The Next Generation of Orthotopic Thyroid Cancer Models: Immunocompetent Orthotopic Mouse Models of BRAF V600E -Positive Papillary and Anaplastic Thyroid Carcinoma

Massachusetts General Hospital, Harvard Medical School, Department of Surgery, Boston, Massachusetts, United States
Thyroid: official journal of the American Thyroid Association (Impact Factor: 4.49). 12/2013; 24(4). DOI: 10.1089/thy.2013.0483
Source: PubMed


While the development of new treatments for aggressive thyroid cancer has advanced in the last 10 years, progress has trailed headways made with other malignancies. A lack of reliable authenticated human cell lines and reproducible animal models is one major roadblock to preclinical testing of novel therapeutics. Existing xenograft and orthotopic mouse models of aggressive thyroid cancer rely on the implantation of highly passaged human thyroid carcinoma lines in immunodeficient mice. Genetically engineered models of papillary and undifferentiated (anaplastic) thyroid carcinoma (PTC and ATC) are immunocompetent; however, slow and stochastic tumor development hinders high-throughput testing. Novel models of PTC and ATC in which tumors arise rapidly and synchronously in immunocompetent mice would facilitate the investigation of novel therapeutics and approaches.

We characterized and utilized mouse cell lines derived from PTC and ATC tumors arising in genetically engineered mice with thyroid-specific expression of endogenous Braf(V600E/WT) and deletion of either Trp53 (p53) or Pten. These murine thyroid cancer cells were transduced with luciferase- and GFP-expressing lentivirus and implanted into the thyroid glands of immunocompetent syngeneic B6129SF1/J mice in which the growth characteristics were assessed.

Large locally aggressive thyroid tumors form within one week of implantation. Tumors recapitulate their histologic subtype, including well-differentiated PTC and ATC, and exhibit CD3+, CD8+, B220+, and CD163+ immune cell infiltration. Tumor progression can be followed in vivo using luciferase and ex vivo using GFP. Metastatic spread is not detected at early time points.

We describe the development of the next generation of murine orthotopic thyroid cancer models. The implantation of genetically defined murine BRAF-mutated PTC and ATC cell lines into syngeneic mice results in rapid and synchronous tumor formation. This model allows for preclinical investigation of novel therapeutics and/or therapeutic combinations in the context of a functional immune system.

Download full-text


Available from: Sareh Parangi, Apr 21, 2015
  • Source
    • "Of the murine lines examined in vitro, we selected the most aggressive murine ATC line, TBP-3743, for implantation and investigation in our immunocompetent model. In addition to harboring oncogenic BRAF, TBP-3743 is p53-null and rapidly forms tumors with locally aggressive features [50]. The control animals in the current study recapitulated our previous observations and developed tumors that lead to dramatic weight loss and death two weeks post-implantation. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Anaplastic (ATC) and refractory papillary thyroid cancer (PTC) lack effective treatments. Inhibition of either oncogenic BRAF or SRC has marked anti-tumor effects in mouse models of thyroid cancer, however, neither drug induces notable apoptosis. Here we report that the SRC-inhibitor dasatinib further sensitizes BRAFV600E-positive thyroid cancer cells to the BRAFV600E-inhibitor PLX4720. Combined treatment with PLX4720 and dasatinib synergistically inhibited proliferation and reduced migration in PTC and ATC cells. Whereas PLX4720 did not induce robust apoptosis in thyroid cancer cells, combined treatment with dasatinib induced apoptosis in 4 of 6 lines. In an immunocompetent orthotopic mouse model of ATC, combined PLX4720 and dasatinib treatment significantly reduced tumor volume relative to PLX4720 treatment alone. Immune cell infiltration was increased by PLX4720 treatment and this effect was maintained in mice treated with both PLX4720 and dasatinib. Further, combined treatment significantly increased caspase 3 cleavage in vivo relative to control or either treatment alone. In conclusion, combined PLX4720 and dasatinib treatment induces apoptosis, increases immune cell infiltration and reduces tumor volume in a preclinical model of ATC, suggesting that the combination of these FDA-approved drugs may have potential for the treatment of patients with ATC or refractory PTC.
    Full-text · Article · Jun 2014 · Oncotarget
  • [Show abstract] [Hide abstract]
    ABSTRACT: Thyroid cancer incidence has been increasing over time, and it is estimated that ∼1950 advanced thyroid cancer patients will die of their disease in 2015. To combat this disease, an enhanced understanding of thyroid cancer development and progression as well as the development of efficacious, targeted therapies are needed. In vitro and in vivo studies utilizing thyroid cancer cell lines and animal models are critically important to these research efforts. In this report, we detail our studies with a panel of authenticated human anaplastic and papillary thyroid cancer (ATC and PTC) cell lines engineered to express firefly luciferase in two in vivo murine cancer models-an orthotopic thyroid cancer model as well as an intracardiac injection metastasis model. In these models, primary tumor growth in the orthotopic model and the establishment and growth of metastases in the intracardiac injection model are followed in vivo using an IVIS imaging system. In the orthotopic model, the ATC cell lines 8505C and T238 and the PTC cell lines K1/GLAG-66 and BCPAP had take rates >90 % with final tumor volumes ranging 84-214 mm(3) over 4-5 weeks. In the intracardiac model, metastasis establishment was successful in the ATC cell lines HTh74, HTh7, 8505C, THJ-16T, and Cal62 with take rates ≥70 %. Only one of the PTC cell lines tested (BCPAP) was successful in the intracardiac model with a take rate of 30 %. These data will be beneficial to inform the choice of cell line and model system for the design of future thyroid cancer studies.
    No preview · Article · Mar 2015 · Hormones and Cancer