Thyroid tumor cells-fibroblasts crosstalk: role of extracellular vesicles

Radioiodine therapy in advanced differentiated thyroid cancer: Resistance and overcoming strategy

Thyroid cancer is the most prevalent endocrine tumor and its incidence is fast-growing worldwide in recent years. Differentiated thyroid cancer (DTC) is the most common pathological subtype which is typically curable with surgery and Radioactive iodine (RAI) therapy (approximately 85%). Radioactive iodine is the first-line treatment for patients with metastatic Papillary Thyroid Cancer (PTC). However, 60% of patients with aggressive metastasis DTC developed resistance to RAI treatment and had a poor overall prognosis. The molecular mechanisms of RAI resistance include gene mutation and fusion, failure to transport RAI into the DTC cells, and interference with the tumor microenvironment (TME). However, it is unclear whether the above are the main drivers of the inability of patients with DTC to benefit from iodine therapy. With the development of new biological technologies, strategies that bolster RAI function include TKI-targeted therapy, DTC cell redifferentiation, and improved drug delivery via extracellular vesicles (EVs) have emerged. Despite some promising data and early success, overall survival was not prolonged in the majority of patients, and the disease continued to progress. It is still necessary to understand the genetic landscape and signaling pathways leading to iodine resistance and enhance the effectiveness and safety of the RAI sensitization approach. This review will summarize the mechanisms of RAI resistance, predictive biomarkers of RAI resistance, and the current RAI sensitization strategies.

Role of Extracellular Vesicles in Thyroid Physiology and Diseases: Implications for Diagnosis and Treatment

Extracellular vesicles are spherical subcellular structures delimited by a lipid bilayer and released by most cells in the human body. They are loaded with a myriad of molecules (i.e., nucleic acids and proteins) depending on their cell of origin and provide the ability to transmit a message to surrounding or distant target cells. In several organs, including the thyroid, abundant recent literature reports that extracellular vesicles are responsible for intercellular communication in physiological and pathological processes, and that their utilization as a potential biomarker of pathological states (i.e., cancer, autoimmune diseases) or as therapeutic delivery vehicles promise clinical options. In this review, we present the current knowledge and understanding regarding the role of extracellular vesicles in developing thyroid diseases and diagnosis.

Thyroid Cancer and Fibroblasts

Thyroid cancer is the most common type of endocrine cancer, and its prevalence continue to rise. Non-metastatic thyroid cancer patients are successfully treated. However, looking for new therapeutic strategies is of great importance for metastatic thyroid cancers that still lead to death. With respect to this, the tumor microenvironment (TME), which plays a key role in tumor progression, should be considered as a new promising therapeutic target to hamper thyroid cancer progression. Indeed, thyroid tumors consist of cancer cells and a heterogeneous and ever-changing niche, represented by the TME, which contributes to establishing most of the features of cancer cells. The TME consists of extracellular matrix (ECM) molecules, soluble factors, metabolites, blood and lymphatic tumor vessels and several stromal cell types that, by interacting with each other and with tumor cells, affect TME remodeling, cancer growth and progression. Among the thyroid TME components, cancer-associated fibroblasts (CAFs) have gained more attention in the last years. Indeed, recent important evidence showed that thyroid CAFs strongly sustain thyroid cancer growth and progression by producing soluble factors and ECM proteins, which, in turn, deeply affect thyroid cancer cell behavior and aggressiveness. Hence, in this article, we describe the thyroid TME, focusing on the desmoplastic stromal reaction, which is a powerful indicator of thyroid cancer progression and an invasive growth pattern. In addition, we discuss the origins and features of the thyroid CAFs, their influence on thyroid cancer growth and progression, their role in remodeling the ECM and their immune-modulating functions. We finally debate therapeutic perspectives targeting CAFs.

Extracellular vesicles from thyroid cancer harbor a functional machinery involved in extracellular matrix remodeling

Extracellular vesicles (EVs) participate in cell-stroma crosstalk within the tumor microenvironment and fibroblasts (Fb) contribute to tumor promotion in thyroid cancer. However, the role of tumor-stroma derived EVs still needs to be deciphered. We hypothesized that the interaction of thyroid tumor cells with Fb would liberate EVs with a specific proteomic profile, which would have an impact on EV-functionality in thyroid tumor progression-related events. Tumor (TPC-1, 8505c) and non-tumor (NThyOri) thyroid cells were co-cultured with human Fb. EVs, obtained by ultracentrifugation of conditioned media, were characterized by nanoparticle tracking analysis and western blotting. EV-proteomic analysis was performed by mass-spectrometry, and metalloproteinases (MMPs) were studied by zymography. EV-exchange was evaluated using immunofluorescence, confocal microscopy and FACS. EVs expressed classical exosome markers, with EVs from thyroid tumor cell-Fb co-cultures showing a proteomic profile related to extracellular matrix (ECM) remodeling. Bidirectional crosstalk between Fb and TPC-1 cells produced significantly more EVs than their isolated cells, and potentiated EV-functionality. In line with this, Fb-TPC-1 derived EVs induced MMP2 activation in NThyOri supernatants, and MMP2 activity could be evidenced in Fb and TPC-1 contact-independent co-cultures. Besides, MMP2 interactors allowed us to discriminate between EVs from thyroid tumoral and non-tumoral milieus. Interestingly, Fb internalized more EVs from TPC-1 than from NThyOri producing cells. Fb and thyroid tumor cell crosstalk produces specialized EVs with an ECM remodeling proteomic profile, enabling activation of MMP2 and possibly facilitating ECM-degradation, which is potentially linked with thyroid tumor progression.

