Papillary Thyroid Cancer Tumors Research Articles

Immune microenvironment in papillary thyroid carcinoma: roles of immune cells and checkpoints in disease progression and therapeutic implications.

Papillary thyroid cancer (PTC) is the most common type of primary thyroid cancer. Despite the low malignancy and relatively good prognosis, some PTC cases are highly aggressive and even develop refractory cancer in the thyroid. Growing evidence suggested that microenvironment in tumor affected PTC biological behavior due to different immune states. Different interconnected components in the immune system influence and participate in tumor invasion, and are closely related to PTC metastasis. Immune cells and molecules are widely distributed in PTC tissues. Their quantity and proportion vary with the host's immune status, which suggests that immunotherapy may be a very promising therapeutic modality for PTC. In this paper, we review the role of immune cells and immune checkpoints in PTC immune microenvironment based on the characteristics of the PTC tumor microenvironment.

CircPCNXL2 promotes papillary thyroid carcinoma progression by regulating fatty acid metabolism induced by anabolic enzyme ACC1

Papillary thyroid cancer (PTC) is an endocrine malignant tumor with a rapidly increasing incidence in recent years. Although the disease prognosis is good in general, there are still some patients with local invasion, distant metastasis and recurrence, which make treatment difficult. This study aimed to investigate the effect of a novel circRNA, circPCNXL2, on the progression of PTC and to explore its underlying mechanism in PTC. In this study, we found that the expression of circPCNXL2 was upregulated in PTC, which was positively correlated with the proliferation of PTC, and knockdown of circPCNXL2 enhanced the cell cycle arrest of PTC and promoted cell apoptosis. Further research revealed that circPCNXL2 can interact with ACC1, a key enzyme of cellular lipid metabolism, and then promote cell growth by affecting the de novo synthesis of fatty acids. Mechanistically, circPCNXL2 enhances the protein activity of ACC1 by reducing ACC1 phosphorylation of ser 79, thereby promoting the formation of fatty acids such as free fatty acids and triglycerides in cells to meet the energy metabolism needs of cells and promote cell growth. In a nude mouse subcutaneous tumorigenesis model, knockdown of circPCNXL2 inhibited the growth of PTC tumors while high levels of circPCNXL2 expression promoted tumor proliferation. This study revealed that circPCNXL2 regulates PTC lipid metabolism by enhancing the protein activity of ACC1 and identified a novel signaling pathway, the circPCNXL2-ACC1 axis, that can be targeted for the treatment of PTC.

Papillary Thyroid Cancer Remodels the Genetic Information Processing Pathways.

The genetic causes of the differentiated, highly treatable, and mostly non-fatal papillary thyroid cancer (PTC) are not yet fully understood. The mostly accepted PTC etiology blames the altered sequence or/and expression level of certain biomarker genes. However, tumor heterogeneity and the patient's unique set of favoring factors question the fit-for-all gene biomarkers. Publicly accessible gene expression profiles of the cancer nodule and the surrounding normal tissue from a surgically removed PTC tumor were re-analyzed to determine the cancer-induced alterations of the genomic fabrics responsible for major functional pathways. Tumor data were compared with those of standard papillary and anaplastic thyroid cancer cell lines. We found that PTC regulated numerous genes associated with DNA replication, repair, and transcription. Results further indicated that changes of the gene networking in functional pathways and the homeostatic control of transcript abundances also had major contributions to the PTC phenotype occurrence. The purpose to proliferate and invade the entire gland may explain the substantial transcriptomic differences we detected between the cells of the cancer nodule and those spread in homo-cellular cultures (where they need only to survive). In conclusion, the PTC etiology should include the complex molecular mechanisms involved in the remodeling of the genetic information processing pathways.

Interactions between LAMP3+ dendritic cells and T-cell subpopulations promote immune evasion in papillary thyroid carcinoma

BackgroundThe incidence of papillary thyroid cancer (PTC) continues to rise all over the world, 10–15% of the patients have a poor prognosis. Although immunotherapy has been applied in clinical practice,...

