OBJECTIVE: To assess the value of DNA methylation level of HYAL2 gene as a molecular marker for differential diagnosis of malignant and benign thyroid tumors. METHODS: DNA methylation of HYAL2 gene in tissue specimens of 190 patients with papillary thyroid cancer (PTC) and 190 age- and gender-matched patients with benign thyroid tumors was examined by mass spectrometry, and the protein expression of HYAL2 was detected immunohistochemically for another 55 pairs of patients. Logistic regression analysis was performed to calculate the odds ratio (OR) and evaluate the correlation of per 10% reduction in DNA methylation with PTC. Receiver operating characteristic (ROC) curve analysis was performed and the area under curve (AUC) was calculated to assess the predictive value of alterations in HYAL2 methylation. RESULTS: Hypomethylation of HYAL2_CpG_3 was significantly correlated with early-stage PTC (OR=1.51, P=0.001), even in stage I cancer (OR=1.42, P=0.007). Age-stratified analysis revealed a significantly stronger correlation between increased HYAL2_CpG_ 3 methylation and early-stage PTC in patients below 50 years than in those older than 50 years (OR: 1.89 vs 1.37, P < 0.05); ROC analysis also showed a larger AUC of 0.787 in younger patients. The results of immunohistochemistry showed that patients with PTC had significantly higher protein expressions of HYAL2 than patients with benign tumors. CONCLUSION The alterations of DNA methylation level of HYAL2 gene is significantly correlated with early-stage PTC, suggesting the value of DNA methylation level as a potential biomarker for differentiation of malignant from benign thyroid tumors.
Adenoma, Oxyphilic/genetics* ; Biomarkers, Tumor/metabolism* ; Cell Adhesion Molecules/metabolism* ; DNA Methylation ; GPI-Linked Proteins/metabolism* ; Humans ; Hyaluronoglucosaminidase/metabolism* ; Immunohistochemistry ; Middle Aged ; Thyroid Cancer, Papillary/pathology* ; Thyroid Neoplasms/pathology*

Targeted gene therapy has become a promising approach for lung cancer treatment. In our previous work, we reported that the targeted expression of microRNA-7 (miR-7) operated by thyroid transcription factor-1 (TTF-1) promoter inhibited the growth of human lung cancer cells in vitro and in vivo; however, the intervention efficiency needed to be further improved. In this study, we identified the core promoter of TTF-1 (from -1299 bp to -871 bp) by 5' deletion assay and screened out the putative transcription factors nuclear factor-1 (NF-1) and activator protein-1 (AP-1). Further analysis revealed that the expression level of NF-1, but not AP-1, was positively connected with the activation of TTF-1 core promoter in human non-small-cell lung cancer (NSCLC) cells. Moreover, the silencing of NF-1 could reduce the expression level of miR-7 operated by TTF-1 core promoter. Of note, we optimized four distinct sequences to form additional NF-1-binding sites (TGGCA) in the sequence of TTF-1 core promoter (termed as ^optTTF-1 promoter), and verified the binding efficiency of NF-1 on the ^optTTF-1 promoter by electrophoretic mobility shift assay (EMSA). As expected, the ^optTTF-1 promoter could more effectively drive miR-7 expression and inhibit the growth of human NSCLC cells in vitro, accompanied by a reduced transduction of NADH dehydrogenase (ubiquinone) 1α subcomplex 4 (NDUFA4)/protein kinase B (Akt) pathway. Consistently, ^optTTF-1 promoter-driven miR-7 expression could also effectively abrogate the growth and metastasis of tumor cells in a murine xenograft model of human NSCLC. Finally, no significant changes were detected in the biological indicators or the histology of some important tissues and organs, including heart, liver, and spleen. On the whole, our study revealed that the optimized TTF-1 promoter could more effectively operate miR-7 to influence the growth of human NSCLC cells, providing a new basis for the development of microRNA-based targeting gene therapy against clinical lung cancer.
Animals ; Humans ; Mice ; Carcinoma, Non-Small-Cell Lung/therapy* ; Lung Neoplasms/metabolism* ; MicroRNAs/metabolism* ; Nuclear Proteins/metabolism* ; Thyroid Gland/pathology* ; Thyroid Nuclear Factor 1/genetics* ; Transcription Factors/metabolism*

