The NAD(+)/Sirtuin Pathway Modulates Longevity through Activation of Mitochondrial UPR and FOXO Signaling.

NAD(+) is an important cofactor regulating metabolic homeostasis and a rate-limiting substrate for sirtuin deacylases. We show that NAD(+) levels are reduced in aged mice and Caenorhabditis elegans and that decreasing NAD(+) levels results in a further reduction in worm lifespan. Conversely, genetic or pharmacological restoration of NAD(+) prevents age-associated metabolic decline and promotes longevity in worms. These effects are dependent upon the protein deacetylase sir-2.1 and involve the induction of mitonuclear protein imbalance as well as activation of stress signaling via the mitochondrial unfolded protein response (UPR(mt)) and the nuclear translocation and activation of FOXO transcription factor DAF-16. Our data suggest that augmenting mitochondrial stress signaling through the modulation of NAD(+) levels may be a target to improve mitochondrial function and prevent or treat age-associated decline.

Impact of Dyslipidemia on the Risk of Second Cancer in Thyroid Cancer Patients: A Korean National Cohort Study.

BACKGROUND: Studies have shown that radioactive iodine therapy (RAIT) affects the development of second cancer in thyroid cancer patients. The impact of other factors, such as dyslipidemia are not clear. METHODS: A retrospective analysis of thyroid cancer patients with a 1,251,913 person-year follow-up was conducted using data from the Health Insurance Review and Assessment database in South Korea from January 2008 to December 2018. We investigated factors related to second cancer development using a nested case-control analysis to avoid length bias. RESULTS: The overall risk of developing second cancer was higher in thyroid cancer patients than in the general population [standardized incidence ratio, 3.34; 95% confidence interval (CI) 3.30-3.39]. Second cancer incidence was higher in patients who received RAIT than in those who did not [odds ratio (OR) 1.130; 95% CI 1.094-1.169]. Moreover, the risk of second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.265; 95% CI 1.223-1.309). After adjustment for RAIT, the incidence of a second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.262; 95% CI 1.221-1.306). CONCLUSIONS: The risk of second cancer development in patients with thyroid cancer appears to be high. Dyslipidemia may be associated with an increased risk of several types of second cancers.

Whole Exome Sequencing Identifies a Novel Hedgehog-Interacting Protein G516R Mutation in Locally Advanced Papillary Thyroid Cancer.

Locally advanced thyroid cancer exhibits aggressive clinical features requiring extensive neck dissection. Therefore, it is important to identify changes in the tumor biology before local progression. Here, whole exome sequencing (WES) using tissues from locally advanced papillary thyroid cancer (PTC) presented a large number of single nucleotide variants (SNVs) in the metastatic lymph node (MLN), but not in normal tissues and primary tumors. Among those MLN-specific SNVs, a novel HHIP G516R (G1546A) mutation was also observed. Interestingly, in-depth analysis for exome sequencing data from the primary tumor presented altered nucleotide 'A' at a very low frequency indicating intra-tumor heterogeneity between the primary tumor and MLN. Computational prediction models such as PROVEAN and Polyphen suggested that HHIP G516R might affect protein function and stability. In vitro, HHIP G516R increased cell proliferation and promoted cell migration in thyroid cancer cells. HHIP G516R, a missense mutation, could be a representative example for the intra-tumor heterogeneity of locally advanced thyroid cancer, which can be a potential future therapeutic target for this disease.

Transaxillary robotic modified radical neck dissection: a 5-year assessment of operative and oncologic outcomes.