Expert consensus on thermal ablation of papillary thyroid cancer (2024 edition)

Ultrasound-guided thermal ablation of papillary thyroid cancer (PTC) has been promoted in clinical practice over the past few years. Thermal ablation has the advantages of being minimally invasive, effective, and safe. However, current guidelines and consensus only focus on low-risk papillary thyroid microcarcinoma. With growing clinical application and accumulating scientific research in thermal ablation for PTC, there is considerable evidence to demonstrate that thermal ablation can treat larger PTC tumors and benefit more patients with PTC. To expand the indications and standardize the technical details and perioperative patient management for PTC ablation, experts from the Society of Tumor Ablation Therapy of the Chinese Anti-Cancer Association, the Ablation Expert Committee of the Chinese Society of Clinical Oncology (CSCO), Chinese Medical Doctor Association College of Interventionalists Tumor Ablation Committee, and Chinese Bethune Spirit Research Association Endocrinology and Diabetes Branch Interventional Endocrine Committee discussed and developed a consensus on thermal ablation of PTC based on the latest research results. This consensus aims to promote the rapid development of thermal ablation for PTC in the clinic.

Abstract 6859: A novel immune checkpoint CD97/CD55 in the initiation and progression of papillary thyroid cancer by scRNA-seq

Abstract Thyroid cancer (TC), as the most common endocrine malignancy, has exhibited a significant increasing trend in incidence in China and globally, with papillary thyroid cancer (PTC) being the most common pathological type. However, the molecular mechanisms driving the initiation and progression of TC remains scarce, posing a bottleneck problem for the precise diagnosis and treatment. Tumors, as a complex heterogeneous composite consisting of tumor cells, immune cells, and stromal cells, have long been considered to play a key role in driving tumor occurrence and malignant progression through the proportion, spatial distribution, and interaction of tumor cells and immune cells in the tumor immune microenvironment(TIME).We performed single-cell RNA sequencing (scRNA-seq) on 16 clinical samples, including normal thyroid tissue, benign nodules, PTC, and PTC with cervical lymph node metastasis(LNM), delineating the cell atlas of the tumor microenvironment (TME) at various stages from normal thyroid to PTC development. Among these, we discovered a previously undefined TNFSF9highCD8+ T cell subset with a distinct transcriptional profile from classical exhausted T cells, which was highly enriched in PTC tumor tissues. Further cell interaction analysis revealed that the highly expressed CD97 receptor on these CD8+ T cells binds to the highly expressed CD55 molecule on PTC tumor cells, promoting the exhaustion of CD8+ T cells, suggesting that CD97/CD55 may be a key new immune checkpoint (IC) inducing CD8+ T cell exhaustion and promoting immune escape of PTC tumor cells. We validated the co-localization of CD97/CD55-mediated CD8+ T cell and tumor cell interactions in PTC patient specimens and spontaneous tumor samples from a mouse PTC model using multiplex immunofluorescence (mIHC). Flow cytometry analysis of the proportion of CD97+ CD8+ T cells in patient and mouse specimens revealed a significant increase in the proportion of CD97+ CD8+ T cells in PTC tumor tissues. Co-culture experiments of activated and expanded CD8+ T cells from peripheral blood mononuclear cells(PBMC) of PTC patients with PTC tumor cells showed that CD55 overexpressing tumor cells inhibited the secretion of cytotoxic cytokines IFN-γ and IL-2 by activated CD8+ T cells through the CD97/CD55 IC signal, thereby weakening the cytotoxity on PTC tumor cells. In summary, the IC regulatory signal formed by the highly expressed CD55 molecule on the surface of PTC tumors and the CD97 receptor on the surface of PTC-specific inhibitory TNFSF9highCD8+ T cells can reshape the TIME, promoting the formation of an immunosuppressive microenvironment, which may represent a novel molecular mechanism promoting immune escape of tumor cells during PTC initiation and progression. Citation Format: Xuan Qin, Jia Li, Dapeng Li, Xing Wan, Xianhui Ruan, Yimeng Liu, Weijing Hao, Kejia Xu, Yi Shi, Yongjun Piao, Xiangqian Zheng. A novel immune checkpoint CD97/CD55 in the initiation and progression of papillary thyroid cancer by scRNA-seq [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6859.

