Yuan Zhuang

Real-Time, Quantitative Lighting-up Detection of Telomerase in Urines of Bladder Cancer Patients by AIEgens

As a biomarker for early cancer diagnosis, telomerase are one of the promising targets for cancer therapeutics. Inspired by the fluorescent emission principle of aggregation-induced emission fluorogens, we creatively designed an AIE-based turn-on method to detect telomerase activity from cell extracts. A positively charged fluorogen (TPE-Z) is not fluorescent when freely diffused in solution. The fluorescence of TPE-Z is enhanced with the elongation of the DNA strand which could light up telomere elongation process. By exploitation of it, we can detect telomerase activity from different cell lines (E-J, HeLa, MCF-7, and HLF) with high sensitivity and specificity. Moreover, our method is successfully employed to demonstrate the applications in bladder cancer diagnosis (41 urine specimens from bladder cancer patients and 15 urine specimens from normal people are detected). The AIE-based method provides a simple one-pot technique for quantification and monitoring of the telomerase activity and shows great potential for future use in clinical tests.

Facile, Fast-Responsive, and Photostable Imaging of Telomerase Activity in Living Cells with a Fluorescence Turn-On Manner

In situ detecting and monitoring intracellular telomerase activity is significant for cancer diagnosis. In this work, we report a facile and fast-responsive bioprobe for in situ detection and imaging of intracellular telomerase activity with superior photostability. After transfected into living cells, quencher group labeled TS primer (QP) can be extended in the presence of intracellular telomerase. Positive charged TPE-Py molecules (AIE dye) will bind to the primer as well as extension repeated units, producing a telomerase activity-related turn-on fluorescence signal. By incorporating positive charged AIE dye and substrate oligonucleotides, in situ light-up imaging and detection of intracellular telomerase activity were achieved. This strategy exhibits good performance for sensitive in situ tracking of telomerase activity in living cells. The practicality of this facile and fast-responsive telomerase detection method was demonstrated by using it to distinguish tumor cells from normal cells and to monitor the change of telomerase activity during treatment with antitumor drugs, which shows its potential in clinical diagnostic and therapeutic monitoring.

Lab in a Tube: Sensitive Detection of MicroRNAs in Urine Samples from Bladder Cancer Patients Using a Single-Label DNA Probe with AIEgens

We demonstrate an ultrasensitive microRNA detection method based on an extremely simple probe with only fluorogens but without quencher groups. It avoids complex and difficult steps to accurately design the relative distance between the fluorogens and quencher groups in the probes. Furthermore, the assay could accomplish various detection limits by tuning the reaction temperature due to the different activity of exonuclease III corresponding to the diverse temperature. Specifically, 1 pM miR-21 can be detected in 40 min at 37 °C, and 10 aM (about 300 molecules in 50 μL) miR-21 could be discriminated in 7 days at 4 °C. The great specificity of the assay guarantees that the real 21 urine samples from the bladder cancer patients are successfully detected by our method.

Facile Probe Design: Fluorescent Amphiphilic Nucleic Acid Probes without Quencher Providing Telomerase Activity Imaging Inside Living Cells

Nowadays, the probe with fluorophore but no quencher is promising for its simple preparation, environmental friendliness, and wide application scope. This study designs a new amphiphilic nucleic acid probe (ANAP) based on aggregation-caused quenching (ACQ) effect without any quencher. Upon binding with targets, the dispersion of hydrophobic part (conjugated fluorene, CF) in ANAP is enhanced as a signal-on model for proteins, nucleic acids, and small molecules detection or the aggregation of CF is enhanced as a signal-off model for ion detection. Meanwhile, because of the high specificity of ANAP, a one-step method is developed powerfully for monitoring the telomerase activity not only from the cell extracts but also from 50 clinic urine samples (positive results from 45 patients with bladder cancer and negative results from 5 healthy people). ANAPs can also readily enter into cells and exhibit a good performance for distinguishing natural tumor cells from the tumor cells pretreated by telomerase-related drugs or normal cells. In contrast to our previous results ( Anal. Chem. 2015 , 87 , 3890 - 3894 ), the present CF is a monomer which is just the structure unit of the previous fluorescent polymer. Since the accurate molecular structure and high DNA/CF ratio of the present CF, these advanced experiments obtain an easier preparation of probes, an improved sensitivity and specificity, and broader detectable targets.