BACKGROUND: Robotic modified radical neck dissection (MRND) using a gasless transaxillary approach has been reported to be a safe and meticulous technique in patients with papillary thyroid carcinoma (PTC) and lateral neck node metastasis (N1b). Few studies, however, have attempted to assess the long-term oncologic outcomes of robotic MRND in these patients. This study aimed to compare perioperative and 5-year oncologic outcomes of robotic MRND with conventional open procedures in patients with N1b PTC. METHODS: Between September 2007 and February 2010, 193 patients with N1b PTC underwent total thyroidectomy and MRND by a single surgeon. Of these, 42 (21.8 %) underwent robotic procedures and 151 (78.2 %) underwent conventional open procedures. All patients received 3.7- to 5.5-GBq radioactive iodine (RAI) ablation, post-therapy whole-body scans (TxWBSs), and diagnostic WBS (DxWBSs) during follow-up. An exact 1:3 matching for age and stage was performed to minimize selection bias, and perioperative and 5-year oncologic outcomes were compared in the matched groups. RESULTS: The mean follow-up period was 66.0 months (range 60-90 months). Number of retrieved cervical lymph nodes (LNs) (p = .102) and postoperative ablation success rates (p = .864) were similar between the two groups. TSH-suppressed serum Tg concentrations after 5 years (0.7 ± 1.5 vs. 2.4 ± 14.1 ng/ml; p = .471) and recurrence rates in the robotic and open groups (1/41 [2.4 %] vs. 3/102 [2.9 %]; p = .864) were similar for the 5-year follow-up period. Four patients experienced recurrence: Three exhibited regional lymph node metastasis, and one showed bilateral lung metastases. CONCLUSION: The perioperative and 5-year oncologic outcomes were similar after robotic and conventional open MRND. Large, prospective randomized controlled trials with long-term follow-up data are needed to validate these results.

Phosphorylation of the nuclear receptor corepressor 1 by protein kinase B switches its corepressor targets in the liver in mice.

UNLABELLED: Nuclear receptor corepressor 1 (NCoR1) is a transcriptional coregulator that has wide-ranging effects on gene expression patterns. In the liver, NCoR1 represses lipid synthesis in the fasting state, whereas it inhibits activation of peroxisome proliferator-activated receptor alpha (PPARα) upon feeding, thereby blunting ketogenesis. Here, we show that insulin by activation of protein kinase B induces phosphorylation of NCoR1 on serine 1460, which selectively favors its interaction with PPARα and estrogen-related receptor alpha (ERRα) over liver X receptor alpha (LXRα). Phosphorylation of NCoR1 on S1460 selectively derepresses LXRα target genes, resulting in increased lipogenesis, whereas, at the same time, it inhibits PPARα and ERRα targets, thereby attenuating oxidative metabolism in the liver. Phosphorylation-gated differential recruitment of NCoR1 to different nuclear receptors explains the apparent paradox that liver-specific deletion of NCoR1 concurrently induces both lipogenesis and oxidative metabolism owing to a global derepression of LXRα, PPARα, and ERRα activity. CONCLUSION: Phosphorylation-mediated recruitment switch of NCoR1 between nuclear receptor subsets provides a mechanism by which corepressors can selectively modulate liver energy metabolism during the fasting-feeding transition.

Long-term oncologic outcome of robotic versus open total thyroidectomy in PTC: a case-matched retrospective study.

PURPOSE: The role of the robot in thyroid surgery remains uncertain, and it is unclear whether robotic total thyroidectomy (R-TT) can be justified as a standard treatment for patients with thyroid cancer. This study compared the long-term operative results and oncologic outcomes of R-TT and conventional open TT (O-TT) after propensity score matching of the cohorts. METHODS: This study retrospectively evaluated patients with papillary thyroid cancer (PTC) who underwent TT with central compartment node dissection (CCND) by a single surgeon in tertiary medical center. Of the 833 patients, 94 (11.3 %) were lost to follow-up. 245 (33.2 %) underwent R-TT, and 494 (66.8 %) underwent O-TT. The mean follow-up duration was 74 (range 61-91) months. Propensity score matching in age, gender, tumor size, extrathyroidal invasion, multiplicity, bilaterality, and TNM stage identified 206 pairs of patients. The long-term oncologic outcomes were assessed in the R-TT and O-TT groups before and after adjustment for baseline covariates. RESULTS: After adjustment for baseline covariates, serum thyroglobulin (Tg) (p = 0.746) and anti-thyroglobulin antibody (TgAb) (p = 0.394) concentrations were similar in the two groups 5 years after surgery. Nine patients experienced locoregional recurrence, six in the O-TT and three in the R-TT group, with all recurrences in regional LNs. Disease-free survival (DFS) was similar in the R-TT and O-TT groups before matching (p = 0.890) and after adjustment for baseline covariates (p = 0.882). CONCLUSION: This represents the first report of 5-year surgical outcomes in patients who underwent R-TT for thyroid cancer. Long-term oncologic quality was similar after R-TT and O-TT.

