Uncovering the Interaction between Intracellular Telomerase Activity and Hydrogen Peroxide during Cancer Cell Apoptosis Utilizing a Dual-Color Fluorescent Nanoprobe.

Uncovering the intrinsic interaction of different bioactive species, i.e., reactive oxygen species (ROS) and telomerase, is of great importance because they play interrelated and interdependent biological roles in living organisms. Nevertheless, exploration of the intracellular ROS/telomerase cross-talk by effective and noninvasive methods remains a great challenge, as it is difficult to simultaneously detect different types of biomolecules (i.e., active small molecules and proteins) in living cells. To address this issue, herein, we report, for the first time, a novel fluorescent nanoprobe for simultaneous determination and in situ imaging of telomerase activity and hydrogen peroxide (H 2 O 2 ) in living cells. With the advantage of high sensitivity and good specificity, this newly fabricated nanoprobe was successfully applied to precisely visualize and monitor the changes in telomerase activity and H 2 O 2 concentration in cancer cells. More significantly, by employing the nanoprobe as a one-step incubation tool, it is found that there is a cross-talk between H 2 O 2 and telomerase activity in the drug-induced cancer cells' apoptosis process, which provides valuable information for gaining fundamental insights into the relationship between ROS and telomerase activity in cancer treatments. This work affords a promising method for revealing the relevant regulatory mechanisms and roles of ROS and telomerase activity in the occurrence, evolvement, and treatment of diseases.