Cells and xenografts

LNCaP prostate cancer cells were obtained from and verified by the American Type Culture Collection (ATCC). The cells were cultured per the recommended standard in a 37 °C humidified incubator with 5% CO₂ atmosphere.

LNCaP subcutaneous xenografts were grown in immunocompromised nude mice (Jackson Laboratory). LNCaP cells were first incubated and grown to confluence. Then, these confluent cells were suspended in 10% Matrigel at a concentration of 2 × 10⁷ cells/60 μL and 60 μL of this Matrigel–cell solution was injected subcutaneously into both flanks of the animal. The mice were then monitored daily for the presence of tumors. As soon as tumors were visible, volume measurements were taken using digital calipers twice a week, and tumor volumes were calculated using the formula volume = (length × width²)/2. Once tumors reached 50,000 mm³ in volume, the mice were sacrificed by overdosing with isofluorane anesthesia, after which the tumors were immediately excised and divided to be placed in optimal cutting temperature compound (OCT), or 4% PFA. All animal experiments were performed according to the guiding principles of the American Physiologic Society and approved by the Institutional Animal Care and Use Committee (IACUC protocol #17106—Dobrucki, PI) at the University of Illinois at Urbana-Champaign.