Human Papillary Thyroid Carcinoma Research Articles

Microarray-based differential expression profiling of long noncoding RNAs and messenger RNAs in formalin-fixed paraffin-embedded human papillary thyroid carcinoma samples.

BackgroundLong noncoding RNAs (lncRNAs) can regulate the expression of genes at almost every level. The altered expression of lncRNAs was observed in many kinds of cancers. Until recently, few studies have focused on the function of lncRNAs in the context of papillary thyroid carcinoma (PTC).MethodsIn the current study, we collected seven PTC and nodular goiter tissue samples and explored mRNA and lncRNA expression patterns in these samples by microarray.ResultsWe observed aberrant expression of 94 lncRNAs and 99 mRNAs in the seven PTC samples as compared to the nodular goiter tissue [fold change (FC) ≥2.0; P<0.01]. To confirm these microarray results, quantitative polymerase chain reaction (q-PCR) was performed to assess the expression of three randomly selected differentially expressed mRNAs and lncRNAs, confirming our microarray findings significantly. We then performed gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses to systematically characterize the twelve significantly differential genes. A co-expression analysis revealed that the lncRNAs n382996, n342483, and n409114 were closely related to the regulation of MT1G, MT1H, and MT1F.ConclusionsIn the present study a string of novel lncRNAs associated with PTC were identified. Further study of these lncRNAs should be performed to identify novel target molecules which may improve diagnosis and treatment of PTC.

Microarray-based differential expression profiling of long noncoding RNAs and messenger RNAs in formalin-fixed paraffin-embedded human papillary thyroid carcinoma samples

Background: Long noncoding RNAs (lncRNAs) can regulate the expression of genes at almost every level. The altered expression of lncRNAs was observed in many kinds of cancers. Until recently, few studies have focused on the function of lncRNAs in the context of papillary thyroid carcinoma (PTC). Methods: In the current study, we collected seven PTC and nodular goiter tissue samples and explored mRNA and lncRNA expression patterns in these samples by microarray. Results: We observed aberrant expression of 94 lncRNAs and 99 mRNAs in the seven PTC samples as compared to the nodular goiter tissue [fold change (FC) ≥2.0; P Conclusions: In the present study a string of novel lncRNAs associated with PTC were identified. Further study of these lncRNAs should be performed to identify novel target molecules which may improve diagnosis and treatment of PTC.

Increased Uptake of At-211 in Thyroid Gland by the Preparation with Ascorbic Acid for Targeted Alpha Therapy of Thyroid Cancer

Astatine-211 (211At) is an alpha-emitting radionuclide suitable for targeted alpha therapy. Because At is a heavier homolog of iodine, astatide ion (At-) is expected to be applied to the treatment of thyroid cancer. In this study, 211At was treated by ascorbic acid (AA) as reducing agent to prepare At-. We aimed to evaluate the uptake change in the thyroid after the preparation of 211At solutions with AA and demonstrate the treatment effect in the differentiated thyroid cancer xenograft mice. Astatine-211 was produced in the 209Bi(α, 2n) reaction and supplied through Shortlived RI Supply Platform. Produced 211At was then separated from the target materials by a dry distillation method and dissolved in pure water. The aliquot of 211At solution was mixed with 1% AA solution to prepare At-. The radiochemical yield was checked by radio-TLC. The crude 211At solution or 211At with AA solution was administered to normal rats (n=3 for both solution) through tail vein under isoflurane anesthesia. In vivo imaging of 211At in the normal rats was then carried out using a gamma camera at 0.5, 3, 6 and 24 hrs after administration. The 211At solution with AA was also administered to mice with implanted K1 cells (human papillary thyroid carcinoma) expressing sodium iodide symporter (NIS). Mice were divided into 4 groups according to the injected dose [1 MBq (n=6), 0.4 MBq (n=6), 0.1 MBq (n=6), control (n=6)]. Distribution of 211At administered in the mice was investigated at 3 and 24 hrs after administration by the gamma camera. The radiochemical yield of At- checked by radio-TLC increased from approximately 20% to 90% after treatment of the crude 211At solution with AA. In vivo imaging of 211At in the normal rats showed high uptakes in the thyroid, the stomach, and the bladder. Uptake of At with AA in thyroid gland was 2–3 times higher compared to crude 211At solution. In the xenograft mice, there was a stable accumulation in the thyroid tumor at 3 and 24 hrs post administration (23 ± 11 %ID and 13 ± 7 %ID, respectively). Tumor growth was immediately inhibited after administration of 211At in a dose-dependent manner. Suppression of tumor growth was maintained until 17, 31, and 41 days after administration of 211At in 0.1, 0.4, and 1 MBq groups, respectively. Uptake of 211At can be enhanced in the normal thyroid by increasing the radiochemical purity of At-. The administered 211At showed good treatment effect in thyroid cancer xenograft, suggesting that 211At solution with AA is promising for the targeted alpha therapy for the thyroid cancer.

