RESUMO

Anaplastic thyroid cancer (ATC) is a highly aggressive type of thyroid cancer (TC). Currently, no effective target treatments are available that can improve overall survival, with ATC representing a major clinical challenge because of its remarkable lethality. Tumor-associated macrophages (TAMs) are the most evident cells in ATCs, and their high density is correlated with a poor prognosis. However, the mechanisms of how TAMs promote ATC progression remain poorly characterized. Here, we demonstrated that the treatment of human monocytes (THP-1 cells) with ATC cell-derived conditioned media (CM) promoted macrophage polarization, showing high levels of M2 markers. Furthermore, we found that STAT3 was activated, and this was correlated with an increased expression and secretion of the inflammatory cytokine interleukin-6. Remarkably, the M2-like macrophages obtained revealed tumor-promoting activity. A cytokine array analysis demonstrated that M2-like macrophage-derived CM contained high levels of TIM3, which is an important immune regulatory molecule. Consistently, TIM3 expression was up-regulated in THP-1 cells cultured with ATC cell-derived CM. Moreover, TIM3 blockade significantly reversed the polarization of THP-1 cells induced by ATC cell-secreted soluble factors. We validated the clinical significance of the TIM3 in human TC by analyzing public datasets and found that the expression of TIM3 and its ligand galectin 9 was significantly higher in human TC tissue samples than in normal thyroid tissues. Taken together, our findings identified a new mechanism by which TIM3 induces tumor-promoting M2-like macrophage polarization in TC. Furthermore, TIM3 interference might be a potential tool for treatment of patients with ATC.

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

RESUMO

Thyroid cancer is the most common endocrine malignancy. Anaplastic thyroid cancer is one of the most aggressive thyroid tumors. It is known that activation of oncogenes and/or inactivation of tumor suppressor genes in tumor cells promotes tumorigenesis. The microenvironment of the tumor also plays a key role on cancer development and progression in a variety of tumors. However, the mechanisms by which tumor-stroma crosstalk in thyroid cancer remains poorly characterized. In this study we aimed to understand how interactions between fibroblasts and anaplastic thyroid cancer cells contribute to thyroid carcinogenesis. We first characterized the phenotypic changes of human fibroblasts in vitro through co-cultures by using transwells as well as by using anaplastic thyroid cancer cells-derived conditioned media. We found that fibroblasts acquired an activated phenotype or also known as cancer-associated fibroblast phenotype after being in contact with soluble factors secreted from anaplastic thyroid cancer cells, compared to the fibroblasts in mono-cultures. All the changes were partly mediated through Src/Akt activation. Treatment with the antioxidant N-acetyl-cysteine reversed in part the metabolic phenotype of activated fibroblasts. Remarkably, conditioned media obtained from these activated fibroblasts promoted cell proliferation and invasion of follicular thyroid cancer cell line, FTC-133 cells. Thus, a reciprocal and dynamic interaction exists between tumor and stromal cells, which results in the promotion of thyroid tumorigenesis. The present studies have advanced the understanding of the molecular basis of tumor-stroma communications, enabling identification and targeting of tumor-supportive mechanisms for novel treatment modalities.

Assuntos

Adenocarcinoma Folicular/patologia , Fibroblastos Associados a Câncer/metabolismo , Células Estromais/patologia , Carcinoma Anaplásico da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Carcinogênese/patologia , Comunicação Celular , Técnicas de Cultura de Células , Desdiferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Técnicas de Cocultura , Meios de Cultivo Condicionados/metabolismo , Progressão da Doença , Humanos , Invasividade Neoplásica/patologia , Comunicação Parácrina , Glândula Tireoide/citologia , Glândula Tireoide/patologia , Microambiente Tumoral

RESUMO

We utilized subcutaneous (SC)- and omental (OM)-derived human primary adipocytes (hPA) from obese male, and investigated whether synthetic analog of leptin, metreleptin, may regulate lipolysis via translocation of STAT3 to the nucleus. We observed that 50 ng/mL of metreleptin increases STAT3 phosphorylation in both SC- and OM-derived hPA. Importantly, we found for the first time that metreleptin is capable of trans-locating STAT3 to the nucleus and STAT3 blockade inhibits metreleptin-induced lipolysis. Our initial data provide novel insights into the role of STAT3 as probable mediator of the action of metreleptin in regulating metabolism.