异黏蛋白在视网膜母细胞瘤中的表达及其与高危因素关系的研究

Expression of metadherin in retinoblastoma and its relationship with histopathological high-risk factors

背景异黏蛋白（MTDH）基因是近年来发现的一个原癌基因，在恶性实体肿瘤中呈高表达，与恶性肿瘤的浸润、侵袭及转移等生物学行为密切相关。目前，国内外鲜见关于MTDH与视网膜母细胞瘤（RB）的相关研究报道。目的研究不同侵袭潜能人RB细胞系及RB组织（石蜡切片）中MTDH的表达，探讨其与肿瘤临床分期、病程、细胞分化、组织病理学高危因素之间的关系。方法应用荧光实时定量PCR（rea]一timePCR）技术检测RB细胞系Y79、WERI—RBI、SO—RB50中MTDHmRNA的表达水平；采用免疫组织化学Elivision法检测MTDH在54例RB组织中的表达情况，并结合临床组织病理学资料进行统计学分析。结果MTDHmRNA在Y79、SO—RB50、WERI．RBl细胞系中的相对表达量分别为6．11±0．17、6．21±0．21及3．97±O．17，3种细胞系中的MTDHmRNA表达差异有统计学意义（F=142．643，P〈0．05），具有潜在侵袭性的Y79细胞系、SO—RB50细胞系中的表达量明显高于WERI—RBl细胞系，差异均有统计学意义（均P=0．000）。MTDH在RB组织中主要表达于细胞膜及细胞质，其中35例（占64．81％）标本为MTDH呈强阳性表达，其中临床分期为E期者MTDH表达积分明显高于D期者，有组织病理学高危因素者MTDH表达积分明显高于无高危因素者，侵犯筛板后视神经者MTDH表达积分明显高于未侵犯者，差异均有统计学意义（P=0．035、0．002、0．017）。不同年龄（P=0．579）、不同患者性别（P=0．513）、不同眼别（P=0．305）、不同病程（P=0．860）、不同细胞分化类型（P=0．537）、不同脉络膜受累范围（P=0．238）及眼前节是否受累（P=0．579）之间RB组织中MTDH表达积分的差异均无统计学意义。结论MTDH在RB组织中呈高表达，MTDH基因的激活可能与RB的侵袭转移机制有关，MTDH基因的检测有可能成为判断RB患者预后的重要指标之一。

Background Metadherin is a newly discovered oncogene. It is highly expressed in some solid tumors and plays a significant role in invasion and metastasis of neoplasm as an important biological marker of aggressive cancers. However, there is little data available for the relationship between metadherin expression and clinicopathologic features of retinoblastoma（RB）. Objective This study was to investigate the expression of the metadherin in RB cell lines and specimens as well as its clinical significance. Methods The expression of metadherin mRNA in different metastatic potential of RB cell lines（Y79 ,WERI-RB1 and SO-RB50）was detected by real-time PCR,and the protein expression of metadherin （MDTH）in paraffin-embedded RB tissue was detected by immunohistochemistry. The relevance of metadherin expression to clinical histopathological features was statistically analyzed. Results The relative expression value of metadherin mRNA was 6.11±0.17,6.21±0. 21 and 3.97±0. 17 in Y79 ,SORB50,WERI-RB1 ,respectively,with a significant difference among the three types of cell lines（ F= 142. 643 ,P〈0. 05）. The relative expression value of metadherin mRNA was significantly higher in Y79 or SO-RB50 than that in WERI-RB1 （P= 0. 000）. The expression of MTDH protein mostly located in the cellular membrane and cytoplasm. Among the 54 RB sections,35 （64.81%）showed a high intensity in expression of metadherin protein. The total score of metadherin protein expression was higher in the E stage of RB than that of D stage （P = 0. 035 ） , in the patients with high-risk factor than those without high-risk factor（P = 0. 002）and the cases with optic nerve invasion compared to non-invasion （ P = 0. 017）. However, no significant differences were found in the expression of metadherin protein between different ages （ P = 0. 579 ） , different genders （ P = 0.513 ） , bilateral eyes （ P = 0. 305 ） , different disease courses （P= 0. 860 ）, various types of differentiation （ P = 0. 537 ）, different degree of the choroid invasion （ P = 0. 238）,and with or without invasion of the anterior ocular segment （P = 0. 579 ）. Conclusions Metadherin appears to be highly expressed in RB ceils. The activation of the MTDH gene is associated with invasion and metastasis of RB. These results imply that the dynamic change of metadherin expression probably is a prognostic indicator of RB.