Long noncoding RNA H19 is a critical oncogenic driver and contributes to epithelial-mesenchymal transition in papillary thyroid carcinoma.

BackgroundGrowing evidence has indicated that the long noncoding RNA H19 (lncRNA H19), frequently deregulated in almost all tumor types tested, acted as a pivotal contributor to both cancer initiation and progression. However, the role of lncRNA H19 in human papillary thyroid carcinoma (PTC) remains controversial. The aim of the study was to investigate the expression and potential function of lncRNA H19 in human PTC.Patients and methodsThe lncRNA H19 level was determined by quantitative real-time (RT)-PCR analyses in 58 PTC tissue samples and their paired paracancerous tissue samples. RNA interference, RT-PCR analysis, and Western blot assay were used to determine the impact of lncRNA H19 on epithelial-mesenchymal transition (EMT) markers in human PTC cells. The migratory and invasive capacities of PTC cells were determined by wound-healing and transwell migration and invasion assays.ResultslncRNA H19 expression was 2.417-fold higher in PTC tissues than their paired paracancerous tissue (95% CI: 1.898–2.935, P<0.0001). Higher level of lncRNA H19 was correlated to elevated expression of Vimentin, ZEB2, Twist, and Snail2. Inhibition of lncRNA H19 resulted in upregulation of E-cadherin and downregulation of Vimentin both at mRNA and protein levels. Conversely, enforced expression of the exogenous lncRNA H19 led to E-cadherin mRNA and protein downregulation and relative upregulation of Vimentin. Moreover, wound-healing and transwell migration and invasion assays showed that lncRNA H19 could promote the migratory and invasive abilities of PTC cells.ConclusionThe level of lncRNA H19 was significantly higher in PTC tissues than paired paracancerous tissue or normal tissues. Overexpression of lncRNA H19 was correlated with higher tumor burden of PTC. It also contributes to EMT process, as well as promotes migration and invasion of PTC cells.

Circular RNA circBACH2 plays a role in papillary thyroid carcinoma by sponging miR-139-5p and regulating LMO4 expression

Circular RNAs (circRNAs) are a class of non-coding RNAs that are broadly expressed in various biological cells and function in regulating gene expression. They are structurally stable and tissue-specific. However, the function of human circRNAs and the role of circRNAs in papillary thyroid carcinoma (PTC) remain to be determined. Herein, the function of circRNA circBACH2 was investigated in human PTC cells. First, we detected the expression of circBACH2 in PTC tissues and PTC cell lines by RT-PCR. FISH was used to confirm the subcellular localization of circBACH2. A luciferase reporter assay and AGO2-RIP was used to confirm the relationship between circBACH2 and miR-139-5p. PTC cells were stably transfected with siRNA against circBACH2 and cell proliferation, migration and invasion were detected to evaluate the effect of circBACH2 in PTC, while tumorigenesis was assayed in nude mice. We found that circBACH2 was highly expressed in PTC tissues and PTC cell lines. Mechanistically, we confirmed that circBACH2 could directly bind to miR-139-5p and relieve suppression of the target LMO4. Functionally, we found that inhibiting circBACH2 expression decreased cell proliferation, migration, and invasion. Finally, down-regulating circBACH2 suppressed the growth of PTC xenografts in nude mice. Our findings indicate that circBACH2 acts as a novel oncogenic RNA that sponges miR-139-5p and can be used as a tumor biomarker of PTC. What’s more, these results revealed that the circBACH2/miR-139-5p/LMO4 axis could be targeted as a potential treatment strategy for PTC.

Expression profile of long noncoding RNAs in human papillary thyroid carcinoma.

