Screening for novel L-type amino acid transporter 1 (SLC7A5) inhibitors using a fluorescent amino acid.
Level 5 - mechanism / opinion, no new human data
In vitro bench study and compound screen using cell lines without human participants.
PubMed 41086683 · doi:10.1016/j.bbrc.2025.152768
What was done
Researchers evaluated the uptake of the fluorescent amino acid (S)-2-Amino-3-(9-oxo-9,10-dihydroacridin-2-yl) propanoic acid hydrochloride (H-Ala (2-Acd)-OH・HCl) and a structural analog, H-Ala (2-Bacd)-OH・HCl, in human Ca9-22 cells. Transport specificity for L-type amino acid transporter 1 (LAT1) was verified by competition assays using the selective LAT1 inhibitor JPH203 and excess natural substrate (leucine). The H-Ala (2-Acd)-OH・HCl probe was then used in Ca9-22 cells to perform a high-throughput screen of over 10,000 compounds for LAT1 inhibitory activity.
What was found
H-Ala (2-Acd)-OH・HCl was specifically transported into Ca9-22 cells via LAT1, and its uptake was suppressed by JPH203 and excess leucine. In contrast, H-Ala (2-Bacd)-OH・HCl exhibited minimal cellular uptake. Screening over 10,000 compounds with the H-Ala (2-Acd)-OH・HCl assay identified several potent LAT1 inhibitors. The abstract reports no numerical values, hit rates, or potency metrics (such as IC50 values).
Why it matters
This fluorescent substrate provides a non-radioactive cell-based assay to monitor LAT1 transport kinetics and facilitates high-throughput screening of small-molecule inhibitors targeting LAT1-dependent diseases, such as cancer and polycystic kidney disease.
Limits
Findings are entirely restricted to in vitro testing in a single cell line (Ca9-22). The abstract provides no quantitative data, chemical structures, toxicity profiles, or in vivo pharmacokinetic and efficacy evaluations for the identified inhibitor hits.
Cited by
- supports LAT1 is an amino acid transporter for the branched-chain amino acid leucine.