Why does Certis use orthotopic models for YourPDX functional testing?

Orthotopic patient-derived xenograft (O-PDX) models serve as personal mouse avatars — replicates of an individual’s unique form of cancer in immuno-compromised mice.1 To create an orthotopic PDX model, Certis scientists surgically implant fragments of expanded tumor tissue from first-generation mice into the location of origin—the same anatomical location from which the original tumor came from in the body. For example, if a tumor biopsy came from the colon, we engraft tissue into the mouse avatars’ colon. This is important because we know from years of research that the microenvironment in which a tumor grows influences drug response, drug resistance and metastatic behavior.2-4

References: 1 Malaney, P., Nicosia, S. V., & Davé, V. (2014). One Mouse, One Patient Paradigm: New Avatars of Personalized Cancer Therapy. Cancer Letters, 344(1), 1–12. 2 Das Thakur, M., Salangsang, F., Landman, A. et al. Modelling Vemurafenib Resistance in Melanoma Reveals a Strategy to Forestall Drug Resistance. Nature. 2013; 494(7436): 251–255. 3 Walters DM, Stokes JB, Adair SJ, et al. Clinical, Molecular and Genetic Validation of a Murine Orthotopic Xenograft Model of Pancreatic Adenocarcinoma Using Fresh Human Specimens. PLoS One. 2013;8(10): e77065. 4 Killion JJ, Radinsky R, Fidler IJ. Orthotopic Models are Necessary to Predict Therapy of Transplantable Tumors in Mice. Cancer Metastasis Rev. 1998-1999;17(3):279–284.