Long non-coding RNAs (lncRNAs) are strongly associated with cancer biology. The objective of this study is to investigate the expression profile of lncRNAs in human papillary thyroid carcinoma (PTC), and to understand the biological role of lncRNAs and their involvement in PTC oncogenesis. The lncRNAs and messenger RNAs (mRNAs) expression in human PTC and paired adjacent non-cancerous thyroid (NCT) tissues were studied by micro-array, and quantitative real-time polymerase chain reaction (qRT-PCR) validated five differentially expressed lncRNAs. We identified 2,925 significantly differentially expressed lncRNAs with potential roles in PTC, (absolute fold change >2.0; p<0.05). Of these, 1,922 were up-regulated and 933 down-regulated and the qRT-PCR results agreed with micro-array results. Gene ontology (GO) enrichment and pathway analysis then investigated gene function and identified significantly enriched pathways in differentially expressed mRNA's. Many of these pathways were related to cancer, including 60 genes associated with "pathways in cancer" and 34 linked to "proteoglycans in cancer". Co-expression network and target prediction analysis of lncRNAs revealed that TCONS_00020457 can have important roles in PTC. In conclusion, the results of this study indicate that lncRNAs can be important regulators in PTC tumorigenesis and provide understanding of the function and mechanism of lncRNAs related to human papillary thyroid carcinoma.

Role of Lin28A/let-7a/c-Myc Pathway in Growth and Malignant Behavior of Papillary Thyroid Carcinoma.

BackgroundLin28 is a gene involved in many biological processes, including development, glucose metabolism, and tumorigenesis. Let-7 miRNA is a tumor-suppressor gene that is frequently inactivated in cancer cells. The role of c-Myc (a target gene of let-7) and the Lin28-let-7-c-Myc pathway in the growth and malignancy of thyroid cancer is unclear. The purpose of the present study was to evaluate the expression of Lin28A, let-7a, and c-Myc in human papillary thyroid carcinoma (PTC) and to investigate their potential mechanisms in the progression of PTC.Material/MethodsLin28A and c-Myc expression were assessed in PTC tissues and PTC cell lines using immunohistochemistry, Western blotting, and real-time PCR. CCK-8 and Transwell assays were performed to evaluate PTC cell proliferation, migration, and invasion in cells in which the expression of Lin28A was downregulated by RNA interference or in which let-7a was overexpressed after transfection with let-7a mimics.ResultsThe expression of Lin28A and c-Myc was upregulated in PTC tissues and cell lines, whereas the expression of let-7a was downregulated in PTC cell lines. Clinically, Lin28A was linked to a higher tumor/node/metastasis stage and the presence of lymph node metastases. Moreover, knockdown of Lin28A activated let-7a processing and inhibited the expression of the downstream gene c-Myc, suppressing cell proliferation, migration, and invasion. Similar results were obtained after let-7a overexpression.ConclusionsThe Lin28A/let-7a/c-Myc pathway is involved in cancer growth and malignant behavior in PTC and is a potential target for therapeutic intervention in this disease.

Mechanism of microRNA-1243 on proliferation and migration of human papillary thyroid carcinoma TPC-1 cells

Objective To observe the biological effects of microRNA (miRNA, miR)-1243 overexpression on proliferation and migration of human papillary thyroid carcinoma cell line TPC-1. Methods The expression of miR-1243 in 2×105 TPC-1 cells was detected by real-time quantitative polymerase chain reaction (RT-qPCR). The capacities of migration and the migration in TPC-1 cells were tested by water soluble methacon compounds (MTS) or Transwell assays, respectively. The candidate targets for miR-1243 were investigated using predication algorithm provided by miRanda and RNAhybrid. Luciferase activity was measured by dual luciferase reporter assay. Results The expression levels of miR-1243 in blank control and negative control groups were 0.97±0.31 and 1.208±0.40 respectively, significantly lower than 932.84±52.34 in miR-1243 mimic transfected group (P=0.000). The relative survival rates of the blank control group and the negative control group were 4.82±0.10 and 4.91±0.09, respectively, which were significantly higher than that of 4.41±0.06 in miR-1243 mimic transfected group (P=0.032). The proliferation ability of TPC-1 cells transfected with miR-1243 was significantly inhibited. The number of migratory cells in the miR-1243 mimic group was 15.5±6.5, which was significantly less than that in the blank control group (33.5±9.5) and the negative control group (31.75±10.75) (P=0.016). The bioinformatics analysis revealed that the AKT serine/threonine kinase 1 (AKT1) mRNA may be the target of miR-1243. The results of dual luciferase assay showed that WT 3’ untranslated region (UTR) of AKT1 cotransfected with miR-1243 mimics significantly decreased luciferase activity (45.92±10.91) as compared with empty vector group (98.97±9.96), mutant group (85.02±11.04) and negative control mimic group (97.38±10.29) (P=0.005). Conclusion Overexpression of miR-1243 can inhibit the proliferation and migration of TPC-1 cells. The miR-1243 may be involved in the regulation of thyroid papillary carcinoma by direct targeting of AKT1. Key words: Thyroid papillary carcinoma; MicroRNA-124; Cell proliferation; Cell migration; AKT serine / threonine kinase 1

