Quality Assessment of Cryopreserved Human Biological Samples from the Biobank of Barretos Cancer Hospital.

Background: Biobanks process, store, and supply biological materials for research. Preanalytical factors, especially storage time and temperature, must be controlled and standardized at all stages when handling biospecimen samples, especially because the literature reports highly contradictory optimal parameters. As large-sample studies are required to better understand the influence of time and temperature on cryopreserved samples' quality for genomic research, this study evaluated the integrity and quality of cryopreserved samples stored for up to 9 years at the biobank of Barretos Cancer Hospital, one of the largest biobanks in Latin America. Methods: We randomly selected 447 samples with tumor tissue paired with buffy coat or peripheral blood mononuclear cells (PBMCs) that were stored from 2008 to 2016. The genetic material quality was evaluated based on RNA integrity (RIN) and DNA integrity (DIN) ≥7, which indicated undegraded samples, and compared with storage time, which means that for DNA storage time, samples <8.1 and ≥8.1 years and for RNA <4.5 and ≥4.5 were used. Results: A total of 190 tumor tissues were eligible for DNA and RNA extraction. Those stored for 8 years had lower DIN (68%) than those stored for a shorter period (92%). A similar pattern, based on storage time (<8.1 and ≥8.1 years), was observed in the buffy coat (74% and 95%, respectively) and PBMCs (54% and 96%, respectively). For RNA extracted from tumor tissues, we observed lower RIN in samples stored for 4.5 years (17%) than in samples stored for a shorter period (45%). Buffy coat and PBMC samples stored at -30°C exhibited greater degradation (26%) than those stored at -80°C (1%). The DIN (p = 0.15) and RNA (p = 0.18) were unrelated to topography type. Conclusion: The temperature, particularly cryopreservation methodology, and storage time were the main factors that affected nucleic acid integrity, especially RNA, during cryopreservation of biospecimens.

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.