BACKGROUNDBrain acid soluble protein 1 (BASP1) is identified as a novel potential tumor suppressor in several cancers. However, its role in thyroid cancer has not been investigated yet. In the present study, the antitumor activities of BASP1 against the growth and migration of thyroid cancer cells were evaluated.

METHODSBASP1 expression in thyroid cancer tissues and normal tissues were examined by immunohistochemical staining and the association between its expression and prognosis was analyzed. pcDNA-BASP1 carrying full length of BASP1 cDNA was constructed to restore the expression of BASP1 in thyroid cancer cell lines (BHT-101 and KMH-2). The cell proliferation in vitro and in vivo was evaluated by WST-1 assay and xenograft tumor models, respectively. Cell cycle distribution after transfection was analyzed using flow cytometry. Cell apoptosis after transfection was examined by annexin V/propidium iodide assay. The migration was examined using transwell assay.

RESULTSBASP1 expression was abundant in normal tissues while it is significantly decreased in cancer tissues (P = 0.000). pcDNA-BASP1 restored the expression of BASP1 and significantly inhibited the growth of BHT-101 and KMH-2 cells as well as xenograft tumors in nude mice (P = 0.000). pcDNA-BASP1 induced G1 arrest and apoptosis in BHT-101 and KMH-2 cells. In addition, pcDNA-BASP1 significantly inhibited the cell migration.

CONCLUSIONSDownregulation of BASP1 expression may play a role in the tumorigenesis of thyroid cancer. Restoration of BASP1 expression exerted extensive antitumor activities against growth and migration of thyroid cancer cells, which suggested that BASP1 gene might act as a potential therapeutic agent for the treatment of thyroid cancer.

Aged ; Animals ; Apoptosis ; genetics ; physiology ; Calmodulin-Binding Proteins ; genetics ; metabolism ; Cell Cycle ; genetics ; physiology ; Cell Line, Tumor ; Cell Movement ; genetics ; physiology ; Cell Proliferation ; genetics ; physiology ; Cytoskeletal Proteins ; genetics ; metabolism ; Female ; Gene Expression Regulation, Neoplastic ; genetics ; physiology ; Humans ; Male ; Membrane Proteins ; genetics ; metabolism ; Mice ; Mice, Nude ; Middle Aged ; Nerve Tissue Proteins ; genetics ; metabolism ; Repressor Proteins ; genetics ; metabolism ; Thyroid Neoplasms ; metabolism ; pathology ; Xenograft Model Antitumor Assays

BACKGROUNDThe Notch-regulated ankyrin repeat protein (NRARP) is recently found to promote proliferation of breast cancer cells. The role of NRARP in carcinogenesis deserves extensive investigations. This study attempted to investigate the expression of NRARP in thyroid cancer tissues and assess the influence of NRARP on cell proliferation, apoptosis, cell cycle, and invasion in thyroid cancer.

METHODSThirty-four cases with thyroid cancer were collected from the Department of General Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine between 2011 and 2012. Immunohistochemistry was used to detect the level of NRARP in cancer tissues. Lentivirus carrying NRARP-shRNA (Lenti-NRARP-shRNA) was applied to down-regulate NRARP expression. Cell viability was tested after treatment with Lenti-NRARP-shRNA using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis and cell cycle distribution were determined by flow cytometry. Cell invasion was tested using Transwell invasion assay. In addition, expressions of several cell cycle-associated and apoptosis-associated proteins were examined using Western blotting after transfection. Student's t-test, one-way analysis of variance (ANOVA), or Kaplan-Meier were used to analyze the differences between two group or three groups.

