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1.
Eur Thyroid J ; 8(1): 31-40, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30800639

ABSTRACT

BACKGROUND: Medullary thyroid carcinoma (MTC) is rare. Nationwide population-based studies are important to evaluate its clinical course. OBJECTIVES: To describe all patients with MTC in Norway during 1994-2016 and compare time-related trends in diagnostics and surgical treatment, including prognostic factors for biochemical cure and disease-specific survival (DSS). METHODS: This retrospective population-based cohort study includes data for 228 out of 237 patients (96%) with MTC; 201 patients were surgically treated. Patients were identified in the 4 regional centers treating MTC and by the Cancer Registry of Norway. Data were collected from patients' files. Trends were compared over 2 study periods. RESULTS: MTC accounted for 4.2% of thyroid carcinomas. During the study periods, the incidence increased from 0.18 to 0.25: 100,000 per year, preoperative diagnostics improved with increased use of calcitonin, ultrasound, and fine-needle cytology (p = 0.010, p < 0,001, and p = 0.001), patients were diagnosed at an earlier tumor stage (p = 0.004), and more patients were cured (p = 0.002). Via multivariate analysis of patients with metastatic lymph nodes, independent prognostic factors for cure were: a low ratio of metastatic and total number of dissected lymph nodes (p = 0.021) and no extrathyroidal extension (p = 0.030). Independent prognostic factors for DSS were: no distant metastasis, a younger age, and a low ratio of metastatic and dissected lymph nodes (p = 0.005, p = 0.020, p = 0.022). CONCLUSIONS: Preoperative diagnostics have improved over time with increased therapeutic control. A low ratio of metastatic and dissected lymph nodes predicts better outcomes in patients with metastatic lymph nodes.

2.
Gene ; 644: 27-37, 2018 Feb 20.
Article in English | MEDLINE | ID: mdl-29247799

ABSTRACT

N-terminal acetylation is a highly abundant and important protein modification in eukaryotes catalyzed by N-terminal acetyltransferases (NATs). In humans, six different NATs have been identified (NatA-NatF), each composed of individual subunits and acetylating a distinct set of substrates. Along with most NATs, NatC acts co-translationally at the ribosome. The NatC complex consists of the catalytic subunit Naa30 and the auxiliary subunits Naa35 and Naa38, and can potentially Nt-acetylate cytoplasmic proteins when the initiator methionine is followed by a bulky hydrophobic/amphipathic residue at position 2. Here, we have identified a splice variant of human NAA30, which encodes a truncated protein named Naa30288. The splice variant was abundantly present in thyroid cancer tissues and in several different human cancer cell lines. Surprisingly, Naa30288 localized predominantly to the nucleus, as opposed to annotated Naa30 which has a cytoplasmic localization. Full-length Naa30 acetylated a classical NatC substrate peptide in vitro, whereas no significant NAT activity was detected for Naa30288. Due to the nuclear localization, we also examined acetyltransferase activity towards lysine residues. Neither full-length Naa30 nor Naa30288 displayed any lysine acetyltransferase activity. Overexpression of full-length Naa30 increased cell viability via inhibition of apoptosis. In contrast, Naa30288 did not exert an anti-apoptotic effect. In sum, we identified a novel and widely expressed Naa30 isoform with a potential non-catalytic role in the nucleus.


Subject(s)
Cell Nucleus/genetics , N-Terminal Acetyltransferase C/genetics , N-Terminal Acetyltransferases/genetics , Protein Isoforms/genetics , RNA Splicing/genetics , Acetylation , Amino Acid Sequence , Cell Line , Cell Line, Tumor , Cell Survival/genetics , HEK293 Cells , HeLa Cells , Humans , Lysine/genetics , MCF-7 Cells , Protein Processing, Post-Translational/genetics , Ribosomes/genetics
3.
Mol Cell Proteomics ; 15(11): 3361-3372, 2016 11.
Article in English | MEDLINE | ID: mdl-27694331

ABSTRACT

N-terminal acetylation (Nt-acetylation) by N-terminal acetyltransferases (NATs) is one of the most common protein modifications in eukaryotes. The NatC complex represents one of three major NATs of which the substrate profile remains largely unexplored. Here, we defined the in vivo human NatC Nt-acetylome on a proteome-wide scale by combining knockdown of its catalytic subunit Naa30 with positional proteomics. We identified 46 human NatC substrates, expanding our current knowledge on the substrate repertoire of NatC which now includes proteins harboring Met-Leu, Met-Ile, Met-Phe, Met-Trp, Met-Val, Met-Met, Met-His and Met-Lys N termini. Upon Naa30 depletion the expression levels of several organellar proteins were found reduced, in particular mitochondrial proteins, some of which were found to be NatC substrates. Interestingly, knockdown of Naa30 induced the loss of mitochondrial membrane potential and fragmentation of mitochondria. In conclusion, NatC Nt-acetylates a large variety of proteins and is essential for mitochondrial integrity and function.