Has_circ_0008274 promotes cell proliferation and invasion involving AMPK/mTOR signaling pathway in papillary thyroid carcinoma.

Circular RNAs (circRNAs) have been known as important regulators in tumorigenesis. Whether circRNAs are involved in papillary thyroid carcinoma (PTC) requires to be determined. In the present study, we aimed to investigate the expression and function of has_circ_0008274 in PTC. Tissue expression of has_circ_0008274 was evaluated in Gene Expression Omnibus datasets (GSE93522). Real-time PCR assays were used to detect the expression of has_circ_0008274 in human PTC tissues and cell lines. The correlation of has_circ_0008274 expression with clinicopathological factors was statistically analyzed. The MTT assay, colony formation assay, transwell assays were performed to analyze and compare cell viability and invasion. Western blot analysis was used to quantify the expression of AMPK/mTOR signaling pathway proteins. We found that has_circ_0008274 was significantly upregulated in PTC tissues, and the level of has_circ_0008274 was negatively associated with TNM stage and lymph node metastasis. Loss-of-function assay indicated that knockdown of has_circ_0008274 suppressed PTC cells proliferation and invasion in vitro. Mechanistically, has_circ_0008274 could inhibit the activation of AMPK/mTOR signaling pathway, which was demonstrated by measuring the expression levels of p-AMPK and p-mTOR. These results demonstrate that increased has_circ_0008274 expression modulates has_circ_0008274 to enhance PTC cells proliferation and invasion. Has_circ_0008274/ AMPK/mTOR axis may be a novel therapeutic candidate target in PTC treatment.

Long noncoding RNA LINC00460 promotes carcinogenesis via sponging miR-613 in papillary thyroid carcinoma.

Long intergenic noncoding RNA 460 (LINC00460) has been identified as a critical regulator for multiple types of cancers. However, the biological role and underlying mechanism in human papillary thyroid carcinoma (PTC) still remain unclear and need to be uncovered. This study was aimed to ascertain the biological role and molecular mechanism of LINC00460 in PTC progression. Our findings revealed that the level of LINC00460 was significantly upregulated in PTC tissues and cell lines, which was positively correlated with advanced tumor-node-metastasis (TNM) stage and lymph node metastasis. Cellular experiments exhibited that knockdown of LINC00460 decreased proliferative, migratory, and invasive abilities of PTC cells. Mechanism assays noted that knockdown of LINC00460 suppressed cell proliferation, migration, and invasion, and inhibited expression of sphingosine kinase 2 (SphK2, a target of miR-613) in PTC cells, at least in part, by regulating miR-613. These findings suggested that LINC00460 could function as a competing endogenous RNA to regulate SphK2 expression by sponging miR-613 in PTC. Targeting LINC00460 could be a promising therapeutic strategy for patients with PTC.

Increased Expression of GARP in Papillary Thyroid Carcinoma.

Regulatory T cells (Tregs) are immunosuppressive immune cells that play an important role in tumor development. Suppression of Treg function is considered to be an effective strategy for cancer therapy. Glycoprotein A repetitions predominant (GARP) has been found on the surface of activated Tregs. GARP has been recently observed in only a few solid tumors including breast, colon, lung cancers, and melanoma. However, its function in cancers remains unknown. Here, we investigated the expression of GARP in human papillary thyroid carcinoma (PTC) and its prognostic significance. In this study, immunohistochemistry was performed to examine the expression of GARP and Foxp3 in 19 human PTC tissues (including 10 cases with and 9 cases without lymph node metastasis) and 20 benign thyroid diseases (including 10 cases with nodular goiter and 10 cases with adenoma). Compared with benign thyroid diseases, we found a significant increase in the expression of GARP in PTC. Increased GARP expression in PTC was positively correlated with increased expression of Foxp3, which is very important for development of Tregs. But, there is no significant association of elevated expression of GARP with lymph node metastasis in PTC. Our results indicate that GARP is implicated in the development of PTC and might be a potential novel target for anticancer therapy. In addition, our findings further support the existence of a positive-feedback loop between GARP and Foxp3.