Crif1 deficiency reduces adipose OXPHOS capacity and triggers inflammation and insulin resistance in mice.

Impaired mitochondrial oxidative phosphorylation (OXPHOS) has been proposed as an etiological mechanism underlying insulin resistance. However, the initiating organ of OXPHOS dysfunction during the development of systemic insulin resistance has yet to be identified. To determine whether adipose OXPHOS deficiency plays an etiological role in systemic insulin resistance, the metabolic phenotype of mice with OXPHOS-deficient adipose tissue was examined. Crif1 is a protein required for the intramitochondrial production of mtDNA-encoded OXPHOS subunits; therefore, Crif1 haploinsufficient deficiency in mice results in a mild, but specific, failure of OXPHOS capacity in vivo. Although adipose-specific Crif1-haploinsufficient mice showed normal growth and development, they became insulin-resistant. Crif1-silenced adipocytes showed higher expression of chemokines, the expression of which is dependent upon stress kinases and antioxidant. Accordingly, examination of adipose tissue from Crif1-haploinsufficient mice revealed increased secretion of MCP1 and TNFα, as well as marked infiltration by macrophages. These findings indicate that the OXPHOS status of adipose tissue determines its metabolic and inflammatory responses, and may cause systemic inflammation and insulin resistance.

Dysregulation of Parkin-mediated mitophagy in thyroid Hürthle cell tumors.

Abnormal accumulation of defective mitochondria is the hallmark of oncocytes, which are frequently observed in thyroid Hürthle cell lesions. Autophagy is an essential cellular catabolic mechanism for the degradation of dysfunctional organelles and has been implicated in several human diseases. It is yet unknown how autophagic turnover of defective mitochondria in Hürthle cell tumors is regulated. We characterized the expression patterns of molecular markers including Beclin1, LC3, PINK1 and Parkin, which are required for autophagy or mitophagy, in human oncocytic lesions of the thyroid. To undertake mechanistic studies, we investigated autophagy and mitophagy using XTC.UC1 cells, the only in vitro model of Hürthle cell tumors. Beclin1 and LC3 were highly expressed in oncocytes of Hürthle cell tumors. XTC.UC1 showed autophagic responses to starvation and rapamycin treatment, whereas they displayed ineffective activation of mitophagy, which is triggered by the coordinated action of PINK1 and Parkin in response to CCCP. This resulted in a decreased turnover of abnormal mitochondria. The mechanisms underlying defective mitophagy and mitochondrial turnover were investigated by genetic analysis of the PARK2 gene in XTC.UC1 and Hürthle cell tumor tissues. XTC.UC1 and several tumors harbored the V380L mutation, resulting in dysfunctional autoubiquitination and decreased E3 ligase activity. Consistently, oncocytes in Hürthle cell tumors displayed comparable expression of PINK1 but decreased Parkin expression in comparison to normal thyrocytes. The introduction of wild-type Parkin sensitized XTC.UC1 to death induced by CCCP. This study provides a possible etiological basis for oncocytic formation in heterogeneous Hürthle cell tumors through insufficient mitophagy leading to ineffective turnover of aberrant mitochondria caused by dysfunctional Parkin-mediated pathways of mitochondria quality control.

Association Between Obesity and BRAFV600E Mutation Status in Patients with Papillary Thyroid Cancer.

