2 research outputs found
Programmable RNA detection with a fluorescent RNA aptamer using optimized three-way junction formation
Discovery of a Highly Specific Anti-methotrexate (MTX) DNA Aptamer for Antibody-Independent MTX Detection
High-dose methotrexate (MTX) therapy
is used to treat a wide variety
of cancers such as leukemia and lymphoma, while the resulting high
blood concentration of MTX faces a risk of life-threatening side effects,
so it is essential to monitor the concentration carefully. Currently,
the MTX concentration is measured using antibody-based kits in a clinical
setting; however, the heterogeneity and batch-to-batch variation of
antibodies potentially compromise the detection limit. Here, we developed
MTX detection systems with chemically synthesizable homogeneous oligonucleotides.
Microbead-assisted capillary electrophoresis (MACE)-SELEX against
MTX successfully identified MSmt7 with a similar level
of specificity to anti-MTX antibodies within three rounds. The 3′-end
of MSmt7 was coupled to a peroxidase-like hemin-DNAzyme
to construct a bifunctional oligonucleotide for MTX sensing, where
MTX in 50% human serum was detected with a limit of detection (LoD)
of 118 nM. Furthermore, amplifying the DNAzyme region with rolling
circle amplification significantly improved the sensitivity with an
LoD of 290 pM. Presented oligonucleotide-based MTX detection systems
will pave the way for antibody-independent MTX detection with reliability
and less cost in the laboratory and the clinic