RESULTSNRARP was highly expressed in thyroid cancer tissues. Lenti-NRARP-shRNA showed significantly inhibitory activities against cell growth at a multiplicity of infection of 10 or higher (P < 0.05). Lenti-NRARP-shRNA-induced G1 arrest (BHT101: 72.57% ± 5.32%; 8305C: 75.45% ± 5.26%) by promoting p21 expression, induced apoptosis by promoting bax expression and suppressing bcl-2 expression, and inhibited cell invasion by suppressing matrix metalloproteinase-9 expression.

CONCLUSIONDownregulation of NRARP expression exerts significant antitumor activities against cell growth and invasion of thyroid cancer, that suggests a potential role of NRARP in thyroid cancer targeted therapy.

Adult ; Aged ; Animals ; Apoptosis ; genetics ; physiology ; Cell Cycle ; genetics ; physiology ; Cell Line, Tumor ; Cell Proliferation ; genetics ; physiology ; Cell Survival ; genetics ; physiology ; Female ; Humans ; In Vitro Techniques ; Kaplan-Meier Estimate ; Male ; Mice ; Mice, Nude ; Middle Aged ; Neoplasm Proteins ; genetics ; metabolism ; Proteins ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; Thyroid Neoplasms ; genetics ; metabolism ; mortality ; pathology

Allosteric Regulation ; Carrier Proteins ; chemistry ; genetics ; metabolism ; Cell Proliferation ; Gene Expression ; Glycolysis ; genetics ; Humans ; Membrane Proteins ; chemistry ; genetics ; metabolism ; Mutation ; Neoplasms ; enzymology ; genetics ; pathology ; Oxidative Phosphorylation ; Protein Conformation ; Protein Multimerization ; Protein Subunits ; chemistry ; genetics ; metabolism ; Thyroid Hormones ; chemistry ; genetics ; metabolism ; Tumor Cells, Cultured

Pyruvate kinase isoform M2 (PKM2) converts phosphoenolpyruvate (PEP) to pyruvate and plays an important role in cancer metabolism. Here, we show that post-translational modifications and a patient-derived mutation regulate pyruvate kinase activity of PKM2 through modulating the conformation of the PKM2 tetramer. We determined crystal structures of human PKM2 mutants and proposed a "seesaw" model to illustrate conformational changes between an inactive T-state and an active R-state tetramers of PKM2. Biochemical and structural analyses demonstrate that PKM2(Y105E) (phosphorylation mimic of Y105) decreases pyruvate kinase activity by inhibiting FBP (fructose 1,6-bisphosphate)-induced R-state formation, and PKM2(K305Q) (acetylation mimic of K305) abolishes the activity by hindering tetramer formation. K422R, a patient-derived mutation of PKM2, favors a stable, inactive T-state tetramer because of strong intermolecular interactions. Our study reveals the mechanism for dynamic regulation of PKM2 by post-translational modifications and a patient-derived mutation and provides a structural basis for further investigation of other modifications and mutations of PKM2 yet to be discovered.
Acetylation ; Allosteric Regulation ; Carrier Proteins ; chemistry ; genetics ; metabolism ; Crystallography, X-Ray ; Fructosediphosphates ; chemistry ; metabolism ; Gene Expression ; Humans ; Kinetics ; Membrane Proteins ; chemistry ; genetics ; metabolism ; Models, Molecular ; Mutation ; Neoplasms ; enzymology ; genetics ; pathology ; Phosphorylation ; Protein Conformation ; Protein Multimerization ; Protein Processing, Post-Translational ; Protein Subunits ; chemistry ; genetics ; metabolism ; Thyroid Hormones ; chemistry ; genetics ; metabolism ; Tumor Cells, Cultured

OBJECTIVETo explore the mechanism of miR-124 inhibiting the proliferative activity of prostate cancer PC3 cells.

