ja5042995_si_001.pdf (1.08 MB)
A Robust Probe for Lighting Up Intracellular Telomerase via Primer Extension To Open a Nicked Molecular Beacon
journal contribution
posted on 2014-06-11, 00:00 authored by Ruocan Qian, Lin Ding, Liwen Yan, Manfei Lin, Huangxian JuA nicked
molecular beacon (MB)-functionalized probe has been designed
for in situ imaging and detection of intracellular telomerase activity.
The nick separates the MB into two segments: a shorter telomerase
primer (TSP) sequence as a part of the 5′-end stem and a longer
sequence to form a loop with one thiol-labeled 3′-end stem.
The MB can be opened by substitutional hybridization of the telomerase-triggered
stem elongation product, which leads to separation of the Cy5 at the
5′-end nick from the gold nanoparticle (AuNP) as the nanocarrier
and thus inhibits the energy transfer from Cy5 to AuNP. Upon endocytosis
of the probe, the TSP can be extended by intracellular telomerase
at its 3′ end to produce the telomeric repeated sequence, which
leads to the inner chain substitution and thus turns on the fluorescence
of Cy5. The probe provides a one-step incubation technique for quantification
and monitoring of the telomerase activity in living cells. The practicality
of the proposed approach for distinguishing tumor cells from normal
cells and monitoring the decrease of telomerase activity during treatment
with antitumor drugs demonstrates its potential in clinical diagnostic
and therapeutic monitoring.