Development Of Papillary Thyroid Carcinoma Research Articles

Study on extracellular matrix metalloproteinase inducer and human epidermal growth factor receptor-2 protein expression in papillary thyroid carcinoma using a quantum dot-based immunofluorescence technique.

The aim of the present study was to investigate the association of extracellular matrix metalloproteinase inducer (EMMPRIN) and human epidermal growth factor receptor (HER)-2 protein expression in papillary thyroid carcinoma with lymph node metastasis (LNM), as well as the correlation between the two types of protein expression. A quantum dot-based immunofluorescence technique was used to detect EMMPRIN and HER-2 protein expression in 75 papillary thyroid carcinoma cases (including 70 cases of papillary thyroid carcinoma tissues and 5 cases of peri-tumor tissues). The positive rate and expression of EMMPRIN and HER-2 were compared and observed. The positive rate of EMMPRIN was 75.71% in papillary thyroid carcinoma tissues and 20.00% in peri-tumor tissues (P<0.05). The positive rate of HER-2 was 45.71% in papillary thyroid carcinoma tissues and 0% in peri-tumor tissues (P>0.05). The expression of EMMPRIN and HER-2 in papillary thyroid carcinoma was significantly associated with LNM (P<0.05). In addition, in the 70 papillary thyroid carcinoma tissues, the expression of EMMPRIN and HER-2 was positively and significantly correlated. In conclusion, this study demonstrates that the co-evolution of EMMPRIN and HER-2 may promote the occurrence and development of papillary thyroid carcinoma and LNM.

Microarray technology to investigate genes associated with papillary thyroid carcinoma.

DNA microarray data on thyroid tissue from patients with papillary thyroid carcinoma (PTC) and from healthy controls were compared in order to investigate the regulatory genes and uncover the underlying regulatory network in PTC. The DNA microarray data set, GSE3678, was downloaded from Gene Expression Omnibus database. This included seven thyroid tissue samples from patients with PTC and seven samples from healthy controls. Raw data were processed and differentially expressed genes (DEGs) were identified using corresponding R packages. Gene regulation analysis was conducted using TRANSFAC® and TRED. A total of 171 DEGs were obtained. A regulatory network was then established, using 104 of the DEGs. Subsequently, pathway enrichment analyses of the genes were conducted using Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool. Three differentially expressed transcription factors were identified: Trefoil factor 3, cut‑like homeobox 2 and forkhead box protein A2. The most significant pathways involving the 104 DEGs were pathways involved in cancer. Biological process analysis using DAVID, suggested that these genes were associated with the positive regulation of gene expression, gene transcription and metabolic processes. The present study identified a range of genes associated with the development of PTC. The results of the present study were beneficial for understanding the regulatory mechanisms involved in PTC, and for developing clinical diagnostic and therapeutic approaches for this disease.

Genomic evidence of reactive oxygen species elevation in papillary thyroid carcinoma with Hashimoto thyroiditis.

Elevated levels of reactive oxygen species (ROS) have been proposed as a risk factor for the development of papillary thyroid carcinoma (PTC) in patients with Hashimoto thyroiditis (HT). However, it has yet to be proven that the total levels of ROS are sufficiently increased to contribute to carcinogenesis. We hypothesized that if the ROS levels were increased in HT, ROS-related genes would also be differently expressed in PTC with HT. To find differentially expressed genes (DEGs) we analyzed data from the Cancer Genomic Atlas, gene expression data from RNA sequencing: 33 from normal thyroid tissue, 232 from PTC without HT, and 60 from PTC with HT. We prepared 402 ROS-related genes from three gene sets by genomic database searching. We also analyzed a public microarray data to validate our results. Thirty-three ROS related genes were up-regulated in PTC with HT, whereas there were only nine genes in PTC without HT (Chi-square p-value < 0.001). Mean log2 fold changes of up-regulated genes was 0.562 in HT group and 0.252 in PTC without HT group (t-test p-value = 0.001). In microarray data analysis, 12 of 32 ROS-related genes showed the same differential expression pattern with statistical significance. In gene ontology analysis, up-regulated ROS-related genes were related with ROS metabolism and apoptosis. Immune function-related and carcinogenesis-related gene sets were enriched only in HT group in Gene Set Enrichment Analysis. Our results suggested that ROS levels may be increased in PTC with HT. Increased levels of ROS may contribute to PTC development in patients with HT.

