Clinicopathological parameters and expression of P-glycoprotein and MRP-1 in retinoblastoma

Ophthalmic Res. 2007;39(4):191-7. doi: 10.1159/000104680. Epub 2007 Jun 26.


Purpose: The immunohistochemical expressions of two multidrug resistance proteins, P-glycoprotein (P-gp) and multidrug resistance-related protein-1 (MRP-1), were studied in retinoblastoma and the correlations with the clinicopathological parameters were assessed.

Method: Sixty-five enucleated eyes containing retinoblastoma were included in the study. Following hematoxylin-eosin staining, tumor differentiation, presence of choroidal invasion, optic nerve invasion, retinal invasion, necrosis and presence of calcification were evaluated with the light microscope. P-gp and MRP-1 expressions were evaluated immunohistochemically.

Results: Fifty-three eyes were enucleated primarily and 12 eyes were operated after failure of chemotherapy. P-gp and MRP-1 expressions were positive in 69.3 and 73.4% of specimens, respectively. There was no statistically significant relationship between the expressions of P-gp and MRP-1, and tumor differentiation, presence of tumor invasion or treatment with chemotherapy.

Conclusion: Retinoblastoma intrinsically expresses both P-gp and MRP-1 and their expressions are not related to tumor differentiation. The expressions of P-gp and MRP-1 do not seem to be induced by chemotherapy and are not related to the degree of tumor invasion.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / metabolism*
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Child
  • Child, Preschool
  • Eye Enucleation
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Immunohistochemistry
  • Infant
  • Male
  • Multidrug Resistance-Associated Proteins / metabolism*
  • Retinal Neoplasms / drug therapy
  • Retinal Neoplasms / metabolism
  • Retinal Neoplasms / pathology*
  • Retinoblastoma / drug therapy
  • Retinoblastoma / metabolism
  • Retinoblastoma / pathology*


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Multidrug Resistance-Associated Proteins
  • multidrug resistance-associated protein 1