Ensuring the Safety and Security of Frozen Lung Cancer Tissue Collections through the Encapsulation of Dried DNA

Abstract

Collected specimens for research purposes may or may not be made available depending on their scarcity and/or on the project needs. Their protection against degradation or in the event of an incident is pivotal. Duplication and storage on a different site is the best way to assure their sustainability. The conservation of samples at room temperature (RT) by duplication can facilitate their protection. We describe a security system for the collection of non-small cell lung cancers (NSCLC) stored in the biobank of the Nice Hospital Center, France, by duplication and conservation of lyophilized (dried), encapsulated DNA kept at RT. Therefore, three frozen tissue collections from non-smoking, early stage and sarcomatoid carcinoma NSCLC patients were selected for this study. DNA was extracted, lyophilized and encapsulated at RT under anoxic conditions using the DNAshell technology. In total, 1974 samples from 987 patients were encapsulated. Six and two capsules from each sample were stored in the biobanks of the Nice and Grenoble (France) Hospitals, respectively. In conclusion, DNA maintained at RT allows for the conservation, duplication and durability of collections of interest stored in biobanks. This is a low-cost and safe technology that requires a limited amount of space and has a low environmental impact.

Establishing a Dedicated Lung Cancer Biobank at the University Center Hospital of Nice (France). Why and How?

“…However, since it was difficult to duplicate the whole collection of lung cancer, five major types of samples were duplicated: (i) samples from non-smoker patients, (ii) samples with a sarcomatoid carcinoma diagnosis, (iii) samples with a small cell carcinoma diagnosis, (iv) samples associated with early stage carcinomas of small size (pT1N0M0 stage), and, (v) samples associated with advanced stage or metastatic carcinomas (pTIIIB/IV stage). For the latter two types of tumor we distinguished patients with short survival (<1 year) and those with long survival (>10 years) [ 55 ]. Around 15% of the collection of frozen tissues (matched normal and tumoral tissues) was duplicated.…”

Long term conservation of DNA at ambient temperature. Implications for DNA data storage

“…This generates an ever-increasing number of samples which are more and more difficult and costly to store or transport. For reviews, see [ 4 – 6 ].…”

“…Other procedures use encapsulation in sol-gel-based silica [ 17 , 18 ] or in silica nanoparticles [ 19 , 20 ], inclusion in salts [ 21 ] or layered double hybrids [ 22 ], dissolution in deep eutectic solvents [ 23 ] or ionic liquids [ 24 ]. As none of these procedures can totally protect DNA from atmosphere or moisture, other ways have been proposed: protection under a gold film [ 25 ] or encapsulation under an inert atmosphere in hermetic stainless-steel capsules, the DNAshells™ (Imagene SA, France) [ 6 , 26 , 27 ].…”

Long term conservation of DNA at ambient temperature. Implications for DNA data storage

“…Other procedures use encapsulation in sol-gel-based silica [17,18] or in silica nanoparticles [19,20], inclusion in salts [21] or layered double hybrids [22], dissolution in deep eutectic solvents [23] or ionic liquids [24]. As none of these procedures can totally protect DNA from atmosphere or moisture, other ways have been proposed: protection under a gold film [25] or encapsulation under an inert atmosphere in hermetic stainless-steel capsules, the DNAshells™ (Imagene SA, France) [6,26,27].…”