Mono-PEGylation of a Thermostable Arginine-Depleting Enzyme for the Treatment of Lung Cancer.

Abstract

L-arginine (L-Arg) depletion induced by randomly PEGylated arginine deiminase (ADI-PEG20) can treat arginosuccinate synthase (ASS)-negative cancers, and ADI-PEG20 is undergoing phase III clinical trials. Unfortunately, ASS-positive cancers are resistant to ADI-PEG20. Moreover, the yield of ADI production is low because of the formation of inclusion bodies. Here, we report a thermostable arginine-depleting enzyme, Bacillus caldovelox arginase mutant (BCA-M: Ser161->Cys161). An abundant amount of BCA-M was easily obtained via high cell-density fermentation and heat treatment purification. Subsequently, we prepared BCA-M-PEG20, by conjugating a single 20 kDa PEG monomer onto the Cys161 residue via thio-chemistry. Unlike ADI-PEG20, BCA-M-PEG20 significantly inhibited ASS-positive lung cancer cell growth. Pharmacodynamic studies showed that a single intraperitoneal injection (i.p). administration of 250 U/mouse of BCA-M-PEG20 induced low L-Arg level over 168 h. The mono-PEGylation of BCA-M prolonged its elimination half-life from 6.4 to 91.4 h (a 14-fold increase). In an A549 lung cancer xenograft model, a weekly administration of 250 U/mouse of BCA-M-PEG20 suppressed tumor growth significantly. We also observed that BCA-M-PEG20 did not cause any significant safety issue in mouse models. Overall, BCA-M-PEG20 showed excellent results in drug production, potency, and stability. Thereby, it has great potential to become a promising candidate for lung cancer therapy.

• Authors: Sai-Fung Chung, Chi-Fai Kim, Sui-Yi Kwok, Suet-Ying Tam, Yu Wai Chen, Hiu-Chi Chong, Siu-Lun Leung, Pui-Kin So, Kwok-Yin Wong, Yun-Chung Leung, Wai-Hung Lo
• Journal: International journal of molecular sciences (Int J Mol Sci) Vol. 21 Issue 12 (Jun 14 2020) ISSN: 1422-0067 [Electronic] Switzerland
• PMID: 32545874 (Publication Type: Journal Article)

Chemical References

• Bacterial Proteins
• Polyethylene Glycols
• Arginine
• Hydrolases
• Arginase
• ADI PEG20

Topics

• A549 Cells
• Animals
• Arginase (chemistry, genetics, pharmacology)
• Arginine (metabolism)
• Bacterial Proteins (chemistry, genetics, pharmacology)
• Drug Stability
• Geobacillus (enzymology, genetics)
• Half-Life
• Humans
• Hydrolases (administration & dosage, pharmacology)
• Injections, Intraperitoneal
• Lung Neoplasms (drug therapy, metabolism)
• Mice
• Models, Molecular
• Mutation
• Polyethylene Glycols (administration & dosage, chemistry, pharmacology)
• Treatment Outcome
• Xenograft Model Antitumor Assays