Generation of a Liver Orthotopic Human Uveal Melanoma Xenograft Platform in Immunodeficient Mice

A rat-based preclinical platform facilitating transcatheter hepatic arterial infusion in immunodeficient rats with liver xenografts of patient-derived pancreatic ductal adenocarcinoma

Liver metastases from pancreatic ductal adenocarcinoma (PDAC) are highly fatal. A rat-based patient-derived tumor xenograft (PDX) model is available for transcatheter therapy. This study aimed to create an immunodeficient rat model with liver xenografts of patient-derived primary PDAC and evaluate efficacy of hepatic arterial infusion chemotherapy with cisplatin in this model. Three patient-derived PDACs were transplanted into the livers of 21 rats each (totally, 63 rats), randomly assigned into hepatic arterial infusion, systemic venous infusion, and control groups (n = 7 each) four weeks post-implantation. Computed tomography evaluated tumor volumes before and four weeks after treatment. Post-euthanasia, resected tumor specimens underwent histopathological examination. A liver-implanted PDAC PDX rat model was established in all 63 rats, with first CT identifying all tumors. Four weeks post-treatment, arterial infusion groups exhibited significantly smaller tumor volumes than controls for all three tumors on second CT. Xenograft tumors histologically maintained adenocarcinoma features compared to original patient tumors. Ki67 expression was significantly lower in arterial infusion groups than in the other two for the three tumors, indicating reduced tumor growth in PDX rats. A liver-implanted PDAC PDX rat model was established as a rat-based preclinical platform. Arterial cisplatin infusion chemotherapy represents a potential therapy for PDAC liver metastasis.

Orthotopic Human Metastatic Uveal Melanoma Xenograft Mouse Models: Applications for Understanding the Pathophysiology and Therapeutic Management of Metastatic Uveal Melanoma

The propensity of uveal melanoma to metastasize to the liver hinders the accrual of micro-metastatic and end-stage disease tissue samples and restricts the investigation of metastatic uveal melanoma (MUM). Pre-clinical experimental animal models of MUM can help elucidate the pathophysiology of metastatic lesions and provide a tool for designing new therapeutic approaches for MUM. Here, we present an advanced model of hepatic metastases that enables quantitatively visualizing the development of individual hepatic tumor clones and estimating their growth kinetics and colonization efficiency. Similar to clinically observed liver metastases, these models enable the assessment of growth kinetics of the liver micro-metastases and the testing of therapeutic approaches for the treatment of MUM. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Experimental patient-derived xenograft mouse model of metastatic uveal melanoma Basic Protocol 2: Experimental liver micro-metastatic mouse model using splenic injection of metastatic uveal melanoma cells.

3D-Printed Collagen Scaffolds Promote Maintenance of Cryopreserved Patients-Derived Melanoma Explants

The development of an in vitro three-dimensional (3D) culture system with cryopreserved biospecimens could accelerate experimental research screening anticancer drugs, potentially reducing costs and time bench-to-beside. However, minimal research has explored the application of 3D bioprinting-based in vitro cancer models to cryopreserved biospecimens derived from patients with advanced melanoma. We investigated whether 3D-printed collagen scaffolds enable the propagation and maintenance of patient-derived melanoma explants (PDMEs). 3D-printed collagen scaffolds were fabricated with a 3DX bioprinter. After thawing, fragments from cryopreserved PDMEs (approximately 1–2 mm) were seeded onto the 3D-printed collagen scaffolds, and incubated for 7 to 21 days. The survival rate was determined with MTT and live and dead assays. Western blot analysis and immunohistochemistry staining was used to express the function of cryopreserved PDMEs. The results show that 3D-printed collagen scaffolds could improve the maintenance and survival rate of cryopreserved PDME more than 2D culture. MITF, Mel A, and S100 are well-known melanoma biomarkers. In agreement with these observations, 3D-printed collagen scaffolds retained the expression of melanoma biomarkers in cryopreserved PDME for 21 days. Our findings provide insight into the application of 3D-printed collagen scaffolds for closely mimicking the 3D architecture of melanoma and its microenvironment using cryopreserved biospecimens.