Recent advances on preclinical model based on patient-derived tumor xenografts have new insight into many clinical fields. According to our literature review, many authors believe that immunodeficient animals such as athymic rats and mice should be used to prevent tissue loss caused by acute rejection to establish patient-derived tumor xenografts models.
However, recent advances showed that the microenvironment has gained attention as an important factor responsible for disease progression. Additionally, researchers attempt to come up with novel findings in chemotherapy drugs and immune modulator to control development of keloid. For these reasons, establishment of reliable animal model of keloids is very important.
In this new model using an immunocompetent animal as a humanized-xenografts model, human keloid scar has been maintained for as long as 4 months. Results of migration assay have demonstrated that typical morphology of keloid fibroblast was preserved based on multiple time point observations despite its aging change. Quantitative real time polymerase chain reaction findings suggested that after implantation, there has been significant increase of vascular endothelial growth factor, CD34, and transforming growth factor beta 1 expression despite insignificant changes of hypoxia inducible factor 1 an matrix metallopeptidase 1, and matrix metallopeptidase 9 gene expression. These findings suggested that implantation of keloids within the immunocompetent animals yields is very useful experimental model in terms of fibrosis.
In summary, the authors have successfully established and propagated patient-derived keloid model using the immunocompetent animals. This model could be used to test novel materials as well as combination therapies and is superior to the conventional cell line experiment models. In addition, the biology of the keloids can easily be assessed to identify predictive markers for responses to treatment regimens that are currently actively under research in various centers.