MiR-219-5p modulates cell growth of papillary thyroid carcinoma by targeting estrogen receptor α.

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy. It has been demonstrated that micro-RNAs (miRNAs) are involved in the development of PTC. The miRNA-chromatin immunoprecipitation microarray assay revealed down-regulation of miR-219-5p; however, the effect of miR-219-5p on PTC cell growth remains unknown. This result implied the critical role of miR-219-5p in the development of PTC. We investigated the association between miR-219-5p and PTC development. Expression of miR-219-5p was monitored in 30 PTC tissue specimens and compared with that in 30 normal thyroid tissue specimens. The effect of miR-219-5p on PTC development was studied by cell proliferation, migration, and apoptosis assays. The underlying mechanism was clarified by a reporter assay and rescue experiment. The current study confirmed that miR-219-5p expression was inhibited in PTC tissue samples. There were statistically significant differences in the expression of miR-219-5p with regard to sex, tumor size, and lymph node metastasis in patients with PTC. Forced expression of miR-219-5p suppressed PTC cell proliferation and migration and promoted apoptosis. Further study showed that estrogen receptor (ER) α was the direct target of miR-219-5p and mediated the effect of miR-219-5p on PTC occurrence. Expression of miR-219-5p was inversely correlated with that of ERα. Importantly, ERα overexpression in PTC cells rescued the inhibitory effect of miR-219-5p on PTC cell proliferation and migration. Thus, our results indicated that miR-219-5p played a critical role in PTC growth by inhibiting ERα. Our investigation identified miR-219-5p as a negative regulator of PTC development through targeting of ERα.

BRAF-activated long non-coding RNA contributes to cell proliferation and activates autophagy in papillary thyroid carcinoma.

Long non-coding RNAs (lncRNAs) are novel regulators in cancer biology. BRAF-activated lncRNA (BANCR) is overexpressed in melanoma and has a potential functional role in melanoma cell migration. However, little is known about the role of BANCR in the development of papillary thyroid carcinoma (PTC). In the present study, BANCR expression was examined in six pairs of PTC and matched adjacent normal tissues. The results revealed that BANCR levels were significantly higher in the PTC tissues and PTC IHH-4 cells compared with the normal controls. Knockdown of BANCR in the IHH-4 cells inhibited proliferation and increased apoptosis of the cells in vitro. Further investigation of the underlying mechanisms revealed that BANCR markedly activated autophagy. Overexpression of BANCR inhibited apoptosis in the IHH-4 cells, whereas inhibition of autophagy stimulated apoptosis in the BANCR-overexpressed cells. BANCR overexpression also increased cell proliferation and the inhibition of autophagy abrogated BANCR overexpression-induced cell proliferation. In addition, the overexpression of BANCR resulted in an increase in the ratio of LC3-II/LC3-I, a marker for autophagy, while the knockdown of BANCR decreased the ratio of LC3-II/LC3-I. These results revealed that BANCR expression levels are upregulated in PTC. Additionally, BANCR increases PTC cell proliferation, which could activate autophagy.

High-sensitivity BRAF mutation analysis: BRAF V600E is acquired early during tumor development but is heterogeneously distributed in a subset of papillary thyroid carcinomas.

