Isolation and antiproliferation of tumor cells by a novel peptide (TC22) from the beetle Tribolium castaneum.

Anticancer peptides (ACPs) are biologically anticancer active molecules that are produced by mammals, plants, insects and microorganisms. Here, a new peptide (TC22) with the amino acid sequence MTVVLLLIVLPLLGGVHSSGIL was identified and characterized from the beetle Tribolium castaneum. We found it inhibited the growth and viability of HeLa and MCF-7 cells. Flow cytometry analysis demonstrated the TC22 induced HeLa cell apoptosis, and activated caspase-9 and caspase-3. Furthermore, TC22 led to ROS generation, and triggered p53 transcription and expression. Taken together, our results indicated that TC22 exhibited high anticancer capacity via activating p53, inducing ROS generation and through a mitochondrial pathway. This research provided a novel natural source peptide with strong anticancer capacity. These findings provide some novel insights on the potential candidate reagent in cancer treatment.