Establishment of an orthotopic patient-derived xenograft mouse model using uveal melanoma hepatic metastasis

Abstract

BackgroundMetastatic uveal melanoma is a highly fatal disease; most patients die from their hepatic metastasis within 1 year. A major drawback in the development of new treatments for metastatic uveal melanoma is the difficulty in obtaining appropriate cell lines and the lack of appropriate animal models. Patient-derived xenograft (PDX) tumor models, bearing ectopically implanted tumors at a subcutaneous site, have been developed. However, these ectopically implanted PDX models have obstacles to translational research, including a low engraftment rate, slow tumor growth, and biological changes after multiple passages due to the different microenvironment. To overcome these limitations, we developed a new method to directly transplant biopsy specimens to the liver of immunocompromised mice.ResultsBy using two metastatic uveal melanoma cell lines, we demonstrated that the liver provides a more suitable microenvironment for tumor growth compared to subcutaneous sites and that surgical orthotopic implantation (SOI) of tumor pieces allows the creation of a liver tumor in immunocompromised mice. Subsequently, 10 of 12 hepatic metastasis specimens from patients were successfully xenografted into the immunocompromised mice (83.3% success rate) using SOI, including 8 of 10 needle biopsy specimens (80%). Additionally, four cryopreserved PDX tumors were re-implanted to new mice and re-establishment of PDX tumors was confirmed in all four mice. The serially passaged xenograft tumors as well as the re-implanted tumors after cryopreservation were similar to the original patient tumors in histologic, genomic, and proteomic expression profiles. CT imaging was effective for detecting and monitoring PDX tumors in the liver of living mice. The expression of Ki67 in original patient tumors was a predictive factor for implanted tumor growth and the success of serial passages in PDX mice.ConclusionsSurgical orthotopic implantation of hepatic metastasis from uveal melanoma is highly successful in the establishment of orthotopic PDX models, enhancing their practical utility for research applications. By using CT scan, tumor growth can be monitored, which is beneficial to evaluate treatment effects in interventional studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-017-1247-z) contains supplementary material, which is available to authorized users.

Stromal fibroblast growth factor 2 reduces the efficacy of bromodomain inhibitors in uveal melanoma

“…OMM1.3 cells were obtained from Bruce Ksander's laboratory in 2014 (Yoshida et al, 2014;Cheng et al, 2015;Kageyama et al, 2017). OMM1.3 cells were obtained from Bruce Ksander's laboratory in 2014 (Yoshida et al, 2014;Cheng et al, 2015;Kageyama et al, 2017).…”

“…Cell culture UM001, UM004 and UM003 cells were derived from human UM metastases and were established at Thomas Jefferson University. OMM1.3 cells were obtained from Bruce Ksander's laboratory in 2014 (Yoshida et al, 2014;Cheng et al, 2015;Kageyama et al, 2017). UM001, UM004 and OMM1.3 were confirmed to harbor the Q209P mutation in GNAQ by Sanger sequencing; UM003 cells express the Q209L GNAQ mutation.…”

Mouse models of uveal melanoma: Strengths, weaknesses, and future directions

“…Others have developed the intrasplenic inoculation, which consistently produces tumors in the liver (Barisione et al, 2015;Gangemi et al, 2014Gangemi et al, , 2012Jin et al, 2018). Finally, direct implantation of cells or tumors into the liver also results in florid growth in an orthotopic model of metastatic uveal melanoma (Kageyama et al, 2017;Ozaki et al, 2016).…”

“…Importantly, the tumors that grow in these mice maintain mutations, chromosomal imbalances, and histopathological features of the tumors from which they were derived (Carita, Nemati, & Decaudin, 2015). These PDX models have also Another exciting recent development has been the generation of PDX models from hepatic uveal melanoma metastases (Kageyama et al, 2017). In these models, tumor specimens obtained after surgery or biopsy were surgically implanted into the livers of NOD SCID gamma mice.…”

Obstacles to improving outcomes in the treatment of uveal melanoma

“…Published work to date supports the poor immunogenicity of UM; the relative lack of CD8+ tumor‐infiltrating lymphocytes in UM suggests a role for combination immunotherapy to exploit endogenous antitumor T‐cell populations. Preclinical efforts to better characterize the tumor microenvironment are under way and are anticipated to deepen our understanding of the immune mechanisms at work in metastatic UM …”