Expression of decoy receptor 3 in diffuse sclerosing variant of papillary thyroid carcinoma: correlation with M2 macrophage differentiation and lymphatic invasion

Construction and validation of a nomogram for predicting cervical lymph node metastasis in diffuse sclerosing variant of papillary thyroid carcinoma

OBJECTIVE

To analyze the risk factors associated with the occurrence of cervical lymph node metastasis (LNM) in patients with diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) and to establish a nomogram model.

METHODS

Clinical data of 199 DSV-PTC patients from SEER database were obtained, and they were randomly divided into training group (n=139) and validation group (n=60). The clinicopathological characteristics were analyzed by logistic regression, including age, marital status, race, gender, tumor size(cm), T stage, M stage, bilaterality, capsular invasion, extrathyroidal extension (ETE), and multifocality. The Validation was carried out using C-index, calibration curves, and Decision Curve Analysis (DCA) in terms of differentiation and calibration of the nomogram model, respectively.

RESULTS

Age, tumor size(cm), capsular invasion, and multifocality were independent risk factors for the development of LNM in patients with DSV-PTC (P<0.05). In the training and validation groups, the C-index of internal validation of the nomogram was 0.808 (95%CI: 0.733-0.755) and 0.813 (95% CI: 0.591-0.868), the calibration curves showed that the model was in good agreement, and the decision curve (DCA) indicated that the nomogram model had good clinical utility.  CONCLUSION: Age, tumor size(cm), capsular invasion, and multifocality are independent risk factors for the development of LNM in DSV-PTC. The nomogram model can predict the risk of developing LNM in DSV-PTC patients and provide clinical guidance.

Crosstalk between Thyroid Carcinoma and Tumor-Correlated Immune Cells in the Tumor Microenvironment

Thyroid cancer (TC) is the most common malignancy in the endocrine system. Although most TC can achieve a desirable prognosis, some refractory thyroid carcinomas, including radioiodine-refractory differentiated thyroid cancer, as well as anaplastic thyroid carcinoma, face a myriad of difficulties in clinical treatment. These types of tumors contribute to the majority of TC deaths due to limited initial therapy, recurrence, and metastasis of the tumor and tumor resistance to current clinically targeted drugs, which ultimately lead to treatment failure. At present, a growing number of studies have demonstrated crosstalk between TC and tumor-associated immune cells, which affects tumor deterioration and metastasis through distinct signal transduction or receptor activation. Current immunotherapy focuses primarily on cutting off the interaction between tumor cells and immune cells. Since the advent of immunotherapy, scholars have discovered targets for TC immunotherapy, which also provides new strategies for TC treatment. This review methodically and intensively summarizes the current understanding and mechanism of the crosstalk between distinct types of TC and immune cells, as well as potential immunotherapy strategies and clinical research results in the area of the tumor immune microenvironment. We aim to explore the current research advances to formulate better individualized treatment strategies for TC patients and to provide clues and references for the study of potential immune checkpoints and the development of immunotherapy technologies.

Potential role of M2 TAMs around lymphatic vessels during lymphatic invasion in papillary thyroid carcinoma

The aim of this study was to examine whether lymphatic invasion in papillary thyroid carcinoma (PTC) occurs when tumour-associated macrophages (TAMs) injure lymphatic vessels together with cancer cells. While there was no difference in the lymphatic vessel density in PTC and follicular thyroid carcinoma (FTC), the number of TAMs around the lymphatic vessels was increased in PTC compared to that in FTC. In particular, TAMs were observed together with cancer cells in lymphatic invasive lesions, and the number of M2 cells inside and outside the lymphatic vessels showed a significant correlation. MMP-2 mRNA was expressed in nonneoplastic stromal cells as well as cancer cells, and double immunofluorescence staining confirmed M2 positivity. Consequently, this study reveals that M2 TAMs around lymphatic vessels within the tumour border of PTC may be associated with the lymphatic invasion of cancer cells. This study represents a step forward in elucidating the mechanism of lymphatic invasion.

Immune Cell Confrontation in the Papillary Thyroid Carcinoma Microenvironment

Background

Papillary thyroid cancer has been associated with chronic inflammation. A systematic understanding of immune cell infiltration in PTC is essential for subsequent immune research and new diagnostic and therapeutic strategies.

Methods

Three different algorithms, single-sample gene set enrichment analysis (ssGSEA), immune cell marker and CIBERSORT, were used to evaluate immune cell infiltration levels (abundance and proportion) in 10 data sets (The Cancer Genome Atlas [TCGA], GSE3467, GSE3678, GSE5364, GSE27155, GSE33630, GSE50901, GSE53157, GSE58545, and GSE60542; a total of 799 PTC and 194 normal thyroid samples). Consensus unsupervised clustering divided PTC patients into low-immunity and high-immunity groups. Weighted gene coexpression network analysis (WGCNA) and gene set enrichment analysis (GSEA) were used to analyze the potential mechanisms causing differences in the immune response.

