Expression of metadherin in retinoblastoma and its relationship with histopathological high-risk factors / 中华实验眼科杂志

ABSTRACT

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 W ERI-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 ehoroid 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 cells.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.