A distinct tumor microenvironment makes anaplastic thyroid cancer more lethal but immunotherapy sensitive than papillary thyroid cancer.

Both anaplastic thyroid cancer (ATC) and papillary thyroid cancer (PTC) originate from thyroid follicular epithelial cells, but ATC has a significantly worse prognosis and shows resistance to conventional therapies. However, clinical trials found that immunotherapy works better in ATC than late-stage PTC. Here, we used single-cell RNA sequencing (scRNA-Seq) to generate a single-cell atlas of thyroid cancer. Differences in ATC and PTC tumor microenvironment components (including malignant cells, stromal cells, and immune cells) leading to the polarized prognoses were identified. Intriguingly, we found that CXCL13+ T lymphocytes were enriched in ATC samples and might promote the development of early tertiary lymphoid structure (TLS). Last, murine experiments and scRNA-Seq analysis of a treated patient's tumor demonstrated that famitinib plus anti-PD-1 antibody could advance TLS in thyroid cancer. We displayed the cellular landscape of ATC and PTC, finding that CXCL13+ T cells and early TLS might make ATC more sensitive to immunotherapy.

Hsa_circ_0092355 Accelerates Papillary Thyroid Cancer Progression by Regulating the miR-543/PDE5A Pathway.

CircRNAs have been found to participate in the progression of various tumors. In the present study, we aimed to clarify the role of hsa_circ_0092355 in papillary thyroid cancer (PTC) cell development. RT-qPCR was used to determine the expression of hsa_circ_0092355, miR-543, and PDE5A. PTC cell proliferation was ascertained via a cell colony formation assay and the CCK-8 test. Western blotting was performed to examine the expression levels of PDE5A and apoptosis-associated proteins (Bcl-2 and Bax) in PTC cells. A scratch wound assay was performed to measure the migration of PTC cells. A mouse xenograft test was performed to assess the effects of hsa_circ_0092355 in vivo. RIP and dual-luciferase reporter assays confirmed the association between miR-543 and hsa_circ_0092355 or PDE5A. Associations between miR-543, hsa_circ_0092355, and PDE5A were evaluated using Pearson's correlation coefficient. Upregulation of hsa_circ_0092355 was observed in PTC tissues. The hsa_circ_0092355 knockdown blocked the proliferation and migration of PTC cells and induced apoptosis. Moreover, hsa_circ_0092355 knockdown blocked PTC xenograft tumor growth in vivo. The miR-543 inhibitor could reverse the changes induced by hsa_circ_0092355 knockdown by hsa_circ_0092355 targeting miR-543. Furthermore, miR-543 suppresses PTC progression by downregulating PDE5A expression. Our findings suggest that the PTC tumor promoter hsa_circ_0092355 may promote carcinogenesis by controlling the miR-543/PDE5A pathway.

LncRNA HAGLROS contribute to papillary thyroid cancer progression by modulating miR-206/HMGA2 expression.

Papillary thyroid cancer (PTC) is one of the most serious diseases of the endocrine system. In view of the limited therapeutic effects of current medical methods, this study starts from the molecular level and looks for potential treatments. The interaction between HAGLROS/miR-206/HMGA2 was studied using multi-omics methods, which provided new ideas and methods for future treatments. Microarray analysis and R language were used for differential analysis to screening experimental targets of lncRNA, miRNA, and mRNA. qRT-PCR was used to detect RNA expression in tissues and cells. Double luciferase reporter assays analyzed and validated binding relationships between different RNAs. Colony formation, flow cytometry, and transwell assays were used to measure the effect of them on cell proliferation, apoptosis, and migration. Microarray analysis identified lncRNAs, miRNAs, and mRNAs differentially expressed in PTC and normal cells, and selected lncRNA HAGLROS, miR-206, and mRNA HMGA2 as study subjects. LncRNA HAGLROS and mRNA HMGA2 were highly expressed in PTC cells while miR-206 was lowly expressed in PTC cells. LncRNA HAGLROS/HMGA2 can inhibit apoptosis of PTC cells, promote proliferation and migration, and miR-206 promotes the above process. HAGLROS and HMGA2 were negatively correlated with miR-206. shHAGLROS promoted miR-206 expression, inhibited HMGA2 expression and repressed PTC tumor growth in mice. HAGLROS promotes the growth of PTC by competitively binding to miR-206 to promote HMGA2 expression.

