In a 144-hour SRB assay, (R)-bicalutamide had a reported IC50 of 2 μM in LNCaP cells; the IC50 was not reached in LNCaP-AR, LNCaP-Rbic or VCaP cells over 0.02–20 μM. In a separate 18-hour LNCaP experiment, 10–20 μM reduced R1881-stimulated BrdU incorporation to near the untreated level. These results show dependence on model and assay conditions. [3]
R-bicalutamide bound to the W741L androgen receptor ligand-binding domain
Biochemical assay · Recombinant human AR LBD (663–919), W741L mutant, expressed in E. coli [1]
The 1.8-Å crystal structure places R-bicalutamide in the mutant AR ligand-binding pocket. The complex retains an agonist-like fold; its B ring occupies space corresponding to Trp-741 in the WT–DHT structure. This is a mutant complex, not a directly observed WT antagonist conformation.
Literature-Reported Treatment Conditions
- Treatment concentration
- 100 μM in the final protein concentration buffer; 10 μM during several purification steps
- Exposure duration
- Crystals formed in 1–2 days
- Method
- Sitting-drop vapor diffusion; X-ray diffraction
- Vehicle
- Final protein buffer: 150 mM Li2SO4, 50 mM Hepes pH 7.2, 10% glycerol, 0.1% n-octyl-β-glucoside, 10 mM DTT
- Reported limits
- Ligand stock solvent not stated; purification concentrations are not cellular exposure recommendations.
Methods and source locations
Compound reported in the paper: (R)-Bicalutamide; Compound label in the paper: R-bicalutamide
Evidence concerns the reported R enantiomer in these models; it is not evidence of Adooq product testing.
Materials and Methods: Cloning, Expression, and Purification; Crystallization; Table 1; Results: Overall Structure; Figures 2 and 4
Diffraction resolution: X-ray crystallography — Crystallization methods; Table 1
Six-day growth-response panel in prostate cancer cell lines
Cell-based study · LNCaP, LNCaP-AR, LNCaP-Rbic and VCaP cells [3]
After 144 hours, the reported IC50 was 2 μM in LNCaP cells. The IC50 was not reached in LNCaP-AR, LNCaP-Rbic or VCaP over the tested range.
Literature-Reported Treatment Conditions
- Treatment concentration
- 0.02–20 μM
- Exposure duration
- 144 hours
- Method
- SRB assay; 5,000 cells/well; octuplicate wells in each of three independent experiments
- Co-treatment
- None reported for this dose-response experiment.
- Reported limits
- R-bicalutamide stock solvent and final vehicle concentration not stated in the read methods.
Methods and source locations
Compound reported in the paper: (R)-Bicalutamide; Compound label in the paper: (R)-bicalutamide
Evidence concerns the reported R enantiomer in these models; it is not evidence of Adooq product testing.
Materials and Methods: Cell Lines and Culture; In vitro Chemosensitivity Assay; Results: Cytotoxic Activity in vitro; Figure 2
LNCaP cell survival by SRB: SRB; graphically determined IC50 — Figure 2, LNCaP row; Results paragraph beginning Cells were exposed
LNCaP-AR, LNCaP-Rbic and VCaP cell survival by SRB: SRB; 0.02–20 μM tested — Figure 2, three corresponding rows and n.r. footnote
Effect on androgen-stimulated DNA synthesis in LNCaP cells
Cell-based study · Quiescent LNCaP cells [3]
R-bicalutamide reduced R1881-stimulated BrdU incorporation to near the untreated level in this 18-hour experiment. Drug-alone and androgen-stimulated conditions were measured separately.
Literature-Reported Treatment Conditions
- Treatment concentration
- 10 or 20 μM
- Exposure duration
- 18 hours
- Method
- BrdU immunofluorescence after a 100 μM BrdU pulse
- Co-treatment
- Parallel drug-alone conditions and co-treatment with 10 nM R1881; R1881-alone and untreated controls.
- Reported limits
- R-bicalutamide vehicle and BrdU pulse duration not stated in the table or read method.
Methods and source locations
Compound reported in the paper: (R)-Bicalutamide; Compound label in the paper: (R)-bicalutamide
Evidence concerns the reported R enantiomer in these models; it is not evidence of Adooq product testing.
Materials and Methods: BrdU Incorporation; Table 1 and footnote
BrdU-positive nuclei: untreated and R1881 alone: Mean of three independent experiments; standard deviation <1.4 — Table 1 and footnote
BrdU-positive nuclei: R-bicalutamide alone: Mean of three independent experiments; standard deviation <1.4 — Table 1 and footnote
BrdU-positive nuclei: R1881 plus R-bicalutamide: Mean of three independent experiments; standard deviation <1.4; no significant difference from control assigned by the authors — Table 1 and footnote
Direct glucuronidation of pure R-bicalutamide by recombinant human UGTs
Biochemical assay · Human UGT1A8, UGT1A9 and UGT2B7 bacculosomes (10 μg protein) [2]
Recombinant UGT1A8, UGT1A9 and UGT2B7 directly glucuronidated pure R-bicalutamide in vitro. The reported Km values were 134.1 ± 8.1, 173.3 ± 35.8 and 133.3 ± 63.6 μM, respectively. These enzyme parameters do not establish systemic clearance or antitumor potency.
Literature-Reported Treatment Conditions
- Treatment concentration
- 1–1000 μM substrate
- Exposure duration
- 2 hours at 37°C
- Method
- LC-MS/MS of glucuronide formation; enzyme kinetic fitting
- Vehicle
- Assay buffer with 1 mM UDPGA and 0.025 μg/ml alamethicin; substrate stock solvent not stated
- Reported limits
- Absolute glucuronide concentrations could not be calibrated with authentic glucuronide standards; assay signal used relative LC-MS/MS peak areas.
Methods and source locations
Compound reported in the paper: (R)-Bicalutamide; Compound label in the paper: (R)-bicalutamide
Evidence concerns the reported R enantiomer in these models; it is not evidence of Adooq product testing.
Materials and Methods: Microsome isolation and glucuronidation assays; LC-MS/MS; Results: recombinant human UGT enzymes; Table 2; Figure 6 caption
R-bicalutamide glucuronidation by UGT1A8: Sigmoidal kinetics; mean ± SD of two independent experiments in triplicate — Table 2, UGT1A8 pure (R)bicalutamide row; Results kinetic-model paragraph
R-bicalutamide glucuronidation by UGT1A9: Substrate-inhibition kinetics; mean ± SD of two independent experiments in triplicate — Table 2, UGT1A9 pure (R)bicalutamide row
R-bicalutamide glucuronidation by UGT2B7: Substrate-inhibition kinetics; mean ± SD of two independent experiments in triplicate — Table 2, UGT2B7 pure (R)bicalutamide row
