Xiaodong Wang

Stabilization of G-quadruplex structures in the promoter region of certain oncogenes is an emerging field in anticancer drug design. Human c-myc gene is one of these oncogenes, and G-quadruplexes have been proven to be the transcriptional controller of this gene. In the present study, the interaction of quindoline derivatives with G-quadruplexes in c-myc was investigated. The experimental results indicated that these derivatives have the ability to induce/stabilize the G-quadruplexes in c-myc, which lead to down-regulation of the c-myc in the Hep G2 cell line. It was found that derivatives with terminal amino groups in their side chains would selectively bind to the isomers with the double nucleotide loops in the absence of K+. Molecular modeling studies revealed the binding mode between the derivatives and the G-quadruplexes is end-stacking at the 3'-position, and the positively charged side chain on the quindoline derivatives may contribute to the selectivity to certain loop isomers of topological quadruplexes as well as the improved stabilization action.

Abstract Expression of a high concentration of H 2 S is closely related to the formation of colon cancer tumors. However, only a few H 2 S‐triggered theranostics agents for colon cancer have been reported to date. Now, a turn‐on theranostics agent was developed by utilizing the in situ reaction of Cu 2 O and endogenous H 2 S at colon tumor sites. Based on in vitro and in vivo experiments, excellent photoacoustic imaging and photothermal therapy were both confirmed by this in situ reaction‐activated colon cancer theranostics method. This work established a simple and efficient strategy for both diagnosis and treatment of colon cancer with a novel trigger mechanism, which provides a new route for colon cancer theranostics based on the in situ reactions at the tumor sites.