Tetraspanin 1 regulates papillary thyroid tumor growth and metastasis through c-Myc-mediated glycolysis.

Papillary thyroid cancer (PTC) is the most common form of thyroid cancer and is characterized by its tendency for lymphatic metastasis, leading to a poor prognosis. Tetraspanin 1 (TSPAN1) is a member of the tetra-transmembrane protein superfamily and has been implicated in tumorigenesis and cancer metastasis in various studies. However, the role of TSPAN1 in PTC tumor development remains unclear. In this study, we aimed to investigate the impact of TSPAN1 on PTC cell behavior. Our results demonstrate that knockdown of TSPAN1 inhibits PTC cell proliferation, migration, and invasion, while overexpression of TSPAN1 has the opposite effect. These findings suggest that TSPAN1 might play a role in the tumorigenesis and invasiveness of PTC. Mechanistically, we found that TSPAN1 activates the ERK pathway by increasing its phosphorylation, subsequently leading to upregulated expression of c-Myc. Additionally, we observed that TSPAN1-ERK-c-Myc axis activation promotes glycolytic activity in PTC cells, as evidenced by the upregulation of glycolytic genes such as LDHA. Taken together, our findings indicate that TSPAN1 acts as an oncogene in PTC by regulating glycolytic metabolism. This discovery highlights the potential of TSPAN1 as a promising therapeutic target for PTC treatment. Further research in this area could provide valuable insights into the development of targeted therapies for PTC patients.

Integrated analysis of tumor microenvironment features to establish a diagnostic model for papillary thyroid cancer using bulk and single-cell RNA sequencing technology

BackgroundCharacterizing tumor microenvironment using single-cell RNA sequencing has been a promising strategy for cancer diagnosis and treatment. However, a few studies have focused on diagnosing papillary thyroid cancer (PTC) through this technology. Therefore, our study explored tumor microenvironment (TME) features and identified potential biomarkers to establish a diagnostic model for papillary thyroid cancer.MethodsThe cell types were identified using the markers from the CellMarker database and published research. The CellChat package was conducted to analyze the cell–cell interaction. The SCEVAN package was used to identify malignant thyroid cells. The SCP package was used to perform multiple single-cell downstream analyses, such as GSEA analysis, enrichment analysis, pseudotime trajectory analysis, and differential expression analysis. The diagnostic model of PTC was estimated using the calibration curves, receiver operating characteristic curves, and decision curve analysis. RT-qPCR was performed to validate the expression of candidate genes in human papillary thyroid samples.ResultsEight cell types were identified in the scRNA-seq dataset by published cell markers. Extensive cell–cell interactions like FN1/ITGB1 existed in PTC tissues. We identified 26 critical genes related to PTC progression. Further, eight subgroups of PTC tumor cells were identified and exhibited high heterogeneity. The MDK/LRP1, MDK/ALK, GAS6/MERTK, and GAS6/AXL were identified as potential ligand-receptor pairs involved in the interactions between fibroblasts/endothelial cells and tumor cells. Eventually, the diagnostic model constructed by TRPC5, TENM1, NELL2, DMD, SLC35F3, and AUTS2 showed a good efficiency for distinguishing the PTC and normal tissues.ConclusionsOur study comprehensively characterized the tumor microenvironment in papillary thyroid cancer. Through combined analysis with bulk RNA-seq, six potential diagnostic biomarkers were identified and validated. The diagnostic model we constructed was a promising tool for PTC diagnosis. Our findings provide new insights into the heterogeneity of thyroid cancer and the theoretical basis for diagnosing thyroid cancer.

