title: Down-regulation of Bcl-2 and Akt induced by combination of photoactivated hypericin and genistein in human breast cancer cells.
abstract: Presented experiment considers combination of genistein and photodynamic therapy with hypericin with a view to achieve higher therapeutic outcome in human breast adenocarcinoma cell lines MCF-7 and MDA-MB-231, both identified in our conditions as photodynamic therapy resistant. Since genistein is known to suppress Bcl-2 expression, we predicted that photodynamic therapy with hypericin might benefit from mutual therapeutic combination. In line with our expectations, combined treatment led to down-regulation of Bcl-2 and up-regulation of Bax in both cell lines as well as to suppression of Akt and Erk1/2 phosphorylation induced by photoactivated hypericin in MCF-7 cells. Although Akt and Erk1/2 phosphorylation was not stimulated by photodynamic therapy with hypericin in MDA-MB-231 cells, it was effectively suppressed in combination. Variations in cell death signaling favoring apoptosis were indeed accompanied by cell cycle arrest in G(2)/M-phase, activation of caspase-7, PARP cleavage and increased occurrence of cells with apoptotic morphology of nucleus. All these events corresponded with suppression of proliferation and significantly lowered clonogenic ability of treated cells. In conclusion, our results indicate that pre-treatment with tyrosine kinase inhibitor genistein may significantly improve the effectiveness of photodynamic therapy with hypericin in MCF-7 and MDA-MB-231 breast cancer cells.
authors.affiliation: Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Safárik University, Moyzesova 11, 040 01 Kosice, Slovakia. peter.ferenc@upjs.sk
authors.forename: Peter
authors.initials: P
authors.lastname: Ferenc
authors.forename: Peter
authors.initials: P
authors.lastname: Solár
authors.forename: Ján
authors.initials: J
authors.lastname: Kleban
authors.forename: Jaromír
authors.initials: J
authors.lastname: Mikes
authors.forename: Peter
authors.initials: P
authors.lastname: Fedorocko
mesh_terms: D000873:Anthracenes; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002455:Cell Division; D045744:Cell Line, Tumor; D015536:Down-Regulation; D005260:Female; D016195:G2 Phase; D019833:Genistein / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010569:Perylene / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D010766:Phosphorylation; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology* / Q000627:therapeutic use; D047428:Protein Kinase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000873:Anthracenes; D017319:Photosensitizing Agents; D047428:Protein Kinase Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D010569:Perylene; C004965:hypericin; D019833:Genistein; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D053179:Caspase 7