Impact of Cold Ischemic Time and Freeze-Thaw Cycles on RNA, DNA and Protein Quality in Colorectal Cancer Tissues Biobanking

Multivariate Evaluation of DNA Quality Differences in Different Preanalytical Procedures in Mouse Livers

Successful histogenetic research relies on proper handling of tissue samples to maximize DNA quality. As the largest gland in the body, the liver is particularly sensitive to sample mishandling owing to its enzymatic and transcriptional activity. However, the impact of preanalytical procedures on the quality of extracted liver DNA remains poorly understood. In this study, we assessed the impact of extraction methods, duration of ex vivo liver ischemia, liver storage time, and temperature on extracted DNA quality. Comprehensive parameters such as DNA yields, purity, DNA integrity number, the percentage of double-stranded DNA (%dsDNA), and PCR amplification of the GAPDH gene fragment were assessed to identify the quality of extracted DNA. Our results revealed that these preanalytical processes had little effect on DIN values and PCR efficiency of GAPDH gene fragments for each sample, whereas the DNA yields, purity, and %dsDNAs varied widely across different processes. For liver DNA extraction, RNase is necessary to isolate "pure" DNA, and the presence of RNase could significantly increase the %dsDNA. In addition, significant increases in the yields, purity, and %dsDNA of extracted DNA were observed in the TissueLyser-processed livers compared with the mortar and pestle or shear cell disruption methods. Further investigation revealed that livers experiencing longer periods of ex vivo ischemia resulted in significantly compromised DNA yields, and to obtain sufficient DNA, the ex vivo liver ischemia should be limited to within 30 minutes. Moreover, compared with storage of livers at -80°C, storage of livers in the vapor phase of liquid nitrogen yielded a higher quality of the extracted DNA. Our findings exhibited significant implications for liver-derived DNA quality assessment and management.

The biobank of barretos cancer hospital: 14 years of experience in cancer research

Despite the developments in cancer research over years, cancer is still one of the leading causes of death worldwide. In Brazil, the number of cancer cases for the several next years (2020-2022) is expected to increase up to 625,000. Thus, translational research has been vital to determine the potential risk, prognostic, and predictive biomarkers in cancer. Therefore, Barretos Cancer Hospital implemented a biobank (BB-BCH) in 2006, which is responsible for processing, storage, and provision of biological materials from cancer and non-cancer participants. Hence, this article aimed to describe BB-BCH's history, experiences, and outcomes and explore its impact on Brazilian translational oncology research scenario. BB-BCH has a multidisciplinary team who are responsible for guaranteeing the quality of all processes as recommended by international guidelines for biobanks. Furthermore, BB-BCH has ample equipment to ensure the quality of all material requested by researchers as genetic material (DNA and RNA) and/or entire biospecimens. From 2006 to 2019, BB-BCH contained 252,069 samples from 44,933 participants, the whole collection is represented by 15 different types of biospecimens collected from them. According to our data, the most collected and stored topography in men is head and neck (29%); in women is breast (28%); and in children is torso and limb (27%) samples. Finally, we supported national and international consortia and projects such as The Cancer Genome Atlas. BB-BCH is a vital knowledge source for scientific community, enabling the development of high-quality studies, with a wide variety of tumor categories and high national representativeness of Brazilian population.