title: Induction of arginosuccinate synthetase (ASS) expression affects the antiproliferative activity of arginine deiminase (ADI) in melanoma cells.
abstract: Arginine deiminase (ADI), an arginine-degrading enzyme, has been used in the treatment of tumours sensitive to arginine deprivation, such as malignant melanoma (MM) and hepatocellular carcinoma (HCC). Endogenous production of arginine is mainly dependent on activity of ornithine transcarbamylase (OTC) and argininosuccinate synthetase (ASS) enzymes. We evaluated the effect of ADI treatment on OTC and ASS expression in a series of melanoma cell lines. Twenty-five primary melanoma cell lines and normal fibroblasts as controls underwent cell proliferation assays and Western blot analyses in the presence or absence of ADI. Tissue sections from primary MMs (N = 20) and HCCs (N = 20) were investigated by immunohistochemistry for ASS expression. Overall, 21/25 (84%) MM cell lines presented a cell growth inhibition by ADI treatment; none of them presented constitutive detectable levels of the ASS protein. However, 7/21 (33%) ADI-sensitive melanoma cell lines presented markedly increased expression levels of the ASS protein following ADI treatment, with a significantly higher IC50 median value. Growth was not inhibited and the IC50 was not reached among the remaining 4/25 (16%) MM cell lines; all of them showed constitutive ASS expression. The OTC protein was found expressed in all melanoma cell lines before and after the ADI treatment. Lack of ASS immunostaining was observed in all analyzed in vivo specimens. Our findings suggest that response to ADI treatment in melanoma is significantly correlated with the ability of cells to express ASS either constitutively at basal level (inducing drug resistance) or after the treatment (reducing sensitivity to ADI).
authors.affiliation: Institute of Biomolecular Chemistry, National Research Council, Traversa La Crucca, 07100 Sassari, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Manca
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Sini
authors.forename: Francesco
authors.initials: F
authors.lastname: Izzo
authors.forename: Paolo A
authors.initials: PA
authors.lastname: Ascierto
authors.forename: Fabiana
authors.initials: F
authors.lastname: Tatangelo
authors.forename: Gerardo
authors.initials: G
authors.lastname: Botti
authors.forename: Giusy
authors.initials: G
authors.lastname: Gentilcore
authors.forename: Marilena
authors.initials: M
authors.lastname: Capone
authors.forename: Nicola
authors.initials: N
authors.lastname: Mozzillo
authors.forename: Carla
authors.initials: C
authors.lastname: Rozzo
authors.forename: Antonio
authors.initials: A
authors.lastname: Cossu
authors.forename: Francesco
authors.initials: F
authors.lastname: Tanda
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Palmieri
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001124:Argininosuccinate Synthase / Q000096:biosynthesis*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D006867:Hydrolases / Q000494:pharmacology*; D007150:Immunohistochemistry; D008545:Melanoma / Q000201:enzymology* / Q000473:pathology; D009954:Ornithine Carbamoyltransferase / Q000096:biosynthesis
chemical_list: D000970:Antineoplastic Agents; D009954:Ornithine Carbamoyltransferase; D006867:Hydrolases; C019723:arginine deiminase; D001124:Argininosuccinate Synthase