Effect of Heat Exposure on Viability and Contractility of Cultured Prostatic Stromal Cells

Abstract

Objectives: Different thermotherapeutic modalities such as transurethral microwave therapy or transurethral needle ablation have been developed to provide effective alternatives to surgical management of benign prostate hyperplasia (BPH). The mechanisms of thermotherapy, however, are not completely understood. We developed a model to investigate the effects of heat application on stromal cell viability and contractility.Methods: Cells isolated from prostatectomy and cystoprostatectomy specimens were cultured in a selective medium. Temperatures ranging from 37 to 50°C were applied for 1 h. Cell contraction was visualized by means of a cell culture microscope equipped with a time–lapse video system. For quantitative analysis, the percentage of contracting cells was evaluated; 10 μM of phenylephrine were applied for adrenergic stimulation of the cells.Results: On immunohistochemistry and phase–contrast microscopy, these cells were identified as prostatic myofibroblasts. Incubation at 50°C for 1 h in vitro induced immediate death of all cells, whereas at 45°C all cells survived. At 37°C 55% of the cells were seen to contract after addition of phenylephrine. Immediately after incubation at 45°C contraction rate decreased to 29%, but returned to 46% 1 day later.Conclusions: With this model, it is possible to study the mechanisms of thermotherapy in vitro. The results suggest that the effects of thermotherapy are due to the induction of cell death rather than to reduced stromal cell contractility. Furthermore, the data show that treatment is probably only successful if temperatures in excess of 50°C are maintained.

hTERT-Immortalized Prostate Epithelial and Stromal-Derived Cells: an Authentic In vitro Model for Differentiation and Carcinogenesis

“…Primary epithelial and stromal cell cultures were established from normal prostate tissue obtained from patients undergoing radical prostatectomy for prostate cancer as previously described (20,21). EP156 cells were derived from a radical prostatectomy specimen of a 66-year-old patient.…”

Treatment Characteristics and Inherent Prostatic Features Do Not Predict Patient Outcome after High-Energy Transurethral Thermotherapy: A Prospective Study of ProstaLund Feedback Treatment™

“…Finally, other treatment-specific factors such as average intraprostatic temperature, average intraprostatic blood flow, recorded cell kill, and consumed energy did not differ significantly between good responders and poor responders. Although the net histopathologic effect of thermotherapy appears to be related to the induction of cell death rather than to a decrease of stromal-cell contractility, 23 denervation of ␣-receptors and a decrease in smoothmuscle tone in the prostatic urethra 2,5 contribute to treatment outcome. These factors may play an even more significant role than the total amount of the gland destroyed during HE TUMT, as substantial clinical improvement is also achieved by machines that produce minimal necrosis.…”

Synthetic and Electrochemical Studies of [2Fe2S] Complexes Containing a 4‐Amino‐1,2‐dithiolane‐4‐carboxylic Acid Moiety

“…A second demonstration highlights the utility of the nanoliter containers in the remote‐controlled, localized delivery of sub‐nanoliter volumes of chemicals to specific cells cultured on substrates. Containers were loaded with PNIPAm soaked in a live/dead (green/red) two‐color fluorescence viability stain10 to stain cells locally in a culture dish and to verify that no necrotic cell death occurred during chemical release as a consequence of the heating11 or exposure to the RF radiation.…”