Subject(s)
Mitochondrial Proteins/metabolism , N-Terminal Acetyltransferase C/genetics , N-Terminal Acetyltransferase C/metabolism , Proteomics/methods , Acetylation , Cell Line, Tumor , Gene Knockdown Techniques , HeLa Cells , Humans , Protein Binding , Protein Interaction Maps , Substrate Specificity
4.
Thyroid ; 26(9): 1225-38, 2016 09.
Article in English | MEDLINE | ID: mdl-27400880

ABSTRACT

BACKGROUND: Multiple endocrine neoplasia type 2A (MEN 2A) is an autosomal dominant syndrome caused by activating germline mutations in the RET (REarranged during Transfection) proto-oncogene. MEN 2A has a strong (>95%) and age-dependent (5-25 years) clinical penetrance of medullary thyroid carcinoma (MTC). Several major studies have analyzed the predictive and prognostic factors for MEN 2A to find indicators that predict the optimal timing of prophylactic thyroidectomy. The aims of this study were to describe all known RET positive MEN 2A patients diagnosed in Norway and to evaluate the clinical course of MTC, as well as its predictive and prognostic factors. METHODS: This nationwide retrospective cohort study included data for 65 (14 index and 51 screening patients) out of a total of 67 MEN 2A patients with the RET gene mutation who were diagnosed in Norway since 1974. Data were collected by reviewing patient files. The variables analyzed were genotype, phenotype, preoperative basal calcitonin, age at thyroid surgery, central lymph node dissection and nodal status at primary surgery, number of surgical procedures, and biochemical cure. Of the 65 patients, 60 had undergone thyroid surgery. The median follow-up period was 9.9 years. The patients were divided into pre-RET-and RET-era, which included patients who had thyroid surgery before January 1, 1994, and after, respectively. RESULTS: In index and screening patients, MTC was found, respectively, in 100% and 45% of cases, central lymph node dissection at primary surgery was done for 64% and 52% of patients, and the median total number of surgical procedures was two (range 1-6) and one (range 1-4). At primary surgery, all patients (n = 13) with lymph node metastases had preoperative basal calcitonin levels ≥68 pg/mL, and all patients (n = 17) without central lymph node dissection and preoperative basal calcitonin <40 pg/mL were biochemically cured. Multivariate analysis showed that preoperative basal calcitonin was a significant predictive factor for MTC superior to age at thyroid surgery when analyzing the entire period (p = 0.009) and the RET-era separately (p = 0.021). Prognostic factors for biochemical cure were preoperative basal calcitonin, central lymph node dissection, and nodal status at primary surgery (p = 0.037, p = 0.002, and p = 0.005) when analyzing the entire period, but only nodal status at primary surgery when the RET-era was considered separately (p = 0.006). CONCLUSIONS: Preoperative basal calcitonin alone can serve as an indicator for optimal timing and the extent of thyroid surgery for MEN 2A patients that could be considered safe. The results are consistent with previously reported data.


Subject(s)
Carcinoma, Medullary/pathology , Multiple Endocrine Neoplasia Type 2a/pathology , Proto-Oncogene Proteins c-ret/genetics , Thyroid Neoplasms/pathology , Thyroidectomy , Adolescent , Adult , Aged , Biomarkers, Tumor/blood , Calcitonin/blood , Carcinoma, Medullary/blood , Carcinoma, Medullary/genetics , Carcinoma, Medullary/surgery , Child , Child, Preschool , Disease Progression , Female , Humans , Lymph Node Excision , Male , Middle Aged , Multiple Endocrine Neoplasia Type 2a/blood , Multiple Endocrine Neoplasia Type 2a/genetics , Multiple Endocrine Neoplasia Type 2a/surgery , Norway , Prognosis , Proto-Oncogene Mas , Thyroid Neoplasms/blood , Thyroid Neoplasms/genetics , Thyroid Neoplasms/surgery , Young Adult
5.
Acta Radiol ; 57(10): 1193-200, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26163534

ABSTRACT

BACKGROUND: Positron emission tomography (PET) with fluor-18-deoxy-glucose (FDG) is widely used for diagnosing recurrent or metastatic disease in patients with differentiated thyroid cancer (DTC). PURPOSE: To assess the diagnostic accuracy of FDG-PET for DTC in patients after ablative therapy. MATERIAL AND METHODS: A systematic search was conducted in Medline/PubMed, EMBASE, Cochrane Library, Web of Science, and Open Grey looking for all English-language original articles on the performance of FDG-PET in series of at least 20 patients with DTC having undergone ablative therapy including total thyroidectomy. Diagnostic performance measures were pooled using Reitsma's bivariate model. RESULTS: Thirty-four publications between 1996 and 2014 met the inclusion criteria. Pooled sensitivity and specificity were 79.4% (95% confidence interval [CI], 73.9-84.1) and 79.4% (95% CI, 71.2-85.4), respectively, with an area under the curve of 0.858. CONCLUSION: F18-FDG-PET is a useful method for detecting recurrent DTC in patients having undergone ablative therapy.


