Pegargiminase Suppresses the Fanconi Anemia Pathway and Promotes Melphalan‐InducedDouble‐Strand Breaks in Uveal Melanoma
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
ABSTRACT Uveal melanoma is a hard‐to‐treat arginine‐dependent cancer secondary to argininosuccinate synthetase 1 (ASS1) loss with half of patients succumbing to liver‐dominant metastases. Arginine deprivation with pegargiminase is a novel antimetabolite strategy for patients with uveal melanoma. We investigated the preclinical rationale for combining pegargiminase with melphalan, an alkylating agent approved recently for the treatment of hepatic‐centric disease. Drug sensitivity of ASS1‐deficient uveal melanoma cell lines was performed in 2D culture using proliferation and cytotoxicity assays, with analysis of cell death, cell cycle, DNA double‐strand breaks, and interrogation of the molecular mechanism of action by RNA‐seq. ADI‐PEG20 and melphalan suppressed uveal melanoma cell line proliferation and triggered cytotoxicity, effects which were enhanced with the drug combination. ADI‐PEG20 downregulated multiple genes of the Fanconi anemia pathway and synergized with melphalan to increase DNA double‐strand breaks. Melphalan and pegargiminase is a rational new drug combination that warrants clinical testing in uveal melanoma. Significance Uveal melanoma is an arginine‐dependent cancer secondary to ASS1 loss and is sensitive to arginine deprivation with pegargiminase (ADI‐PEG20). pcmr70104-li-0001 Here, we show that pegargiminase suppresses multiple Fanconi anemia pathway genes and synergizes to increase DNA double‐strand breaks in uveal melanoma cells, with enhanced cytotoxicit
Abstract
ABSTRACT Uveal melanoma is a hard‐to‐treat arginine‐dependent cancer secondary to argininosuccinate synthetase 1 (ASS1) loss with half of patients succumbing to liver‐dominant metastases. Arginine deprivation with pegargiminase is a novel antimetabolite strategy for patients with uveal melanoma. We investigated the preclinical rationale for combining pegargiminase with melphalan, an alkylating agent approved recently for the treatment of hepatic‐centric disease. Drug sensitivity of ASS1‐deficient uveal melanoma cell lines was performed in 2D culture using proliferation and cytotoxicity assays, with analysis of cell death, cell cycle, DNA double‐strand breaks, and interrogation of the molecular mechanism of action by RNA‐seq. ADI‐PEG20 and melphalan suppressed uveal melanoma cell line proliferation and triggered cytotoxicity, effects which were enhanced with the drug combination. ADI‐PEG20 downregulated multiple genes of the Fanconi anemia pathway and synergized with melphalan to increase DNA double‐strand breaks. Melphalan and pegargiminase is a rational new drug combination that warrants clinical testing in uveal melanoma. Significance Uveal melanoma is an arginine‐dependent cancer secondary to ASS1 loss and is sensitive to arginine deprivation with pegargiminase (ADI‐PEG20). pcmr70104-li-0001 Here, we show that pegargiminase suppresses multiple Fanconi anemia pathway genes and synergizes to increase DNA double‐strand breaks in uveal melanoma cells, with enhanced cytotoxicity and PARP and caspase‐dependent apoptosis. pcmr70104-li-0002 Clinical trials of pegargiminase plus melphalan are warranted in uveal melanoma. pcmr70104-li-0003 bullet pcmr70104-list-0001 highlights pcmr70104-abs-5002 ADI‐PEG20 enhances melphalan‐induced DNA DSBs in UM cells. We describe potentiation of DNA DSBs in UM cell lines upon treatment with ADI‐PEG20 and melphalan (92.1 cells with STRIDE by intoDNA). ADI‐PEG20 suppresses multiple members of the FA pathway—a known resistance mechanism for melphalan—providing a rationale for exploring this drug combination in the clinic. graphical