The homogeneous distribution of BRAF V600E in papillary thyroid carcinoma (PTC) has been called into question by recent reports. These studies claim that BRAF V600E is heterogeneous and is limited to tumor cell subsets in the majority of PTCs. The objective of the study was to understand the allele distribution of BRAF V600E by evaluating the percentage of mutated neoplastic cells in a group of PTCs using two different highly sensitive analytical approaches: allele-specific locked nucleic acid PCR and 454 next-generation sequencing targeted to BRAF exon 15. BRAF V600E was investigated using allele-specific locked nucleic acid PCR on 155 consecutive samples of PTC. Mutated cases were reanalyzed by 454 next-generation sequencing and immunohistochemistry. Because the evaluation of genetic heterogeneity in tumor samples can be profoundly biased by contamination with normal cells, all mutation frequency data were normalized to the real amount of neoplastic cells within each tumor. Eighty-five of 155 PTCs (54.8%) were BRAF V600E mutated. The distribution of mutated neoplastic cells within the tumor was as follows: greater than 80% in 37 of 85 (43.5%), 30-80% in 39 of 85 (45.9%), and less than 30% in 9 of 85 (10.6%). In most of the PTCs with less than 80% BRAF V600E-positive neoplastic cells, the mutation was present in large neoplastic cell subpopulations. Tumors with less than 30% mutated neoplastic cells were smaller than tumors with a percentage of mutated cells greater than 80% or between 30% and 80% (P < .05). BRAF V600E is heterogeneously distributed in some PTCs. The large BRAF V600E neoplastic cell subpopulations found in mutated cases is consistent with the view that the BRAF V600E is acquired early during PTC development.

Relationships of FOXE1 and ATM genetic polymorphisms with papillary thyroid carcinoma risk: a meta-analysis.

We conducted the meta-analysis of all relevant case-control studies aiming to evaluate the relationships of common polymorphisms in forkhead box E1 (FOXE1) and ataxia telangiectasia mutated (ATM) genes to the risk of papillary thyroid carcinoma (PTC). A range of electronic databases were searched without language restrictions: Web of Science (1945 ~ 2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966 ~ 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), and the Chinese Biomedical Database (CBM) (1982 ~ 2013). This meta-analysis was conducted using the STATA 12.0 software. Crude odds ratio (OR) with their 95 % confidence interval (CI) were calculated. Eight case-control studies with 2,085 PTC patients and 10,341 healthy controls were included. Fourteen common polymorphisms were evaluated, including rs3758249 A > G, rs907577 G > A, rs1867277 G > A, rs3021526 C > T, rs1443434 G > T, rs907580 G > A, rs965513 A > G, rs944289 C > T, and rs189037 G > A polymorphisms in the FOXE1 gene and rs373759 G > A, rs4988099 A > G, rs1801516 G > A, rs664677 T > C, and rs609429 G > C polymorphisms in the ATM gene. Our results demonstrated that the FOXE genetic polymorphisms might be closely related to an increased risk of developing PTC under five genetic models (all P < 0.005), especially for rs3758249, rs907577, rs1867277, rs3021526, rs1443434, rs907580, rs704839, rs894673, and rs10119760 polymorphisms. Nevertheless, no positive associations were found between the ATM genetic polymorphisms and the development of PTC (all P > 0.05). The current meta-analysis provided evidence that FOXE1 genetic polymorphisms may contribute to increased PTC risk, especially for rs3758249, rs907577, rs1867277, rs3021526, rs1443434, rs907580, rs704839, rs894673, and rs10119760 polymorphisms. However, the ATM genetic polymorphisms may not be important dominants of susceptibility to PTC.

The role of microRNAs in regulation of RAR[beta] and its function in development of papillary thyroid carcinoma

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Comparison of metabolic ratios of urinary estrogens between benign and malignant thyroid tumors in postmenopausal women

BackgroundEstrogen metabolism may be associated with the pathophysiological development of papillary thyroid carcinoma (PTC).MethodsTo evaluate the differential estrogen metabolism between benign and malignant PTCs, estrogen profiling by gas chromatography–mass spectrometry was applied to urine samples from postmenopausal patients with 9 benign tumors and 18 malignant stage I and III/IV PTCs.ResultsThe urinary concentration of 2-methoxyestradiol was significantly lower in the stage I malignant patients (3.5-fold; P < 0.025) than in the benign group. The metabolic ratios of 16α-OH-estrone/estrone and estriol/estradiol, which are responsible for 16α-hydroxylase activity, were increased more than 2.5-fold in the advanced-stage malignant PTC (P < 0.02 each). The more than 6.2-fold decrease in the urinary 2-/16α-hydroxylase ratio in stage III/IV malignant PTC was consistent with the ratio in postmenopausal patients with endocrine gland cancers. In addition, reductive 17β-hydroxysteroid dehydrogenase (17β-HSD; estradiol/estrone or estriol/16α-OH-estrone) was present at significantly higher levels in subjects with stage III/IV malignant PTCs than in benign subjects (>3.5-fold difference; P < 0.002). In particular, the estriol/16α-OH-estrone ratio differentiated between the benign and early-stage malignant patients (P < 0.01).ConclusionsIncreased 16α-hydroxylation and/or a decreased 2-/16α-ratio, as well increased reductive 17β-HSD, with regard to estrogen metabolism could provide potential biomarkers. The devised profiles could be useful for differentiating malignant thyroid carcinomas from benign adenomas in postmenopausal women.

