Examination of three-dimensional xenografts derived from HNSCC and Melanoma cell lines deploying the CAM assay

Introduction A proportion of patients affected by advanced head and neck squamous cell carcinoma suffer from an inadequate response to targeted therapies. Examination of the underlying processes requires scientific methods addressing the complexity and heterogeneity of this tumor entity. Due to the immature specific immune system the Hen’s Egg Test on Chorioallantoic Membrane (so-called CAM assay) allows xenotransplantation of foreign cells and tissues to identify resistance mechanisms and adaptation processes.

Method HNSCC cell lines SCC-193 (n=9) and FaDu (n=7) as well as the melanoma cell line A375 (n=11) were transferred into collagenous matrices and xenotransplanted into the CAM assay. Photographic and intravital microscopy images were taken over a period of 7 days after transplantation and were supplemented with immunohistochemical staining such as Ki-67.

Result Group comparison exhibits marked ingrowth of FaDu tumors into the mesenchymal layer of the CAM. The A375 tumors infiltrated sporadically, whereas the SCC-193 tumors showed no infiltrative growth in the CAM assay. Immunohistochemically, proliferation zones, necrotic areas and connection to the vascular network of the CAM can be visualized in the FaDu tumors.

Conclusion Xenotransplantation in particular of FaDu tumors into the CAM assay allows the examination of tumor microenvironment, invasion processes and resistance mechanisms of HNSCC tumors in an in vivo model without the formal requirement of animal experimental approval.

Publication History

Article published online:
12 May 2023