Establishment Of A Realistic Patient Derived Xenograft (Pdx) Model For Prostate Cancer Bone Metastasis

Bone metastases are frequent and fatal outcome of advanced prostate cancer. Many of the currently used preclinical models lack typical characteristics of the heterogenic human disease. We improved existing methodology by using fresh patient-derived material in a xenograft model of bone metastasis. Clinical prostate tumor specimens were collected from robotic-assisted laparoscopic radical prostatectomy operations in Turku University Hospital (Turku, Finland). Patient-derived tumor tissue of Gleason grade 8-10 tumors (n = 5) were cut into small pieces, digested overnight, and then cell suspension was intratibially inoculated into the bone marrow cavity of nude mice (n = 8-10/patient). X-ray pictures were taken and blood samples were collected once a month. Mice were sacrificed 6 months after tumor cell inoculation, and hind limbs and lungs were collected for histological and immunohistochemical analysis. PSA was measured from serum using commercial kit. X-rays demonstrated osteosclerotic bone lesions. Immunohistochemical analysis showed that 80% of tumors in bone expressed similar characteristics compared with original tumor (androgen receptor AR, prostate specific antigen PSA, proliferation marker Ki67). However, no changes were seen in serum PSA. Lung metastases were detected in 50% of tumor-bearing mice. Interestingly, the most of lung metastases were negative for AR and PSA, which indicates that the cell population that forms metastases may be undifferentiated clone of heterogenic tumor and therefore the most aggressive. Our platform provides new tools for prostate cancer research. Citation Format: Yvonne Konkol, Maija Valta, Jenni Bernoulli, Pekka Taimen, Peter Bostrom, Pirkko Harkonen, Jussi Halleen, Johanna M. Tuomela. Establishment of a realistic patient-derived xenograft (PDX) model for prostate cancer bone metastasis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 637.