颅底脊索瘤中突变型p53相关的临床和细胞水平研究

Mutant p53-related clinical and cellular studies in skull base chordoma

目的探讨突变型p53在颅底脊索瘤中的表达与患者预后及临床特点的关联,并在细胞层面验证突变型p53在颅底脊索瘤中的功能。方法纳入2005年1月—2014年12月在首都医科大学附属北京天坛医院接受手术治疗的颅底脊索瘤患者49例,应用石蜡切片进行免疫组织化学染色,分析突变型p53表达与颅底脊索瘤患者预后及临床特点的关系。应用siRNA敲降脊索瘤细胞系UCH-1中的p53基因,分析敲降前后细胞功能的变化。结果在蛋白水平,突变型p53表达水平是肿瘤术后进展的风险因素,随突变型p53表达水平升高,肿瘤进展风险增加(OR:1.040,95%CI:1.007~1.073,P=0.016);另外,骨质浸润型肿瘤较非浸润型中突变型p53表达升高(t=3.319,P=0.002),质地硬的较质地软的肿瘤突变型p53表达升高(t=-3.503,P=0.001),血供丰富型较不丰富型肿瘤突变型p53表达升高(t=2.081,P=0.043)。细胞水平,与对照组相比,p53敲降组的细胞活力在不同时间点间有差异(F=305.715,P=0.000);p53敲降组细胞凋亡率低于对照组(t=-3.961,P=0.017);与对照组相比,p53敲降组在第6(t=-5.232,P=0.014)、12(t=4.778,P=0.017)及24(t=-9.303,P=0.003)小时穿透至下室的肿瘤细胞均增多。结论颅底脊索瘤中突变型p53表达升高可导致术后肿瘤进展风险增加,其表达与肿瘤质地、侵袭性和血供情况相关;突变型p53表达受抑制后脊索瘤细胞增殖和侵袭能力提高,凋亡减少。

Objective To investigate the expression of mutant p53 in skull base chordoma and its association with patients’prognosis and clinical features,and to verify the function of mutant p53 in skull base chordoma at the cellular level.Methods A total of 49 patients with skull base chordoma who underwent surgical treatment in Beijing Tiantan Hospital,Capital Medical University,from January 2005 to December 2014 were enrolled,and paraffin sections were used for immunohistochemical staining to analyze the association of the expression of mutant p53 with the prognosis and clinical features of the patients with skull base chordoma.The p53 gene in the skull base chordoma cell line UCH-1 was knocked down by siRNA to analyze the change in cell function before and after knockdown.Results At the protein level,the expression level of mutant p53(odds ratio=1.040,95%confidence interval:1.007~1.073,P=0.016)was a risk factor for tumor progression after surgery;in addition,the expression of mutant p53 in bone-infiltrating tumors was significantly higher than that in noninfiltrating tumors(t=3.319,P=0.002),the expression of mutant p53 in hard tumors was significantly higher than that in soft tumors(t=-3.503,P=0.001),and the expression of mutant p53 in tumors with rich blood supply was significantly higher than that in tumors without rich blood supply(t=2.081,P=0.043).At the cellular level,there was a significant difference in cell viability between the control group and the p53 knockdown group at different time points(F=305.715,P=0.000),and the p53 knockdown group had a significantly lower cell apoptosis rate than the control group(t=-3.961,P=0.017).Compared with the control group,the p53 knockdown group had a significant increase in the number of tumor cells penetrating into the lower compartment at 6 hours(t=-5.232,P=0.014),12 hours(t=4.778,P=0.017),and 24 hours(t=-9.303,P=0.003).Conclusions The increased expression of mutant p53 in skull base chordoma may increase the risk of tumor progression after surgery,and the expression of mutant p53 is associated with tumor texture,invasion,and blood supply.There are increases in the proliferation and invasion abilities of chordoma cells and a reduction in apoptosis after the expression of p53 is inhibited.