The Combination of Arginine Deprivation and 5-Fluorouracil Improves Therapeutic Efficacy in Argininosuccinate Synthetase Negative Hepatocellular Carcinoma

International Journal of Molecular Sciences

Vajarabhongsa Bhudhisawasdi¹  Chunjing Wu²  Medhi Wangpaichitr²  Niramol Savaraj²  Ying-Ying Li²  Thaniya Sricharunrat³  Angkana Thongkum⁴  Panida Navasumrit⁴  Varabhorn Parnlob⁴  Mathuros Ruchirawat⁴ 

[1] Department of Surgery, Faculty of Medicine, Khonkaen University, Khonkaen 40000, Thailand;Division of Hematology/Oncology, Miami Veterans Affairs Healthcare System, Miami, FL 33125, USA;Laboratory Unit of Pathology, Chulabhorn Hospital, Laksi, Bangkok 10210, Thailand;Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Laksi, Bangkok 10210, Thailand;

关键词: ASS(-)Hepatocellular carcinoma;    ADI-PEG20;    5-FU;    thymidylate synthase;    ASS re-expression;    pyrimidine metabolism;   

DOI  :  10.3390/ijms18061175

来源: DOAJ

【 摘 要 】

Argininosuccinate synthetase (ASS), a key enzyme to synthesize arginine is down regulated in many tumors including hepatocellular carcinoma (HCC). Similar to previous reports, we have found the decrease in ASS expression in poorly differentiated HCC. These ASS(-) tumors are auxotrophic for arginine. Pegylated arginine deiminase (ADI-PEG20), which degrades arginine, has shown activity in these tumors, but the antitumor effect is not robust and hence combination treatment is needed. Herein, we have elucidated the effectiveness of ADI-PEG20 combined with 5-Fluorouracil (5-FU) in ASS(-)HCC by targeting urea cycle and pyrimidine metabolism using four HCC cell lines as model. SNU398 and SNU387 express very low levels of ASS or ASS(-) while Huh-1, and HepG2 express high ASS similar to normal cells. Our results showed that the augmented cytotoxic effect of combination treatment only occurs in SNU398 and SNU387, and not in HepG2 and Huh-1 (ASS(+)) cells, and is partly due to reduced anti-apoptotic proteins X-linked inhibitor of apoptosis protein (XIAP), myeloid leukemia cell differentiation protein (Mcl-1) and B-cell lymphoma-2 (Bcl-2). Importantly, lack of ASS also influences essential enzymes in pyrimidine synthesis (carbamoyl-phosphate synthetase2, aspartate transcarbamylase and dihydrooratase (CAD) and thymidylate synthase (TS)) and malate dehydrogenase-1 (MDH-1) in TCA cycle. ADI-PEG20 treatment decreased these enzymes and made them more vulnerable to 5-FU. Transfection of ASS restored these enzymes and abolished the sensitivity to ADI-PEG20 and combination treatment. Overall, our data suggest that ASS influences multiple enzymes involved in 5-FU sensitivity. Combining ADI-PEG20 and 5-FU may be effective to treat ASS(-)hepatoma and warrants further clinical investigation.

【 授权许可】

Unknown