METHODSLuciferase reporter gene assay was used to examine the specific binding ability of miR-124 to PKM2 mRNA 3'-UTR. After miR-124 was transfected mimic to PC3 cells, the expression levels of PKM2 mRNA and protein were detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot, respectively. The effects of miR-124 mimic and PKM2 siRNA on the proliferative activity of the PC3 cells were determined by MTT assay.

RESULTSThe expressions of PKM2 mRNA and protein were upregulated (5.12 +/- 0.35) times and (4.05 +/- 0.20) times respectively in the PC3 cells as compared with those in the RWPE-1 cells (P < 0.05). Luciferase reporter gene assay demonstrated that miR-124 targeted PKM2 3'-UTR. At 24 hours after transfection with miR-124 mimic, the PKM2 protein expression in the PC3 cells was downregulated (0.16 +/- 0.04) times (P < 0.05), while the PKM2 mRNA level was not changed significantly (P > 0.05), as compared with the control group. MTT assay showed that both miRNA-124 mimic and PKM2 siRNA could inhibit the proliferation of the PC3 cells, but the former exhibited a greater inhibitory effect than the latter. After transfection with miR-124 mimic and PKM2 siRNA, the cell growth rates were (66.20 +/- 5.10)% vs (82.10 +/- 6.35)% at 24 hours (P < 0.05) and (49.34 +/- 2.37)% vs (70.10 +/- 5.80)% at 48 hours (P < 0.05).

CONCLUSIONmiR-124 can suppress the proliferation of PC3 cells by regulating the PKM2 gene.

Carrier Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; genetics ; Humans ; Male ; Membrane Proteins ; genetics ; metabolism ; MicroRNAs ; genetics ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; Thyroid Hormones ; genetics ; metabolism ; Transfection

B-RafV600E mutant is found in 40-70% of papillary thyroid carcinoma (PTC) and has an important role in the pathogenesis of PTC. The sodium iodide symporter (NIS) is an integral plasma membrane glycoprotein that mediates active iodide transport into the thyroid follicular cells, and B-RafV600E has been known to be associated with the loss of NIS expression. In this study, we found that B-RafV600E inhibited NIS expression by the upregulation of its promoter methylation, and that specific regions of CpG islands of NIS promoter in B-RafV600E harboring PTC were highly methylated compared with surrounding normal tissue. Although DNA methyltransferase 3a and 3b (DNMT3a,3b) were not increased by B-RafV600E, DNMT1 expression was markedly upregulated in PTC and B-RafV600E expressing thyrocytes. Furthermore, DNMT1 expression was upregulated by B-RafV600E induced NF-kappaB activation. These results led us to conclude that NIS promoter methylation, which was induced by B-RafV600E, is one of the possible mechanisms involved in NIS downregulation in PTC.
Base Sequence ; Carcinoma/*genetics/metabolism/pathology ; Cells, Cultured ; DNA (Cytosine-5-)-Methyltransferase/analysis/*genetics/metabolism ; DNA Methylation ; Down-Regulation ; *Gene Expression Regulation, Neoplastic ; Humans ; Molecular Sequence Data ; *Point Mutation ; Promoter Regions, Genetic ; Proto-Oncogene Proteins B-raf/*genetics/metabolism ; Symporters/analysis/*genetics/metabolism ; Thyroid Gland/cytology/metabolism/pathology ; Thyroid Neoplasms/*genetics/metabolism/pathology ; Up-Regulation

