Chorioallantoic membrane assay revealed the role of TIPARP (2,3,7,8-tetrachlorodibenzo-p-dioxin-inducible poly (ADP-ribose) polymerase) in lung adenocarcinoma-induced angiogenesis.

ABSTRACT

BACKGROUND: The chorioallantoic membrane (CAM) assay is a well-established technique to evaluate tumor invasion and angiogenesis and may overcome the shortcoming of the patient-derived xenograft (PDX) mouse model. Currently, few reports have described lung cancer invasion and angiogenesis in the CAM assay. We therefore used the CAM assay in the evaluation of lung cancer. METHOD: Lung cancer cell line-derived organoids or lung cancer cell lines were transplanted into the CAM on embryonic development day (EDD) 10, and an analysis was performed on EDD 15. Microscopic and macroscopic images and movies of the grafts on the CAM were captured and analyzed. The relationships between the graft and chick vessels were evaluated using immunohistochemistry. RESULTS: We transplanted lung cancer cell lines and cell line-derived organoid into a CAM to investigate angiogenesis and invasion. They engrafted on the CAM at a rate of 50-83%. A549-OKS cells showed enhanced cell invasion and angiogenesis on the CAM in comparison to A549-GFP cells as was reported in vitro. Next, we found that A549-TIPARP cells promoted angiogenesis on the CAM. RNA-seq identified 203 genes that were upregulated more than twofold in comparison to A549-GFP cells. A pathway analysis revealed many upregulated pathways related to degradation and synthesis of the extracellular matrix in A549-TIPARP cells. CONCLUSIONS: The CAM assay can be used to evaluate and research invasion and angiogenesis in lung cancer. The elevated expression of TIPARP in lung cancer may induce angiogenesis by remodeling the extracellular matrix.