Preclinical therapeutics ex ovo quail eggs as a biomimetic automation-ready xenograft platform

Abstract

Preclinical cancer research ranges from in vitro studies that are inexpensive and not necessarily reflective of the tumor microenvironment to mouse studies that are better models but prohibitively expensive at scale. Chorioallantoic membrane (CAM) assays utilizing Japanese quail (Coturnix japonica) are a cost-effective screening method to precede and minimize the scope of murine studies for anti-cancer efficacy and drug toxicity. To increase the throughput of CAM assays we have built and optimized an 11-day platform for processing up to 200 quail eggs per screening to evaluate drug efficacy and drug toxicity caused by a therapeutic. We demonstrate ex ovo concordance with murine in vivo studies, even when the in vitro and in vivo studies diverge, suggesting a role for this quail shell-free CAM xenograft assay in the validation of new anti-cancer agents.

Experimental Tumor Induction and Evaluation of Its Treatment in the Chicken Embryo Chorioallantoic Membrane Model: A Systematic Review

“…Eleven articles included in this systematic review [38,53,[63][64][65][66][67][68][69][70][71] carried out tumor induction in the CAM using the ex ovo model by transferring the contents of the egg to a plate. The most common day on which studies break the egg and transfer its contents to a plate is day 3 (64%), followed by day 2 (9%), although 27% of the studies do not specify the day (Figure 6A).…”

A Novel Breast Cancer Xenograft Model Using the Ostrich Chorioallantoic Membrane—A Proof of Concept

“…After cell engraftment, an adhesive tape was used to cover the window, and eggs were kept in the incubator for further growth. Tumor growth and embryo viability were examined daily until day DD 34, as was already reported [ 22 , 24 ].…”

“…Among avian CAM models, the CAM of the chicken embryo is the best studied [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. There is already a first report on quail CAM [ 22 ]. However, to the best of our knowledge, no work on the ostrich CAM has been reported to date.…”

CAM Model: Intriguing Natural Bioreactor for Sustainable Research and Reliable/Versatile Testing

“…No CAM experiments reach the hatching period of the eggs, which, for chickens, is set at day 21 of embryonic life; however, experimentation can be carried out either in ovo or ex ovo, Latin for “inside the egg” and “outside the egg”, respectively. Initially for both methods, fertilized eggs from avian species (i.e., quail, turkey, and duck [ 48 , 49 , 50 , 50 , 51 , 52 , 53 , 54 ]), most commonly chicken, are kept in a humidified incubator at a constant humidity of 45% and a temperature of 37 °C for up to 15 days, by which time experimentation is allowed without the need to seek ethics committee approval. Indeed, as stated earlier, as sanctioned by Institutional Animal Care and Use Committee (IACUC), the chicken embryo is not considered a living organism until the 17th day of embryonic life [ 38 , 39 ].…”