Cognitive Function, APOE Gene Polymorphisms, and Thyroid Status Associations in Postmenopausal Women in Poland.

BACKGROUND: The objective of the study was to analyze a potential association between cognitive functions and thyroid status in postmenopausal women with different polymorphisms of the apolipoprotein E gene (APOE). METHODS: The examined population included 402 postmenopausal women from south-eastern Poland. The evaluation of cognitive functions was made with the use of the diagnostic Central Nervous System-Vital Signs equipment (Polish version). Multiplex polymerase chain reactions were performed to assess APOE polymorphisms. The thyroid hormone tests were assessed by an accredited laboratory. RESULTS AND CONCLUSION: Lower results of cognitive functions were associated with the presence of the ε4 APOE allele in postmenopausal women. The ε4 APOE polymorphism was associated with a higher concentration of thyroid-stimulating hormone and lower concentrations of free triiodothyronine and total triiodothyronine.

Autoimmune polyglandular syndrome type 2 manifested as Hashimoto's thyroiditis and adrenocortical insufficiency, in Turner syndrome woman, with onset following introduction of treatment with recombinant human growth hormone.

Autoimmune polyglandular syndrome is a constellation of signs and symptoms of simultaneous insufficiencies of several endocrine glands. Autoimmune polyglandular syndrome type 2 (APS 2) may be diagnosed when the adrenocortical insufficiency is associated with an autoimmune thyroid disease (Hashimoto's thyroiditis or Graves' disease), and/or insulin-dependent diabetes mellitus. Turner syndrome is the most common chromosomal disorder in females, caused by complete or partial X chromosome monosomy. We present the case of a 20-year-old woman with Turner syndrome, in whom APS 2 (Hashimoto's thyroiditis and adrenocortical insufficiency) has been diagnosed after introduction of recombinant human growth hormone (rhGH) therapy. In Turner syndrome, examination of the patient must regularly be conducted in order to diagnose a possible onset of autoimmune diseases; respective treatment must be applied as soon as the diagnosis is established. In particular, therapy of rhGH, used for short stature treatment, may be a trigger factor of adrenal insufficiency. The cortisol level in blood should be assessed before rhGH administration and carefully monitored during the therapy, especially in case of autoimmune thyroid disease coexistence.

Persistent remission of Graves` disease or evolution from Graves' disease to Hashimoto's thyroiditis in childhood - a report of 6 cases and clinical implications.

BACKGROUND: The main clinical manifestations of autoimmune thyroid diseases are Graves' disease (GD) and Hashimoto's thyroiditis (HT). Graves' disease is the cause of most cases of hyperthyroidism in childhood. Indications for radical therapy (surgery or 131I treatment) in children are still a matter of discussion, as sustained (sometimes very long) remission of GD is possible, while the radical therapy almost always leads to hypothyroidism. Spontaneous evolution from GD with hyperthyroidism to HT with hypothyroidism may also be observed. OBJECTIVE: The aim of the study was to analyze the clinical course of 6 cases of hyperthyroid girls with GD in whom a normalization of previously increased autoantibodies against thyrotropin (TSH) receptor (anti-TSHR) was observed together with a significant increase in autoantibodies against thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg), with concomitant hypo- or euthyroidism but no recurrence of hyperthyroidism. SUBJECTS: Patients' age at diagnosis ranged from 5.0 to 16.5 years. Two (2) patients had Turner syndrome, another one (1), diabetic, was on insulin therapy. RESULTS: In all the girls, antithyroid drugs were administered and euthyroid state was achieved during the first 2.0-3.5 months of the treatment. Mild side effects were observed in only one case. The therapy was continued up to 1.5-4.0 years. Relapses during the therapy were observed in 2 cases. Up to now, no relapses have been observed for 0.5-7.5 years since the therapy withdrawal in 5 patients (1 patient was lost to follow-up), 2 patients are currently treated with levothyroxine due to hypothyroidism. CONCLUSIONS: It seems that the prolonged pharmacotherapy with antithyroid drugs, followed by observation after remission of hyperthyroidism, may be an appropriate therapeutic option at least in some children with GD as they can be cured without radical therapy and the potential risks of such treatment.

Resistance to thyroid hormone due to a novel mutation in the thyroid beta receptor (THRß) gene coexisting with autoimmune thyroid disease-A case report.

Resistance to thyroid hormone (RTH) is a syndrome characterized by impaired responsiveness of target tissues to thyroid hormones. The relationship between RTHß and thyroid autoimmunity has been under research. In this study, we demonstrate a case report of a woman with a novel mutation in THRß gene coexisting with autoimmune thyroid disease (AITD). The 36-year-old woman has been treated since childhood for a thyroid disease. Based on high levels of thyroid hormones (THs) and elevated concentrations of thyroperoxidase and thyroglobulin antibodies (TPOAb and TgAb, respectively), she received unnecessary long-term treatment with methimazole and finally underwent subtotal thyroidectomy. After the surgery, her TSH level remained significantly elevated, despite the treatment with 150 + 15 µg of thyroxine and triiodothyronine. A sequence analysis of the THRß gene revealed a novel dinucleotide substitution affecting codon 453, resulting in the replacement of the normal proline with an asparagine (c.1357_1358delinsAA, p.(Pro453Asn)). The mutation has not been described in the literature yet; however, THRß codon 453 represents a mutational hot spot, frequently altered in the TH receptor ß gene. After establishing the diagnosis of RTH, the patient was treated with 300 µg of thyroxine, which showed clinical improvement and normalization of TSH. The coexistence of RTHß and AITD may additionally impede establishment of a proper diagnosis, leading to unnecessary therapy and delayed correct treatment. The presented case encourages a closer cooperation between clinical endocrinologists and geneticists.

