骨肉瘤细胞和组织H3K27me3表达与临床病理特征相关性研究

Expression of H3K27me3 in osteosarcoma and its relationship with clinicopathological characteristics

目的组蛋白H3K27三甲基化(H3K27me3)在肿瘤发生发展过程中起着重要作用,研究发现H3K27me3在肝癌和前列腺癌等恶性肿瘤中的表达和临床病理特征存在相关性,但其在骨肉瘤中的研究相对较少。本研究分析H3K27me3在骨肉瘤细胞和组织中的表达及其与临床病理的关系,并探讨H3K27me3在骨肉瘤发生和发展中的作用和意义。方法所有切片均来自于河北医科大学第四医院骨科2005-01-01-2011-01-01手术切除的标本。采用蛋白印迹法检测骨肉瘤MG-63、U2-OS、Sa-OS细胞系及hFOB1.19成骨细胞中H3K27me3表达的水平差异;采用免疫组织化学染色方法检测53例骨肉瘤组织及16例骨软骨瘤组织中H3K27me3的表达水平。Kaplan-Meier分析比较H3K27me3高表达和低表达患者生存率之间的差异。并应用Cox回归模型分析其表达水平对预后影响。结果hFOB1.19、MG-63、U2-OS和Sa-OS中H3K27me3蛋白表达水平分别为0.37±0.06、0.86±0.06、0.79±0.07和0.83±0.05,与hFOB1.19细胞中H3K27me3表达相比,3组骨肉瘤细胞系中H3K27me3蛋白表达水平均显著升高,P=0.023;与骨软骨瘤组织相比(56.3%),H3K27me3在骨肉瘤组织中高表达(84.9%),二者差异有统计学意义(P<0.001),并与肿瘤大小、肺转移、Enneking分期和生存率有关,P值分别为0.037、0.020、0.023和0.046。且其表达水平与患者生存期显著相关,P=0.012。结论 H3K27me3在骨肉瘤细胞及骨肉瘤组织中呈高表达,并与肿瘤的临床病理特征相关,可能会是骨肉瘤患者重要的预后因子及治疗靶点。

OBJECTIVE H3K27me3 plays an important role in the development of tumor.Previous studies have found that there is a correlation between the expression of H3K27me3 and pathological characteristics in liver and prostate cancer and other malignant tumors.However,the research about osteosarcoma is relatively less.The aims of this study were to investigate the expression of H3K27me3 in osteosarcoma tissue and cell lines and to evaluate its correlation with clinicopathological parameters of osteosarcoma and to study the role of H3K27me3 in the initiation and progression of osteosarcoma.METHODS All slices were from the department of orthopedics,the Fourth Hospital of Hebei Medical University,2005-01-01 to 2011-01-01.The protein expression of H3K27me3 was detected by Western blot in osteosarcoma cell lines MG-63,U2-OS,Sa-OS and human osteoblast cell hFOB1.19.Immunohistochemistry（IHC）was utilized to examine the protein expression of H3K27me3 in 53osteosarcoma specimens and 16 osteochondroma specimens.Differences between survival curves were assessed for statistical significance with the log-rank test.The Cox regression model was used to analyze the effect of H3K27me3 expression level on the prognosis of the patients.RESULTS In hFOB1.19,MG-63,U2-OS,Sa-OS,H3K27me3 protein expression levels were 0.37±0.06,0.86±0.06,0.79±0.07 and 0.83±0.05.Compared with hFOB1.19 cell,H3K27me3protein expression levels were significantly increased（P=0.023）.Compared with chondrosarcoma（56.3%）,the high expression of H3K27me3 was significant higher in osteosarcoma tissues（84.9%）.The expression levels of H3K27me3 were significantly associated with tumor size,metastasis,Enneking stage,shorter overall survival（Pvalues were 0.037,0.020,0.023 and 0.046,respectively）and its expression level was significantly correlated with the survival time of the patients（P=0.012）.CONCLUSIONS H3K27me3 is highly expressed in osteosarcoma cells and osteosarcoma tissues,and correlates closely to the clinical and pathological features.It may be an important prognostic factor and therapeutic target for osteosarcoma therapy.