Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy include senescence, XXXX , and autophagy, but not apoptosis.

@entity1 @entity263 @entity2667 @entity39 @entity1067 @entity26 @entity1194 @entity98
UNASSIGNED: In comparison to more differentiated cells, @entity263 stem-like cells are radioresistant, which could explain radio-recurrent @entity263 . Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive @entity26 species (ROS). Primary prostate epithelial cells were cultured from @entity1 samples of @entity1067 and @entity263 prior to treatment with PDT or gamma irradiation. Cell viability was measured using @entity98 and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by @entity2667 staining and @entity1194 staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced @entity39 and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against @entity263 .
