Banking of fresh-frozen prostate tissue: methods, validation and use

OBJECTIVE To describe the establishment, methods, validation and use of a bank of fresh-frozen human prostate tissue. MATERIALS AND METHODS On obtaining informed patient consent, protocols were followed for banking prostate tissue from any type of prostatectomy or cystoprostatectomy. A pseudobanking procedure was devised to determine the accuracy of assessing the histopathological status of the banked tissue. RNA was extracted, its quality assessed and used for quantitative real-time reverse transcription-polymerase chain reaction for the serine protease hepsin. RESULTS To date prostate tissue from 112 patients has been banked, with pseudobanking in 58. The histopathological assessment showed pseudobanked tissue matched adjacent unbanked tissue in 98% of cases for benign vs malignant diagnoses, and in 92% of carcinomas for the Gleason score. Hepsin expression was significantly higher in malignant than in benign tissues (P < 0.0001). CONCLUSION We established a validated method for banking human fresh-frozen prostate tissue and applied it successfully. Hepsin expression can be used to differentiate malignant and benign prostate tissue, and as an indicator of tissue heterogeneity.