Hypoxic papillary thyroid carcinoma cells-secreted exosomes deliver miR-221-3p to normoxic tumor cells to elicit a pro-tumoral effect by regulating the ZFAND5

Papillary thyroid cancer (PTC) has seen a worldwide expansion in incidence in the past three decades. Tumor-derived exosomes have been associated with the metastasis of cancer cells and are present within the local hypoxic tumor microenvironment, where they mediate intercellular communication by transferring molecules including microRNAs (miRNAs) between cells. Although miRNAs have been shown to serve as non-invasive biomarkers for cancer diagnosis, the role of hypoxia-induced tumor-derived exosomes in PTC progression remains unclear. Herein, we investigated the differentially expressed miRNA expression profiles from GEO datasets (GSE191117 and GSE151180) by using the DESeq package in R and identified a novel role for miR-221-3p as an oncogene in PTC development. In vivo and in vitro loss and gain assays were used to clarify the mechanism of hypoxic PTC cells derived exosomal-miR-221-3p in PTC. miR-221-3p was upregulated in human PTC plasma exosomes, tissues and cell lines. We found that hypoxic PTC cells derived exosomal-miR-221-3p promoted normoxic PTC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro, while inhibition of miR-221-3p limited PTC tumor growth in our PTC xenograft model in nude mice. We finally identified ZFAND5, to be a miR-221-3p target. Mechanistically, hypoxic PTC cell lines-derived exosomes carrying miR-221-3p promoted PTC tumorigenesis by regulating ZFAND5. Our findings further the understanding of the underlying mechanisms associated with PTC progression and identify exosomal-miR-221-3p as a potential biomarker for the diagnosis and prognosis of PTC patients. Our study also suggests that miR-221-3p inhibitors could be a potential treatment strategy for PTC.

B cells and tertiary lymphoid structures are associated with survival in papillary thyroid cancer.

The function of B cells in papillary thyroid cancer (PTC) is controversial. The role of B-cell-related tertiary lymphoid structures (TLSs) is still unclear. Whether B cells exert their anti-tumor effect through forming TLS in PTC needs further investigation. We detected the percentage of B cells in PTC tissues by multi-parameter flow cytometry. Paraffin-embedded tumor tissues of 125 PTC patients were collected and stained with Haematoxylin-Eosin (H&E) for inflammatory infiltration analysis in combination with clinical features. Multiplexed immunohistochemistry (mIHC) was performed to verify the TLSs in above inflammatory infiltration. Correlation of B cells and TLSs with prognosis was analyzed using the TCGA database. We observed that PTC patients with higher expression of B lineage cell genes had improved survival and the percentage of B cells in the PTC tumor tissues was variable. Moreover, PTC tumor tissues with more B cells were surrounded by immune cell aggregates of varying sizes. We furtherly confirmed the immune cell aggregates as TLSs with different maturation stages. By analyzing PTC data from TCGA database, we found the maturation stages of TLSs were associated with genders and clinical stages among PTC patients. Moreover, patients with high TLSs survived longer and had a better prognosis. B cells are associated with the existence of TLSs which have different maturation stages in PTC. Both B cells and TLSs are associated with the survival rate of PTC. These observations indicate that the anti-tumor effects of B cells in PTC are associated with TLSs formation.

The role of lactate metabolism-related LncRNAs in the prognosis, mutation, and tumor microenvironment of papillary thyroid cancer.

Lactate, a byproduct of glucose metabolism, is primarily utilized for gluconeogenesis and numerous cellular and organismal life processes. Interestingly, many studies have demonstrated a correlation between lactate metabolism and tumor development. However, the relationship between long non-coding RNAs (lncRNAs) and lactate metabolism in papillary thyroid cancer (PTC) remains to be explored. Lactate metabolism-related lncRNAs (LRLs) were obtained by differential expression and correlation analyses, and the risk model was further constructed by least absolute shrinkage and selection operator analysis (Lasso) and Cox analysis. Clinical, immune, tumor mutation, and enrichment analyses were performed based on the risk model. The expression level of six LRLs was tested using RT-PCR. This study found several lncRNAs linked to lactate metabolism in both The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) datasets. Using Cox regression analysis, 303 lactate LRLs were found to be substantially associated with prognosis. Lasso was done on the TCGA cohort. Six LRLs were identified as independent predictive indicators for the development of a PTC prognostic risk model. The cohort was separated into two groups based on the median risk score (0.39717 -0.39771). Subsequently, Kaplan-Meier survival analysis and multivariate Cox regression analysis revealed that the high-risk group had a lower survival probability and that the risk score was an independent predictive factor of prognosis. In addition, a nomogram that can easily predict the 1-, 3-, and 5-year survival rates of PTC patients was established. Furthermore, the association between PTC prognostic factors and tumor microenvironment (TME), immune escape, as well as tumor somatic mutation status was investigated in high- and low-risk groups. Lastly, gene expression analysis was used to confirm the differential expression levels of the six LRLs. In conclusion, we have constructed a prognostic model that can predict the prognosis, mutation status, and TME of PTC patients. The model may have great clinical significance in the comprehensive evaluation of PTC patients.

