@article {BRAUNS1713, author = {SETH CLINT BRAUNS and PIETER MILNE and RYNO NAUD{\'E} and MARYNA VAN DE VENTER}, title = {Selected Cyclic Dipeptides Inhibit Cancer Cell Growth and Induce Apoptosis in HT-29 Colon Cancer Cells}, volume = {24}, number = {3A}, pages = {1713--1720}, year = {2004}, publisher = {International Institute of Anticancer Research}, abstract = {Background: An increasing number of cyclic dipeptides (CDPs), particularly those containing proline, have been shown to exhibit important biological activity. Materials and Methods: We investigated the potential of seven proline-based CDPs to inhibit cancer cell growth in HT-29, HeLa and MCF-7 cell lines. We also tested whether any of the CDPs were able to induce apoptosis in HT-29 cells. Results: The SRB assay showed that only cyclo(Phe-Pro) (10 mM) exhibited more than 50\% growth inhibition (p\<0.01). The MTT assay was used to demonstrate a dose-dependent (0.008-10 mM) growth inhibition by cyclo(Phe-Pro). Hoechst 33342 staining showed that 5 mM cyclo(Phe-Pro) induced chromatin condensation in 18.3{\textpm}2.8\% (p\<0.01) of HT-29 cells after 72 hours. Furthermore, annexin V binding revealed phosphatidylserine externalisation in cyclo(Phe-Pro)-treated HT-29 cells. Conclusion: Our findings demonstrate that cyclo(Phe-Pro) inhibits the growth of HT-29, MCF-7 and HeLa cells and induces apoptosis in HT-29 colon cancer cells, suggesting a potential antitumour activity. Copyright{\textcopyright} 2004 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved}, issn = {0250-7005}, URL = {https://ar.iiarjournals.org/content/24/3A/1713}, eprint = {https://ar.iiarjournals.org/content/24/3A/1713.full.pdf}, journal = {Anticancer Research} }