Kinga Krawczyk-Rusiecka

Cyclooxygenase-2 expression and its association with thyroid lesions.

Cyclooxygenase (COX), also known as prostaglandin H synthase, catalyses the formation of prostaglandins from arachidonic acid. It can be expressed in response to various stimuli, such as hormones, mitogens, cytokines, other inflammatory mediators and growth factors. The product of COX-2 activity has been implicated in carcinogenesis by promoting angiogenesis, inhibiting apoptosis, increasing cell invasion and stimulating cell proliferation. It has also been proved that the regular intake of non-steroidal anti-inflammatory drugs (NSAIDs) decreases the risk of developing colon and breast cancers. Thus, it speaks for an important role of COX-2 in growth processes of various types of neoplasms. The connection between COX-2 activity and carcinogenesis has also been examined in human thyroid neoplasms. COX-2 overexpression has been reported in thyroid cancers and also in inflammatory conditions. In consequence there is significant interest whether COX-2 could be of importance as a molecular marker of malignancy in the case of thyroid carcinoma.

COX-2 expression in papillary thyroid carcinoma (PTC) in cytological material obtained by fine needle aspiration biopsy (FNAB).

BackgroundCOX-2 is an enzyme isoform that catalyses the formation of prostanoids from arachidonic acid. An increased COX-2 gene expression is believed to participate in carcinogenesis. Recent studies have shown that COX-2 up-regulation is associated with the development of numerous neoplasms, including skin, colorectal, breast, lung, stomach, pancreas and liver cancers. COX-2 products stimulate endothelial cell proliferation and their overexpression has been demonstrated to be involved in the mechanism of decreased resistance to apoptosis. Suppressed angiogenesis was found in experimental animal studies as a consequence of null mutation of COX-2 gene in mice. Despite the role of COX-2 expression remains a subject of numerous studies, its participation in carcinogenesis or the thyroid cancer progression remains unclear.MethodsTwenty three (23) patients with cytological diagnosis of PTC were evaluated. After FNAB examination, the needle was washed out with a lysis buffer and the obtained material was used for COX-2 expression estimation. Total RNA was isolated (RNeasy Micro Kit), and RT reactions were performed. β-actin was used as endogenous control. Relative COX-2 expression was assessed in real-time PCR reactions by an ABI PRISM 7500 Sequence Detection System, using the ΔΔCT method.ResultsCOX-2 gene expression was higher in patients with PTC, when compared to specimens from patients with non-toxic nodular goitre (NTG).ConclusionsThe preliminary results may indicate COX-2 role in thyroid cancer pathogenesis, however the observed variability in results among particular subjects requires additional clinical data and tumor progression analysis.

Assessment of cyclooxygenase-1 and 2 gene expression levels in chronic autoimmune thyroiditis, papillary thyroid carcinoma and nontoxic nodular goitre

IntroductionThe cyclooxygenases are a group of enzymes catalyzing the formation of prostaglandins from arachidonic acid. Cyclooxygenase-1 (COX-1) is a constitutive form, thought to be a “housekeeping gene”, with constant levels of expression in most tissues. COX-1 expression in the thyroid gland, except for medullary thyroid carcinoma, has not been a subject of much interest. Cyclooxygenase-2 (COX-2) can be expressed in response to various stimuli, such as mitogens, hormones, cytokines, growth factors. The product of COX-2 activity has been implicated in carcinogenesis.Recent studies have shown that up-regulation of COX-2 is associated with numerous neoplasms. Hereby, we present a study analysing COX-1 and COX-2 expression in papillary thyroid carcinoma (PTC), Hashimoto thyroiditis (HT) and nontoxic nodular goitre (NNG) in fine needle aspiration biopsy (FNAB) washouts and in postoperative tissue.Material and methodsCytological specimens from 120 patients (105 females and 15 males) have been studied, including patients with HT, PTC and NNG. Moreover, we have examined postoperative tissue specimens from 51 patients with PTC and NNG.The methods of molecular analysis have included extraction of total RNA from FNAB cytological material and postoperative tissues, spectrophotometric assessment of the RNA purity, cDNA synthesis in reverse transcription reaction and an analysis of genes expression data by real-time PCR.ResultsThe performed analysis has revealed statistically significant higher expression level of the COX-2 gene in PTC group, in comparison with HT and NNG groups (in both cytological and postoperative material).In PTC patients, COX-2 gene expression levels in the material obtained by FNAB were similar to those in the postoperative thyroid tissue.No correlations between COX-2 gene expression level and TNM staging in PTC samples have been observed.There were no correlations between COX-2 expression and anti-TPO antibodies level, or patient’s sex or age in the studied groups. Also, there were no correlations of COX-1 gene expression level among PTC, HT and NNG groups.ConclusionsOur results suggest that COX-2 gene does not participate in the mechanisms involved in molecular association of HT with PTC. However, in case of PTC itself, it may play some role in neoplastic transformation.

