title: Enterolactone glucuronide and β-glucuronidase in antibody directed enzyme prodrug therapy for targeted prostate cancer cell treatment.
abstract: Evidence from preclinical and animal studies demonstrated an anticancer effect of flaxseed lignans, particularly enterolactone (ENL), against prostate cancer. However, extensive first-pass metabolism following oral lignan consumption results in their systemic availability primarily as glucuronic acid conjugates (ENL-Gluc) and their modest in vivo effects. To overcome the unfavorable pharmacokinetics and improve their effectiveness in prostate cancer, antibody-directed enzyme prodrug therapy (ADEPT) might offer a novel strategy to allow for restricted activation of ENL from circulating ENL-Gluc within the tumor environment. The anti-prostate-specific membrane antigen (PSMA) antibody D7 was fused with human β-glucuronidase (hβG) via a flexible linker. The binding property of the fusion construct, D7-hβG, against purified or cell surface PSMA was determined by flow cytometry and Octet Red 384 system, respectively, with a binding rate constant, Kd,of 2.5 nM. The enzymatic activity of D7-hβG was first tested using the probe, 4-methylumbelliferone glucuronide. A 3.8-fold greater fluorescence intensity was observed at pH 4.5 at 2 h compared with pH 7.4. The ability of D7-hβG to activate ENL from ENL-Gluc was tested and detected using LC-MS/MS. Enhanced generation of ENL was observed with increasing ENL-Gluc concentrations and reached 3613.2 ng/mL following incubation with 100 μM ENL-Gluc at pH 4.5 for 0.5 h. D7-hβG also decreased docetaxel IC50value from 23 nM to 14.9 nM in C4-2 cells. These results confirmed the binding and activity of D7-hβG and additional in vitro investigation is needed to support the future possibility of introducing this ADEPT system to animal models.
authors.affiliation: Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, Canada.
authors.forename: Yunyun
authors.initials: Y
authors.lastname: Di
authors.affiliation: Laboratory of Molecular Cell Biology, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Shaoping
authors.initials: S
authors.lastname: Ji
authors.affiliation: Department of Urology, Medical Center, University of Freiburg, Freiburg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Wolf
authors.affiliation: Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, Canada.
authors.forename: Ed S
authors.initials: ES
authors.lastname: Krol
authors.affiliation: Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, Canada. jane.alcorn@usask.ca.|College of Pharmacy and Nutrition, University of Saskatchewan, 104 Clinic Place, Saskatoon, Saskatchewan, S7N 2Z4, Canada. jane.alcorn@usask.ca.
authors.forename: Jane
authors.initials: J
authors.lastname: Alcorn
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000818:Animals; D000906:Antibodies / Q000627:therapeutic use*; D000954:Antigens, Surface / Q000276:immunology*; D019556:COS Cells; D002522:Chlorocebus aethiops; D005966:Glucuronidase / Q000627:therapeutic use*; D020719:Glucuronides / Q000627:therapeutic use*; D043425:Glutamate Carboxypeptidase II / Q000276:immunology*; D006801:Humans; D017705:Lignans / Q000627:therapeutic use*; D008297:Male; D011355:Prodrugs / Q000627:therapeutic use*; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use*
chemical_list: D000906:Antibodies; D000954:Antigens, Surface; D020719:Glucuronides; D017705:Lignans; D011355:Prodrugs; D011993:Recombinant Fusion Proteins; D005966:Glucuronidase; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone
keywords: ADEPT; enterolactone; enterolactone glucuronide; flaxseed lignans; β-glucuronidase