Cinnamaldehyde induces apoptosis and enhances anti-colorectal cancer activity via covalent binding to HSPD1.

Colorectal cancer (CRC) is a common malignant tumor with high morbidity and mortality rates worldwide. Although surgical resection and adjuvant radiotherapy/chemotherapy are the mainstays of CRC treatment, the efficacy is unsatisfactory due to several limitations, including high drug resistance. Accordingly, there is a dire need for new drugs or a novel combination approach to treat this patient population. Herein, we found that cinnamaldehyde (CA) could exert an antitumor effect in HCT-116 cell lines. Target fishing, molecular imaging, and live-cell tracing using an alkynyl-CA probe revealed that the heat shock 60 kDa protein 1 (HSPD1) protein was the target of CA. The covalent binding of CA with HSPD1 altered its stability. Furthermore, our results demonstrated that CA could induce cell apoptosis by inhibiting the PI3K/Akt signaling pathway and enhanced anti-CRC activity both in vitro and in vivo. Meanwhile, CA combined with different chemotherapeutic agents was beneficial to patients resistant to anti-CRC drug therapy.