Expression of the NOB1 gene and its clinical significance in papillary thyroid carcinoma

The aim of this study was to explore the relationships between expression of the NIN1/RPN12 binding protein 1 homologue gene (NOB1) in papillary thyroid carcinoma tissue and clinicopathological variables. Expression of NOB1 in papillary thyroid carcinoma, normal thyroid and benign thyroid tumour tissue was evaluated at the mRNA and protein levels by real-time fluorescence quantitative reverse transcription-polymerase chain reaction and immunohistochemistry, respectively. Relationships between immunohistochemical scores and several clinicopathological variables were also examined. Expression of NOB1 mRNA and protein in papillary thyroid carcinomatissue was significantly higher than in normal thyroid tissue and benign thyroid tissue, while there was no significant difference between normal thyroid tissue and benign thyroid tumour tissue. A high level of NOB1 protein expression was associated with large tumour size and Union for International Cancer Control stage, but was not significantly correlated with sex or age. Compared with normal thyroid and benign thyroid tumour tissue, papillary thyroid carcinomas showed higher expression of NOB1, which indicates that the expression level of the NOB1 gene in the thyroid may play a key role in the occurrence and development of papillary thyroid carcinoma.

The Expression of Tumor-Associated Macrophages in Papillary Thyroid Carcinoma

Solid tumors contain not only malignant cells, but also extracellular matrix and many other nonmalignant cells including fibroblasts, endothelial cells, and inflammatory cells such as macrophages, neutrophils, and lymphocytes. The presence of inflammatory cells within solid tumors suggests that the inflammatory microenvironment could play a major role in promoting tumorigenesis and progression. Macrophage infiltrates in the context of or surrounding a variety of malignancies represent the host's immune response to the tumor [1,2]. It was recently reported that tumor-associated macrophages (TAMs) had important roles in the tumor progression and metastasis of various cancers, including advanced thyroid cancer [3-9]. However, the role of TAMs in papillary thyroid carcinoma (PTC) has not been fully elucidated. Fiumara et al. [10] studied the tissue distribution and prognostic significance of TAMs in a retrospective series of 121 PTCs. They found tumor-infiltrating macrophages in approximately 70% of cases. Phagocytosis of neoplastic cells by macrophages was observed in approximately 15% of tumors, and none of these tumors developed distant metastases. These data suggest that neoplastic cell phagocytosis by macrophages and lymphocytic infiltration play a protective role in the development of distant metastases in patients with PTC. Conversely, emerging data suggest that TAMs promote tumor progression and metastasis in PTC. Ryder et al. [8] reported that an increased density of TAMs was associated with tumor progression in advanced thyroid cancers and that there was a significant correlation between increased TAMs and histological grade, tumor invasiveness, and decreased cancerrelated survival in PTC. Very recently, they also reported that TAMs promoted PTC progression in BRAF-induced PTC mouse models, and that targeting CCR2-expressing cells during BRAF induction reduced TAM density and impaired PTC development [11]. These results suggested that therapeutic strategies targeting TAMs may be beneficial in the treatment of advanced PTC. Qing et al. [9] investigated TAMs density in both benign thyroid lesions and PTC tumors by CD68 immunostaining. They found that the overall density of TAMs was significantly higher in PTC tumors compared with thyroid goiter and follicular adenoma. In addition, the density of TAMs was positively associated with lymph node (LN) metastasis in TNM stages III/VI compared with stages I/II. However, no association was observed with other common tumor features, including BRAF mutation. In this issue, Kim et al. [12] investigated the expression of TAMs in 36 PTC patients with LN metastasis using immunohistochemical staining with anti-CD68 antibody. They reported that a higher density of TAMs was correlated with larger tumor size, suggesting a protumorigenic role of TAMs in PTCs. Comparing clinicopathologic characteristics among low (<25%) and high (25% to 70%) TAM density groups, primary tumor size was larger