Apolipoprotein D expression in retinoblastoma

The presence of apolipoprotein D (apoD) synthesis in brain suggests that this protein could play a major role in mediating neuronal degeneration and regeneration in the central nervous system (CNS). For instance, apoD is overexpressed in neural tissues in Niemann-Pick's type C disease, after acute CNS injury and cerebral ischemia, Alzheimer's disease and by a number of different tumors such as breast, prostate, ovarian and endometrial carcinomas. Recent data have raised the possibility that apoD expression could be a marker of cellular differentiation and growth arrest. By immunohistochemistry, we evaluated the tumoral expression of apoD in retinoblastoma, a tumor that results from malignant transformation of primitive retinal cells before final differentiation, and analyzed the possible relationship with clinicopathological parameters such as: age, sex, histological type, staging, local invasion, metastasis, preoperative or postoperative treatment and bilateral tumors. A total of eleven retinoblastomas (55%) showed apoD-positive immunostaining, but no significant correlation was found between apoD expression and patient or tumor characteristics.