Photodynamic therapy reduces cell viability, migration and triggers necroptosis in prostate tumor cells.

Prostate cancer is the most common cancer in American men, aside from skin cancer. As an alternative cancer treatment, photodynamic laser therapy (PDT) can be used to induce cell death. We evaluated the PDT effect, using methylene blue as a photosensitizer, in human prostate tumor cells (PC3). PC3 were subjected to four different conditions: DMEM (control); laser treatment (L-660 nm, 100 mW, 100 J.cm-2); methylene blue treatment (MB-25 µM, 30 min), and MB treatment followed by low-level red laser irradiation (MB-PDT). Groups were evaluated after 24 h. MB-PDT treatment reduced cell viability and migration. However, because MB-PDT did not significantly increase the levels of active caspase-3 and BCL-2, apoptosis was not the primary mode of cell death. MB-PDT, on the other hand, increased the acid compartment by 100% and the LC3 immunofluorescence (an autophagy marker) by 254%. Active MLKL level, a necroptosis marker, was higher in PC3 cells after MB-PDT treatment. Furthermore, MB-PDT resulted in oxidative stress due to a decrease in total antioxidant potential, catalase levels, and increased lipid peroxidation. According to these findings, MB-PDT therapy is effective at inducing oxidative stress and reducing PC3 cell viability. In such therapy, necroptosis is also an important mechanism of cell death triggered by autophagy.

Rat postnatal prostate development is impaired by in vitro high-glucose environment.

The prostate development has an important postnatal period where cell proliferation begins at the first days after birth and is related to gland growth and ramification. Any metabolic and/or hormonal changes occurring during the postnatal period can interfere with prostate branching. Hyperglycemia is a common condition in low-weight preterm babies at neonatal period and also a disorder found in the offspring of obese mothers. Thus, this study aimed to investigate the in vitro effects of a glucose-rich environment during prostate postnatal development. Wistar rats prostate were removed at birth and cultured for 1, 2 and 3 days in DMEM under normal (5.5 mM) or elevated (7 and 25 mM) glucose concentrations. Samples were processed for morphological analysis, PCNA and smooth muscle α-actin immunohistochemistry, evaluation of active caspase-3, ERK1/2 and Wnt5a gene expression. High glucose concentrations reduced the number of prostatic buds and proliferating cells. The natural increase in smooth muscle cells and collagen deposition observed in control prostates during the first 3 days of development was reduced by elevated glucose concentrations. The amount of active caspase-3 was higher in prostates incubated at 7 mM and TGF-ß levels also increased sharply after both glucose concentrations. Additionally, high glucose environment decreased ERK 1/2 activation and increased Wnt5a expression. These data show that high levels of glucose during the first postnatal days affected prostate development by inhibiting cell proliferation which impairs bud branching and this was associated with anti-proliferative signals such as decreased ERK1/2 activation and increased Wnt5a expression.