骨肉瘤发生中p53蛋白表达对细胞凋亡的调节

目的研究骨肉瘤发生中p53蛋白表达对细胞调亡的调节。方法利用原位脱氧核糖核酸末端转移酶(In situ terminal deoxynucleotide transferase;ISTdT)标记技术和SP免疫组织化学方法分别检测骨肉瘤和良性骨肿瘤组织中凋亡细胞和p53蛋白的表达。结果骨肉瘤中p53蛋白的阳性率(76.9%，50/65)和阳性表达强度明显高于良性骨肿瘤组织(21.1%，4/19)(分别为P＜0.01和P＜0.05)，但4种亚型之间差异无显著性(P＞0.05)。骨肉瘤组织中凋亡细胞密度均明显低于良性骨肿瘤组织(P＜0.01)，但各亚型之间两者亦均无明显差异(P＞0.05)；骨肉瘤和良性骨肿瘤组织中p53蛋白表达与凋亡细胞密度呈明显的线性负相关(r=-0.8954,P＜0.01)，其表达增强则凋亡细胞密度逐渐降低。结论在骨肉瘤发生中p53基因突变可能是一种频发事件。突变型p53基因可能是通过其蛋白过度表达抑制肿瘤细胞凋亡，导致骨肉瘤的发生和发展。

Regulation of P53 Protein to Apoptosis in Osteosarcomas

Objective:To study regulation of p53 protein to apoptosis in osteosarcomas.Methods:In situ terminal deoxynucleotide transferase labeling was used for detecting apoptotic cells,and immunohistochemistry for p53 protein in 65 osteosarcomas and 19 benign osteomas.Results:The positive rate and intensity of p53 protein in osteosarcomas (76.9%) were higher than that in benign osteomas (21.1%) (P<0.01 and P<0.05 respectively),but no significant difference was found between 4 subtypes of osteosarcomas (P>0.05).The densities of apoptotic cells in 4 subtypes of osteosarcomas were significantly lower than that in benign osteomas,but no significant difference was found between 4 subtypes of osteosarcomas (P>0.05).There was significantly linearly negative correlation between apoptosis density and expression strength of p53 protein.Conclusions:p53 gene mutation may be a common event in osteosarcoma genesis,and mutant p53 proteins,which suppressed apoptosis of tumor cells,may lead to genesis and development of osteosarcoma.