Subject(s)
Fluorodeoxyglucose F18 , Neoplasm Recurrence, Local/diagnostic imaging , Positron-Emission Tomography/methods , Radiopharmaceuticals , Thyroid Neoplasms/diagnostic imaging , Thyroid Neoplasms/pathology , Humans
6.
Acta Radiol ; 56(11): 1350-60, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25770086

ABSTRACT

BACKGROUND: Positron emission tomography (PET) using fluor-18-deoxyglucose (18F-FDG) with or without computed tomography (CT) is generally accepted as the most sensitive imaging modality for diagnosing recurrent differentiated thyroid cancer (DTC) in patients with negative whole body scintigraphy with iodine-131 (I-131). PURPOSE: To assess the potential incremental value of ultrasound (US) over 18F-FDG-PET-CT. MATERIAL AND METHODS: Fifty-one consecutive patients with suspected recurrent DTC were prospectively evaluated using the following multimodal imaging protocol: (i) US before PET (pre-US) with or without fine needle biopsy (FNB) of suspicious lesions; (ii) single photon emission computed tomography (≥3 GBq I-131) with co-registered CT (SPECT-CT); (iii) 18F-FDG-PET with co-registered contrast-enhanced CT of the neck; (iv) US in correlation with the other imaging modalities (post-US). Postoperative histology, FNB, and long-term follow-up (median, 2.8 years) were taken as composite gold standard. RESULTS: Fifty-eight malignant lesions were identified in 34 patients. Forty lesions were located in the neck or upper mediastinum. On receiver operating characteristics (ROC) analysis, 18F-FDG-PET had a limited lesion-based specificity of 59% at a set sensitivity of 90%. Pre-US had poor sensitivity and specificity of 52% and 53%, respectively, increasing to 85% and 94% on post-US, with knowledge of the PET/CT findings (P < 0.05 vs. PET and pre-US). Multimodal imaging changed therapy in 15 out of 51 patients (30%). CONCLUSION: In patients with suspected recurrent DTC, supplemental targeted US in addition to 18F-FDG-PET-CT increases specificity while maintainin sensitivity, as non-malignant FDG uptake in cervical lesions can be confirmed.


Subject(s)
Multimodal Imaging , Thyroid Neoplasms/diagnostic imaging , Tomography, Emission-Computed, Single-Photon/methods , Adult , Aged , Biopsy, Fine-Needle , Female , Fluorodeoxyglucose F18 , Humans , Image Interpretation, Computer-Assisted , Male , Middle Aged , Prospective Studies , Radiopharmaceuticals , Sensitivity and Specificity , Thyroid Neoplasms/pathology , Thyroid Neoplasms/surgery , Tomography, X-Ray Computed , Ultrasonography
7.
J Clin Endocrinol Metab ; 100(4): 1359-67, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25636048

ABSTRACT

CONTEXT: Mild primary hyperparathyroidism (PHPT) is a common disease especially in middle-aged and elderly women. The diagnosis is frequently made incidentally and treatment strategies are widely discussed. OBJECTIVE: To study the effect of parathyroidectomy (PTX) compared with observation (OBS) on biochemistry, safety, bone mineral density (BMD), and new fractures. DESIGN: Prospective, randomized controlled study (SIPH study), with a 5-year follow-up. SETTING: The study was conducted at multicenter, tertiary referral centers. PATIENTS: Of 191 randomized patients with mild PHPT, biochemical data were available for 145 patients after 5 years, with a mean age at inclusion of 62.8 years (OBS group, 9 males) and 62.1 years (PTX group, 10 males). INTERVENTION: Parathyroidectomy vs observation. MAIN OUTCOME MEASURES: Biochemistry, BMD, and new radiographic vertebral fractures. RESULTS: Serum-calcium and PTH-levels normalized after surgery and did not deteriorate by observation. BMD Z-scores were normal at inclusion in the lumbar spine (LS) and femoral neck (FN). For LS, BMD Z-scores were stable for 5 years with observation, but decreased in FN (P < .02). After surgery, BMD Z-scores increased significantly in both compartments (P < .02 for both), with a highly significant treatment effect of surgery compared to observation (P < .001). During follow-up, five new clinically unrecognized vertebral fractures were found in 5 females, all in the OBS group (P = .058). CONCLUSION: Even though new vertebral fractures occurred only in the observation group, the frequency was not significantly different from the surgery group. Longer follow-up is needed before firm conclusions can be drawn about the long-term safety of observation, as opposed to surgery.


Subject(s)
Hyperparathyroidism, Primary/epidemiology , Hyperparathyroidism, Primary/therapy , Parathyroidectomy , Spinal Fractures/epidemiology , Aged , Female , Humans , Hyperparathyroidism, Primary/complications , Hyperparathyroidism, Primary/diagnostic imaging , Lumbar Vertebrae/diagnostic imaging , Male , Middle Aged , Observation , Parathyroidectomy/statistics & numerical data , Severity of Illness Index , Spinal Fractures/diagnostic imaging , Spinal Fractures/etiology , Thoracic Vertebrae/diagnostic imaging , Urinary Calculi/diagnostic imaging , Urinary Calculi/epidemiology , Urography , Watchful Waiting/statistics & numerical data
8.
Ann Surg ; 259(4): 800-6, 2014 Apr.
Article in English | MEDLINE | ID: mdl-23979292

