scholarly journals Tryptophan Side-Chain Oxidase Enzyme Suppresses Hepatocellular Carcinoma Growth through Degradation of Tryptophan

2021 ◽  
Vol 22 (22) ◽  
pp. 12428
Author(s):  
Yang Ai ◽  
Ben Wang ◽  
Shuai Xiao ◽  
Sang Luo ◽  
Yefu Wang
Keyword(s):  
Hepatocellular Carcinoma ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Amino Acid ◽  
High Performance ◽  
De Novo ◽  
Carcinoma Cells ◽  
Side Chain ◽  
Reaction Products ◽  
Hepatocellular Carcinoma Cells

Tryptophan metabolism plays a role in the occurrence and development of hepatocellular carcinoma cells. By degrading certain amino acids, tumor growth can be limited while maintaining the body’s normal nutritional requirements. Tryptophan side-chain oxidase (TSO) enzyme can degrade tryptophan, and its inhibitory effect on hepatocellular carcinoma cells is worthy of further study. To investigate the degradation effect on tryptophan, TSO was isolated and purified from qq Pseudomonas. The reaction products were identified with high performance liquid chromatography (HPLC) and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS). De novo sequencing provided the complete amino acid sequence of TSO. The results of CCK-8, colony formation, transwell, and qPCR confirmed that TSO had inhibitory effects on the proliferation and migration of HCCLM3 (human hepatocarcinoma cell line) and HepG2 cells. The results of flow cytometry confirmed its apoptotic activity. In animal experiments, we found that the tumor-suppressive effect was better in the oncotherapy group than the intraperitoneal injection group. The results of immunohistochemistry also suggested that TSO could inhibit proliferation and promote apoptosis. In conclusion, a specific enzyme that can degrade tryptophan and inhibit the growth of hepatoma cells was authenticated, and its basic information was obtained by extraction/purification and amino acid sequencing.

Influence of Resveratrol on Sphingolipid Metabolism in Hepatocellular Carcinoma Cells in Lipid Overload State

2019 ◽  
Vol 19 (1) ◽  
pp. 121-129
Author(s):  
Tomasz Charytoniuk ◽  
Ewa Harasim-Symbor ◽  
Agnieszka Polak ◽  
Krzysztof Drygalski ◽  
Klaudia Berk ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liquid Chromatography ◽  
High Performance ◽  
Metabolic Diseases ◽  
De Novo ◽  
Carcinoma Cells ◽  
Sphingolipid Metabolism ◽  
Gas Liquid Chromatography ◽  
Hepatocellular Carcinoma Cells ◽  
Ceramide Synthesis

Background: Obesity is characterized by increased long chain fatty acids (LCFA) uptake and impaired lipid metabolism in hepatocytes. Consequently, an enhanced intracellular lipid content, including sphingolipids, may lead to lipotoxicity. It is believed that resveratrol (RSV), one of the most extensively studied plant-derived polyphenols, and its interaction with sphingolipid metabolism may constitute one of the major therapeutic targets for cancer and metabolic diseases treatment. Objective: The aim of this study was to ascertain, whether resveratrol may affect sphingolipid metabolic pathways, enzymes and transporters in a lipid overload state. Methods: The experiments were conducted on hepatocellular carcinoma cells (HepG2) incubated with RSV and/or Palmitic Acid (PA) at the concentration of 0.5 mM and 50 µM, respectively for 16h. Intra- and extracellular sphingolipid concentrations were assessed by high-performance liquid chromatography and gas liquid chromatography. Moreover, the expression of caspase 3, selected fatty acid transporters and sphingolipid metabolism pathway proteins were estimated by Western Blot. Results: RSV alone and together with PA significantly increased the intracellular concentration of ceramide, sphinganine and sphingosine as well as the expression of enzymes related to de novo ceramide synthesis pathway. Moreover, in our study, we observed augmented ceramide and sphingomyelin efflux into the incubation media in these groups. In addition, RSV substantially reduced intracellular triacylglycerols accumulation in lipid overload conditions. Conclusion: The above-mentioned findings suggest that RSV, at least partially, demonstrates a potential protective effect on HepG2 cells in a lipid overload state.

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