in the high density group compared to the low density group (2.0±0.1 vs. 1.5±0.1; P=0.009). However, there was no significant association between high TAM density and poorer clinicopathologic characteristics including multifocality, LN metastasis, and extrathyroidal extension. These data were not in agreement with those of previous studies, which reported that high TAM density was correlated with tumor invasiveness and poor clinicopathologic characteristics, excepting tumor size [8,9,11]. Kim et al. [12] also analyzed the morphological characteristics of TAMs in PTC. They found that TAMs had thin, elongated cytoplasmic extensions, forming a canopy structure over tumor cells, and that the morphological characteristics of thyroid cancer tissue were well maintained irrespective of the presence of TAMs. In view of this, they inferred that TAMs do not play key role in tumor development in PTC. However, Caillou et al. [13] reported that anaplastic thyroid cancer displayed a very dense network of interconnected ramified TAMs in direct contact with intermingled cancer cells, and that this TAM network was directly related to the aggressiveness of thyroid cancer. Unfortunately, Kim et al. [12] conducted this study using anti-CD68 antibody on only a small sample of PTCs with LN metastasis. A major limitation of this study was the lack of follow-up data with which to evaluate long-term outcomes. Therefore, further studies using a more specific antibody and larger sample sizes of various stages of PTC are warranted to investigate the role of TAMs in tumor development, tumor invasiveness, and metastasis of PTC. Finally, TAM-targeted pharmacologic therapy in patients with advanced thyroid cancer should also be investigated.

The association between papillary thyroid carcinoma and histologically proven Hashimoto's thyroiditis: a meta-analysis

No consensus exists on the association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT). To resolve this controversy, this study aimed to evaluate the relationship between the two conditions using a meta-analysis. We searched relevant published studies using citation databases including PubMed, Embase, and ISI Web of Science. The effect sizes of clinicopathologic parameters were calculated by odds ratio (OR), weighted mean difference, or hazard ratio (HR). The effect sizes were combined using a random-effects model. Thirty-eight eligible studies including 10 648 PTC cases were selected. Histologically proven HT was identified in 2471 (23.2%) PTCs. HT was more frequently observed in PTCs than in benign thyroid diseases and other carcinomas (OR=2.8 and 2.4; P<0.001). PTCs with coexisting HT were significantly related to female patients (OR=2.7; P<0.001), multifocal involvement (OR=1.5; P=0.010), no extrathyroidal extension (OR=1.3; P=0.002), and no lymph node metastasis (OR=1.3; P=0.041). Moreover, PTCs with HT were significantly associated with long recurrence-free survival (HR=0.6; P=0.001). Our meta-analysis showed that PTC is significantly associated with pathologically confirmed HT. PTC patients with HT have favorable clinicopathologic characteristics compared with PTCs without HT. However, patients with HT need to be carefully monitored for the development of PTC.

The role of microRNA-21 in papillary thyroid cancer cells

Objective To explore the roles of microRNA (miR)-21 in the thyroid papillary carcinoma (TPC-1) cells.Methods Transit in the TPC-1 transfection of miR-21,Immunohistochemical detection of programmed cell death 4 (PDCD4) expression after transfection;transfected with miR-21 TPC-1 cell proliferation measured by tetrazolium (MTT) assay; flow cytometry detection of transfected TPC-1 cells withereddie.Results By transfection group were detected by immunohistochemistry,cytoplasmic brown color,the control group showed no staining,transfected group programmed cell death 4 (PDCD4) expression was significantly higher than the methyl thiazol MTT assay transfected cell viability was significantly be promoted (P ＜ 0.05).Transfection group apoptosis rate was (3.13 ± 0.34) ％,and a blank group,the apoptosis rate of the empty plasmid group (8.03 ± 0.02) ％ (9.51 ± 0.54) ％ (P ＜ 0.05),apoptosis of the transfected cells is significantly reduced.Conclusion PDCD4 is a miR-21 target genes of high expression of miR-21 can promote the development of papillary thyroid carcinoma. Key words: Thyroid carcinoma; MicroRNA-21 ; Programmed cell death 4; Apoptosis

