CYSTEINE DEPRIVATION AS A POTENTIAL THERAPEUTIC MODALITY FOR OVARIAN CARCINOMA

Abstract

Cysteine is a non-essential amino acid well known for its anti-oxidative property. Despite oxidative stress being an ever-present phenomenon in cancer, there are rather limited studies that assess the importance of cysteine amino acid in cancers. The current study aimed to examine the importance of cysteine amino acid, using ovarian clear cell carcinoma (OCCC) as the cancer model. OCCC expresses high cystathionase (CTH), the enzyme responsible for endogenous cysteine synthesis. It was therefore hypothesized that OCCC requires cysteine for survival. In accordance, independent individual amino acid starvation showed cysteine deprivation exert the most prominent cytotoxicity, even exceeded that caused by withdrawal of other amino acids, including the essential ones. Using pharmacologically induced cysteine deprivation, the study demonstrated its therapeutic anti-cancer applications and dissected the underlying mechanisms responsible for its cytotoxicity. The study showcased cysteine roles in cancer beyond its anti-oxidative function.