Abstract: Objective To investigate the expression of PAX6， Ki-67 and MMP-9 in retinoblastoma (RB) cells and to evaluate their relationship with clinical histopathological characteristics as well as their clinical significance. Design Experimental study. Participants 40 cases of paraffin-embedded RB tissues. Methods The expression of PAX6, Ki-67 and MMP-9 in paraffin-embedded RB tissues was detected by immunohistochemistry. The relationship between these expressions and clinical histopathological characteristics was analyzed. The inter correlation between these expressions was analyzed as well. Main Outcome Measures The expression of  PAX6, Ki-67 and MMP-9 in RB tissue； the clinical and histopathological features. Results The positive expression rates of PAX6, Ki-67 and MMP-9 in RB tissue were 52.5%, 55.0%, 57.5%, respectively. The expression of Ki-67 in the 3-year or older age group was significantly higher than that in the age <3 year  group(χ2=6.825, P=0.016), but no significant differences were found in the expression of PAX6 (χ2=0.631, P=0.511) or MMP-9(χ2=0.129, P=1.000) between different age groups. Meanwhile, no significant differences were found in the expressions of all three proteins between different genders or laterality groups. The expression of PAX6 (P=0.017), Ki-67 (P=0.046) and MMP-9 (P=0.038) in the retrolaminar optic nerve infiltrated group were all significantly higher than the retrolaminar optic nerve non-infiltrated group. The expression of PAX6 (χ2=8.120, P=0.010) and Ki-67 (χ2=6.465, P=0.025) protein in the non-preoperative chemotherapy group were significantly higher than the preoperative chemotherapy group. The expression of PAX6 was significantly correlated with Ki-67(r=0.347, P=0.028). Conclusion The high expression of PAX6 promotes the proliferation of retinoblastoma cells. The overexpression of PAX6, Ki-67 and MMP-9 may contribute to the invasion of retinoblastoma together. Chemotherapy inhibits the expression of PAX6 and Ki-67 in retinoblastoma, reducing the risk of invasion and metastasis to some degree. (Ophthalmol CHN, 2014, 23: 343-347)

Key words:  , retinoblastoma； PAX6； Ki-67； MMP-9； immunohistochemistry； histopathology； chemotherapy