Soluble Human Leukocyte Antigen-G and Its Insertion/Deletion Polymorphism in Papillary Thyroid Carcinoma: Novel Potential Biomarkers of Disease?

Human leukocyte antigen-G (HLA-G), a nonclassical major histocompatibility complex class I antigen, plays a pivotal role in immune tolerance and a paradoxical role in cancers. Our aims were to evaluate plasma soluble HLA-G (sHLA-G) concentrations and the 14-bp insertion/deletion polymorphism of the HLA-G gene in patients with papillary thyroid carcinoma (PTC) or Hashimoto's thyroiditis (HT) and to assess the possible association of these parameters with PTC aggressiveness. Samples for the analysis of sHLA-G and +14/-14-bp HLA-G polymorphism were obtained from 121 patients with HT and 183 with PTC; 245 gender- and age-matched healthy subjects served as controls. PTC histopathological aggressiveness was defined according to the last American Thyroid Association guidelines. Positive serum antithyroid antibody titers were observed in 22% of PTC patients and lymphocyte infiltration of thyroid parenchyma at histological examination in 21%, whereas both circulating and histological autoimmunity was detectable in 12% of PTC patients. No differences in the +14/-14-bp polymorphism frequencies were observed between the study groups. The prevalence of detectable sHLA-G was lower in healthy controls (52%) as compared with both HT (57%) and PTC (62%) patients. By stratifying the study groups according to sHLA-G level of positive subjects, significantly higher plasma sHLA-G values in PTC (42.9 ± 3.3 ng/ml; P = 0.002) and HT patients (49.1 ± 2.6 ng/ml; P < 0.002) as compared with healthy controls (8.5 ± 1.8 ng/ml) were obtained. Moreover, PTC patients with detectable plasma sHLA-G levels showed a higher aggressive behavior (P < 0.04) than those without. Although confirming the frequent association between PTC and chronic autoimmune thyroiditis, these data suggest that elevated circulating sHLA-G levels, besides an important signal of alterations of immune homeostasis, may be considered a potential, novel marker of PTC histopathological aggressiveness at diagnosis. Additional studies are needed to confirm the actual role and clinical relevance of the HLA-G complex in PTC development and progression.

Association between a promoter polymorphism (rs2192752, –1028A/C) of interleukin 1 receptor, type I (IL1R1) and location of papillary thyroid carcinoma in a Korean population

The interleukin 1 receptor, type I (IL1R1) is important in the pathogenesis of cancer. We investigated whether single nucleotide polymorphisms (SNPs) of IL1R1 contribute to the development of papillary thyroid carcinoma (PTC), in addition to the clinicopathological features such as the size, number, location, extrathyroidal invasion and metastasis of PTC. Three promoter SNPs (rs949963 -615G/A, rs2192752 -1028A/C and rs3917225 -1099A/G) in IL1R1 were genotyped using direct sequencing in 118 patients with PTC and 347 controls. The odds ratio (OR), 95% confidence interval (CI) and P value were analysed using SNPStats and SNPAnalyzer Pro. For the exact results, Fisher's exact test and Bonferroni correction (P(c)) were performed. The three promoter SNPs of IL1R1 were not associated with PTC development. For the clinicopathological features of PTC, rs2192752 was associated with location (one lobe versus both lobes): dominant model, OR = 3.11, 95% CI = 1.39-6.96, P(c) = 0.015; log-additive model, OR = 2.79, 95% CI = 1.38-5.66, P(c) = 0.0087. The C allele frequency of rs2192752 was higher in the both lobes group (28.0%) than the one lobe group (12.3%) (OR = 2.77, 95% CI = 1.40-5.48, P(c) = 0.009). However, rs949963 and rs3917225 were not correlated with clinicopathological features including location of PTC. The IL1R1 promoter SNP rs2192752 may contribute to the location of PTC, and the C allele of rs2192752 may be a risk factor for the development of PTC in both lobes.