Mechanisms of Normalisation of Bone Metabolism during Recovery from Hyperthyroidism: Potential Role for Sclerostin and Parathyroid Hormone

Sclerostin, a protein expressed by osteocytes, is a negative regulator of bone formation. The aim of the study was to investigate the relationship between parathyroid hormone (PTH) and markers of bone metabolism and changes of sclerostin concentrations before and after treatment of hyperthyroidism. Patients and Methods. The study involved 33 patients (26 women), age (mean ± SD) 48 ± 15 years, with hyperthyroidism. Serum sclerostin, PTH, calcium, and bone markers [osteocalcin (OC) and collagen type I cross-linked C-telopeptide I (CTX)] were measured at diagnosis of hyperthyroidism and after treatment with thiamazole. Results. After treatment of hyperthyroidism a significant decrease in free T3 (FT3) and free T4 (FT4) concentrations was accompanied by marked decrease of serum sclerostin (from 43.7 ± 29.3 to 28.1 ± 18.4 pmol/L; p < 0.001), OC (from 35.6 ± 22.0 to 27.0 ± 14.3 ng/mL; p < 0.001), and CTX (from 0.49 ± 0.35 to 0.35 ± 0.23 ng/dL; p < 0.005), accompanied by an increase of PTH (from 29.3 ± 14.9 to 39.8 ± 19.8; p < 0.001). During hyperthyroidism there was a positive correlation between sclerostin and CTX (r s = 0.41, p < 0.05) and between OC and thyroid hormones (with FT3   r s = 0.42, with FT4   r s = 0.45, p < 0.05). Conclusions. Successful treatment of hyperthyroidism results in a significant decrease in serum sclerostin and bone markers concentrations, accompanied by an increase of PTH.

The role of phosphoinositide 3-kinase subunits in chronic thyroiditis

BackgroundThe risk of neoplastic transformation in patients with chronic thyroiditis (Hashimoto’s thyroiditis – HT) is slightly increased. Genetic background of this observation is still unclear. PI3K isoforms are linked with inflammatory and neoplastic processes, thus they appear to be interesting subjects of a research in this respect. The aim of our study was to assess the PIK3CA, PIK3CB, PIK3CD and PIK3CG genes expression levels in HT.MethodsFollowing conventional cytological examination, 67 thyroid FNAB specimens, received from patients with HT, were quantitatively evaluated regarding PIK3CA, PIK3CB, PIK3CD and PIK3CG expression levels by real-time PCR in the ABI PRISM ®7500 Sequence Detection System.ResultsThe performed analysis has revealed significantly higher expression levels (RQ) of PIK3CD, PIK3CG and PIK3CA genes in comparison with PIK3CB gene (p<0.05) and significantly higher gene expression level of PIK3CD in comparison with PIK3CA (p<0.05).ConclusionThe observed increased PIK3CD, PIK3CG genes expression in HT is probably related to lymphocyte infiltration commonly seen in this condition, however, the role of increased PIK3CA gene expression in the multi-step carcinogenesis process cannot be excluded.

Relationship between urine lipid peroxidation, anthropometric parameters and parameters associated with goitre formation in school-age children

Introduction Oxidative stress has been implicated in the normal ageing process and the pathogenesis of several diseases, including goitre. The aim of the study was to evaluate the relationship between urine lipid peroxidation (LPO) and anthropometric parameters as well as the parameters associated with goitre formation in children. Material and methods The subjects included 172 healthy children (93 girls and 79 boys) aged 8–15, divided into 4 age groups – group I (8–9 years), group II (10–11 years), group III (12–13 years) and group IV (14–15 years) – and into 2 groups based on the BSA: the BSA-1 group (≤ 0.55 m2) and the BSA-2 group (> 0.55 m2). Results The value of LPO was the highest in group I but the difference between the groups was not statistically significant (p = 0.074). In the BSA-1 group, the LPO was higher than in the BSA-2 group (12.75 ±6.90 nmol/ml and 10.79 ±4.86 nmol/ml, respectively; p = 0.023). We found a weak, negative linear correlation between LPO and age (r = –0.216; p < 0.005), body mass (r = –0.153; p < 0.05), height (r = –0.152; p < 0.05) and BSA (r = –0.151; p < 0.05). Conclusions Anthropometric parameters of school-age children independently of age are negatively associated with oxidative damage to membrane lipids, whereas factors promoting goitrogenesis do not contribute to this process.

Evaluation of the effectiveness of iodine prophylaxis in Poland based on over 20 years of observations of iodine supply in school-aged children in the central region of the country

Introduction Due to the mild-to-moderate iodine deficiency in Poland, in 1997 iodine prophylaxis based on obligatory salt iodization was introduced. We attempted to evaluate the effectiveness of such prophylaxis, based on over 20 years of observations of iodine supply in school-aged children in Opoczno district (Central Poland). Material and methods A group of 603 children (316 girls and 287 boys), aged 6–14, was examined at 4 time points: in the years 1994, 1999, 2010 and 2016. The children were tested for urine iodine concentration (UIC) and in each child the thyroid volume was measured ultrasonographically. Results The median UIC in 1994 (45.5 μg/l) indicated moderate iodine deficiency, while after introducing prophylaxis it corresponded to adequate values (1999 – 101.1 μg/l, 2010 – 100.6 μg/l, 2016 – 288.3 μg/l); however, the last value was higher than the previous two. The thyroid size, assessed by ultrasonography and presented as volume/body surface area (V/BSA), in 1994 was 6.55 × 10–6 m; this value was higher than at other time points (2.73 × 10–6 m in 1999, 2.73 × 10–6 m in 2010, and 2.70 × 10–6 m in 2016). Conclusions Iodine prophylaxis has proved effective in eliminating iodine deficiency. In recent years, the diversification of iodine sources, despite the reduction of salt consumption, has led to an increase in median UIC to values close to the upper limit of UIC, accepted as normal. Further increase in iodine supply may be unfavourable for health; therefore constant monitoring of iodine prophylaxis is required.