Abstract
Purpose :
Endothelin-1 can be considered to be an autocrine/paracrine growth factor via its specific receptors (particularly B). Blockage of the receptors can sensitize human tumor cells to apoptosis. Both effects have been shown in cutaneous melanomas. Our goal was to investigate whether endothelin-1 (ET-1) and its endothelin-beta receptor (ET-BR) are expressed in human conjunctival melanomas.
Methods :
Five conjunctival specimens that were histopathologically and immunohistochemically diagnosed as malignant conjunctival melanoma were immunhistochemically analyzed for the presence, localization and amount of ET-1 and ET-BR expression by specific antibodies.
Results :
ET-1 and ET-BR was detected in all specimens. Morphometric density of ET-1 immunopositive cells was 15±18 cells per high-power field (HPF) within the central part of the tumor and 50±21 cells/HPF in the outer tumor periphery. The density of ET-BR immunopositive cells was 18±21 cells/HPF within the tumor center and 53±27 cells/HPF in the tumor periphery. ET-1 and ET-BR expressions were significantly higher in the periphery than in the center of the tumor (p<0.001, respectively).
Conclusions :
Conjunctival melanomas express endothelin-1 and endothelin-beta receptors especially in the outer periphery of the tumor. Blocking the endothelin-1 cascade might be an interesting therapeutic option for conjunctival melanomas as well.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.