A research-based tumor tissue bank of gynecologic oncology: Characteristics of nucleic acids extracted from normal and tumor tissues from different sites

This article describes a gynecology and pathology-oriented tumor tissue bank that is approaching the research requirements of modern molecular oncology and compared characteristics of nucleic acids extracted from preserved tissues. Through August 2000, 8869 specimens, including fresh neoplastic tissues and normal counterparts, body fluids (ascites, tumor content, and blood), and cervical scrapings, were procured from 1853 patients. DNA and RNA were extracted from a random sampling of normal (n = 50) and tumor (n = 53) tissues from the uterine cervix (n = 47), endometrium (n = 24), and ovary (n = 32). As expected, tumor tissues conferred a higher yield of DNA (1.56 ± 1.24 versus 0.94 ± 0.72 μg/mg tissue, P = 0.001) and RNA (5.04 ± 6.21 versus 2.12 ± 1.76 μg/ml, P <0.001) than normal tissues. However, the RNA message abundance, as measured by RNA yield/DNA yield, was not different between tumor and normal tissues. With a similar content of DNA in the endometrium, uterine cervix, and ovary, RNA yield was higher in the endometrium than the others (P = 0.013). In tumors from these three sites, similar yields of DNA and RNA were noted. Overall the yield of DNA remained unchanged from specimens preserved for as long as 7 years, although at this length of storage, RNA yield became lower and variable. This study provides the basic characteristics of nucleic acids derived from normal and tumor tissues and ensures future research utility of these frozen specimens.