Relative Contribution of Metabolic Syndrome Components in Relation to Obesity and Insulin Resistance in Postmenopausal Osteoporosis.

Introduction. Osteoporosis (OP) affects 30% of postmenopausal women, often complicated by metabolic syndrome (MetS) with a still controversial role. We aimed to characterize MetS and its components in relation to bone mineral density (BMD), body mass index (BMI), and insulin resistance. Methods. Patients (n = 188) underwent DEXA scans, spine X-rays, and metabolic and hormonal investigations, including bone biomarkers, muscular strength, and physical performance tests, while insulin resistance was evaluated by the Homeostasis Model Assessment (HOMA-IR). Results. Patients with a normal BMD or osteopenia (n = 68) and with OP (n = 120) displayed 51.5% and 30.8% of MetS, but without differences in insulin resistance. When BMD was studied as a function of the cumulative MetS criteria and centiles of BMI, lower levels of BMD were observed beyond an inflection point of 27.2 kg/m2 for BMI, allowing for further stratification as lean and overweight/obese (OW/OB) subjects. In contrast with lean individuals (n = 74), in OW/OB patients (n = 46), MetS was associated with HbA1c (p < 0.0037, OR 9.6, 95% CI [1.64-55.6]) and insulin resistance (p < 0.0076, OR 6.7, 95% CI [1.49-30.8]) in the context where BMD values were lower than those predicted from BMI in non-OP subjects. In OP patients with fragility fractures (31% of MetS), glycemia also appeared to be the dominant factor for MetS (p < 0.0005, OR 4.1, 95% CI [1.63-10.39]). Conclusions. These data indicate a detrimental effect of insulin resistance in MetS on OP patients, while the prevalence of the syndrome depends on the proportion of obesity. These findings provide new insights into the pathogenic role of MetS and reveal the need to consider different strata of BMI and insulin resistance when studying postmenopausal OP.

Matrix metalloproteinase-9 (MMP-9) promoter -1562C/T functional polymorphism is associated with an increased risk to develop micropapillary thyroid carcinoma.

BACKGROUND: Matrix metalloproteinase-9 (MMP-9) is an important mediator of tumor initiation and progression. The MMP-9 promoter -1562C/T functional polymorphism increases gene expression and was identified as a susceptibility factor for various cancers. OBJECTIVE: To evaluate the influence of the MMP-9 promoter genotype on the risk of developing papillary thyroid cancer (PTC) and to correlate cancer patient genotype with the clinical and pathological phenotype. METHODS: We evaluated 236 patients with nodular thyroid disease pre-thyroidectomy (119 benign disease, 117 PTC). Genomic DNA was isolated from whole blood and the MMP-9 -1562C/T genotype was evaluated by PCR-RFLP analysis. RESULTS: Genotype frequencies were in Hardy-Weinberg equilibrium for all groups. The T allele was significantly more frequent in cancer compared to benign disease (17.5% vs 10.1%), p= 0.019. Patients with the CT or CT+TT genotype had an increased risk of developing PTC, specifically micropapillary thyroid carcinoma (MPTC) (CT genotype: OR = 6.467, p= 0.00006; CT+TT: OR = 6.859, p= 0.00002), but not more advanced stages (CT: p= 0.094; CT+TT: p= 0.157). The -1562C/T genotype did not significantly correlate with tumor histological subtype, invasion or TNM stage. CONCLUSION: The MMP-9 -1562C/T functional polymorphism may indicate susceptibility to develop thyroid cancer, specifically intrathyroidal clinically non-relevant MPTC. This suggests that although this genotype might be a predisposing factor, other genetic/epigenetic events are needed for cancer progression.

Serum soluble urokinase plasminogen activator receptor as a potential biomarker of renal impairment severity in diabetic nephropathy.

AIMS: To investigate serum soluble form of urokinase-type plasminogen activator receptor (suPAR) in patients with diabetic kidney disease (DKD) and biopsy-proven diabetic nephropathy (DN), its correlation with histological parameters and its capacity as a biomarker for renal impairment severity. METHODS: We conducted a cross-sectional study on 75 patients with diabetes mellitus (DM) and DKD, among whom 28 had biopsy-proven DN. RESULTS: Among the 75 patients, 9 (12%) had type 1 and 66 (88%) type 2 DM. The median value of the serum suPAR level was 2857.2 pg/mL (1916.4-3700) in the entire cohort and 2472.1 pg/mL (1782.6-3745.8) in the biopsy-proven DN subgroup, respectively. suPAR was significantly correlated with diabetes duration, diabetic retinopathy, anti-proteinuric treatment, albuminuria, kidney function, DN class, interstitial fibrosis and tubular atrophy (IFTA) score and with interstitial inflammation score. suPAR had a good accuracy for the association with chronic kidney disease (CKD) stages G3b-5, macroalbuminuria, DN class IV, IFTA score 3 and interstitial inflammation score 2. CONCLUSIONS: Serum suPAR was increased in DN patients and was associated with DM duration, diabetic retinopathy, renoprotective treatment, kidney function, proteinuria, DN class, IFTA and interstitial inflammation scores. Also, suPAR had a good capacity as a biomarker for advanced renal impairment and severe histological lesions of DN.

