The Alterations Of PTEN And P53 Genes In Retinoblastoma

Objective To clarify the roles of alterations of PTEN and p53 genes in the process of retinoblastoma,in the present study we investigated the aberrant protein expressions of PTEN and p53 genes and analysis the correlation of these two genes.Moreover,investigating the mutations of exon5 and exon8 of PTEN in retinoblastoma to approach the relationship between which and biological behavior of retinoblastoma.Methods①Forty retinoblastoma and sixteen normal retina tissues were collected to detect the protein expressions of PTEN and p53 genes using immunohistochemistry PV-9000 method.②Thirty-five retinoblastoma and sixteen normal retina tissues were used to investigate the mutations of exon5 and exon8 of PTEN gene using polymerase chain reaction and DNA sequencing analysis.The results associated with clinical pathological features were analyzed.Results①The positive protein expression rate of PTEN gene in normal retina was 100%, which was significantly higher than that in retinoblastoma(55%)(P＜0.01).There was no relationship between the protein expression of PTEN and sex differences(P＞0.05),however, there was significant difference between the protein expression of PTEN and clinical stage, pathological typing and whether there was optic nerve infiltration(P＜0.05).②The positive protein expression rate of p53 gene was 57.5%in retinoblastoma,which was significantly higher than that in normal retina(0%)(P＜0.05).There was no relationship between the protein expression of p53 and sex differences(P＞0.05),but there was significant difference between the protein expression of p53 and clinical stage,pathological typing and whether there was optic nerve infiltration(P＜0.05).③The protein expressions of PTEN and p53 genes were negatively correlated(r=-0.3710,P＜0.05).④PTEN total mutation rate was 14.29%,there was significant difference to compare with which in normal retina(0%)(P＜0.05).⑤There was no relationship between the rate of PTEN mutation of retinoblastoma and clinical stage, pathological type and whether there was optic nerve infiltration(P＞0.05).However,the mutant rate of PTEN of retinoblastoma which was at early clinical stage,differentiated and without optic nerve infiltration was much higher than that at late clinical stage,un-differentiated and with optic nerve infiltration.Conclusion①PTEN gene and p53 gene played synergies in the occurrence of retinoblastoma and jointly promoted the process of malignant progression of RB.②There was no relationship between the rate of PTEN mutation of retinoblastoma and clinical stage, pathological type and whether there was optic nerve infiltration,however,it showed a decreased trend along with the poorer differentiation,increased clinical stage,and decreased mutation rate,which suggested that PTEN mutation occurred in cases with better biological behavior.③The protein expression rate of PTEN demonstrated significantly higher than mutation rate,indicating that gene mutation was not the unique reason of PTEN protein deletion in retinoblastoma.④The mutation and protein deletion of PTEN gene was closely related to the occurrence and development of retinoblastoma,which was contribute to the early clinical diagnosis,intervention and treatment.