周围神经肿瘤DNA倍体分析及P53表达意义

目的通过对良、恶性周围神经肿瘤DNA倍体分析,佐以检测p53基因表达,研究其与生物学行为之间的关系及临床鉴别诊断的意义。方法采用流式细胞术对65例良、恶性周围神经肿瘤石蜡包埋组织进行肿瘤单细胞DNA倍体分析;同时,采用免疫组化技术对P53蛋白表达进行检测。结果23例良性肿瘤DNA倍体检测均为二倍体;42例恶性周围神经鞘瘤（MPNST）中检出异倍体4例,二者差别无意义。SPF、PI值在良、恶性周围神经肿瘤中差别有显著意义（χ^2=28.674、23.730,P〈0.001）,且与MPNST病理组织学分级呈正相关（rs=0.418、0.347,P〈0.01、0.05）。P53阳性表达在MPNST显著高于良性者（χ^2=34.719,P〈0.001）;P53阳性表达强度与MPNST恶性程度呈正相关（rs=0.326,P〈0.05）。P53阳性表达强度与异倍体的出现及SPF、PI值均呈正相关（rs=0.318～0.354,P〈0.05）。结论SPF、PI值在良性周围神经肿瘤向恶性转化过程中会不断升高,对良、恶性周围神经肿瘤的鉴别诊断有临床应用价值。检测P53表达是鉴别诊断良、恶性以及判断MPNST恶性程度高低的一种有价值的方法。

THE SIGNIFICANCE OF DNA PLOIDY ANALYSIS AND P53 EXPRESSION IN PERIPHERAL NERVE SHEATH TUMORS

Objective To explore the relationship between DNA ploidy together with p53 expression and the biologic behaviors of peripheral nerve sheath tumors and study their clinical significance in differential diagnosis. Methods Flow cytometry was used to analyze DNA ploidy in paraffin embedded tissue samples from 65 cases of benign and malignant peripheral nerve sheath tumors （MPNST）. P53 protein expression was examined with immunohistoehemistry. Results All of the 23 cases of benign tumors were diploid, while four out of 42 MPNST patients were aneuploid. The difference was insignificant between the benign and MPNST. But the values of SPF and PI between the benign and MPNST groups were significantly different （χ^2= 28. 674,23. 730; P〈0. 001）; Furthermore, the SPF and PI values were positively correlated with the histological grade of MPNST （rs = 0. 418; 0. 347;P〈0. 01,0. 05）. P53 protein expression in MPNST was significantly higher than that in the benign peripheral nerve sheath tumors （χ^2= 34. 719,P〈0. 001）. The intensity of P53 expression was positively correlated with the malignancy of MPNST （rs = 0. 326 ,P〈0.05）, as well as with the positive rate of aneuploidy, the values of SPF and PI （rs =0. 318-0. 354 ,P〈0.05）. Conclusion The SPF and PI values were gradually increased during the transformation of benign peripheral nerve sheath tumors into MPNST. Therefore, SPF and PI may be used as indicators for differential diagnosis of benign and MPNST. P53 expression is a valuable factor for differential diagnosis between benign and MPNST, and for estimating the malignancy of MPNST.