Results

Compared with normal tissues, PTC tissues had a higher overall immune level and higher abundance levels and proportions of M2 macrophages, Tregs, monocytes, neutrophils, dendritic cells (DCs), mast cells (MCs), and M0 macrophages. Compared with early PTC, advanced PTC showed higher immune infiltration and higher abundance levels and proportions of M2 macrophages, Tregs, monocytes, neutrophils, DCs, MCs, and M0 macrophages. Compared to the low-immunity group, the high-immunity group exhibited more advanced stages, larger tumor sizes, greater lymph node metastases, higher tall-cell PTCs, lower follicular PTC proportions, more BRAF mutations, and fewer RAS mutations. Epstein-Barr virus (EBV) infection was the most significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for key module genes.

Conclusions

In human PTC, M2 macrophages, Tregs, monocytes, neutrophils, DCs, MCs, and M0 macrophages appear to play a tumor-promoting role, while M1 macrophages, CD8+ T cells, B cells, NK cells, and T follicular helper (TFH) cells (including eosinophils, γδ T cells, and Th17 cells with weak supporting evidence) appear to play an antitumor role. During the occurrence and development of PTC, the overall immune level was increased, and the abundance and proportion of tumor-promoting immune cells were significantly increased, indicating that immune escape had been aggravated. Finally, we speculate that EBV may play an important role in changing the immune microenvironment of PTC tumors.

Epithelial-to-mesenchymal transition in thyroid cancer: a comprehensive review

The Metastatic progression of solid tumors, such as thyroid cancer is a complex process which involves various factors. Current understanding on the role of epithelial-mesenchymal transition (EMT) in thyroid carcinomas suggests that EMT is implicated in the progression from follicular thyroid cancer (FTC) and papillary thyroid cancer (PTC) to poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid cancer (ATC). According to the literature, the initiation of the EMT program in thyroid epithelial cells elevates the number of stem cells, which contribute to recurrent and metastatic diseases. The EMT process is orchestrated by a complex network of transcription factors, growth factors, signaling cascades, epigenetic modulations, and the tumor milieu. These factors have been shown to be dysregulated in thyroid carcinomas. Therefore, molecular interferences restoring the expression of tumor suppressors, or thwarting overexpressed oncogenes is a hopeful therapeutic method to improve the treatment of progressive diseases. In this review, we summarize the recent findings on EMT in thyroid cancer focusing on the main role-players and regulators of this process in thyroid tumors.

The Immune Landscape of Thyroid Cancer in the Context of Immune Checkpoint Inhibition

Immune cells play critical roles in tumor prevention as well as initiation and progression. However, immune-resistant cancer cells can evade the immune system and proceed to form tumors. The normal microenvironment (immune cells, fibroblasts, blood and lymphatic vessels, and interstitial extracellular matrix (ECM)) maintains tissue homeostasis and prevents tumor initiation. Inflammatory mediators, reactive oxygen species, cytokines, and chemokines from an altered microenvironment promote tumor growth. During the last decade, thyroid cancer, the most frequent cancer of the endocrine system, has emerged as the fifth most incident cancer in the United States (USA), and its incidence is steadily growing. Inflammation has long been associated with thyroid cancer, raising critical questions about the role of immune cells in its pathogenesis. A plethora of immune cells and their mediators are present in the thyroid cancer ecosystem. Monoclonal antibodies (mAbs) targeting immune checkpoints, such as mAbs anti-cytotoxic T lymphocyte antigen 4 (anti-CTLA-4) and anti-programmed cell death protein-1/programmed cell death ligand-1 (anti-PD-1/PD-L1), have revolutionized the treatment of many malignancies, but they induce thyroid dysfunction in up to 10% of patients, presumably by enhancing autoimmunity. Combination strategies involving immune checkpoint inhibitors (ICIs) with tyrosine kinase (TK) or serine/threonine protein kinase B-raf (BRAF) inhibitors are showing considerable promise in the treatment of advanced thyroid cancer. This review illustrates how different immune cells contribute to thyroid cancer development and the rationale for the antitumor effects of ICIs in combination with BRAF/TK inhibitors.

Decoy Receptor 3 Expression Is Associated With Wild-Type EGFR Status, Poor Differentiation of Tumor, and Unfavorable Patient Outcome

OBJECTIVES

The role of decoy receptor 3 (DcR3) in lung cancer, particularly adenocarcinoma, has not been well studied. In this study, we aim to investigate the expression profile and the clinicopathologic implications of DcR3 expression in lung adenocarcinoma.

METHODS

Immunohistochemistry was used to examine DcR3 expression in 461 lung adenocarcinomas. The differences in DcR3 expression among the various histopathologic patterns were analyzed. The relationship between DcR3 expression and clinicopathologic parameters, including epidermal growth factor receptor (EGFR) mutation, was also investigated.

RESULTS

DcR3 expression was more frequently expressed in solid, micropapillary, and acinar patterns (P < .0001) and in tumors with wild-type EGFR status (P = .018). In addition, DcR3 expression portends a less favorable disease-free survival in stage I patients (P = .012).

