p120ctn、Kaiso及MTA2基因在胸腺瘤中的表达及临床病理意义

Expression of P120 catenin,Kaiso and metastasis tumor antigen-2 in thymoma

目的研究p120连接蛋白(p120ctn)、Kaiso和肿瘤转移相关基因2(MTA2)在胸腺瘤中的表达,及与组织学分型、临床分期和生物学行为的关系。方法采用免疫组化SP法,检测137例胸腺瘤、3例胸腺癌和18例正常胸腺组织中p120ctn、Kaiso和MTA2的表达。结果正常胸腺上皮细胞中p120ctn为细胞膜(+),Kaiso和MTA2为(-)。胸腺瘤细胞中出现p120ctn胞膜弱(+)和胞质异位(+),阳性率为76.6%(105/137);在胸腺瘤细胞胞质中,Kaiso阳性率为69.3%(95/137);MTA2主要表达于胸腺瘤细胞核,阳性率为70.8%(97/137)。胸腺瘤细胞中,p120ctn异位胞质表达、Kaiso胞质表达及MTA2核表达阳性率间存在较好的一致性(Kappa=0.559,P<0.001;Kappa=0.512,P<0.001;Kappa=0.652,P<0.001)和相关性(r=0.733,P<0.001;r=0.652,P<0.001;r=0.708,P均<0.001),并与组织学分型及临床分期相关(P<0.05)。高危(B2、B3型)胸腺瘤组的p120ctn、Kaiso和MTA2阳性率均高于低危(A、AB和B1型)胸腺瘤组(P<0.001),MasaokaⅢ/Ⅳ期胸腺瘤组均高于Ⅰ/Ⅱ期胸腺瘤组(P<0.001)。结论 p120ctn和Kaiso同时胞质(+)及MTA2胞核(+)增强与胸腺瘤组织学分型和Masaoka临床分期呈正相关,3种基因表达的定位和强度可反映出胸腺瘤的生物学行为。

Objective To discuss whether expression of p120ctn, Kaiso and metastasis tumor antigen-2 （MTA2） reflects the biological behavior of thymoma. Methods p120ctn, Kaiso and MTA2 expression were examined in 137 cases of thymoma, 3 thymic carcinoma and 18 normal thymus tissues using immunohistochemistry, and the relationship of these proteins with histological type and clinical stage was investigated. Results In normal thymic epithelial cells, pl20etn was expressed on the cell membrane; Kaiso and MTA2 were not detected. Membranous pl20ctn expression reduced in thymoma epithelial cells; 76. 6% （105/137） of thymomas expressed cytoplasmic pl20ctn. Cytoplasmic Kaiso was detected in 69. 3% （95/137） and nuclear MTA2 was detected in 70. 8% （97/137） of the thymomas. There were good consistencies （Kappa =0.559, 0.512, 0.652; all P 〈0.001） and correlations （r =0.733, 0.652, 0.708; all P 〈 0. 001） between cytoplasmic p120ctn, cytoplasmic Kaiso and nuclear MTA2 expression in thymoma. All the three biomarkers were associated with histological type and clinical stage in thymoma （ P 〈 0. 05 ）. Cytoplasmic pl20ctn and Kaiso expression and nuclear MTA2 expression were higher in high-risk （type B2, B3 ） thymomas and Masaoka stage Ⅲ/Ⅳ thymomas than low-risk （ type A, AB and B1 ） or stage Ⅰ/Ⅱ thymomas （ both P 〈 0. 001 ）. Conclusion Cytoplasmic pl20ctn and Kaiso expression and nuclear MTA2 expression are correlated positively with histological type and Masaoka stage, and localization and expression of these biomarkers reflect the biological behavior of thymoma to some extent.