Patient-derived xenograft cryopreservation and reanimation outcomes are dependent on cryoprotectant type

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Abstract

Patient-derived xenografts (PDX) are being increasingly utilized in preclinical oncologic research. Maintaining large colonies of early generation tumor-bearing mice is impractical and cost-prohibitive. Optimal methods for efficient long-term cryopreservation and subsequent reanimation of PDX tumors are critical to any viable PDX program. We sought to compare the performance of "Standard" and "Specialized" cryoprotectant media on various cryopreservation and reanimation outcomes in PDX tumors. Standard (10% DMSO media) and Specialized (Cryostor®) media were compared between overall and matched PDX tumors. Primary outcome was reanimation engraftment efficiency (REE). Secondary outcomes included time to tumor formation (TTF), time to harvest (TTH), and potential loss of unique PDX lines. Overall 57 unique PDX tumors underwent 484 reanimation engraftment attempts after previous cryopreservation. There were 10 unique PDX tumors cryopreserved with Standard (71 attempts), 40 with Specialized (272 attempts), and 7 with both (141 attempts). Median frozen time of reanimated tumors was 29 weeks (max. 177). Tumor pathology, original primary PDX growth rates, frozen storage times, and number of implantations per PDX model were similar between cryoprotectant groups. Specialized media resulted in superior REE (overall: 82 vs. 39%, p < 0.0001; matched: 97 vs. 36%, p < 0.0001; >52 weeks cryostorage: 59 vs. 9%, p < 0.0001), shorter TTF (overall 24 vs. 54 days, p = 0.0051; matched 18 vs. 53 days, p = 0.0013) and shorter TTH (overall: 64 vs. 89 days, p = 0.009; matched: 47 vs. 88 days, p = 0.0005) compared to Standard. Specialized media demonstrated improved REE with extended duration cryostorage (p = 0.048) compared to Standard. Potential loss of unique PDX lines was lower with Specialized media (9 vs. 35%, p = 0.017). In conclusion, cryopreservation with a specialized cryoprotectant appears superior to traditional laboratory-based media and can be performed with reliable reanimation even after extended cryostorage.

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Record: found
Abstract: found
Article: not found

Freezing of living cells: mechanisms and implications.

P. Mazur (1984)

Cells can endure storage at low temperatures such as--196 degrees C for centuries. The challenge is to determine how they can survive both the cooling to such temperatures and the subsequent return to physiological conditions. A major factor is whether they freeze intracellularly. They do so if cooling is too rapid, because with rapid cooling insufficient cell water is removed osmotically to eliminate supercooling. Equations have been developed that describe the kinetics of this water loss and permit one to predict the likelihood of intracellular freezing as a function of cooling rate. Such predictions agree well with observations. Although the avoidance of intracellular freezing is usually necessary for survival, it is not sufficient. Slow freezing itself can be injurious. As ice forms outside the cell, the residual unfrozen medium forms channels of decreasing size and increasing solute concentration. The cells lie in the channels and shrink in osmotic response to the rising solute concentration. Prior theories have ascribed slow freezing injury to the concentration of solutes or the cell shrinkage. Recent experiments, however, indicate that the damage is due more to the decrease in the size of the unfrozen channels. This new view of the mechanism of slow freezing injury ought to facilitate the development of procedures for the preservation of complex assemblages of cells of biological, medical, and agricultural significance.

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Record: found
Abstract: not found
Article: not found

Ice-free cryopreservation of mouse embryos at −196 °C by vitrification

W Rall, G Fahy (1985)

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Article: not found

An in vivo platform for translational drug development in pancreatic cancer.

M Amador, Collins Karikari, Ralph H. Hruban … (2006)

Effective development of targeted anticancer agents includes the definition of the optimal biological dose and biomarkers of drug activity. Currently available preclinical models are not optimal to this end. We aimed at generating a model for translational drug development using pancreatic cancer as a prototype. Resected pancreatic cancers from 14 patients were xenografted and expanded in successive groups of nude mice to develop cohorts of tumor-bearing mice suitable for drug therapy in simulated early clinical trials. The xenografted tumors maintain their fundamental genotypic features despite serial passages and recapitulate the genetic heterogeneity of pancreatic cancer. The in vivo platform is useful for integrating drug screening with biomarker discovery. Passages of tumors in successive cohorts of mice do not change their susceptibility to anticancer agents and represent a perpetual live bank, facilitating the application of new technologies that will result in the creation of an integrated stable database of tumor-drug response data and biomarkers.