BACKGROUND: The prevalence of papillary thyroid cancer (PTC) is thought to be related to obesity, which affects the prognosis for PTC patients. However, the mechanisms implicated in the relationship between obesity and PTC is a matter for debate. In this study, we aimed to gain insight into the relationship between obesity and the clinicopathological features of PTC, including the BRAFV600E mutation. METHODS: The medical records of 1121 PTC patients were reviewed and the relationships between anthropometric factors, biochemical parameters, and clinicopathological parameters, including BRAFV600E mutation status, were analyzed. RESULTS: Body mass index (BMI) showed a strong association with advanced TNM stage (p < 0.001) and BRAFV600E mutation status (p = 0.008). We also found that BRAFV600E (+) patients had a higher body weight (p = 0.024) and a higher BMI (p = 0.003) than patients with BRAFV600E (-) PTC. In addition, BRAFV600E (+) PTC patients had a significantly higher incidence of extrathyroidal extension (p = 0.025) and more advanced T, N, TNM stage (p < 0.001) than BRAFV600E (-) PTC patients. Consistent with this observation, female BRAFV600E (+) PTC patients had a higher BMI (p = 0.011) and more aggressive tumor behaviors than female BRAFV600E (-) PTC patients. In multivariate analysis, BMI was persistently associated with BRAFV600E mutation in the entire cohort (odds ratio [OR] 1.387; 95 % CI 1.036-1.859; p = 0.028) and in the female subcohort (OR 1.221; 95 % CI 1.014-1.631; p = 0.046). CONCLUSION: The positive association between BMI and BRAFV600E supports the hypothesis that excessive bodyweight influences tumor progression.

IGF-1 receptor deficiency in thyrocytes impairs thyroid hormone secretion and completely inhibits TSH-stimulated goiter.

Although thyroid-stimulating hormone (TSH) is known to be a major regulator of thyroid hormone biosynthesis and thyroid growth, insulin-like growth factor 1 (IGF-1) is required for mediating thyrocyte growth in concert with TSH in vitro. We generated mice with thyrocyte-selective ablation of IGF-1 receptor (TIGF1RKO) to explore the role of IGF-1 receptor signaling on thyroid function and growth. In 5-wk-old TIGF1RKO mice, serum thyroxine (T4) concentrations were decreased by 30% in concert with a 43% down-regulation of the monocarboxylate transporter 8 (MCT8), which is involved in T4 secretion. Despite a 3.5-fold increase in circulating concentrations of TSH, thyroid architecture and size were normal. Furthermore, thyrocyte area was increased by 40% in WT thyroids after 10 d TSH injection, but this effect was absent in TSH-injected TIGF1RKO mice. WT mice treated with methimazole and sodium perchlorate for 2 or 6 wk exhibited pronounced goiter development (2.0 and 5.4-fold, respectively), but in TIGF1RKO mice, goiter development was completely abrogated. These data reveal an essential role for IGF-1 receptor signaling in the regulation of thyroid function and TSH-stimulated goitrogenesis.

Impact of thyroid hormone replacement on the risk of second cancer after thyroidectomy: a Korean National Cohort Study.

We aimed to investigate the effect of thyroid hormone administration on the risk of second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer. Data were extracted from the medical billing data of the Health Insurance Review and Assessment Service in South Korea. Patients between 19 and 80 years old who underwent thyroid surgery at least once between January 2009 and June 2020 were included. Data of patients with second primary cancer and control patients with matched age, sex, operation date, and follow-up duration were extracted at a ratio of 1:4. A nested case-control analysis was performed to exclude length bias to confirm the correlation between the duration of thyroid hormone administration, dose, and incidence of second primary cancer. Of the 261,598 patients who underwent surgery for thyroid cancer included in the study, 11,790 with second primary cancer and 47,160 without second primary cancer were matched. The average dose of thyroid hormone increased the adjusted odds ratio (OR) for both low (≤ 50 µg, OR 1.29, confidence interval (CI) 1.12-1.48) and high (< 100 µg, OR 1.24, CI 1.12-1.37) doses. Analyzing over time, the adjusted OR of second primary cancer increased, especially in short (≤ 1 year) (OR 1.19; CI 1.06-1.34) and long (> 5 years) duration (OR 1.25; CI 1.10-1.41). In conclusion, insufficient and excessive thyroid hormone replacement might be linked to increased second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer.