Copy number alteration and uniparental disomy analysis categorizes Japanese papillary thyroid carcinomas into distinct groups.

The aim of the present study was to investigate chromosomal aberrations in sporadic Japanese papillary thyroid carcinomas (PTCs), concomitant with the analysis of oncogene mutational status. Twenty-five PTCs (11 with BRAFV600E, 4 with RET/PTC1, and 10 without mutation in HRAS, KRAS, NRAS, BRAF, RET/PTC1, or RET/PTC3) were analyzed using Genome-Wide Human SNP Array 6.0 which allows us to detect copy number alteration (CNA) and uniparental disomy (UPD), also referred to as copy neutral loss of heterozygosity, in a single experiment. The Japanese PTCs showed relatively stable karyotypes. Seven cases (28%) showed CNA(s), and 6 (24%) showed UPD(s). Interestingly, CNA and UPD were rarely overlapped in the same tumor; the only one advanced case showed both CNA and UPD with a highly complex karyotype. Thirteen (52%) showed neither CNA nor UPD. Regarding CNA, deletions tended to be more frequent than amplifications. The most frequent and recurrent region was the deletion in chromosome 22; however, it was found in only 4 cases (16%). The degree of genomic instability did not depend on the oncogene status. However, in oncogene-positive cases (BRAFV600E and RET/PTC1), tumors with CNA/UPD were less frequent (5/15, 33%), whereas tumors with CNA/UPD were more frequent in oncogene-negative cases (7/10, 70%), suggesting that chromosomal aberrations may play a role in the development of PTC, especially in oncogene-negative tumors. These data suggest that Japanese PTCs may be classified into three distinct groups: CNA+, UPD+, and no chromosomal aberrations. BRAFV600E mutational status did not correlate with any parameters of chromosomal defects.

Polymorphisms of TGFBR2 contribute to the progression of papillary thyroid carcinoma

Transforming growth factor, beta receptor II (70/80 kDa) (TGFBR2) is a tumor suppressor. Mutations in the TGFBR2 gene appear to have an increased risk of developing several cancers. To investigate whether TGFBR2 polymorphisms are associated with the development of papillary thyroid carcinoma (PTC), three single nucleotide polymorphisms (SNPs) of TGFBR2 (rs764522, -1444C/G; rs3087465, -834G/A; rs2228048, Asn389Asn) were selected and genotyped by direct sequencing in 92 PTC patients and 330 control subjects. We also assessed the relationships between three SNPs of TGFBR2 and clinicopathologic characteristics of PTC such as size ( 1 cm), number (unifocality and multifocality), location (one lobe and both lobe), extrathyroidal invasion, and lymph node metastasis. SNPStats and Haploview version 4.2 were used to analyze genetic data. Multiple logistic regression models (codominant1, codominant2, dominant, recessive, overdominant, and log-additive) were performed to calculate odds ratios (ORs), 95% confidence intervals (CIs), and P values. The three examined SNPs were not associated with PTC. In clinicopathologic characteristics, two promoter SNPs (rs3087465 and rs764522) were associated with lymph node metastasis (rs3087465, P=0.009 in the codominant1 model, P=0.043 in the dominant model, P= 0.003 in the overdominant model; rs764522, P=0.021 in the codominant1 model, P=0.044 in the dominant model, P=0.016 in the overdominant model). The synonymous SNP rs2228048 was associated with extrathyroidal invasion (P=0.024 in the dominant model, P=0.015 in the log-additive model). The allele frequency of rs2228048 was significantly different between PTC with extrathyroidal invasion and PTC without extrathyroidal invasion (P=0.018, OR=0.46, 95% CI=0.24–0.88). These results suggest that TGFBR2 may be associated with the progression of PTC in Korean population.