ABSTRACT

OBJECTIVE: This investigation aimed at exploring the suitability of nonendocrine manifestations preceding medullary thyroid cancer (MTC) for early diagnosis of multiple endocrine neoplasia type 2B (MEN 2B). BACKGROUND: MEN 2B patients, running a high risk of metastatic MTC, must be diagnosed early for biochemical cure. METHODS: Forty-four MEN 2B patients carrying inherited (3 patients) and de novo (41 patients) M918T RET mutations were examined for signs and symptoms prompting MEN 2B. RESULTS: All 3 patients with inherited mutations were diagnosed before the age of 1 year and cured of their C-cell disease. Among 41 patients with de novo mutations, MEN 2B was diagnosed in 12 patients after recognition of nonendocrine manifestations [intestinal ganglioneuromatosis (6 patients), oral symptoms (5 patients), ocular ("tearless crying") (4 patients), and skeletal stigmata (1 patient) alone or concomitantly]. In the remaining 29 patients with de novo mutations, the diagnosis of MEN 2B was triggered by symptomatic MTC (28 patients) or pheochromocytoma (1 patient). The former patients, being significantly (P < 0.001) younger (means of 5.3 vs 17.6 years) and having lower calcitonin levels (means of 115 vs 25,519 pg/mL), smaller tumors (67% vs 0% were ≤10 mm) and less often extrathyroidal extension (0% vs 81%), lymph node (42% vs 100%), and distant metastases (8% vs 79%), were biochemically cured more often (58% vs 0%). CONCLUSIONS: MTC is curable in patients with de novo mutations when nonendocrine MEN 2B components are quickly appreciated and surgical intervention is performed before patients turn 4 years old.


Subject(s)
Biomarkers, Tumor/genetics , Multiple Endocrine Neoplasia Type 2b/diagnosis , Proto-Oncogene Proteins c-ret/genetics , Thyroid Neoplasms/surgery , Thyroidectomy , Adolescent , Adrenal Gland Neoplasms/diagnosis , Adrenal Gland Neoplasms/etiology , Adrenal Gland Neoplasms/genetics , Adrenal Gland Neoplasms/surgery , Adult , Carcinoma, Neuroendocrine , Child , Child, Preschool , Female , Follow-Up Studies , Genetic Markers , Humans , Infant , Kaplan-Meier Estimate , Male , Multiple Endocrine Neoplasia Type 2b/complications , Multiple Endocrine Neoplasia Type 2b/genetics , Multiple Endocrine Neoplasia Type 2b/surgery , Mutation , Neck Dissection , Pheochromocytoma/diagnosis , Pheochromocytoma/etiology , Pheochromocytoma/genetics , Pheochromocytoma/surgery , Retrospective Studies , Thyroid Neoplasms/diagnosis , Thyroid Neoplasms/etiology , Thyroid Neoplasms/genetics , Treatment Outcome , Young Adult
9.
Langenbecks Arch Surg ; 398(6): 869-74, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23778974

ABSTRACT

BACKGROUND: Primary aldosteronism (PA) is a frequent cause (about 10 %) of hypertension. Some cases of PA were recently found to be caused by mutations in the potassium channel KCNJ5. Our objective was to determine the mutation status of KCNJ5 and seven additional candidate genes for tumorigenesis: YY1, FZD4, ARHGAP9, ZFP37, KDM5C, LRP1B, and PDE9A and, furthermore, the surgical outcome of PA patients who underwent surgery in Western Norway. METHODS: Twenty-eight consecutive patients with aldosterone-producing adrenal tumors (20 patients with single adenoma, 8 patients with unilateral multiple adenomas or hyperplasia) who underwent surgery were included in this study. All patients were operated on by uncomplicated laparoscopic total adrenalectomy. Genomic DNA was isolated from tumor and non-tumor adrenocortical tissue, and DNA sequencing revealed the mutation status. RESULTS: Ten out of 28 (36 %) patients with PA displayed tumor mutations in KCNJ5 (p. G151R and L168R) while none were found in the corresponding non-tumor samples. No mutations were found in the other seven candidate genes screened. The presence of KCNJ5 mutations was associated with lower blood pressure and a higher chance for cure by surgery when compared to patients harboring the KCNJ5 wild type. CONCLUSIONS: KCNJ5 mutations are associated with a better surgical outcome. Preoperative identification of the mutation status might have impact on surgical strategy (total vs. subtotal adrenalectomy).


Subject(s)
Adrenal Gland Neoplasms/genetics , Adrenal Gland Neoplasms/surgery , G Protein-Coupled Inwardly-Rectifying Potassium Channels/genetics , Gene Expression Regulation, Neoplastic , Hyperaldosteronism/genetics , Hyperaldosteronism/surgery , Adrenal Gland Neoplasms/physiopathology , Adrenalectomy/adverse effects , Adrenalectomy/methods , Adult , Cohort Studies , Female , Follow-Up Studies , Genetic Predisposition to Disease , Humans , Hyperaldosteronism/physiopathology , Laparoscopy/adverse effects , Laparoscopy/methods , Male , Middle Aged , Mutation , Norway , Postoperative Complications/genetics , Postoperative Complications/physiopathology , Retrospective Studies , Risk Assessment , Treatment Outcome
10.
ACS Chem Biol ; 8(6): 1121-7, 2013.
Article in English | MEDLINE | ID: mdl-23557624