Impact of thyroid cancer on the cancer risk in patients with non-alcoholic fatty liver disease or dyslipidemia.

The raised prevalence of obesity has increased the incidence of obesity-related metabolic diseases such as dyslipidemia (DL) and non-alcoholic fatty liver disease (NAFLD), along with the development and progression of various types of cancer, including thyroid cancer. In this study, we investigated whether thyroid cancer in patients with DL and NAFLD could be a risk factor for other cancers. To achieve our goal, we generated two independent cohorts from our institution and from the National Health Insurance System in South Korea. Based on the ICD-10 code, we conducted exact matching (1:5 matching) and estimated the overall risk of thyroid cancer for other cancers in patients with DL or NAFLD. Univariate and multivariate analyses showed that the hazard ratio (HR) of thyroid cancer was 2.007 (95% Confidence Interval [CI], 1.597-2.522) and 2.092 (95% CI, 1.546-2.829), respectively in the institutional cohort and 1.329 (95% CI, 1.153-1.533) and 1.301 (95% CI, 1.115-1.517), respectively in the nationwide cohort. Risk analysis revealed a significant increase in the HR in lip, tongue, mouth, lung, bone, joint, soft tissue, skin, brain, male cancers and lymphoma after thyroid cancer occurred. Thyroid cancer in patients with DL or NAFLD might be a valuable factor for predicting the development of other cancers.

Comparative Analysis of Driver Mutations and Transcriptomes in Papillary Thyroid Cancer by Region of Residence in South Korea.

BACKGRUOUND: Radiation exposure is a well-known risk factor for papillary thyroid cancer (PTC). South Korea has 24 nuclear reactors in operation; however, no molecular biological analysis has been performed on patients with PTC living near nuclear power plants. METHODS: We retrospectively included patients with PTC (n=512) divided into three groups according to their place of residence at the time of operation: inland areas (n=300), coastal areas far from nuclear power plants (n=134), and nuclear power plant areas (n=78). After propensity score matching (1:1:1) by age, sex, and surgical procedure, the frequency of representative driver mutations and gene expression profiles were compared (n=50 per group). Epithelial-mesenchymal transition (EMT), BRAF, thyroid differentiation, and radiation scores were calculated and compared. RESULTS: No significant difference was observed in clinicopathological characteristics, including radiation exposure history and the frequency of incidentally discovered thyroid cancer, among the three groups. BRAFV600E mutation was most frequently detected in the groups, with no difference among the three groups. Furthermore, gene expression profiles showed no statistically significant difference. EMT and BRAF scores were higher in our cohort than in cohorts from Chernobyl tissue bank and The Cancer Genome Atlas Thyroid Cancer; however, there was no difference according to the place of residence. Radiation scores were highest in the Chernobyl tissue bank but exhibited no difference according to the place of residence. CONCLUSION: Differences in clinicopathological characteristics, frequency of representative driver mutations, and gene expression profiles were not observed according to patients' region of residence in South Korea.

Immune response and mesenchymal transition of papillary thyroid carcinoma reflected in ultrasonography features assessed by radiologists and deep learning.

