KIF14 and E2F3 mRNA expression in human retinoblastoma and its phenotype association

PURPOSE: We quantified mRNA expression of candidate genes for proliferation (KIF14 and E2F3) in a large retinoblastoma tumor cohort and associated with disease phenotype. METHODS: KIF14 and E2F3 mRNA expression was quantified by real time PCR in 57 retinoblastoma (RB) tumors, 3 RB cell lines, and control samples that included 4 each fetal, age-matched, adult retinas. Immunohistochemistry was done to confirm KIF14 and E2F3 protein expression in tumor cells. The mRNA expression levels were correlated with disease phenotypes including the significance of chemotherapy on tumors. RESULTS: There was statistically significant overexpression of KIF14 and E2F3 mRNA in tumors compared with control retinas (p<0.0001). Further, E2F3 also showed a significant overexpression compared to RB cell lines (p=0.01). Immunohistochemistry confirmed KIF14 and E2F3 protein overexpression in tumor cells. KIF14 had significant mRNA overexpression with older age (p=0.01) in presenting patients and in unilateral RB patients (p=0.04). Chemotherapy-treated tumors showed a significant decrease in KIF14 and E2F3 expression compared to untreated tumors (p<0.01 and 0.001, respectively). CONCLUSIONS: This report confirms significant mRNA overexpression of KIF14 and E2F3 together in a large cohort of RB tumors. The decreased expression in chemotherapy treated cases needs further validation in a large chemotherapy-treated cohort.