CancerLettere, zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 410988) zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 119- 122 Elaevier Scientific Publishers IreJand Ltd. 119 RE’I’INOIC BINDING IN MELANOMAS OF THE EYE AND IN NORMAL CHOROID F. DAXECKER’, Ch. MARTHb and G. DAXENBICHLEW ‘Department of Ophthalmology and *Department of Obstetrics and Gynecology. University of Inwbruck, Anich8tnrsse SS, A-6020 Innsbruck (Au&d kceived 16 February 1999) (Accepted 14 April 1999) SUMMARY Binding proteins for retinoie acid (cellular retinoid acid binding protein, CRABP), and for vitamin A (cellular retinol binding protein, CRBP) have been demonstrated in various cell types; these binding proteins display the characteristics of receptors. In the present study CRABP and CRBP levels were measured in 9 melanomas of the choroid. CRABP was detected in 2 of the melanomas, whereas CRBP was measurable in 1 melanoma. In comparison samples of normal choroid contained CRABP and CRBP in all cases investigated. Key words: Retinoic acid binding protein; Retinol binding protein; Melanoma of the ehoroid; Retinoids; Retinoie acid binding protein in normal choroids. INTRODUCTION Retinoic acid- and retinol binding proteins have been demonstrated in normal and pathological tissues [1,2,7,10,18]. CRABP and CRBP can be present in both, the cytoplasm and nucleus, they display the characteristics of receptors, i.e. they have a high binding affinity and specificity but limited capacity. Retinoic acid (RA) affects cellular differentiation, especially of epithelial cells, and vitamin A plays a well defined role in the biochemistry of vision [15]. Vitamin A is suggested to have antineoplastic activity as its absence was associated with an increased incidence of tumors [S]. Retinoids have been successfully used in the treatment of skin disorders, precancerous states, and malignant tumors [3-51. The purpose of this sudy was to investigate CRABP and CRBP in tumors and in normal choroid. MATERIAL AND METHODS The enucleated eye was opened immediately after surgical removal, the 0304-3333/33/$03.50 0 1999 Elsevier Scientific Publishers Ireland Ltd. Published and Printed in Ireland.