637的布鲁氏菌肉汤悬液经口接种到20只蒙古沙鼠体内。另外20只沙鼠接种布鲁氏菌肉汤作为对照。在感染后25周和45周，分别处死10只感染沙鼠和10只未感染的对照沙鼠。取出每只沙鼠的胃并打开进行宏观观察。通过逆转录聚合酶链反应（RT-PCR）和免疫组织化学研究分析c-fos在蒙古沙鼠幽门螺杆菌诱导的胃癌前期病变中的表达。将每个胃窦黏膜的一半进行解剖以分离RNA并进行RT-PCR。β-肌动蛋白用作管家基因，与c-fos作为对照进行扩增。通过凝胶图像系统分析c-fos的PCR产物，并以c-fos/β-肌动蛋白的比值反映c-fos的水平。使用c-fos单克隆抗体和链霉亲和素-生物素-酶复合物试剂盒进行c-fos的免疫染色。

结果

在本研究中，所有感染动物体内均持续检测到幽门螺杆菌。感染幽门螺杆菌25周后，60%的感染动物（6/10）胃窦和胃体出现溃疡。组织学检查显示，所有动物均出现严重炎症，尤其是靠近溃疡的区域，固有层和黏膜下层出现多灶性淋巴滤泡。感染幽门螺杆菌45周后，所有感染动物均出现严重萎缩性胃炎，80%的感染动物（8/10）出现肠化生，60%的感染动物（6/10）出现发育异常。感染幽门螺杆菌25周（1.84±0.79）和45周（1.59±0.37）后，c-fos mRNA水平显著高于对照动物（0.74±0.22，P<0.01）。与蒙古沙鼠正常胃上皮相比，幽门螺杆菌诱导的癌前期病变中，c-fos mRNA水平在第25周增加了2.5倍（P<0.01），在第45周增加了2.1倍（P<0.01）。免疫组织化学染色显示c-fos仅在细胞核中染色。此外，从正常上皮到癌前期病变，c-fos阳性细胞呈逐渐增加趋势。