title: Bcl-2 proapoptotic proteins distribution in U-87 MG glioma cells before and after hypericin photodynamic action.
abstract: Apoptosis is a key process in the development and maintenance of tissue homeostasis. This process of controlled cell death is tightly regulated by a balance between cell survival and damage signals. We focused our attention towards one apoptotic pathway, the intrinsic mitochondrial one where Bcl-2 family of proteins plays the major role. We are particularly interested in two pro-apoptotic players Bak and Bax from this family. Here we investigated their role in apoptosis triggered by photodynamic action. Targeted photodynamic therapy (PDT) is a promising approach to diagnose and treat different types of cancer. We show the localization of Bax and Bak in U-87 MG human glioma cells incubated with photosensitizer hypericin (Hyp) before and after photodynamic action. Apoptotic stimulus by Hyp photodynamic action causes Bax translocation into mitochondria. However our results suggest that under these conditions there are two populations of mitochondria: one which contains Bax and Bak simultaneously, and is almost exclusively localized near the plasma membrane; the other which contains Bax only and is distributed throughout the cell. The different protein content and spatial distribution of these two populations suggest that they can play different roles in response to apoptotic stimuli.
authors.affiliation: Department of Biophysic, Institute of Physical Sciences, P. J. Safarik University, Kosice, Slovak Republic.
authors.forename: Lucia
authors.initials: L
authors.lastname: Balogová
authors.forename: Mária
authors.initials: M
authors.lastname: Maslaňáková
authors.forename: Lenka
authors.initials: L
authors.lastname: Dzurová
authors.forename: Pavol
authors.initials: P
authors.lastname: Miškovský
authors.forename: Katarína
authors.initials: K
authors.lastname: Stroffeková
mesh_terms: D000873:Anthracenes; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism*; D006801:Humans; D008027:Light; D010569:Perylene / Q000008:administration & dosage / Q000031:analogs & derivatives*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism* / Q000528:radiation effects*; D014018:Tissue Distribution; D016896:Treatment Outcome
chemical_list: D000873:Anthracenes; D017319:Photosensitizing Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D010569:Perylene; C004965:hypericin