BACKGROUND/AIMS: 5'-Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that monitors intracellular AMP/adenosine triphosphate (ATP) ratios and is a key regulator of the proliferation and survival of diverse malignant cell types. In the present study, we investigated the effect of activating AMPK by 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR) in thyroid cancer cells. METHODS: We used FRO thyroid cancer cells harboring the BRAF(V600E) mutation to examine the effect of AICAR on cell proliferation and cell survival. We also evaluated the involvement of mitogen-activated protein kinase (MAPK) pathways in this effect. RESULTS: We found that AICAR treatment promoted AMPK activation and suppressed cell proliferation and survival by inducing p21 accumulation and activating caspase-3. AICAR significantly induced activation of p38 MAPK, and pretreatment with SB203580, a specific inhibitor of the p38 MAPK pathway, partially but significantly rescued cell survival. Furthermore, small interfering RNA targeting AMPK-alpha1 abolished AICAR-induced activation of p38 MAPK, p21 accumulation, and activation of caspase-3. CONCLUSIONS: Our findings demonstrate that AMPK activation using AICAR inhibited cell proliferation and survival by activating p38 MAPK and proapoptotic molecules in FRO thyroid cancer cells. These results suggest that the AMPK and p38 MAPK signaling pathways may be useful therapeutic targets to treat thyroid cancer.
AMP-Activated Protein Kinases/genetics/metabolism ; Aminoimidazole Carboxamide/*analogs & derivatives/pharmacology ; Antineoplastic Agents/*pharmacology ; Caspase 3/metabolism ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cell Survival/drug effects ; Cyclin-Dependent Kinase Inhibitor p21/metabolism ; Dose-Response Relationship, Drug ; Enzyme Activation ; Enzyme Activators/pharmacology ; Humans ; Mutation ; Protein Kinase Inhibitors/pharmacology ; Proto-Oncogene Proteins B-raf/genetics ; RNA Interference ; Ribonucleotides/*pharmacology ; Signal Transduction/*drug effects ; Thyroid Neoplasms/*enzymology/genetics/pathology ; Time Factors ; Transfection ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/*metabolism

PURPOSE: We investigated the merit of ultrasound (US) features and BRAF(V600E) mutation as an additional study of cytology and compared the diagnostic performances of cytology alone, cytology with US correlation, cytology with BRAF(V600E) mutation, and a combination of cytology, US, and BRAF(V600E) mutation all together. MATERIALS AND METHODS: This study included 185 patients (mean age, 48.4 years; range 20-77 years) with 191 thyroid nodules who underwent US-guided fine-needle aspiration (FNA) with an additional BRAF(V600E) mutation test. Three radiologists highly experienced in thyroid imaging retrospectively reviewed US images and classified each nodule into two categories (positive for malignancy or negative for malignancy). Interobserver variability (IOV) of US assessment between the three readers was estimated using the generalized kappa statistic of Landis and Koch. We also calculated the diagnostic performances of these studies. RESULTS: There were 131 cases of malignancy (131/191, 68.6%) and 60 cases of benign nodules (60/191, 31.4%). In terms of IOV of US assessment, the generalized kappa value was 0.242, indicating fair agreement was reached. The combination of cytology with BRAF(V600E) showed higher specificity (100%) and positive predictive value (PPV) (100%) compared to the combination of cytology, BRAF(V600E), and US (specificity 28.3%, 66.7%, 68.3%; PPV 74.6%, 86.6%, 86.8%, respectively; p<0.001). However, cytology with BRAF(V600E) showed lower sensitivity (84.7%) than cytology with BRAF(V600E) and US (96.2%, 98.5%, 95.4%, respectively; p<0.001). CONCLUSION: Considering the diagnostic performance and low reproducibility of US, the combination of FNA with BRAF(V600E) is the most reliable and objective method for diagnosing thyroid malignancy.
Adult ; Aged ; Biological Markers ; Biopsy, Fine-Needle ; Carcinoma/*diagnosis/genetics/*ultrasonography ; Cytodiagnosis ; Female ; Humans ; Male ; Middle Aged ; Proto-Oncogene Proteins B-raf/*genetics ; Retrospective Studies ; Thyroid Gland/metabolism/pathology ; Thyroid Neoplasms/*diagnosis/genetics/*ultrasonography ; Thyroid Nodule/metabolism/pathology ; Young Adult