硒对氧化偶氮甲烷所致结肠癌模型大鼠睾丸精原细胞P16蛋白表达的影响

EFFECT OF SELENIUM ON PROTEIN P16 EXPRESSION IN THE TESTICLE SPERMATOGONIUM OF RAT WITH COLON CANCER INDUCED BY AZOXYMETHANE

目的观察硒对氧化偶氮甲烷(AOM)所致结肠癌大鼠睾丸精原细胞P16蛋白表达的影响。方法随机将20只3周龄断乳雄性SD大鼠分为:正常对照组、实验对照组、AOM致癌前喂食亚硒酸钠水组、AOM致癌后喂食亚硒酸钠水组。每周腹腔注射AOM 15 mg/kg,持续2周,造成大鼠结肠癌模型。用4 mg/L Na2SeO3水溶液分别在AOM致癌前、后开始进行干预,并持续至实验结果。各组均于34周后取两侧睾丸,用免疫组织化学方法,观察大鼠睾丸精原细胞内P16蛋白的表达,并进行图像分析。结果正常组大鼠的睾丸内未见精原细胞表达P16蛋白,而实验对照组、硒干预AOM致癌组(AOM致癌前、后喂食亚硒酸钠水)的精原细胞P16均呈阳性表达,阳性产物呈深棕色,定位于细胞核中,细胞质内仅有少量表达。实验对照组、AOM致癌前、后喂食亚硒酸钠水组阳性表达逐渐增强,组间具有显著性差异(P<0.05)。结论硒可增强AOM所致结肠癌大鼠精原细胞P16蛋白的表达。

Objective To observe effect of selenium on the protein P16 expression in the testicle spermatogonium of rat borne with colon cancer induced by azoxymethane （AOM）. Methods Twenty 3 week-old SD male rats were randomly divided into four groups normal control group, experimental control group, the group selenium was given before AOM induced colon cancer group, the group selenium was given after AOM induced colon cancer group. To induce rat colon cancer, 3 week-old SD male rats received ip injections of AOM at a dose of 15 mg/kg once a week for two weeks. Selenium （selenite, Na2SeO3,4 mg/L） began to be provided in drinking water before and after AOM administrations, and lasted for the whole experiment period. The rats testes were drew from the 34. week-old rats. hnmunohistochemical method was used to detecte the expression of protein P16 in the rat testicle spermatogonium and image analysis was used to analyze the immunoreactivity. Results No expression of the protein P16 was found in the normal rat testicle spermatogonium, but a significant increase was seen in the rat testicle spermatogonium in the following groups： experimental control group, the group selenium was given before AOM induced colon cancer, the group selenium was given after AOM induced colon cancer, and significant difference was found between each group（ P 〈 0.05）. Deep brown color of immunoreactivity was found to localize in the nucleus, and the expression was much in the cytoplasm less. Conclusion Selenium can coordinate the expression of the protein P16 in the testicle spermatogonium of rat colon cancer induce by AOM.