Intratumoral Bacteria Dysbiosis Is Associated with Human Papillary Thyroid Cancer and Correlated with Oncogenic Signaling Pathways

Emerging evidence suggests that microbial dysbiosis plays vital roles in many human cancers. However, knowledge of whether the microbial community in thyroid tumor is related to tumorigenesis remains elusive. In this study, we aimed to explore the microbial community in thyroid tissues and its contribution to papillary thyroid cancer (PTC). In parallel, we performed microbial profiling and transcriptome sequencing in the tumor and adjacent normal tissues of a large cohort of 340 PTC and benign thyroid nodule (BTN) patients. Distinct microbial signatures were identified in PTC, BTN, and their adjacent non-tumor tissues. Intra-thyroid tissue bacteria were verified by means of bacteria staining, fluorescence in situ hybridization, and immunoelectron microscopy. We found that 17 bacterial taxa were differentially abundant in PTC compared with BTN, which included enrichment in PTC of the pathobionts Rhodococcus, Neisseria, Streptococcus, Halomonas, and Devosia, and depletion of the beneficial bacteria Amycolatopsis. These differentially abundant bacteria could differentiate PTC tumor tissues (PTC-T) from BTN tissues (BTN-T) with an area under the curve (AUC) of 81.66%. Microbial network analysis showed increased correlation strengths among the bacterial taxa in PTC-T in comparison with BTN-T. Immune-function-corresponding bacteria (i.e., Erwinia, Bacillus, and Acinetobacter) were found to be enriched in PTC with Hashimoto’s thyroiditis. Moreover, our integrative analysis revealed that the PTC-enriched bacteria had a positive association with key PTC-oncogenic pathway-related genes, including BRAF, KRAS, IRAK4, CTNNB1, PIK3CA, MAP3K7, and EGFR. In conclusion, our results suggest that intratumor bacteria dysbiosis is associated with the thyroid tumorigenesis and oncogenic signaling pathways of PTC.

IncRNA XIST Stimulates Papillary Thyroid Cancer Development through the miR-330-3p/PDE5A Axis

Long non-coding RNAs (lncRNAs) possess both tumor suppressive and oncogenic functions in papillary thyroid cancer (PTC). Among all the thyroid cancers, PTC is the most prevalent form. Herein, we aim to determine the regulatory mechanisms and functions of lncRNA XIST in the multiplication, invasion, and survival of PTC. Quantitative reverse transcription polymerase chain reaction and Western blot experiments were performed to determine the patterns of lncRNA XIST, miR-330-3p, and PDE5A expressions. The subcellular localization of XIST was determined through subcellular fractionation. Bioinformatics analyses were performed to determine miR-330-3p's relationships with XIST and PDE5A, which were further confirmed through luciferase reporter assays. Loss-of-function combined with Transwell, CCK-8, and caspase-3 activity experiments were performed to determine the mechanism of the XIST/miR-330-3p/PDE5A axis in regulating the malignancy of PTC cells. Xenograft tumor experiment was employed to study the influence of XIST on tumor development in vivo. The PTC cell lines and tissues manifested considerably high levels of lncRNA XIST expression. The XIST knockdown inhibited proliferation, blocked migration, and strengthened apoptosis among PTC cells. Moreover, its knockdown suppressed PTC tumor development in vivo. XIST repressed miR-330-3p to stimulate the malignant behaviors of PTC. Through the downregulation of PDE5A, miR-330-3p attenuated the capability of PTC cells to grow, migrate, and survive. lncRNA XIST promotes tumor development in PTC through the regulation of the miR-330-3p/PDE5A axis. The findings from this study provide new insights into the treatment of PTC.