ABSTRACT

The N-termini of 80-90% of human proteins are acetylated by the N-terminal acetyltransferases (NATs), NatA-NatF. The major NAT complex, NatA, and particularly the catalytic subunit hNaa10 (ARD1) has been implicated in cancer development. For example, knockdown of hNaa10 results in cancer cell death and the arrest of cell proliferation. It also sensitized cancer cells to drug-induced cytotoxicity. Human NatE has a distinct substrate specificity and is essential for normal chromosome segregation. Thus, NAT inhibitors may potentially be valuable anticancer therapeutics, either directly or as adjuvants. Herein, we report the design and synthesis of the first inhibitors targeting these enzymes. Using the substrate specificity of the enzymes as a guide, we synthesized three bisubstrate analogues that potently and selectively inhibit the NatA complex (CoA-Ac-SES4; IC50 = 15.1 µM), hNaa10, the catalytic subunit of NatA (CoA-Ac-EEE4; Ki = 1.6 µM), and NatE/hNaa50 (CoA-Ac-MLG7; Ki* = 8 nM); CoA-Ac-EEE4 is a reversible competitive inhibitor of hNaa10, and CoA-Ac-MLG7 is a slow tight binding inhibitor of hNaa50. Our demonstration that it is possible to develop NAT selective inhibitors should assist future efforts to develop NAT inhibitors with more drug-like properties that can be used to chemically interrogate in vivo NAT function.


Subject(s)
Acetyltransferases/antagonists & inhibitors , Drug Design , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Acetylation , Acetyltransferases/metabolism , Amino Acid Sequence , Humans , Kinetics , Models, Molecular , Peptides/chemistry , Peptides/pharmacology , Substrate Specificity
11.
PLoS One ; 8(2): e56019, 2013.
Article in English | MEDLINE | ID: mdl-23418495

ABSTRACT

OBJECTIVE: Parathyroid hormone (PTH) and vitamin D are the most important hormones regulating calcium metabolism. In primary hyperparathyroidism (PHPT) excessive amounts of PTH are produced. Bone turnover is enhanced, leading to reduced bone mineral density and elevated levels of serum calcium. The aim of this study was to investigate relations between serum levels of 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and bone mineral density, as well as known genetic polymorphisms in the vitamin D receptor and enzymes metabolising vitamin D in patients with PHPT. DESIGN/SUBJECTS: We conducted a cross-sectional study of 52 patients with PHPT. RESULTS: Mean level of 25(OH)D was 58.2 nmol/L and median 1,25(OH)(2)D level was 157 pmol/L. Among our patients with PHPT 36.5% had 25(OH)D levels below 50 nmol/L. Serum 1,25(OH)(2)D was inversely correlated to bone mineral density in distal radius (p = 0.002), but not to bone mineral density at lumbar spine or femoral neck. The vitamin D receptor polymorphism Apa1 (rs7975232) was associated with bone mineral density in the lumbar spine. CONCLUSIONS: The results suggest that PHPT patients with high blood concentrations of 1,25(OH)(2)D may have the most deleterious skeletal effects. Randomized, prospective studies are necessary to elucidate whether vitamin D supplementation additionally increases serum 1,25(OH)(2)D and possibly enhances the adverse effects on the skeleton in patients with PHPT.


Subject(s)
Bone Density/genetics , Hyperparathyroidism, Primary/genetics , Polymorphism, Single Nucleotide , Receptors, Calcitriol/genetics , Vitamin D/analogs & derivatives , Adult , Aged , Alleles , Bone and Bones/physiopathology , Cross-Sectional Studies , Female , Genotype , Humans , Hyperparathyroidism, Primary/blood , Hyperparathyroidism, Primary/physiopathology , Male , Middle Aged , Prospective Studies , Vitamin D/blood
12.
Thyroid ; 21(11): 1217-25, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22007921

ABSTRACT

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.


Subject(s)
GTP-Binding Proteins/biosynthesis , Neoplasm Proteins/biosynthesis , Receptors, Cell Surface/biosynthesis , Thyroid Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Carcinoma , Carcinoma, Papillary , Extracellular Signal-Regulated MAP Kinases/metabolism , Female , GTP-Binding Proteins/genetics , Humans , MAP Kinase Signaling System , Male , Middle Aged , Mutation , Neoplasm Proteins/genetics , Proto-Oncogene Proteins B-raf/genetics , Receptors for Activated C Kinase , Receptors, Cell Surface/genetics , Thyroid Cancer, Papillary , Thyroid Neoplasms/genetics , Thyroid Neoplasms/pathology , Young Adult
13.
PLoS One ; 6(9): e24713, 2011.
Article in English | MEDLINE | ID: mdl-21935442

