Screening of 5- and 6-Substituted Amiloride Libraries Identifies Dual-uPA/NHE1 Active and Single Target-Selective Inhibitors.

Abstract

The K+-sparing diuretic amiloride shows off-target anti-cancer effects in multiple rodent models. These effects arise from the inhibition of two distinct cancer targets: the trypsin-like serine protease urokinase-type plasminogen activator (uPA), a cell-surface mediator of matrix degradation and tumor cell invasiveness, and the sodium-hydrogen exchanger isoform-1 (NHE1), a central regulator of transmembrane pH that supports carcinogenic progression. In this study, we co-screened our library of 5- and 6-substituted amilorides against these two targets, aiming to identify single-target selective and dual-targeting inhibitors for use as complementary pharmacological probes. Closely related analogs substituted at the 6-position with pyrimidines were identified as dual-targeting (pyrimidine 24 uPA IC50 = 175 nM, NHE1 IC50 = 266 nM, uPA selectivity ratio = 1.5) and uPA-selective (methoxypyrimidine 26 uPA IC50 = 86 nM, NHE1 IC50 = 12,290 nM, uPA selectivity ratio = 143) inhibitors, while high NHE1 potency and selectivity was seen with 5-morpholino (29 NHE1 IC50 = 129 nM, uPA IC50 = 10,949 nM; NHE1 selectivity ratio = 85) and 5-(1,4-oxazepine) (30 NHE1 IC50 = 85 nM, uPA IC50 = 5715 nM; NHE1 selectivity ratio = 67) analogs. Together, these amilorides comprise a new toolkit of chemotype-matched, non-cytotoxic probes for dissecting the pharmacological effects of selective uPA and NHE1 inhibition versus dual-uPA/NHE1 inhibition.

• Authors: Benjamin J Buckley, Ashna Kumar, Ashraf Aboelela, Richard S Bujaroski, Xiuju Li, Hiwa Majed, Larry Fliegel, Marie Ranson, Michael J Kelso
• Journal: International journal of molecular sciences (Int J Mol Sci) Vol. 22 Issue 6 (Mar 15 2021) ISSN: 1422-0067 [Electronic] Switzerland
• PMID: 33804289 (Publication Type: Journal Article)

Chemical References

• Diuretics
• SLC9A1 protein, human
• Sodium-Hydrogen Exchanger 1
• Amiloride
• Urokinase-Type Plasminogen Activator

Topics

• Amiloride (chemical synthesis, chemistry, pharmacology)
• Breast Neoplasms (drug therapy, genetics, pathology)
• Cell Line, Tumor
• Diuretics (chemical synthesis, chemistry, pharmacology)
• Female
• Humans
• Models, Molecular
• Neoplasm Invasiveness (genetics, pathology)
• Sodium-Hydrogen Exchanger 1 (antagonists & inhibitors, genetics)
• Structure-Activity Relationship
• Urokinase-Type Plasminogen Activator (antagonists & inhibitors, genetics)