INTRODUCTION: Ultrasonography (US) features of papillary thyroid cancers (PTCs) are used to select nodules for biopsy due to their association with tumor behavior. However, the molecular biological mechanisms that lead to the characteristic US features of PTCs are largely unknown. OBJECTIVES: This study aimed to investigate the molecular biological mechanisms behind US features assessed by radiologists and three convolutional neural networks (CNN) through transcriptome analysis. METHODS: Transcriptome data from 273 PTC tissue samples were generated and differentially expressed genes (DEGs) were identified according to US feature. Pathway enrichment analyses were also conducted by gene set enrichment analysis (GSEA) and ClusterProfiler according to assessments made by radiologists and three CNNs - CNN1 (ResNet50), CNN2 (ResNet101) and CNN3 (VGG16). Signature gene scores for PTCs were calculated by single-sample GSEA (ssGSEA). RESULTS: Individual suspicious US features consistently suggested an upregulation of genes related to immune response and epithelial-mesenchymal transition (EMT). Likewise, PTCs assessed as positive by radiologists and three CNNs showed the coordinate enrichment of similar gene sets with abundant immune and stromal components. However, PTCs assessed as positive by radiologists had the highest number of DEGs, and those assessed as positive by CNN3 had more diverse DEGs and gene sets compared to CNN1 or CNN2. The percentage of PTCs assessed as positive or negative concordantly by radiologists and three CNNs was 85.6% (231/273) and 7.1% (3/273), respectively. CONCLUSION: US features assessed by radiologists and CNNs revealed molecular biologic features and tumor microenvironment in PTCs.

Heteroepitaxial Growth of B5 -Site-Rich Ru Nanoparticles Guided by Hexagonal Boron Nitride for Low-Temperature Ammonia Dehydrogenation.

Ruthenium is one of the most active catalysts for ammonia dehydrogenation and is essential for the use of ammonia as a hydrogen storage material. The B5 -type site on the surface of ruthenium is expected to exhibit the highest catalytic activity for ammonia dehydrogenation, but the number of these sites is typically low. Here, a B5 -site-rich ruthenium catalyst is synthesized by exploiting the crystal symmetry of a hexagonal boron nitride support. In the prepared ruthenium catalyst, ruthenium nanoparticles are formed epitaxially on hexagonal boron nitride sheets with hexagonal planar morphologies, in which the B5 sites predominate along the nanoparticle edges. By activating the catalyst under the reaction condition, the population of B5 sites further increases as the facets of the ruthenium nanoparticles develop. The electron density of the Ru nanoparticles also increases during catalyst activation. The synthesized catalyst shows superior catalytic activity for ammonia dehydrogenation compared to previously reported catalysts. This work demonstrates that morphology control of a catalyst via support-driven heteroepitaxy can be exploited for synthesizing highly active heterogeneous catalysts with tailored atomic structures.

Long Non-Coding RNA-Based Functional Prediction Reveals Novel Targets in Notch-Upregulated Ovarian Cancer.

Notch signaling is a druggable target in high-grade serous ovarian cancers; however, its complexity is not clearly understood. Recent revelations of the biological roles of lncRNAs have led to an increased interest in the oncogenic action of lncRNAs in various cancers. In this study, we performed in silico analyses using The Cancer Genome Atlas data to discover novel Notch-related lncRNAs and validated our transcriptome data via NOTCH1/3 silencing in serous ovarian cancer cells. The expression of novel Notch-related lncRNAs was down-regulated by a Notch inhibitor and was upregulated in high-grade serous ovarian cancers, compared to benign or borderline ovarian tumors. Functionally, Notch-related lncRNAs were tightly linked to Notch-related changes in diverse gene expressions. Notably, genes related to DNA repair and spermatogenesis showed specific correlations with Notch-related lncRNAs. Master transcription factors, including EGR1, CTCF, GABPα, and E2F4 might orchestrate the upregulation of Notch-related lncRNAs, along with the associated genes. The discovery of Notch-related lncRNAs significantly contributes to our understanding of the complex crosstalk of Notch signaling with other oncogenic pathways at the transcriptional level.

Cell non-autonomous effect of hepatic growth differentiation factor 15 on the thyroid gland.

