| ObjectiveThe incidence of gastric cancer is the highest among all the malignant tumors in our country, and the second of the world. There are more than 160000 cases of death of gastic cancer every year. It is indicated by research that gastric cancer is a disease results from multiple factors, and has close relationships with more than 140 kinds of genes and their protein products, including not only cancer gene, anti-cancer gene, and genes related with the cells cycle, but also some growth factors such as epidermis growth factor 1, platelet growth factor A, trefoil factors and so on. In 1988, Correa advanced a hypothesis of nature history form of intestine-type gastric cancer. In this hypothesis, it thinks the growth procedure of gastric mucosa from normal status to tumors is: normal gastric mucosa of superficial gastritis-chronic atrophic gastritis and intestinal metaplasia -moderate or serious abnormal hyperplasia-early stage gastriccancer- progressive stage gastric cancer. The influence of multiple factors changes the gastric mucosa from normal status to precancerous changes gradually, even then to gastric cancer. There are particular expression of gene difference in both the period from normal gastric mucosa to precancer and the precancer to gastric cancer. Only with the discovering of the relationship and rule between the changes of expression level of the said genes and their protein products with the different phases of the development of gastric cancer, can we correctly predict gastric cancer. The former researches on the relationship between the expression of anti-cancer genes and their protein products and the development of gastric cancer are collected in P53, P16, P27, P33, and RB (Retinoblastomagene) and DCC (Deletedincolorectalcancer), but researches on the role that the trefoil factor family(TFFs) and their protein play in the development of gastric cancer are not found so far.The TFFs, which was discovered in the recent decade, is the protective factors for the gastric and intestinal mucosa. Human's TFFs consists of three members, namely TFF1, TFF 2, and TFF 3, the common characteristic of which is the trefoil-formed region in their secondary structures. Under normal conditions, the distribution of TFFs has tissue peculiarity that, TFF 1 distributes mainly in stomach, TFF2 distributes mainly in gastric antrum and mucosa of duodenum, and TFF3 distributes mainly in intestines. This peculiarity disappears once the gastric and intestinal mucosa is damaged, and the expression will increase. It is proved by experiment that the TFFs are not only able to accelerate the healing of the damaged mucosa, but also related to the occurrence of tumors in intestines and stomach In the gene knock-out model of mouse, the stomachepithelia of all the mouse present to be serious hyperplasia, hypogenesis, or formation of adenoma on gastric antrum, and some of them develope invasive gastric adenocarcinoma. And it is also discovered that TFF1 can inhibit the proliferation of the AGS cell line of stomach adenocarcinoma, and its inhibition has dependence on dosage. Through the RT-PCR method, Pia Azarschab and others found that aspirin (1-2 mM) could result in 6 times' increase of the expression of TFF2, and it is not very clear whether this circumstance is related to the fact that long-term taking of aspirin can prevent gastric cancer to some extent. Therefore some people presume that TFFs might be some kind of anti-tumor factors.In this experiment, immunohistochemical method is applied to detect TFF1 and TFF2 for orientation and semi-quatitation with the paraffin wax samples of normal gastric mucosa, intestinal metaplasia of gastric mucosa, atypical hyperplasia tissue and gastric cancer tissue. With observation on the expressive level of these two kinds of proteins during the development of gastric mucosa's pathological change, the purpose is to explore the function and significance that TFF1 and TFF2 play in the precancerous lesion and the occurrence of stomach cancer.Method120 cases have been rando... |
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