title: Coumarin A/AA induces apoptosis-like cell death in HeLa cells mediated by the release of apoptosis-inducing factor.
abstract: It has been demonstrated that naturally occurring coumarins have strong biological activity against many cancer cell lines. In this study, we assessed the cytotoxicity induced by the naturally isolated coumarin A/AA in different cancer cell lines (HeLa, Calo, SW480, and SW620) and in normal peripheral-blood mononuclear cells (PBMCs). Cytotoxicity was evaluated using the MTT assay. The results demonstrate that coumarin A/AA was cytotoxic in the four cancer cell lines tested and importantly was significantly less toxic in PBMCs isolated from healthy donors. The most sensitive cancer cell line to coumarin A/AA treatment was Hela. Thus, the programmed cell death (PCD) mechanism induced by this coumarin was further studied in this cell line. DNA fragmentation, histomorphology, cell cycle phases, and subcellular distribution of PCD proteins were assessed. The results demonstrated that DNA fragmentation, but not significant cell cycle disruptions, was part of the PCD activated by coumarin A/AA. Interestingly, it was found that apoptosis-inducing factor (AIF), a proapoptotic protein of the mitochondrial intermembrane space, was released to the cytoplasm in treated cells as detected by the western blot analysis in subcellular fractions. Nevertheless, the active form of caspase-3 was not detected. The overall results indicate that coumarin A/AA induces a caspase-independent apoptotic-like cell death program in HeLa cells, mediated by the early release of AIF and suggest that this compound may be helpful in clinical oncology.
authors.affiliation: Department of Biology, National Autonomous University of Mexico, Coyoacán, Mexico, D.F., México.
authors.forename: Carolina
authors.initials: C
authors.lastname: Alvarez-Delgado
authors.forename: Ricardo
authors.initials: R
authors.lastname: Reyes-Chilpa
authors.forename: Elizabet
authors.initials: E
authors.lastname: Estrada-Muñiz
authors.forename: C Adriana
authors.initials: CA
authors.lastname: Mendoza-Rodríguez
authors.forename: Angelina
authors.initials: A
authors.lastname: Quintero-Ruiz
authors.forename: José
authors.initials: J
authors.lastname: Solano
authors.forename: Marco A
authors.initials: MA
authors.lastname: Cerbón
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D051033:Apoptosis Inducing Factor / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D048430:Cell Shape / Q000187:drug effects; D003374:Coumarins / Q000737:chemistry / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology; D008954:Models, Biological
chemical_list: D051033:Apoptosis Inducing Factor; D003374:Coumarins; D053148:Caspase 3