The Relationship between Advanced Oxidation Protein Products, Vascular Calcifications and Arterial Stiffness in Predialysis Chronic Kidney Disease Patients.

Background and Objectives: Cardiovascular morbidity and mortality are increased in patients with chronic kidney disease (CKD). It is likely that the accumulation of uremic toxins resulting in increased oxidative stress (OS) is a major contributing factor, but no clear link has been identified. The purpose of this research is to establish if advanced oxidation protein product (AOPP) levels in the serum of predialysis patients are a contributing factor to vascular calcification and increased arterial stiffness. Materials and Methods: After obtaining the informed consent, 46 predialysis patients (CKD stages G3-G5) were included in the study. In order to identify vascular calcifications, hand and pelvic radiographs were performed. Valvular calcifications were identified using cardiac ultrasound. AOPP were measured using a commercially available ELISA kit. The relationships between serum AOPP values and biochemical parameters relevant in the evaluation of CKD patients were analyzed. In addition to identifying the differences in AOPP levels between patients with/without vascular or valvular calcifications, the research focused on describing the relationship between OS and arterial stiffness assessed by oscillometric pulse-wave velocity (PWV) measurement. Results: No significant relationship between serum AOPP and vascular or valvular calcifications was highlighted, but significant correlations of AOPP with C-reactive protein (p = 0.025), HDL-cholesterol levels (p = 0.04), HbA1c (p = 0.05) and PWV values (p = 0.02) were identified. Conclusions: The usefulness of (OS) measurement in clinical practice remains debatable; however, the relationship between AOPP and arterial stiffness could be valuable in improving cardiovascular risk assessment of patients with CKD.

Serum Matrix metalloproteinase-9 (MMP-9) can help identify patients with papillary thyroid cancer at high risk of persistent disease: Value and limitations of a potential marker of neoplasia.

BACKGROUND: Matrix metalloproteinase-9 (MMP-9) is an important mediator of invasion and metastasis in neoplasia. In thyroid cancer expression levels correlate with aggressiveness but data on peripheral MMP-9 levels are less definitive. OBJECTIVE: Prospective study evaluating serum MMP-9 in the diagnosis and prognosis of papillary thyroid cancer. METHODS: Serum samples of MMP-9 were drawn before surgery in 185 consecutively enrolled patients with nodular thyroid disease, stratified on pathology as benign disease (N= 88) and papillary thyroid cancer (N= 97). Serum MMP-9 was measured by an immunometric assay. RESULTS: MMP-9 levels were not different between benign vs malignant pathology (p= 0.3). In papillary thyroid cancer there was no significant difference in MMP-9 levels between histologies, TNM stage and invasive/non-invasive cancers. High-risk patients with multiple features of aggressiveness had significantly higher MMP-9 levels compared to low-intermediate risk patients (767.5 ± 269.2 ng/ml vs 563.7 ± 228.4 ng/ml, p= 0.019). A cut-off of 806 ng/ml distinguished high from low-intermediate risk patients with a sensitivity of 60% and a specificity of 87.36%, p= 0.018. In patients with available follow-up data (N= 78), MMP-9 was higher in patients who required ⩾ 2 doses of 131I therapy (p= 0.009) and in those with biochemical evidence of persistent disease/who required additional therapy to achieve disease-free status (p= 0.017). CONCLUSION: Serum MMP-9 is not useful in the diagnosis of PTC, but preliminary data shows that high pre-surgical serum MMP-9 levels may identify patients at higher risk of persistent disease who require intensive treatment. Large volume prospective studies are required to confirm this observation.

Alterations of regulatory factors and DNA methylation pattern in thyroid cancer.

