Expression And Significance Of GLI1 And MDM2 In Rhabdomyosarcoma

Aims: Previous research has shown GLI1 and MDM2 genes are amplifications or gains in RMS. It has been reported that Hh-Gli signaling pathway can regulate P53-MDM2 in tumors. Here,we aim to detect the protein expressions of GLI1 and MDM2 and analyze the relationship of these expressions with the clinicopathological variables of RMS.Methods: GLI1 and MDM2 protein expressions in 44 RMS samples and 36 normal muscle samples were examined via immunohistochemistry. The relationships of these protein expressions with the clinicopathological features and prognosis of RMS were analyzed by SPSS 17.0.Results:(1) The positive GLI1 expression rate in 44 RMS samples was 61.36%, and it was significantly higher than that of the normal muscle samples(χ2 = 33.345, P < 0.001). GLI1 expression correlated with presence of the PAX3-FOXO1 fusion gene(χ2 = 4.208, P = 0.040) and lymph node metastasis(χ2 = 4.476, P = 0.034), and a significant association was found between GLI1 expression and overall survival(OS)(χ2 = 7.104, P = 0.008), where the patients with GLI1 expression experienced unfavorable outcome than those without GLI1 expression.(2) The positive MDM2 expression rate in the 44 RMS samples was 13.64%, and it was significantly higher than those of the normal muscle samples(χ2 = 5.307, P = 0.021). However, there was no association between MDM2 expression and any of the clinicopathological parameters or OS.(3) We further investigated the relationship between GLI1 and MDM2, but the significant correlation between these two expressions was not found(r = 0.079, P = 0.581).Conclusion:(1) GLI1 expression may be an important parameter of prognosis evaluation in RMS patients.(2) Further investigation is needed to explore the role of MDM2 in RMS tumorigenicity.