High-Frequency Ultrasound-Guided Injection for the Generation of a Novel Orthotopic Mouse Model of Human Thyroid Carcinoma

Ultrasound Guided Surgery as a Refinement Tool in Oncology Research

Refinement is one of the ethical pillars of the use of animals in research. Ultrasonography is currently used in human medicine as a surgical tool for guided biopsies and this idea can be applied to preclinical research thanks to the development of specific instruments. This will eliminate the necessity of a surgical opening for implanting cells in specific organs or taking samples from tissues. The approach for the injection will depend on the target but most of the case is going to be lateral, with the probe in a ventral position and the needle going into from the lateral. This is the situation for the thyroid gland, heart, liver, spleen, kidney, pancreas, uterus, and testicles. Other approaches, such as the dorsal, can be used in the spleen or kidney. The maximum injected volume will depend on the size of the structure. For biopsies, the technical protocol is similar to the injection knowing that in big organs such as the liver, spleen, or kidney we can take several samples moving slightly the needle inside the structure. In all cases, animals must be anesthetized and minimum pain management is required after the intervention.

Pre-existing Thyroiditis Ameliorates Papillary Thyroid Cancer: Insights From a New Mouse Model

Papillary thyroid cancer (PTC) often co-occurs with Hashimoto's thyroiditis, an association that has long been reported in clinical studies yet remains controversial. Some studies, in fact, have suggested a protective effect of thyroiditis while others have not. We generated a mouse model where PTC and thyroiditis develop in a predictable manner, combining the oncogenic drive of the BRAFv600E mutation (inducible by tamoxifen) to the thyroiditis susceptibility of the NOD.H2h4 strain (inducible by iodine). A total of 113 NOD.H2h4_TPO-CRE-ER_BRAFV600E mice (50 followed throughout lifetime and 63 sacrificed at 16 weeks post tamoxifen) were used to determine whether the PTC phenotype differs when thyroiditis precedes or coincides with the onset of PTC. Mice with pre-existing thyroiditis lived longer (median survival of 28.2 weeks post tamoxifen) than those with concomitant (25.6 weeks) or no (24.5 weeks) thyroiditis (P < 0.01 by Laplace regression). PTC developed less frequently (33%) in the pre-existing thyroiditis group than the concomitant (100%) or no (100%) thyroiditis groups (P < 0.001 by chi-squared) and showed less aggressive histopathological features. The intratumoral mononuclear cell infiltration was more prominent in mice with pre-existing thyroiditis (P = 0.002 vs the other groups) and sustained by a significant expansion of effector memory CD8 + T cells and CD19 + B cells. These findings shed light on the controversial PTC-thyroiditis association and emphasize the contribution of intratumoral T and B lymphocytes to the evolution of PTC.

Magnetic Resonance Imaging for Translational Research in Oncology

The translation of results from the preclinical to the clinical setting is often anything other than straightforward. Indeed, ideas and even very intriguing results obtained at all levels of preclinical research, i.e., in vitro, on animal models, or even in clinical trials, often require much effort to validate, and sometimes, even useful data are lost or are demonstrated to be inapplicable in the clinic. In vivo, small-animal, preclinical imaging uses almost the same technologies in terms of hardware and software settings as for human patients, and hence, might result in a more rapid translation. In this perspective, magnetic resonance imaging might be the most translatable technique, since only in rare cases does it require the use of contrast agents, and when not, sequences developed in the lab can be readily applied to patients, thanks to their non-invasiveness. The wide range of sequences can give much useful information on the anatomy and pathophysiology of oncologic lesions in different body districts. This review aims to underline the versatility of this imaging technique and its various approaches, reporting the latest preclinical studies on thyroid, breast, and prostate cancers, both on small laboratory animals and on human patients, according to our previous and ongoing research lines.

