van der Pol J P, Blom D J, Flens M J, Luyten G P, de Waard-Siebinga I, Koornneef L, Scheper R J, Jager M J
Department of Ophthalmology, Academic Medical Center, University of Amsterdam, The Netherlands.
Invest Ophthalmol Vis Sci. 1997 Nov;38(12):2523-30.
Metastatic uveal melanoma is strongly resistant to chemotherapy, and multidrug resistance (MDR) may be involved. To investigate the role of MDR, the presence of the MDR-associated proteins P-glycoprotein (Pgp), MRP, and lung resistance protein (LRP) was determined on primary choroidal melanomas and cell lines.
A panel of primary choroidal melanomas was examined for the presence of MDR-associated proteins by immunohistochemical analysis. In cell lines established from four primary choroidal melanomas and one metastatic choroidal melanoma, the expression of MDR-associated proteins was determined with monoclonal antibodies in cytospin preparations and flow cytometry. In addition, the functional capacities of transporter proteins Pgp and MRP as adenosine triphosphate-driven efflux pumps were determined by measuring the cellular accumulation and efflux of the fluorescent dyes rhodamine 123 and calcein-AM, with and without the presence of specific pump inhibitors PSC833 and probenecid.
Low levels of Pgp and MRP were detected in most primary tumors and in some cell lines. Measurable transporter function of Pgp could be determined in cell line OCM-1. Lung-resistance protein was present in all primary tumors and cell lines and showed high expression levels.
This study revealed the involvement of LRP and at least a minor role of Pgp and MRP in chemoresistance of choroidal melanoma. Compared with cutaneous melanomas, uveal melanomas appear to express slightly higher levels of Pgp. These findings provide insights into the drug-resistant phenotype of this disease and can aid in the design of therapeutic protocols.
转移性葡萄膜黑色素瘤对化疗具有很强的抗性，可能涉及多药耐药性（MDR）。为了研究MDR的作用，我们检测了原发性脉络膜黑色素瘤和细胞系中与MDR相关的蛋白P-糖蛋白（Pgp）、多药耐药相关蛋白（MRP）和肺耐药蛋白（LRP）的存在情况。
通过免疫组织化学分析检测一组原发性脉络膜黑色素瘤中与MDR相关蛋白的存在情况。在由四个原发性脉络膜黑色素瘤和一个转移性脉络膜黑色素瘤建立的细胞系中，用单克隆抗体在细胞涂片制剂和流式细胞术中测定与MDR相关蛋白的表达。此外，通过测量荧光染料罗丹明123和钙黄绿素-AM在有无特异性泵抑制剂PSC833和丙磺舒存在下的细胞摄取和流出，确定转运蛋白Pgp和MRP作为三磷酸腺苷驱动的流出泵的功能能力。
在大多数原发性肿瘤和一些细胞系中检测到低水平的Pgp和MRP。在细胞系OCM-1中可确定Pgp的可测量转运功能。肺耐药蛋白存在于所有原发性肿瘤和细胞系中，并显示出高表达水平。
本研究揭示了LRP的参与以及Pgp和MRP在脉络膜黑色素瘤化疗耐药中至少起次要作用。与皮肤黑色素瘤相比，葡萄膜黑色素瘤似乎表达略高水平的Pgp。这些发现为该疾病的耐药表型提供了见解，并有助于治疗方案的设计。
