2 research outputs found
Chick Chorioallantoic Membrane as a Patient-Derived Xenograft Model for Uveal Melanoma : Imaging Modalities for Growth and Vascular Evaluation
Background: Patient-derived tumor xenografts (PDXs) have emerged as valuable preclinical
in vivo models in oncology as they largely retain the polygenomic architecture of the human tumors
from which they originate. Although animal models are accompanied by cost and time constraints
and a low engraftment rate, PDXs have primarily been established in immunodeficient rodent models
for the in vivo assessment of tumor characteristics and of novel therapeutic cancer targets. The chick
chorioallantoic membrane (CAM) assay represents an attractive alternative in vivo model that has
long been used in the research of tumor biology and angiogenesis, and can overcome some of these
limitations. Methods: In this study, we reviewed different technical approaches for the establishment
and monitoring of a CAM-based uveal melanoma PDX model. Forty-six fresh tumor grafts were
acquired after enucleation from six uveal melanoma patients and were implanted onto the CAM on
ED7 with Matrigel and a ring (group 1), with Matrigel (group 2), or natively without Matrigel or a ring
(group 3). Real-time imaging techniques, such as various ultrasound modalities, optical coherence
tomography, infrared imaging, and imaging analyses with Image J for tumor growth and extension, as
well as color doppler, optical coherence angiography, and fluorescein angiography for angiogenesis,
were performed on ED18 as alternative monitoring instruments. The tumor samples were excised on
ED18 for histological assessment. Results: There were no significant differences between the three
tested experimental groups regarding the length and width of the grafts during the development
period. A statistically significant increase in volume (p = 0.0007) and weight (p = 0.0216) between
ED7 and ED18 was only documented for tumor specimens of group 2. A significant correlation of the
results for the cross-sectional area, largest basal diameter, and volume was documented between the
different imaging and measurement techniques and the excised grafts. The formation of a vascular
star around the tumor and of a vascular ring on the base of the tumor was observed for the majority
of the viable developing grafts as a sign of successful engraftment. Conclusion: The establishment of
a CAM-PDX uveal melanoma model could elucidate the biological growth patterns and the efficacy
of new therapeutic options in vivo. The methodological novelty of this study, investigating different
implanting techniques and exploiting advances in real-time imaging with multiple modalities, allows precise, quantitative assessment in the field of tumor experimentation, underlying the feasibility of
CAM as an in vivo PDX model