ABSTRACT

Protein N(α)-terminal acetylation (Nt-acetylation) is considered one of the most common protein modification in eukaryotes, and 80-90% of all soluble human proteins are modified in this way, with functional implications ranging from altered protein function and stability to translocation potency amongst others. Nt-acetylation is catalyzed by N-terminal acetyltransferases (NATs), and in yeast five NAT types are identified and denoted NatA-NatE. Higher eukaryotes additionally express NatF. Except for NatD, human orthologues for all yeast NATs are identified. yNatD is defined as the catalytic unit Naa40p (Nat4) which co-translationally Nt-acetylates histones H2A and H4. In this study we identified and characterized hNaa40p/hNatD, the human orthologue of the yeast Naa40p. An in vitro proteome-derived peptide library Nt-acetylation assay indicated that recombinant hNaa40p acetylates N-termini starting with the consensus sequence Ser-Gly-Gly-Gly-Lys-, strongly resembling the N-termini of the human histones H2A and H4. This was confirmed as recombinant hNaa40p Nt-acetylated the oligopeptides derived from the N-termini of both histones. In contrast, a synthetically Nt-acetylated H4 N-terminal peptide with all lysines being non-acetylated, was not significantly acetylated by hNaa40p, indicating that hNaa40p catalyzed H4 N(α)-acetylation and not H4 lysine N(ε)-acetylation. Also, immunoprecipitated hNaa40p specifically Nt-acetylated H4 in vitro. Heterologous expression of hNaa40p in a yeast naa40-Δ strain restored Nt-acetylation of yeast histone H4, but not H2A in vivo, probably reflecting the fact that the N-terminal sequences of human H2A and H4 are highly similar to each other and to yeast H4 while the N-terminal sequence of yeast H2A differs. Thus, Naa40p seems to have co-evolved with the human H2A sequence. Finally, a partial co-sedimentation with ribosomes indicates that hNaa40p co-translationally acetylates H2A and H4. Combined, our results strongly suggest that human Naa40p/NatD is conserved from yeast. Thus, the NATs of all classes of N-terminally acetylated proteins in humans now appear to be accounted for.


Subject(s)
Acetyltransferases/chemistry , Acetyltransferases/metabolism , Histones/metabolism , Yeasts/enzymology , Acetylation , Acetyltransferases/genetics , Amino Acid Sequence , Humans , Immunoprecipitation , Molecular Sequence Data , N-Terminal Acetyltransferase D , Protein Binding , Sequence Homology, Amino Acid
14.
PLoS One ; 6(6): e20481, 2011.
Article in English | MEDLINE | ID: mdl-21698093

ABSTRACT

BACKGROUND: Primary hyperparathyroidism (PHPT) is characterised by increased production of parathyroid hormone (PTH) resulting in elevated serum calcium levels. The influence on bone metabolism with altered bone resorption is the most studied clinical condition in PHPT. In addition to this, patients with PHPT are at increased risk of non-skeletal diseases, such as impaired insulin sensitivity, arterial hypertension and increased risk of death by cardiovascular diseases (CVD), possibly mediated by a chronic low-grade inflammation. The aim of this study was to investigate whether adipose tissue reflects the low-grade inflammation observed in PHPT patients. METHODOLOGY/PRINCIPAL FINDINGS: Subcutaneous fat tissue from the neck was sampled from 16 non-obese patients with PHPT and from 16 patients operated for benign thyroid diseases, serving as weight-matched controls. RNA was extracted and global gene expression was analysed with Illumina BeadArray Technology. We found 608 differentially expressed genes (q-value<0.05), of which 347 were up-regulated and 261 were down-regulated. Gene ontology analysis showed that PHPT patients expressed increased levels of genes involved in immunity and defense (e.g. matrix metallopeptidase 9, S100 calcium binding protein A8 and A9, CD14, folate receptor 2), and reduced levels of genes involved in metabolic processes. Analysis of transcription factor binding sites present in the differentially expressed genes corroborated the up-regulation of inflammatory processes. CONCLUSIONS/SIGNIFICANCE: Our findings demonstrate that PHPT strongly influences gene regulation in fat tissue, which may result in altered adipose tissue function and release of pathogenic factors that increase the risk of CVD.


Subject(s)
Adipose Tissue/metabolism , Energy Metabolism/genetics , Gene Expression Regulation , Hyperparathyroidism, Primary/genetics , Inflammation Mediators/metabolism , Base Sequence , Case-Control Studies , DNA Primers , Female , Humans , Male , Oligonucleotide Array Sequence Analysis , Polymerase Chain Reaction
16.
Case Rep Med ; 20102010.
Article in English | MEDLINE | ID: mdl-20814560

ABSTRACT

Internal jugular vein thrombosis is a serious event with potentially fatal outcome, where the clinical symptoms may be vague or absent. This paper refers to a rare case where routine carotid Doppler ultrasound prior to coronary artery bypass grafting (CABG) and aortic valve replacement (AVR) in a 76-year-old man, incidentally revealed thrombosis of the right internal jugular vein. Thoracic CT demonstrated an underlying, large, benign substernal multinodular goiter, mainly involving the right lobe, causing compression and displacement of the great vessels. A successful, one-stage operation including ligation of the internal jugular vein to avoid pulmonary embolism and hemithyroidectomy, combined with the scheduled CABG and AVR, was performed. This case illustrates that benign substernal goiter may be associated with asymptomatic internal jugular vein thrombosis. Carotid Doppler ultrasound should involve evaluation of the internal jugular vein concerning thrombosis as its presence may reveal space-occupying lesions in the thorax.

