An antibody-based approach for the in situ evaluation of mouse contribution in human stem cell-derived xenografts

Abstract

Studying human xenografts in mice is a widely used and powerful approach in both, stem cell and cancer research. Since the indispensible role of invaded host cells for teratoma respectively tumor development became evident, sensitive methods to detect mouse infiltration are in demand. For this purpose, in situ-labeling is generally preferred since it allows to draw valuable conclusions on host cell properties such as cell morphology, location and structural assembly. Unlike existing approaches, which employ species-specific antibodies to detect distinct cell types such as endothelial cells, immune cells or fibroblasts, our protocol exploits the species-specific detection of a proven housekeeping protein to visualize the microenvironment as a whole. So far undescribed, this 24-hours fluorescent immunohistochemistry (IHC) protocol enables the detection of mouse cells irrespective of a particular cell type or subpopulation and thus allows to draw are more comprehensive picture of host cell contribution in a single detection step.

Opportunities for targeted therapies: trametinib as a therapeutic approach to canine oral squamous cell carcinomas

“…We began by conducting Western blots for each cell line against a cyclophilin A (CyPA, an abundant and ubiquitous cytosolic protein) antibody known to bind murine protein specifically. This antibody had previously been demonstrated to selectively stain murine cells which invaded xenograft models of human cells in mice 52 . The canine CyPA has an even lower sequence identity to murine CyPA than does the human protein ( Supplemental Figure S1 ).…”

Establishment and characterisation of testicular cancer patient-derived xenograft models for preclinical evaluation of novel therapeutic strategies

“…3 a–c). Infiltration of murine stroma cells into the PDX tumours was assessed by staining for cyclophilin A, a protein involved in protein folding and recently identified as a sensitive target for detection of murine microenvironment in human tumour xenografts, using a mouse selective antibody 21 , 22 . The primary patient tumours from TC1, TC4 and TC5 were indeed negative for cyclophilin A, whereas mouse-specific infiltration was observed in all three PDX generations (P0–P2) of TC1, TC4 and TC5 (Fig.…”