The thyroid gland plays an essential role in the regulation of body energy expenditure to maintain metabolic homeostasis. However, to date, there are no studies investigating the morphological and functional changes of the thyroid gland due to mitochondrial stress in metabolic organs such as the liver. We used data from the Genotype-Tissue Expression portal to investigate RNA expression patterns of the thyroid gland according to the expression of growth differentiation factor 15 (GDF15) such as the muscles and liver. To verify the effect of hepatic GDF15 on the thyroid gland, we compared the morphological findings of the thyroid gland from liver-specific GDF15 transgenic mice to that of wild type mice. High GDF15 expression in the muscles and liver was associated with the upregulation of genes related to hypoxia, inflammation (TGF-α via NFκB), apoptosis, and p53 pathway in thyroid glands. In addition, high hepatic GDF15 was related to epithelial mesenchymal transition and mTORC1 signaling. Electron microscopy for liver-specific GDF15 transgenic mice revealed short mitochondrial cristae length and small mitochondrial area, indicating reduced mitochondrial function. However, serum thyroid stimulating hormone (TSH) level was not significantly different. In our human cohort, those with a high serum GDF15 level showed high fasting glucose, alanine transaminase, and alkaline phosphatase but no difference in TSH, similar to the data from our mice model. Additionally, high serum GDF15 increased the risk of lymph node metastasis to lateral neck. The hepatic GDF15 affected thyroid morphogenesis via a TSH-independent mechanism, affecting aggressive features of thyroid cancers.

Non-genomic activation of the AKT-mTOR pathway by the mitochondrial stress response in thyroid cancer.

Cancer progression is associated with metabolic reprogramming and causes significant intracellular stress; however, the mechanisms that link cellular stress and growth signalling are not fully understood. Here, we identified a mechanism that couples the mitochondrial stress response (MSR) with tumour progression. We demonstrated that the MSR is activated in a significant proportion of human thyroid cancers via the upregulation of heat shock protein D family members and the mitokine, growth differentiation factor 15. Our study also revealed that MSR triggered AKT/S6K signalling by activating mTORC2 via activating transcription factor 4/sestrin 2 activation whilst promoting leucine transporter and nutrient-induced mTORC1 activation. Importantly, we found that an increase in mtDNA played an essential role in MSR-induced mTOR activation and that crosstalk between MYC and MSR potentiated mTOR activation. Together, these findings suggest that the MSR could be a predictive marker for aggressive human thyroid cancer as well as a useful therapeutic target.

Pyrosequencing cut-off value identifying BRAFV600E mutation in fine needle aspiration samples of thyroid nodules.

CONTEXT: Recently, tremendous efforts have been made towards the development of sensitive techniques to detect the BRAF(V600E) mutation in fine needle aspiration biopsy (FNAB) samples. However, newly developed quantitative and semi-quantitative methods, such as dual-priming oligonucleotide (DPO)-based multiplex polymerase chain reaction (PCR), have the potential to generate false-positive (FP) results. OBJECTIVES: To eliminate the possibility of FP results, we generated a receiver operating characteristic (ROC) curve to investigate the diagnostic accuracy of pyrosequencing using quantitative data. DESIGN: Cytological diagnoses of 983 thyroid nodules were made according to the Bethesda System 2007. The BRAF(V600E) mutation was analysed by pyrosequencing, and statistical analyses were performed. RESULTS: Of the 983 nodules, 902 were adopted to evaluate the diagnostic value of pyrosequencing. The number of pathologically confirmed malignancies was 192, of which 182 were papillary thyroid cancer (PTC). By generating an ROC curve, we defined the optimal cut-off value of the mutant allele peak as 5·95% (area under the curve, 0·849; sensitivity, 0·55; 1-specificity, 0). When we applied this selective cut-off value, the number of PTCs positive for BRAF(V600E) was 99 (54·4% of the total number of PTCs). With cytology alone, the diagnostic sensitivity and specificity of detecting malignancy were 71·2% and 100%, respectively. Pyrosequencing improved the diagnostic sensitivity from 71·2% to 78·5% (McNemar's test, P < 0·001), without any change in the diagnostic specificity. When 'suspicious for malignancy' was considered a positive cytological outcome, pyrosequencing increased the diagnostic sensitivity of cytology from 95·8% to 96·9%; however, this improvement did not show statistical significance (McNemar's test, P > 0·05). CONCLUSIONS: Pyrosequencing is an effective method for detecting the BRAF(V600E) mutation in FNAB samples. By allowing the optimal cut-off value to be determined, pyrosequencing improves the diagnostic sensitivity while eliminating the possibility of FP results.