PURPOSE: DNA methylation plays an important role in thyroid oncogenesis. The aim of this study was to investigate the connection between global and local DNA methylation status and to establish the levels of important DNA methylation regulators (TET family and DNMT1) in thyroid tumours: follicular adenoma-FA, papillary thyroid carcinoma-PTC (classic papillary thyroid carcinoma-cPTC and papillary thyroid carcinoma follicular variant fvPTC). METHODS: Global DNA methylation profile in thyroid tumours tissue (41 paired samples) was assessed by 5-methylcytosine and 5-hydroxymethylcytosine levels evaluation (ELISA), along with TETs and DNMT1 genes expression quantification. Also, it was investigated for the first time TET1 and TET2 promoter's methylation in thyroid tumours. BRAF V600E mutation and RET/PTC translocation testing were performed on all investigated samples. In vitro studies upon DNA methylation in K1 thyroid cancer cells were performed with demethylating agents (5-AzaC and vitamin C). RESULTS: TET1 and TET2 displayed a significantly reduced gene expression level in PTC, while DNMT1 gene presented a high level of expression. PTC samples presented increased levels of 5-methylcytosine and low levels of 5-hydroxymethylcytosine. 5-methylcytosine levels were associated with TET1/TET2 expression levels. TET1 gene expression was significantly lower in patients positive for BRAF mutation and with RET/PTC rearrangement. TET2 gene was found hypermethylated in thyroid carcinoma patients overall, especially in PTC-follicular variant samples (p= 0.0002), where TET2 gene expression levels were significantly reduced (p= 0.0031). Furthermore, the data indicate for all thyroid cancer patients a good sensitivity (81.08%) and specificity (86.49%) regarding the use of TET1 (p< 0.0001), and TET2 (71.79%, 64.10%, p= 0.0001) hypermethylation as biomarkers for thyroid oncogenesis. CONCLUSIONS: These results suggest that TET1/TET2 gene expression and methylation may serve as potential diagnostic tools for thyroid neoplasia. Our study showed that the methylation of TET1 increases in malignant thyroid tumours. fvPTC patients presented lower methylation levels compared to cPTC and could be a discriminatory factor between two cancer types and benign lesions. TET2 is a poorer discriminator between FA and fvPTC, but it can be useful for cPTC identification. K1-cells treated with demethylating agents showed a demethylation effect, especially upon TET2 gene. The cumulative effect of L-AA and 5-AzaC proved to have a potent combined demethylating effect on genes promoter's activation and could open new perspectives for thyroid cancer therapy.

Methylation of tumour suppressor genes associated with thyroid cancer.

BACKGROUND: Thyroid carcinoma is the most common endocrine malignancy worldwide. Changes in DNA methylation can cause silencing of normally active genes, especially tumour suppressor genes (TSG) or activation of normally silent genes. OBJECTIVE: The aim of this study is to evaluate the degree of promoter methylation for a panel of markers for thyroid neoplasms and to establish their relationship with thyroid oncogenesis. METHODS: To generate a comprehensive DNA methylation signature of TSGs involved in thyroid neoplasia, we use Human TSG EpiTect Methyl II Signature PCR Array-Qiagen for 24 samples (follicular adenomas and papillary thyroid carcinomas) compared with normal thyroid tissue. We extended the evaluation for three TSGs (TP73, WIF1, PDLIM4) using qMS-PCR. Statistical analysis was performed with GraphPad Prism. RESULTS: We noted four important genes NEUROG1, ESR1, RUNX3, MLH1, which presented methylated promoter in tumour samples compared to normal. We found new characteristic of thyroid tumours: methylation of TP73, WIF1 and PDLIM4 TSGs, which can contribute to thyroid neoplasia. A significant correlation between BRAF V600E mutation and RET/PTC rearrangements with TIMP3 and CDH13, RARB methylation, respectively was observed. CONCLUSIONS: TSGs promoter hypermethylation is a hallmark of cancer and a test that uses methylation quantification method is suitable for diagnosis and prognosis of thyroid cancer.

Endoplasmic Reticulum Chaperones Are Potential Active Factors in Thyroid Tumorigenesis.

The study aimed to evaluate the proteomic changes in benign follicular adenoma versus malignant follicular variant of papillary thyroid carcinoma. Tumor and nontumor adjacent samples were analyzed by liquid nanochromatography mass spectrometry, and protein abundance was evaluated by label-free quantification. Western blotting and quantitative real-time polymerase chain reaction were used to validate and complement the mass spectrometry data. The results demonstrated deregulated expression of four endoplasmic reticulum chaperones (78 kDa glucose-regulated protein, endoplasmin, calnexin, protein disulfide-isomerase A4), glutathione peroxidase 3 and thyroglobulin, all of them involved in thyroid hormone synthesis pathway. The altered tissue abundance of endoplasmic reticulum chaperones in thyroid cancer was correlated with serum expression levels. The identified proteins significantly discriminate between adenoma and carcinoma in both thyroid tissue and corresponding sera. Data are available via ProteomeXchange with identifier PXD004322.