Overexpression of SET and MYND Domain-Containing Protein 2 (SMYD2) Is Associated with Tumor Progression and Poor Prognosis in Patients with Papillary Thyroid Carcinoma.

BackgroundsSET and MYND domain-containing protein 2 (SMYD2), which is identified as a protein-lysine methyltransferase, plays a crucial role in the progression of some tumors such as bladder carcinoma. However, the clinical significance of SMYD2 in patients with papillary thyroid carcinoma (PTC) has not been elucidated. In the present study, we aimed to investigate the expression and role of SMYD2 in human PTC.Material/MethodsClinicopathological analysis was performed in 107 patients with PTC. Expression of SMYD2 was determined by immunohistochemistry staining, quantitative RT-PCR, or Western blotting in PTC tissues, adjacent normal tissues, and PTC cells (K1 and B-CPAP). The prognostic value of SMYD2 in PTC patients was assessed by univariate and multivariate analysis. Clinical outcomes were evaluated by Kaplan-Meier log-rank tests. Cell proliferation was examined in PTC cells following overexpression or knockdown of SMYD2.ResultsSMYD2 was highly expressed in PTC tissues compared to adjacent thyroid tissues. Additionally, high expression of SMYD2 was significantly related to tumor size, lymph node metastasis, and TNM stage. Moreover, SMYD2 was identified as an independent prognosis factor by multivariate analysis. Using 2 PTC cell lines, K1 and B-CPAP, we demonstrated that high expression of SMYD2 can promote tumor cell proliferation.ConclusionsSMYD2 expression was upregulated in PTC tissues and significantly related to the poorer prognosis of PTC patients. Our studies suggested the potential role of SMYD2 as a new therapeutic target and prognostic biomarker in human PTC.

FKBP51 promotes migration and invasion of papillary thyroid carcinoma through NF-κB-dependent epithelial-to-mesenchymal transition.

FK506-binding protein 51 (FKBP51) is a member of the immunophilin family, with relevant roles in multiple signaling pathways, tumorigenesis and chemoresistance. However, the function of FKBP51 in papillary thyroid carcinoma (PTC) remains largely unknown. In the present study, increased FKBP51 expression was detected in PTC tissues as compared with adjacent normal tissues, and the expression level was associated with clinical tumor, node and metastasis stage. Using FKBP51-overexpressing K1 cells and FKBP51-knockdown TPC-1 cells, both human PTC cell lines, it was identified that FKBP51 promoted the migration and invasion of PTC, without affecting cell proliferation. Further investigation revealed that FKBP51 activated the NF-κB pathway and epithelial-to-mesenchymal transition (EMT) genes, and EMT was suppressed when NF-κB was inhibited. It was also assessed whether FKBP51 promoted the formation of cytoskeleton to promote migration and invasion of PTC using a tubulin tracker; however, no evidence of such an effect was observed. These results suggested that FKBP51 promotes migration and invasion through NF-κB-dependent EMT.

LncRNA SNHG15 acts as a ceRNA to regulate YAP1-Hippo signaling pathway by sponging miR-200a-3p in papillary thyroid carcinoma