Mouse models of thyroid cancer: Bridging pathogenesis and novel therapeutics

Due to a global increase in the incidence of thyroid cancer, numerous novel mouse models were established to reveal thyroid cancer pathogenesis and test promising therapeutic strategies, necessitating a comprehensive review of translational medicine that covers (i) the role of mouse models in the research of thyroid cancer pathogenesis, and (ii) preclinical testing of potential anti-thyroid cancer therapeutics. The present review article aims to: (i) describe the current approaches for mouse modeling of thyroid cancer, (ii) provide insight into the biology and genetics of thyroid cancers, and (iii) offer guidance on the use of mouse models for testing potential therapeutics in preclinical settings. Based on research with mouse models of thyroid cancer pathogenesis involving the RTK, RAS/RAF/MEK/ERK, PI3K/AKT/mTOR, SRC, and JAK-STAT signaling pathways, inhibitors of VEGFR, MEK, mTOR, SRC, and STAT3 have been developed as anti-thyroid cancer drugs for "bench-to-bedside" translation. In the future, mouse models of thyroid cancer will be designed to be ''humanized" and "patient-like," offering opportunities to: (i) investigate the pathogenesis of thyroid cancer through target screening based on the CRISPR/Cas system, (ii) test drugs based on new mouse models, and (iii) explore the underlying mechanisms based on multi-omics.

miRNA expression and function in thyroid carcinomas: a comparative and critical analysis and a model for other cancers

As in many cancer types, miRNA expression profiles and functions have become an important field of research on non-medullary thyroid carcinomas, the most common endocrine cancers. This could lead to the establishment of new diagnostic tests and new cancer therapies. However, different studies showed important variations in their research strategies and results. In addition, the action of miRNAs is poorly considered as a whole because of the use of underlying dogmatic truncated concepts. These lead to discrepancies and limits rarely considered. Recently, this field has been enlarged by new miRNA functional and expression studies. Moreover, studies using next generation sequencing give a new view of general miRNA differential expression profiles of papillary thyroid carcinoma. We analyzed in detail this literature from both physiological and differential expression points of view. Based on explicit examples, we reviewed the progresses but also the discrepancies and limits trying to provide a critical approach of where this literature may lead. We also provide recommendations for future studies. The conclusions of this systematic analysis could be extended to other cancer types.

Preclinical Imaging for the Study of Mouse Models of Thyroid Cancer

Thyroid cancer, which represents the most common tumors among endocrine malignancies, comprises a wide range of neoplasms with different clinical aggressiveness. One of the most important challenges in research is to identify mouse models that most closely resemble human pathology; other goals include finding a way to detect markers of disease that common to humans and mice and to identify the most appropriate and least invasive therapeutic strategies for specific tumor types. Preclinical thyroid imaging includes a wide range of techniques that allow for morphological and functional characterization of thyroid disease as well as targeting and in most cases, this imaging allows quantitative analysis of the molecular pattern of the thyroid cancer. The aim of this review paper is to provide an overview of all of the imaging techniques used to date both for diagnosis and theranostic purposes in mouse models of thyroid cancer.

Athymic nude mice as an experimental model for cancer treatment

Athymic nude mice, a murine strain bearing spontaneous deletion in the Foxn1 gene that causes deteriorated or absent thymus (which results in inhibited immune system with reduction of number of T cells), represent a widely used model in cancer research having long lasting history as a tool for preclinical testing of drugs. The review describes three models of athymic mice that utilize cancer cell lines to induce tumors. In addition, various methods that can be applied in order to evaluate activity of anticancer agents in these models are shown and discussed. Although each model has certain disadvantages, they are still considered as inevitable instruments in many fields of cancer research, particularly in finding new drugs that would more effectively combat the cancer disease or enhance the use of current chemotherapy. Finally, the review summarizes strengths and weaknesses as well as future perspectives of the athymic nude mice model in cancer research.

Perspectives for immunotherapy in endocrine cancer

The fight against cancer has seen major breakthroughs in recent years. More than a decade ago, tyrosine kinase inhibitors targeting constitutively activated signaling cascades within the tumor inaugurated a new era of oncological therapy. Recently, immunotherapy with immune checkpoint inhibitors has started to revolutionize the treatment of several malignancies, most notably malignant melanoma, leading to the renaissance and the long-awaited breakthrough of immunooncology. This review provides an overview of the basis of immunotherapy from its initial concepts of anti-tumor immunity and cell-based therapy to the development of immune checkpoint inhibitors and discusses published studies and the perspectives of immunooncology for the treatment of endocrine malignancies.