CONCLUSIONS

The expression of DcR3 might be involved in the differentiation and progression of lung adenocarcinoma. Therefore, DcR3 may be applied clinically for prediction of tumor progression in stage I lung adenocarcinoma.

Bleomycin inhibits proliferation and induces apoptosis in TPC-1 cells through reversing M2-macrophages polarization

Papillary thyroid carcinoma (PTC) is one of the most common types of thyroid malignancy. Previous studies have demonstrated that the density of tumor-associated macrophages (TAMs) within the tumor microenvironment affects the progression of PTC due to the imbalance in M1/M2 macrophage subtypes. M2 macrophages induce anti-inflammatory effects and promote tumor progression, whereas M1 macrophages destroy tumor cells. Therefore, reversing TAM polarization to M1 may be a novel strategy for the treatment of cancer. Although bleomycin (BLM) is a commonly used anti-cancer drug, which regulates the secretion of relevant cytokines, high dose and long-term treatment with BLM may lead to pulmonary fibrosis. In the present study, flow cytometry data revealed that low dose treatment with BLM (5 or 10 mU/ml) facilitated the expression of the M1 phenotype markers cluster of differentiation (CD)80 and C-C chemokine receptor 7, and concurrently suppressed the M2 marker CD206 on M2-macrophages. Reverse transcription-quantitative polymerase chain reaction data revealed that the expression levels of tumor necrosis factor-α and interleukin-1β markedly increased, whereas the expression of IL-10 decreased in M2 macrophages treated with BLM. A fluorescein isothiocyanate-dextran uptake experiment revealed that BLM increased the phagocytic capacity of M2, however not M1 or M0 macrophages. In addition, to verify the effect of BLM-treated M2 macrophages on thyroid carcinoma cells, a co-culture system of macrophages and the human PTC cell line TPC-1, was established. BLM-treated M2 macrophages increased the number of cells in early and late apoptosis and inhibited the migration, proliferation and invasion of TPC-1 cells. These results suggest that a low dose and indirect effect of BLM may induce suppressive effects on PTC by selectively reversing M2 macrophage polarization to M1, which may provide a novel strategy for cancer treatment.

Decoy receptor 3: an endogenous immunomodulator in cancer growth and inflammatory reactions

Decoy receptor 3 (DcR3), also known as tumor necrosis factor receptor (TNFR) superfamily member 6b (TNFRSF6B), is a soluble decoy receptor which can neutralize the biological functions of three members of tumor necrosis factor superfamily (TNFSF): Fas ligand (FasL), LIGHT, and TL1A. In addition to ‘decoy’ function, recombinant DcR3.Fc is able to modulate the activation and differentiation of dendritic cells (DCs) and macrophages via ‘non-decoy’ action. DcR3-treated DCs skew T cell differentiation into Th2 phenotype, while DcR3-treated macrophages behave M2 phenotype. DcR3 is upregulated in various cancer cells and several inflammatory tissues, and is regarded as a potential biomarker to predict inflammatory disease progression and cancer metastasis. However, whether DcR3 is a pathogenic factor or a suppressor to attenuate inflammatory reactions, has not been discussed comprehensively yet. Because mouse genome does not have DcR3, it is not feasible to investigate its physiological functions by gene-knockout approach. However, DcR3-mediated effects in vitro are determined via overexpressing DcR3 or addition of recombinant DcR3.Fc fusion protein. Moreover, CD68-driven DcR3 transgenic mice are used to investigate DcR3-mediated systemic effects in vivo. Upregulation of DcR3 during inflammatory reactions exerts negative-feedback to suppress inflammation, while tumor cells hijack DcR3 to prevent apoptosis and promote tumor growth and invasion. Thus, ‘switch-on’ of DcR3 expression may be feasible for the treatment of inflammatory diseases and enhance tissue repairing, while ‘switch-off’ of DcR3 expression can enhance tumor apoptosis and suppress tumor growth in vivo.

The immune network in thyroid cancer

The immune system plays critical roles in tumor prevention, but also in its initiation and progression. Tumors are subjected to immunosurveillance, but cancer cells generate an immunosuppressive microenvironment that favors their escape from immune-mediated elimination. During chronic inflammation, immune cells can contribute to the formation and progression of tumors by producing mitogenic, prosurvival, proangiogenic and lymphangiogenic factors. Thyroid cancer is the most frequent type of endocrine neoplasia and is the most rapidly increasing cancer in the US. In this review, we discuss recent findings on how different immune cells and mediators can contribute to thyroid cancer development and progression.

Tumor-Associated Inflammatory Cells in Thyroid Carcinomas

The complex interactions between immune cells and tumor cells in cancer play a major role in tumor development and subsequent patient outcomes. Different types of tumor-associated inflammatory cells (TAICs), such as dendritic cells, macrophages, lymphocytes, and mast cells, have been recognized for many years in several tumors; however, the role of TAICs in cancer is still not completely understood. This review article focuses on the major types of TAICs, including their general role in cancer and, more specifically, their role and distribution in thyrocyte-derived carcinomas.