β-catenin attenuation leads to up-regulation of activating NKG2D ligands and tumor regression in BrafV600E-driven thyroid cancer cells.

BRAFV600E mutations frequently occur in papillary thyroid cancer (PTC). β-catenin, encoded by CTNNB1, is a key downstream component of the canonical Wnt signaling pathway and is often overexpressed in PTC. BRAFV600E-driven PTC tumors rely on Wnt/β-catenin signaling to sustain growth and progression. In the present study, we investigated the tumorigenicity of thyroid cancer cells derived from BRAFV600E PTC mice following Ctnnb1 ablation (BVE-Ctnnb1null). Remarkably, the tumorigenic potential of BVE-Ctnnb1null tumor cells was lost in nude mice. Global gene expression analysis of BVE-Ctnnb1null tumor cells showed up-regulation of NKG2D receptor activating ligands (H60a, H60b, H60c, Raet1a, Raet1b, Raet1c, Raet1d, Raet1e, and Ulbp1) and down-regulation of inhibitory MHC class I molecules H-2L and H-2K2 in BVE-Ctnnb1null tumor cells. In vitro cytotoxicity assay demonstrated that BVE-Ctnnb1wt tumor cells were resistant to NK cell-mediated cytotoxicity, whereas BVE-Ctnnb1null tumor cells were sensitive to NK cell-mediated killing. Furthermore, the overexpression of any one of these NKG2D ligands in the BVE-Ctnnb1wt cell line resulted in a significant reduction of tumor growth in nude mice. Our results indicate that active β-catenin signaling inhibits NK cell-mediated immune responses against thyroid cancer cells. Targeting the β-catenin signaling pathway may have significant therapeutic benefits for BRAF-mutant thyroid cancer by not only inhibiting tumor growth but also enhancing host immune surveillance.

Immune profiling identifies CD8+ T-cell subset signatures as prognostic markers for recurrence in papillary thyroid cancer.

Thyroid tissue has a special immune microenvironment that is not well characterized. Whether immune cells have a prognostic value in the recurrence of papillary thyroid cancer (PTC) needs further investigation. Multinodular non-toxic goiter (MNG) was taken as normal tissue for the difficulty in obtaining completely normal thyroid tissue (normal thyroid function, no thyroiditis, and no nodules). We compared the composition of mononuclear cells (MNCs) in peripheral blood and thyroid tissues from MNG and PTC patients by high-dimensional flow cytometry profiling and verified the results by multiplex immunohistochemistry. The recurrence rates of PTC patients with different CD8+T cell subset signatures were compared using TCGA database. We observed that the immune cell composition of MNG was different from that in peripheral blood. Thyroid tissue contains higher percentages of T cells and NK cells. Moreover, the percentages of memory T cells and Treg cells were higher in thyroid than in peripheral blood and increased in PTC tumors. We further focused on the antitumoral CD8+T cells and found that the expression patterns of PD-1, CD39, and CD103 on CD8+T cells were different between MNG and PTC. Importantly, we found higher percentages of PD-1+CD39+CD103+CD8+T and PD-1+CD39+CD103-CD8+T cells in PTC tumor tissues from recurrent patients than non-recurrent patients. By analyzing PTC data from TCGA database, we found that the expression patterns of these molecules were associated with different pathologic types and genders among PTC patients. Moreover, patients with PD-1hiCD39loCD103hiCD8hi, PD-1hiCD39hiCD103loCD8hi, and PD-1loCD39hiCD103hiCD8hi expression patterns have a higher 10-year recurrence-free survival. The immune microenvironment in MNG tissue is distinct from that in peripheral blood and paratumor tissue. More memory CD8+T cells were detected in PTC, and expression patterns of PD-1, CD39, and CD103 on CD8+T cells were significantly different in physiology and gender and associated with the recurrence rate of PTC. These observations indicate that CD8+T cell signatures may be useful prognostic markers for PTC recurrence.