Over the past decade, lncRNAs have been widely reported in human malignant tumors, including papillary thyroid carcinoma. LncRNA SNHG15 has been validated to be a tumor facilitator in several types of malignancies. The present study focused on the biological role of SNHG15 in papillary thyroid carcinoma. Based on the result of qPCR analysis, we identified the strong expression of SNHG15 in human papillary thyroid carcinoma tissues and cell lines. Moreover, Kaplan–Meier method was utilized to analyze the internal relevance between SNHG15 expression and overall survival rate of patients with papillary thyroid carcinoma. Loss-of-function assays were designed and conducted to determine the inhibitory effects of silenced SNHG15 on the cell growth and migration in papillary thyroid carcinoma. The mechanical investigation indicated that SNHG15 upregulated YAP1 by sponging miR-200a-3p. Moreover, results of gain-of-function assays validated the anti-oncogenic function of miR-200a-3p in papillary thyroid carcinoma. Finally, results of rescue assays validated the function of SNHG15-miR-200a-3p-YAP1 axis in papillary thyroid carcinoma. YAP1 is known as an oncogene and a core factor of Hippo pathway. Here, we demonstrated that SNHG15 inactivated Hippo signaling pathway in papillary thyroid carcinoma. In summary, our findings demonstrated that SNHG15 serves as a competitively endogenous RNA (ceRNA) to regulate YAP1-Hippo signaling pathway by sponging miR-200a-3p in papillary thyroid carcinoma.

Activity of ecto-5'-nucleotidase (NT5E/CD73) is increased in papillary thyroid carcinoma and its expression is associated with metastatic lymph nodes.

The incidence of papillary thyroid carcinoma (PTC) has been increasing, which raised the interest in its molecular pathways. Although the high expression of ecto-5'-nucleotidase (NT5E) gene expression and NT5E enzymatic activity in several types of cancer is associated with tumor progression, its role in PTC remains unknown. Here, we investigated the AMP hydrolysis in human normal thyroid cells and PTC cells, in primary culture, and the association of NT5E expression with clinical aspects of PTC patients. AMPase activity was higher in thyroid cells isolated from PTC, as compared to normal thyroid (P = 0.0063). Significant correlation was observed between AMPase activity and NT5E levels in primary thyroid cell cultures (r = 0.655, P = 0.029). NT5E expression was higher in PTC than in the adjacent non-malignant thyroid tissue (P = 0.0065) and were positively associated with metastatic lymph nodes (P = 0.0007), risk of recurrence (P = 0.0033), tumor size (P = 0.049), and nodular hyperplasia in the adjacent thyroid parenchyma, when compared to normal thyroid or lymphocytic thyroiditis (P = 0.0146). After adjusting for potential confounders, the malignant/non-malignant paired expression ratio of NT5E mRNA was independently associated with metastatic lymph nodes (P = 0.0005), and tumor size (P=0.0005). In addition, the analysis of PTC described in the TCGA database also showed an association between higher expression of NT5E and metastatic lymph nodes, and tumor microinvasion. These results support the hypothesis that NT5E have a role in PTC microenvironment and might be a potential target for PTC therapy.

Profile and clinical implication of circular RNAs in human papillary thyroid carcinoma.

BackgroundDifferently expressed circular RNAs (circRNAs) have been reported to play a considerable role in tumor behavior; however, the expression profile and biological function of circRNAs in papillary thyroid carcinoma (PTC) remains unknown. Thus, the study was aimed to characterize the circRNA expression profile to comprehensively understand the biological behavior of PTC.MethodsWe investigated the expression profile of circRNAs using circRNA microarray in three pairs of PTC and adjacent normal tissues. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to validate eight candidate circRNAs in 40 paired PTC tumors and adjacent normal samples. Next, we employed a bioinformatics tool to identify putative miRNA and circRNA-associated downstream genes, followed by constructing a network map of circRNA-miRNA-mRNA interactions and exploring the potential role of the candidate circRNAs.ResultsIn total, 206 up- and 177 downregulated circRNAs were identified in PTC tissues (fold change >1.5; P < 0.05). The expression levels of eight candidate circRNAs confirmed by qRT-PCR were significantly different between the PTC and normal samples. The downstream genes of candidate circRNAs participated in various biological processes and signaling pathways. The most up and downregulated circRNAs were hsa_circRNA_007148 and hsa_circRNA_047771. The lower expression level of hsa_circRNA_047771 was associated BRAFV600 mutation, lymph node metastasis (LNM), as well as with advanced TNM stage (all P < 0.05). The higher expression level of hsa_circRNA_007148 was significantly correlated with LNM (P < 0.05). The areas under receiver operating curve were 0.876 (95% CI [0.78–0.94]) for hsa_circRNA_047771 and 0.846 (95% CI [0.75–0.96]) for hsa_circRNA_007148.DiscussionThe study suggests that dysregulated circRNAs play a critical role in PTC pathogenesis. PTC-related hsa_circRNA_047771 and hsa_circRNA_007148 may serve as potential diagnostic biomarkers and prognostic predictors for PTC patients.

