Abstract:  Objective To detect the protein expression of PAX6，MATH5 and BRN3b in retinoblastoma (RB) and normal retinal tissue. Design Case-control study. Participants Ten cases of fresh RB solid tumors and ten cases of normal retinal tissue. Methods Objectives were collected and studied by WesternBlot to compare the protein expression of Pax6, Math5 and Brn3b in fresh RB solid tumors with those in normal retinal tissue. Main Outcome Measrues The protein expression of Pax6, Math5 and Brn3b. Results The protein expresion of Pax6, Math5 and Brn3b were positive in both groups. Pax6, Math5 and Brn3b protein expression in RB tumors increased significantly compared with those in normal retinal tissue (P all<0.001). The protein expression of Math5 positively correlated with the Pax6 expression（r=0.949, P<0.001）, and the protein expression of Brn3b positively correlated with the Math5 expression（r=0.927, P<0.001）. Conclusion  PAX6 gene has a role in differentiation of RB cells through up-regulated the protein expression of MATH5 and BRN36 gene.

Key words: retinoblastoma, differentiation, Pax6, Math5, Brn3b