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


METHODS
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.


CONCLUSIONS
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.
Kamburoğlu
Günhal
G
Department of Ophthalmology, Hacettepe University School of Medicine, Ankara, Turkey.
Kiratli
Hayyam
H
Söylemezoğlu
Figen
F
Bilgiç
Sevgül
S
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015353:Eye Enucleation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism*; D019572:Retinal Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D012175:Retinoblastoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C421109:multidrug resistance-associated protein 1