17.
Langenbecks Arch Surg ; 395(7): 851-8, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20683623

ABSTRACT

PURPOSE: Approximately 5% of differentiated thyroid carcinomas are of familial origin. These familial nonmedullary thyroid carcinomas (FNMTC) have an increased risk of multifocal disease and lymph node involvement. Consequently, higher recurrence rates and decreased disease-specific survival rates are described. The best surgical approach is discussed controversially. PATIENTS AND METHODS: A survey among the international members of the German Society of Endocrine Surgeons revealed 20 families with two or more first-degree relatives with FNMTC. The mean age of the 41 patients (30 female, 11 male) with FNMTC was 40.6 years (18-73 years). RESULTS: Total thyroidectomy was performed in 31 of 41 patients (76%). Ninety-five percent of the tumors were papillary carcinomas. Two of 41 patients had follicular carcinomas. Ten patients (24%) with papillary carcinomas were diagnosed with Hashimoto's thyroiditis. The mean tumor size was 1.45 cm. FNMTC was multifocal in 12 patients (29%). A systematic lymph node dissection was performed in 21 of 41 patients (51%). Lymph nodes metastases were found in seven of these 21 patients. Twenty-eight of the patients (68%) underwent postoperative radioiodine ablation. After a mean follow-up of 7.2 years, 39 patients (95%) were disease free. One patient developed local recurrence and lung metastases, 10 and 25 years, respectively, after initial diagnosis. Another patient died 2 years postoperatively from advanced metastatic disease. CONCLUSIONS: FNMTC is associated with an early onset of small, mostly papillary thyroid carcinomas and an increased risk of multifocality and lymph node involvement. Total thyroidectomy and systematic neck dissection are recommended together with radioiodine ablation. Screening for first-degree relatives should start at age 18 years.


Subject(s)
Lymph Nodes/pathology , Thyroid Neoplasms/pathology , Thyroid Neoplasms/surgery , Thyroidectomy/methods , Adenocarcinoma, Follicular/genetics , Adenocarcinoma, Follicular/mortality , Adenocarcinoma, Follicular/pathology , Adenocarcinoma, Follicular/secondary , Adenocarcinoma, Follicular/surgery , Adenocarcinoma, Papillary/genetics , Adenocarcinoma, Papillary/mortality , Adenocarcinoma, Papillary/pathology , Adenocarcinoma, Papillary/secondary , Adenocarcinoma, Papillary/surgery , Adolescent , Adult , Aged , Biopsy, Needle , Cohort Studies , Disease-Free Survival , Female , Genetic Predisposition to Disease , Germany , Humans , Immunohistochemistry , Lung Neoplasms/secondary , Lymph Node Excision/methods , Lymphatic Metastasis , Male , Middle Aged , Neck Dissection/methods , Neoplasm Invasiveness/pathology , Neoplasm Staging , Pedigree , Prognosis , Risk Assessment , Survival Analysis , Thyroid Neoplasms/genetics , Thyroid Neoplasms/mortality , Treatment Outcome , Young Adult
18.
BMC Cancer ; 10: 313, 2010 Jun 21.
Article in English | MEDLINE | ID: mdl-20565970

ABSTRACT

BACKGROUND: The cytochrome P450 (CYP) enzymes 2C19, 2D6, and 3A5 are responsible for converting the selective estrogen receptor modulator (SERM), tamoxifen to its active metabolites 4-hydroxy-tamoxifen (4OHtam) and 4-hydroxy-N-demethyltamoxifen (4OHNDtam, endoxifen). Inter-individual variations of the activity of these enzymes due to polymorphisms may be predictors of outcome of breast cancer patients during tamoxifen treatment. Since tamoxifen and estrogens are both partly metabolized by these enzymes we hypothesize that a correlation between serum tamoxifen and estrogen levels exists, which in turn may interact with tamoxifen on treatment outcome. Here we examined relationships between the serum levels of tamoxifen, estrogens, follicle-stimulating hormone (FSH), and also determined the genotypes of CYP2C19, 2D6, 3A5, and SULT1A1 in 90 postmenopausal breast cancer patients. METHODS: Tamoxifen and its metabolites were measured by liquid chromatography-tandem mass spectrometry. Estrogen and FSH levels were determined using a sensitive radio- and chemiluminescent immunoassay, respectively. RESULTS: We observed significant correlations between the serum concentrations of tamoxifen, N-dedimethyltamoxifen, and tamoxifen-N-oxide and estrogens (p < 0.05). The genotype predicted CYP2C19 activity influenced the levels of both tamoxifen metabolites and E1. CONCLUSIONS: We have shown an association between tamoxifen and its metabolites and estrogen serum levels. An impact of CYP2C19 predicted activity on tamoxifen, as well as estrogen kinetics may partly explain the observed association between tamoxifen and its metabolites and estrogen serum levels. Since the role of estrogen levels during tamoxifen therapy is still a matter of debate further prospective studies to examine the effect of tamoxifen and estrogen kinetics on treatment outcome are warranted.


