转入WIF-1或5-氮杂-2’-脱氧胞苷去甲基化抑制骨肉瘤模型鼠的肿瘤生长

摘要

背景：WIF-1是一种抑癌基因，由于启动子过度甲基化从而导致其在大多数肿瘤中的表达下调，而DNA甲基化抑制剂可使一些基因发生去甲基化从而恢复其表达。　　目的：在骨肉瘤动物模型中转入WIF-1或使用5-氮杂-2’-脱氧胞苷去甲基化处理后，观察瘤体的病理学差异及WIF-1 mRNA和蛋白的表达变化。　　方法：建立鼠骨肉瘤模型，分为3组，对照组：不做任何处理；5-氮杂-2’-脱氧胞苷组：每只每日注射适量5-氮杂-2’-脱氧胞苷去甲基化剂；WIF-1组：每只每日注射适量Wnt/β-catenin信号转导通路抑制剂WIF-1。用药后第7天开始每7 d称裸鼠体质量，测量肿瘤短径(a)和长径(b)，分别计算各组肿瘤的相对体积，计算用药后第7，14，21，28，56天的肿瘤相对增长率。分别于用药后第7，14，21，28，56天5个时间点脱颈处死每组各4只裸鼠，剥取肿瘤组织称瘤质量，对瘤体做病理分析，检测用药第56天3组骨肉瘤组织中WIF-1蛋白、WIF-1 mRNA的表达情况。　　结果与结论：①用药组与对照组相比，第7，14，21，28，56天的裸鼠体质量有所增加，但用药组与对照组之间差异无显著性意义。②用药组的肿瘤体积较对照组明显减小，用药组WIF-1 mRNA、WIF-1蛋白表达较对照组均出现不同程度的升高。③结果表明 WIF-1的启动子区基因甲基化是骨肉瘤发生发展的机制之一，在骨肉瘤动物模型中转入WIF-1或采用5-氮杂-2'-脱氧胞苷去甲基化处理可抑制肿瘤生长。%BACKGROUND:WIF-1 is a tumor suppressor gene. Promoter hypermethylation causes WIF-1 down-regulationin most tumors. DNA methylation inhibitor can lead to gene demethylation and restore its expression. OBJECTIVE:To observe the differences of tumor pathology and, WIF-1 mRNAand proteinchanges using WIF-1 or 5-aza-2'-deoxycytidine demethylation in animalmodels of osteosarcoma. METHODS:Murine osteosarcoma models were established and divided into three groups. In the control group, no treatment was given. In the 5-aza-2'-deoxycytidine group, an appropriate amount of 5-aza-2'-deoxycytidine was injected ineach mouse daily. In the WIF-1 group, an appropriate amount of Wnt/β-catenin signal transduction pathway inhibitor WIF-1 was injected in each mouse daily. Seven days after medication, the weight of nude mouse was weighed every 7 days. Short tumor diameter (a) and the long diameter (b) were measured. Therelative tumor volume was calculated. The relative growth rate of tumor was calculated at 7, 14, 21, 28 and 56 days. Four nude mice from ach group were sacrificed by puling the neck at 7, 14, 21, 28 and 56 days after medication. Tumor tissues were stripped and the weight of them was weighed. Pathological analysis of the tumor was conducted. The expression of WIF-1protein and WIF-1 mRNA was detected in osteosarcoma at 56 days after medication in the three groups. RESULTS AND CONCLUSION:(1) Compared withthe medication and control groups, the weight of nude mice was increased at 7, 14, 21, 28 and 56 days in the treatment group. No significant difference was found between the medication and control groups. (2) The tumor size was significantly smaler in themedication group than in the control group. WIF-1 mRNA and WIF-1 protein expression was increased in the medication group compared with the control group to different degrees. (3) Results suggested that WIF-1 gene promoter methylation is one of the mechanisms of the development of osteosarcoma. Use of WIF-1 or 5-aza-2'-deoxycytidine demethylation can inhibit tumor growth in animal models of osteosarcoma.