Purchase this article with an account.
Jinfeng Cao, Kate Richards, Ekaterina S. Jordanova, Marina Marinkovic, Daan Hurkmans, Sjoerd G. van Duinen, Pieter A. van der Velden, Martine J Jager; Expression of PD-L1 and PD-1 in conjunctival melanoma. Invest. Ophthalmol. Vis. Sci. 2016;57(12):2404.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Current therapies of conjunctival melanoma (CM) include surgical excision combined with adjuvant cryotherapy, brachytherapy, and/or topical chemotherapy. However, therapeutic strategies with regard to metastases are often ineffective. As blocking the interaction between the programmed cell death (PD)-1 protein and its ligand, PD-L1, has been reported to have significant antitumor effects in other malignancies, we studied whether conjunctival melanoma express PD-L1 and PD-1 in vivo and in vitro.
30 conjunctival malignant lesions obtained from 27 patients were collected. The presence of PD-L1 and PD-1 was assessed by immunofluorescence. Real-time qRT-PCR was performed to detect the gene expression of PD-L1 and PD-1 in three CM cell lines (CRMM1, CRMM2 and CM2005.1). Flow cytometry was used to analyse the cell surface expression of PD-L1 and PD-1 of CM cell lines.
19% of CM cases showed PD-L1 positivity in the tumor cells, while 57% of cases expressed PD-L1 in the stromal cells. PD-1 protein was expressed in 70% of cases, either in the tumor or stroma. The cell lines showed different PD-L1 expression at both the mRNA level and membranous protein level, and could be stimulated by IFNγ treatment. Although PD-1 gene expression could be upregulated upon IFNγ treatment among three CM cell lines, the protein level on cell membrane was low and was not upregulated following IFNγ stimulation.
The PD-L1/ PD-1 pathway is activated in many cases of CM and these results support the need to evaluate anti-PD-L1/ PD-1 therapy in CM patients.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only