The Role of Fragile Sites in Sporadic Papillary Thyroid Carcinoma

The incidence of thyroid cancer is increasing, especially papillary thyroid carcinoma (PTC), making it currently the fastest-growing cancer among women. Reasons for this increase remain unclear, but several risk factors including radiation exposure and improved detection techniques have been suggested. Recently, the induction of chromosomal fragile site breakage was found to result in the formation of RET/PTC1 rearrangements, a common cause of PTC. Chromosomal fragile sites are regions of the genome with a high susceptibility to forming DNA breaks and are often associated with cancer. Exposure to a variety of external agents can induce fragile site breakage, which may account for some of the observed increase in PTC. This paper discusses the role of fragile site breakage in PTC development, external fragile site-inducing agents that may be potential risk factors for PTC, and how these factors are especially targeting women.

Positive family history of thyroid disease as a risk factor for differentiated thyroid carcinoma

Apart from the environmental risk factors for differentiated thyroid carcinoma (DTC), such as iodine deficiency and ionising radiation, it seems that there are also other, biological risk factors, for example, familial predisposition to thyroid disease. The aim of the study was to assess the occurrence of thyroid disease in the families of patients with DTC. A case-control study was conducted in a group of 232 patients with DTC and in 342 age- and sex-matched healthy subjects. Eighty patients were diagnosed with follicular thyroid carcinoma, 127 with papillary thyroid carcinoma, and 25 with oxyphilic thyroid carcinoma. The questionnaire included questions on the presence of thyroid diseases in first-degree relatives. The relative risk of DTC and the effect of factors associated with thyroid diseases in the family were assessed by the logistic regression model. Thyroid disease was more common in the families of DTC patients than in the control group: 18.5% of the patients and 9.6% of the control group had a parent with thyroid disease (OR = 2.12, 95% CI: 1.26-3.55); 16.8% of the patients and 7.7% of the control group had a sibling with thyroid disease (OR = 2.27, 95% CI: 1.31-3.95). Familial thyroid disease may be a risk factor for DTC. A positive family history of thyroid disease is associated to a larger extent with the development of papillary thyroid carcinoma than with that of follicular thyroid carcinoma.

Receptor for Activated Protein C Kinase 1 (RACK1) Is Overexpressed in Papillary Thyroid Carcinoma

The receptor for activated C kinase 1 (RACK1) has been shown to be overexpressed in several types of cancers such as breast, colon, melanomas, and lung. RACK1 is linked to Ras-Raf-mediated signal transduction and transformed foci formation of 3T3 cells in vitro, and since this pathway is central in papillary thyroid carcinoma (PTC) oncogenesis, we hypothesized that RACK1 could play a role in the development or maintenance of PTC. No report on RACK1 expression in thyroid tissue is available; the present study was therefore aimed at identifying possible correlation of RACK1 expression at the mRNA or protein level in normal thyroid tissue compared to PTC. We used TaqMan quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry to study the RACK1 gene and protein expression in matched tumor and nontumor samples from 59 PTC patients. The tumor samples were divided into two main categories, low-risk (group 1-3) and high-risk (group 4-6), in accordance with both histological classification and clinical appearance. RACK1 mRNA and protein levels were found highly overexpressed in tumor samples, whereas Ki-Ras mRNA was found to be relatively unchanged. B-Raf mRNA expression was low and detected only in tumor samples. Sequencing analysis detected no mutations in RACK1 or Ki-Ras, but 62.7% of the patients harbored the B-Raf single-nucleotide substitution T1799A (codon V600E). Phosphorylated extracellular signal-regulated kinase (pERK) immunohistochemistry analysis demonstrated activation of the mitogen-activated protein kinase (MAPK) pathway in tumor cells. Poorly differentiated and undifferentiated PTCs expressed significantly higher RACK1 mRNA levels than well-differentiated PTCs (p<0.017). Taken together, our findings point to an important role of RACK1 protein in PTC development and progression. Our data also emphasize the importance of assessing protein expression and not only mRNA levels.