High RPMB predicts poor disease-free survival of male N1 papillary thyroid cancer after adjuvant radioiodine therapy

The current recommendation for the use of adjuvant radioactive iodine (RAI) therapy in papillary thyroid cancer (PTC) after radical surgery is based on clinicopathological factors; however, this recommendation remains controversial. Our present study established a new biomarker, RPMB (promotor methylation burden of DNA repair genes (DRGs)), to identify a patient subgroup suitable for adjuvant RAI therapy. We defined RPMB as the ratio of methylated DRGs to the total number of DRGs. Methylation profiles of 498 PTC tumors and their clinical data were retrieved from the Cancer Genome Atlas (TCGA) database. DRGs of PTC subjects were found to be much more hypomethylated than controls across the whole profile (all p < 0.001). PTC patients with higher RPMBs tended to be ≥45 years old and female, and these PTCs were commonly unifocal, with N0 disease, wild-type BRAF, and mutated RAS. The subgroup analysis indicated that high RPMBs were significantly associated with poor disease-free survival (DFS) in male patients with PTC (HR = 4.855, 95% CI: 1.527–15.433, p = 0.007). Moreover, Kaplan–Meier analysis showed that high RPMBs could significantly predict poor DFS in male patients after R0 resection for N1 disease (HR: 5.431, 95% CI: 1.045–28.219, p = 0.024), and the p-value was very close to significance in these patients after adjuvant RAI therapy (HR: 6.269, 95% CI: 0.693–56.714, p = 0.062). Multivariate analysis indicated that both male sex (HR = 14.565, 95%CI: 2.153–98.507, p = 0.006) and high RPMBs (HR = 11.206, 95%CI: 1.622–77.405, p = 0.014) were independent unfavorable factors for DFS after adjuvant RAI therapy. Therefore, RPMB might be a potential predictor for identifying suitable male patients with PTC who can benefit from adjuvant RAI therapy.

Active Surveillance of Papillary Thyroid Cancer: Frequency and Time Course of the Six Most Common Tumor Volume Kinetic Patterns.

Background: The change in size of the papillary thyroid cancer (PTC) nodule during active surveillance has traditionally been characterized as either stable, increasing, or decreasing based on changes in maximal tumor diameter or tumor volume. More recently, it has been observed that the changes in tumor size observed during observation are more complex with tumor volume kinetic patterns that can be characterized either as stable (Pattern I), early increase in volume (Pattern II), later increase in volume (Pattern III), early increase in volume followed by stability (Pattern IV), stability followed by an increase in volume (Pattern V), or a decrease in tumor volume (Pattern VI). Methods: The frequency, time course, and clinical correlates of these six tumor volume kinetic patterns were analyzed in a cohort of 483 patients with low-risk PTC up to 1.5 cm in maximal diameter followed with active surveillance at our center for a median of 3.7 years. Results: The cumulative incidence of an increase in tumor volume for the entire cohort was 15.9% [confidence interval (CI) 11.8-20.0] at 5 years. At 5 years, most tumors demonstrated stability (78.8%, Pattern I) with 10.0% showing early growth (Pattern II), 4.1% late growth (Pattern III), 1.9% growth then stability (Pattern IV), 0.6% stability then growth (Pattern V), and 5.6% with a decrease in tumor volume (Pattern VI). Tumor volume doubling time during exponential growth significantly differed across the kinetic patterns, with median values of 2.4, 7.1, and 3.3 years for Patterns II, III, and IV, respectively (p < 0.01). Similarly, the time to a change in tumor volume was significantly different across the kinetic patterns, with median values of 1.5, 3, 1.6, 4.7, and 4.1 years for Patterns II, III, IV, V, and VI, respectively (analysis of variance, p < 0.01). Clinical correlates at baseline were not associated with tumor volume kinetic pattern. Conclusions: These six kinetic tumor volume patterns provide a comprehensive description of the changes in PTC tumor volume observed during the first 5 years of active surveillance.