Biobanking of human pancreas cancer tissue: impact of ex-vivo procurement times on RNA quality.

BACKGROUND

Tissue banking has become a major initiative at many oncology centers. The influence of warm ex-vivo ischemia times, storage times, and biobanking protocols on RNA integrity and subsequent microarray data is not well documented.

METHODS

A prospective institutional review board-approved protocol for the banking of abdominal neoplasms was initiated at Memorial Sloan-Kettering Cancer Center in 2001. Sixty-four representative pancreas cancer specimens snap-frozen at various ex-vivo procurement times (< or =10 min, 11-30 min, 31-60 min, >1 h) and banked during three time periods (2001-2004, 2004-2006, 2006-2008) were processed. RNA integrity was determined by microcapillary electrophoresis using the RNA integrity number (RIN) algorithm and by results of laser-capture microdissection (LCM).

RESULTS

Overall, 42% of human pancreas cancer specimens banked under a dedicated protocol yielded RNA with a RIN of > or =7. Limited warm ex-vivo ischemia times did not negatively impact RNA quality (percentage of tissue with total RNA with RIN of > or =7 for < or =10 min, 42%; 11-30 min, 58%; 31-60 min, 33%; >60 min, 42%), and long-term storage of banked pancreas cancer biospecimens did not negatively influence RNA quality (total RNA with RIN of > or =7 banked 2001-2004, 44%; 2004-2006, 38%; 2006-2008, 50%). RNA retrieved from pancreatic cancer samples with RIN of > or =7 subject to LCM yielded RNA suitable for further downstream applications.

CONCLUSIONS

Fresh-frozen pancreas tissue banked within a standardized research protocol yields high-quality RNA in approximately 50% of specimens and can be used for enrichment by LCM. Quality of tissues of the biobank were not adversely impacted by limited variations of warm ischemia times or different storage periods. This study shows the challenges and investments required to initiate and maintain high-quality tissue repositories.