gms | German Medical Science

Objectives: The elasticity of cell culture substrates influences multiple cell properties. Herein we investigate the influence of substrate elasticity (SE) on the cultivation of prostate cancer (PCa) cells thus aiming to optimize primary cell culture on a long-term basis. The change of elasticity in a malignant prostate impressively demonstrates the importance of this characteristic on cellular function in this tumor tissue.

Methods: By using the biocompatible silicone Sylgard 184, different SE can be prepared, according to defined mixing ratios of base and crosslinker. The resulting cell properties were studied by bright-field microscopy and immunofluorescence using image analysis as well as proliferation and migration assays. In addition, cellular communication was characterized as a function of underlying SE using a Boyden chamber.

Results: LNCaP cells showed a reduction in cell surface area and roundness as well as an increase in perimeter and diameter on 90 kPa substrates (malignant tissue) compared to 50 kPa (healthy tissue). These parameters indicate improved metabolic activity, which was confirmed in subsequent proliferation studies. Further, the actin cytoskeleton was characterized, showing increased expression and orientation on stiffer substrates. Similarly, higher migratory activity on stiffer substrates was detected in wound healing assays. In addition, the interaction between healthy PNT-2 cells and PCa cells was examined in a Boyden chamber as a function of the underlying SE, with PNT-2 cells exhibiting higher attraction to LNCaP cells on softer substrates.

Conclusions: SE significantly influences the cultivation of PCa cells and seems to be able to ideally mimic the original tissue properties by appropriately elastic silicone substrates. Through further investigation, we plan to specifically optimize PCa primary cell culture and develop an in vitro metastasis assay.