AP-2α expression in papillary thyroid carcinoma predicts tumor progression and poor prognosis.

BackgroundThe activator protein (AP)-2α is involved in a wide variety of biologic processes in tumor. However, little is known about the role of AP-2α in human papillary thyroid carcinoma (PTC).MethodsThe immunohistochemical method was used to detect AP-2α expression in 63 PTC cases. Western blotting was carried out to assess the change in expression of certain proteins. The bioinformatics analysis of 496 PTC samples comes from The Cancer Genome Atlas (TCGA). The Gene Set Enrichment Analysis (GSEA) was performed using TCGA data set. Cell transfection was used to induce related protein expression or to repress it by RNA interference procedures.ResultsOur results demonstrated that AP-2α expression was higher in tumor tissues than the corresponding adjacent nontumor tissues, the positive substances of AP-2α were observed mainly in the cytoplasm of PTC, and AP-2α was positively correlated with histologic type (P=0.026) of PTC patients. The high expression of AP-2α mRNA was associated significantly with tumor stages (P=0.011), histologic type (P=0.019), and independently predicted shorter overall survival (P=0.005) based on TCGA analysis. Patients with high AP-2α mRNA expression have shorter overall survival compared to those with low AP-2α mRNA expression, particularly in advanced tumor stages (III and IV) of PTC patients (P=0.011). Multivariate analysis suggested that AP-2α mRNA expression might be an independent prognostic indicator for the survival of patients with PTC (P=0.037). Moreover, the association between enhanced AP-2α expression and two pathways (notch signaling and focal adhesion) was revealed by GSEA, and then confirmed by cellular experiments.ConclusionTaken together, our findings suggest that AP-2α may be a potential prognostic molecular marker and therapeutic target for PTC patients.

MicroRNA-409-3p suppresses cell proliferation and cell cycle progression by targeting cyclin D2 in papillary thyroid carcinoma.

MicroRNAs (miRs) function as tumor suppressors or oncogenes in tumor development and progression. The present study reported that miR-409-3p was significantly downregulated in human papillary thyroid carcinoma (PTC) tissues and cell lines. Overexpression of miR-409-3p suppressed cell proliferation and induced cell cycle G0/G1 phase arrest in PTC cells. Further study revealed that the transcriptional regulator cyclin D2 was a target of miR-409-3p, as miR-409-3p bound directly to its 3'-untranslated region and the miR-409-3p mimic reduced the protein expression levels of cyclin D2. In addition, restoration of cyclin D2 expression reversed the inhibitive effect of miR-409-3p on PTC cells. To the best of our knowledge, these findings demonstrate for the first time that miR-409-3p functions as a tumor suppressor in PTC and could serve as an efficient agent for therapy of PTC.

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.

Preliminary screening and analysis of metastasis-related lncRNA and co-expressed papillary thyroid carcinoma mRNA.

The objective of the present study was to investigate the long non-coding RNA (lncRNA) and mRNA expression profiles that are associated with the invasion and metastasis of papillary thyroid carcinoma (PTC). Transwell invasion assays were used to screen three highly invasive sub-strains of the human PTC IHH4 cell line: IHH4-M1, IHH4-M2 and IHH4-M3. In addition, tumor-bearing nude mice were used to identify the invasive and metastatic capacity of the three sub-strains. Agilent lncRNA microarray chips were used to screen 795 differentially expressed lncRNAs and 788 differentially expressed mRNAs. A total of 10 lncRNAs and 10 mRNAs were randomly selected for RT-qPCR validation to confirm that the results were consistent with the microarray chips, suggesting that the results of the microarray chip analysis were relatively accurate. Gene ontology enrichment-based cluster analysis revealed that the differentially expressed genes were mainly associated with steroid biosynthesis, bioadhesion, intercellular adhesion and other metastasis-associated biological processes. The results of the pathway cluster analysis identified that the differentially expressed genes were associated with tumor metastasis-associated signaling pathways, including the cholesterol metabolic signaling pathway, the sterol regulatory element-binding protein signaling pathway and the integrin signaling pathway, suggesting that lncRNA may regulate PTC metastasis through various signaling pathways. The present study screened and constructed PTC metastasis-associated lncRNA and mRNA expression profiles, and it provides a molecular basis for the future study of high-risk molecular markers of PTC.