Development of a Bioluminescent Human Osteosarcoma Model in Humanized NSG Mice: A Pilot Study

Abstract

Background/Aim: Osteosarcoma is the most common type of bone cancer, but current therapeutic interventions remain largely insufficient. The development of new treatment strategies is needed, and moreover, optimal rodent models are necessary for testing the efficacy of new treatment modalities of osteosarcoma. Humanized mice carry human hematopoietic and immune systems, and are considered an ideal tool to study human diseases including cancer immunology. Herein, we performed a preliminary study toward developing an in vivo bioluminescent osteosarcoma model using humanized immunodeficient (NSG) mice. Materials and Methods: To establish the xenograft and orthotopic mouse model, NSG mice engrafted with human CD34 + hematopoietic stem cells were injected with luciferaseexpressing KHOS/NP cells at two different time points. Bioluminescence images were obtained to monitor in vivo tumor growth and metastasis. Influence of the degree of human cell engraftment on tumor growth and metastatic behavior was analyzed and compared between the two groups. Results: KHOS/NP-luc cells injected in humanized NSG mice formed macroscopic tumors. The percentage of human CD45+ cells in these models was similar, but the percentage of human CD45+CD3+ and their subset was higher in the late-injection group compared to that of the early-injection group. The rate of KHOS/NP tumor growth was higher in the early-injection group than in the late-injection group. In the present study, human hematopoietic cell engraftment was not influenced by KHOS/NP cell injection, but KHOS/NP osteosarcoma showed more aggressive behavior in the early-injection group than that in the late-injection group, forming larger tumor volumes and earlier metastases. Conclusion: The results indicated that tumor growth and progression in humanized NSG mice may have been influenced by higher levels of human cell engraftment, especially T cells. Although there exist some limitations to our study, our preliminary results can provide the basis for the development of a humanized osteosarcoma mouse model. Osteosarcoma is the most common malignant bone tumor with a peak incidence occurring in adolescents. As the survival rate of patients with osteosarcoma has reached a plateau, the development of new treatment strategies based on its molecular characteristics are needed (1-3). As investigators search for novel agents, optimal in vitro or in vivo testing models are necessary. Animal models are widely used as preclinical platforms to test the efficacy of new treatment modalities. Due to the importance of bone and immune microenvironments in osteosarcoma, animal models recapitulating the human immune system are desirable in order to obtain more insight into the processes of osteosarcoma initiation, progression, and metastasis, as well as treatment sensitivity (4, 5). Super immunodeficient mice, such as NOD-scid IL2rγ null (NSG) mice, engraft human cells and tissues more efficiently than other models (6). Meanwhile, humanized mice carry human hematopoietic and immune systems and are co...

The adaptation model of immunity: Is the goal of central tolerance to eliminate defective T cells or self‐reactive T cells?

“…However, human T cells in these mice are not exposed to human MHC-peptide complex or human dendritic cells, yet they tolerate human tumour cell lines carrying HLA mismatch. 43,[46][47][48] Although no acute GVHD is evident in these mice, chronic GVHD is reported after 24 weeks in two NSG cohorts humanized with CD34 + grafts from different donors. 49 According to the SNS model, human T cells should reject HLA mismatched tumour cells, which is not the case.…”

“…In these mice, hypervariability of TcR 45 allows flexibility of human T cells in recognizing mouse MHC‐peptide complex during positive selection. However, human T cells in these mice are not exposed to human MHC‐peptide complex or human dendritic cells, yet they tolerate human tumour cell lines carrying HLA mismatch 43,46–48 . Although no acute GVHD is evident in these mice, chronic GVHD is reported after 24 weeks in two NSG cohorts humanized with CD34 + grafts from different donors 49 .…”

Transcriptome Profiling and Characterization of Peritoneal Metastasis Ovarian Cancer Xenografts in Humanized Mice

“…Orthotopic xenografts can offer a more accurate representation of the metastatic behavior of tumors and their TME [42, 43]. Previous studies have explored the development of orthotopic xenograft models in Hu-mice, using luciferase-positive human pancreatic and osteosarcoma cells [44, 45]. The orthotopic OC xenograft model in Hu-mice, using the OV-90 luciferase cell line and PDX cells, was initially employed to verify the response to nivolumab [19].…”

Transcriptome profiling and characterization of peritoneal metastasis ovarian cancer xenografts in humanized mice

“…| (2024) 14:11894 | https://doi.org/10.1038/s41598-024-60501-z www.nature.com/scientificreports/ models in Hu-mice, using luciferase-positive human pancreatic and osteosarcoma cells 46,47 . The orthotopic OC xenograft model in Hu-mice, using the OV-90 luciferase cell line and PDX cells, was initially employed to verify the response to nivolumab 19 .…”