| Objective:ASC gene is an anti-cancer gene related to the apoptosis of cells. It is seperated and identified when studying leucocythemia and mammary cancer. Researches have already indicated that the frequent methylation exists in the promoter of ASC gene in mammary cancer,oophoroma and nucleus cancer. And some other researches indicated that ASC ,the methylated gene contributing to the apoptosis can be reversed by using demethylation reagent and expressed again and ASC gene may serve as a new focus for the prevention and treatment of lung cancer.Caspase means the asparagic acid idio-hydrolase containing cysteine, which falls into the cysteine protease category and functions as the main performer in the apoptosis of the cells. Caspase can be divided into 3 categories: start-up type, effect type and inflammation type. The start-up caspase includes caspase-2, caspase-8, caspase-9, caspase-10, all of which starts apoptosis and adjusts effect type through self-activation; effect caspase includes caspase-3, caspase-6, caspase-7, all of which can decompose the cell albumen and perform apoptosis; inflammation caspase includes caspase-1, caspase-4, caspase-5 and so on. The caspase usually exists in the cells as inactive zymogen composed of three components: an N-tip front area, a large-sized subunit and a small-sized subunit. When the zymogen molecules are activated, the large-sized subunit and the small-sized subunit would dissociate and become organized enzymes in the form of tetramer. For caspases can activate themselves and each other, they would show cascade amplification once the apoptosis is triggered.The function of ASC to contribute to apoptosis is realized through CARD dependent polymerization and after activating caspase-9 to mediate apoptosis viae. And researches has proved that the activity, strength and weakness of caspase-3, caspase-8 are directly related to apoptosis of cells.It has already been proved that ASC mediates the activation of caspase-1 as an upstream matter and gets invulved in the inflammation response. For it is an upstream matter conducted by caspase signal, would its abnormal expression directly influences the expression of caspase? If we can study the expression of ASC and caspase-1 in the carcinoma of colon and their relationship, it would be beneficial for us to explore the expression and the clinical significance of them in the constitution of carcinoma of colon constitution and the constitution beside the cancer.Methods: The immunohistochemical LSAB method applied to conduct the ASC and caspase-1 determination for 30 specimens of colon carcinoma without chemoradiotherapy before operation and other related paraneoplastic tissues.Results:The positive rate of ASC in the paraneoplastic tissues and the tumorous tissues were 60.00%(18/30)and 13.33%(4/30), respectively. There was a significant difference between the groups(p < 0.01). The positive rate of caspase-1 were 60.00%( 18/30) and 30.00%( 9/30) , respectively. There was a significant difference between the groups(p<0.05).There was no obvious correlations between the expression of ASC and caspase-1 in the tumorous tissue(sP>0.05). And there was high correlations in the paraneoplastic tissues(p<0.01).Conclusion: There is a low ASC,caspase-1 expression in colon carcinoma and it is a low than in the paraneoplastic tissues; it was no obvious correlations between the expression of ASC and Caspase-1 in the tumorous tissues; And there was high correlations in the paraneoplastic tissues; Which suggesting that ASC, caspase-1plays an important role in the apoptosis, incidence and development of colon carcinoma. |
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