Comparative Proteomic Profiling of Ectosomes Derived from Thyroid Carcinoma and Normal Thyroid Cells Uncovers Multiple Proteins with Functional Implications in Cancer

Proteins carried by tumor-derived ectosomes play an important role in cancer progression, and are considered promising diagnostic markers. In the present study, a shotgun nanoLC–MS/MS proteomic approach was applied to profile and compare the protein content of ectosomes released in vitro by normal human thyroid follicular epithelial Nthy-ori 3-1 cells and human anaplastic thyroid carcinoma (TC) 8305C cells. Additionally, the pro-migratory and pro-proliferative effects of Nthy-ori 3-1- and 8305C-derived ectosomes exerted on the recipient cells were assessed in wound closure and Alamar Blue assays. A total of 919 proteins were identified in all replicates of 8305C-derived ectosomes, while Nthy-ori 3-1-derived ectosomes contained a significantly lower number of 420 identified proteins. Qualitative analysis revealed 568 proteins present uniquely in 8305C-derived ectosomes, suggesting their applicability in TC diagnosis and management. In addition, 8305C-derived ectosomes were able to increase the proliferation and motility rates of the recipient cells, likely due to the ectosomal transfer of the identified cancer-promoting molecules. Our description of ectosome protein content and its related functions provides the first insight into the role of ectosomes in TC development and progression. The results also indicate the applicability of some of these ectosomal proteins for further investigation regarding their potential as circulating TC biomarkers.

BRAFV600E Induction in Thyrocytes Triggers Important Changes in the miRNAs Content and the Populations of Extracellular Vesicles Released in Thyroid Tumor Microenvironment

Papillary thyroid cancer (PTC) is the most common endocrine malignancy for which diagnosis and recurrences still challenge clinicians. New perspectives to overcome these issues could come from the study of extracellular vesicle (EV) populations and content. Here, we aimed to elucidate the heterogeneity of EVs circulating in the tumor and the changes in their microRNA content during cancer progression. Using a mouse model expressing BRAF^V600E, we isolated and characterized EVs from thyroid tissue by ultracentrifugations and elucidated their microRNA content by small RNA sequencing. The cellular origin of EVs was investigated by ExoView and that of deregulated EV-microRNA by qPCR on FACS-sorted cell populations. We found that PTC released more EVs bearing epithelial and immune markers, as compared to the healthy thyroid, so that changes in EV-microRNAs abundance were mainly due to their deregulated expression in thyrocytes. Altogether, our work provides a full description of in vivo-derived EVs produced by, and within, normal and cancerous thyroid. We elucidated the global EV-microRNAs signature, the dynamic loading of microRNAs in EVs upon BRAF^V600E induction, and their cellular origin. Finally, we propose that thyroid tumor-derived EV-microRNAs could support the establishment of a permissive immune microenvironment.

Ivabradine-Stimulated Microvesicle Release Induces Cardiac Protection against Acute Myocardial Infarction

Ivabradine can reduce heart rate through inhibition of the current I(f) by still unexplored mechanisms. In a porcine model of ischemia reperfusion (IR), we found that treatment with 0.3 mg/kg Ivabradine increased plasma release of microvesicles (MVs) over Placebo, as detected by flow cytometry of plasma isolated from pigs 7 days after IR, in which a tenfold increase of Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) containing (both high and low-glycosylated) MVs, was detected in response to Ivabradine. The source of MVs was investigated, finding a 37% decrease of CD31+ endothelial cell derived MVs, while CD41+ platelet MVs remained unchanged. By contrast, Ivabradine induced the release of HCN4+ (mostly cardiac) MVs. While no differences respect to EMMPRIN as a cargo component were found in endothelial and platelet derived MVs, Ivabradine induced a significant release of EMMPRIN+/HCN4+ MVs by day 7 after IR. To test the role of EMMPRIN+ cardiac MVs (EMCMV), H9c2 cell monolayers were incubated for 24 h with 10⁷ EMCMVs, reducing apoptosis, and increasing 2 times cell proliferation and 1.5 times cell migration. The in vivo contribution of Ivabradine-induced plasma MVs was also tested, in which 10⁸ MVs isolated from the plasma of pigs treated with Ivabradine or Placebo 7 days after IR, were injected in pigs under IR, finding a significant cardiac protection by increasing left ventricle ejection fraction and a significant reduction of the necrotic area. In conclusion ivabradine induces cardiac protection by increasing at least the release of EMMPRIN containing cardiac microvesicles.

Role of extracellular vesicles in the progression, diagnosis and treatment of thyroid cancer (Review)

Extracellular vesicles (EVs) enclose a myriad of proteins and nucleic acids that are released in the extracellular milieu of cells through EVs. These secreted molecules serve as signaling factors that can alter the biological characteristics of tumor cells. Several studies have suggested that EVs are associated with tumor proliferation, metastasis and microenvironmental regulation in thyroid carcinoma (TC). The biomolecules in EVs can serve as differential diagnostic biomarkers for TC. Moreover, EVs derived from natural killer (NK) cells can be developed as potential immunotherapeutic agents, since they can actively target and kill tumor cells in TC. Recent years have witnessed a steep rise in the number of TC cases, and thus, accurate diagnosis and novel TC treatment strategies are being actively explored. The present review discusses the recent research investigations on EVs as far as the biological, clinical diagnosis and treatment of primary TC tumors are concerned. In addition, the new opportunities and challenges encountered in the practical applications of EVs in thyroid carcinoma are outlined.