Subject(s)
Breast Neoplasms/blood , Breast Neoplasms/drug therapy , Estrogens/blood , Follicle Stimulating Hormone/blood , Tamoxifen/blood , Tamoxifen/therapeutic use , Aged , Aged, 80 and over , Antineoplastic Agents, Hormonal/blood , Antineoplastic Agents, Hormonal/therapeutic use , Aryl Hydrocarbon Hydroxylases/genetics , Breast Neoplasms/genetics , Cytochrome P-450 CYP2C19 , Cytochrome P-450 CYP2D6/genetics , Cytochrome P-450 CYP3A/genetics , Female , Genotype , Humans , Middle Aged , Polymerase Chain Reaction , Polymorphism, Genetic/genetics , Postmenopause , Treatment Outcome
19.
Tidsskr Nor Laegeforen ; 130(7): 724-8, 2010 Apr 08.
Article in Norwegian | MEDLINE | ID: mdl-20379332

ABSTRACT

BACKGROUND: We wanted to check if our routines for diagnosing and treating primary operable breast cancer and ductal carcinoma in situ were concordant with national guidelines and quality standards. MATERIAL AND METHODS: Data were retrospectively collected from medical journals for all relevant patients operated at Alesund Hospital, Norway from 1.11.02 to 1.05.08. RESULTS: 487 breasts were operated in 478 patients. A triple-diagnostic approach (mammography/ultrasound, clinical examination and biopsy) was used in 98 % of patients and ultrasound-guided core-needle-biopsy in 86 %. For 82 % of patients one visit in an out-patient-department was enough to conclude with a malignant diagnosis. A sentinel node biopsy was taken for 378 of 457 (83 %) patients operated in the axilla; a sentinel node was found in 93 % of them. Three (median) sentinel nodes were removed (spread in the range 1 - 12). 51 % of patients had breast-conserving surgery. From diagnosis of cancer to completion of all surgical procedures, 57 patients (12 %) had two operations, three (0.6 %) had three operations (in the breast and axilla), and 89 % of patients had completed all surgery within three weeks.13 % of patients had postoperative complications. After axillary lymph-node dissection, 20 % of patients had lymph-oedema/shoulder/arm pain. Three patients had ipsilateral relapse in the breast or thoracic wall. None had axillary relapse after sentinel-node biopsy. The median observation time was 26 months (0 - 66 months). INTERPRETATION: The results of diagnosis and treatment in our hospital are in good accordance with our national guidelines and quality standards.


Subject(s)
Breast Neoplasms , Adult , Aged , Aged, 80 and over , Breast Neoplasms/diagnosis , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Carcinoma in Situ/diagnosis , Carcinoma in Situ/pathology , Carcinoma in Situ/surgery , Carcinoma, Ductal, Breast/diagnosis , Carcinoma, Ductal, Breast/pathology , Carcinoma, Ductal, Breast/surgery , Female , Guideline Adherence , Humans , Lymph Node Excision , Mammography , Mastectomy, Segmental , Middle Aged , Neoplasm Recurrence, Local , Norway , Postoperative Complications/etiology , Practice Guidelines as Topic , Quality Assurance, Health Care , Retrospective Studies , Sentinel Lymph Node Biopsy
20.
Int J Cancer ; 127(12): 2777-89, 2010 Dec 15.
Article in English | MEDLINE | ID: mdl-21351257

ABSTRACT

The human protein N(α)-terminal acetyltransferase A complex (hNatA), composed of the catalytic hNaa10p (hArd1) and auxiliary hNaa15p (hNat1/NATH/Tubedown) subunits, was reported to be important for cell survival and growth of various types of cancer. However, little is known about the mechanisms mediating growth inhibition and apoptosis following loss of hNatA function. Here, we have screened 11 different thyroid cell lines for hNAA10 RNAi phenotypes and observed mostly growth inhibition, which was independent of TP53 functional status and developed by several different mechanisms involving (i) downregulation of cyclin D1, (ii) increase in p27/Kip1 and (iii) inactivation of Rb/E2F pathway. hNatA depletion in aggressive thyroid cancer cell lines (8305C, CAL-62 and FTC-133) with mutated TP53 increased sensitivity to drug-induced cytotoxicity, but in a cell type specific manner: 8305C (TRAIL), CAL-62 (daunorubicin) and FTC-133 (troglitazone). Cells harboring wild-type TP53 were also prone to apoptosis via the p53 pathway after hNatA downregulation. Importantly, in hNatA-depleted cells DNA-damage signaling was activated in the absence of exogenous DNA damage independent on TP53 status. Our findings indicate that several mechanisms of growth inhibition and apoptosis may be induced by hNatA knockdown and that hNatA knockdown could be exploited for use in combinatorial chemotherapy.


Subject(s)
Apoptosis , Arylamine N-Acetyltransferase/genetics , Isoenzymes/genetics , RNA Interference , Thyroid Neoplasms/enzymology , Thyroid Neoplasms/pathology , Tumor Suppressor Protein p53/metabolism , Blotting, Western , Carcinoma/enzymology , Carcinoma/genetics , Carcinoma/pathology , Carcinoma, Papillary/enzymology , Carcinoma, Papillary/genetics , Carcinoma, Papillary/pathology , Cell Cycle , Cell Differentiation , Cell Proliferation , Drug Resistance, Neoplasm , Humans , Immunoenzyme Techniques , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Reverse Transcriptase Polymerase Chain Reaction , Thyroid Neoplasms/genetics , Tumor Cells, Cultured , Tumor Suppressor Protein p53/genetics
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