Is the PIK3CA gene expression level in FNAB washouts equivalent to that in postoperative tissue specimens of papillary thyroid carcinoma?

INTRODUCTION: Papillary thyroid carcinoma (PTC) is the most common malignant tumor of the thyroid gland. The pathogenesis of PTC remains still mostly enigmatic, although PI3K/PTEN/AKT pathway has been proposed to play a role in development of PTC. Moreover, the significance of genetic analysis in the material from fine-needle aspiration biopsy (FNAB) in PTC patients has recently been demonstrated. Hereby, we present a study analyzing expression of PIK3CA in FNAB washouts of PTC and a comparison of the level of that expression with respective expression in postoperative PTC tissue. Furthermore, we have assessed correlation between tumor size, evaluated according to pTNM scale, and level of PIK3CA gene expression in postoperative PTC tissue. METHODS: Total RNA was extracted by use of an RNeasy Micro Kit (Qiagen, Hilden, Germany) in FNAB material, and RNeasy Midi Kit (Qiagen, Hilden, Germany) in tissue material. The purity of total RNA was assessed by NanoDrop® ND-100 spectrophotometr. One hundred nanograms of total RNA were used in the first strand cDNA synthesis with TaqMan® Reverse Transcripton Reagents (Applied Biosystems, Branchburg, New Jersey, USA). The gene expression level of PIK3CA was analyzed by real-time PCR in the ABI PRISM ®7500 Sequence Detection System in the 21 (17 women, 4 men) FNAB and 20 (16 women, 4 men) postsurgical specimens of PTC. pTNM staging of PTC was assessed based on UICC classification. RESULTS: Overexpression of PIK3CA was confirmed in FNAB washout specimens and in postoperative tissues of PTC, in comparison to macroscopically unchanged thyroid tissue. Furthermore, statistically significant differences in PIK3CA gene expression levels between both examined groups were not confirmed. Moreover, correlation between pTNM staging and level of PIK3CA gene expression in PTC samples was not found. CONCLUSION: The genetic analysis of overexpression of PIK3CA in FNAB washout specimens may be equivalent of postsurgical PTC tissue. A possibility of its future clinical application in FNAB specimens - adequate or undetermined for cytological analysis - awaits for evaluation. The level of expression of PIK3CA is independent of primary thyroid tumour size, evaluated according pTNM scale.

Assessment of cyclin D1 gene expression as a prognostic factor in benign and malignant thyroid lesions.

OBJECTIVE: Cyclin D1, encoded by CCND1 (cyclin D1) gene with locus in chromosome 11q13, is a protein that plays the key role in the passage through the restriction point in G1 phase of cell cycle. The aim of the study were: 1) an assessment of CCND1 gene expression level in benign and malignant thyroid lesions and 2) the evaluation of possible correlations between gene expression and the histopathological variants of papillary thyroid carcinoma (PTC), or tumour size, classified according to TNM definition of primary tumours (in case of PTC only) or patient's sex or age. DESIGN: Thirty five (35) tissue samples were analysed: 24 cases of PTC, 4 cases of medullary thyroid carcinoma (MTC), 4 cases of follicular adenoma (FA) and 3 cases of nodular goitre (NG). In real-time polymerase chain reaction (real-time PCR), two-step RT-PCR (reverse transcriptase-polymerase chain reaction) in an ABI PRISM 7500 Sequence Detection System was employed. Cyclin D1 gene expression level was assessed, calculating the mean relative quantification rate (RQ rate) increase for each sample. RESULTS: The level of cyclin D1 gene expression was significantly higher in malignant thyroid tumours (PTC, MTC), as compared with that in macroscopically unchanged thyroid tissue, FA and/or NG groups. However, the differences of RQ rate value between different PTC variants were statistically insignificant. No correlation was found between RQ values and patients' sex or age. On the other hand, the correlation was observed between RQ values and tumour size. CONCLUSIONS: Cyclin D1 gene expression in various thyroid lesions may be helpful in diagnostically doubtful cases. However, our results--mostly due to the small numbers of cases in the groups other than PTC--do not yet allow considering cyclin D1 gene as a molecular prognostic marker.

Investigation of V600E BRAF mutation in papillary thyroid carcinoma in the Polish population.

UNLABELLED: Papillary thyroid carcinoma (PTC) is the most common malignancy of the thyroid gland. The high incidence of RET/PTC and Trk rearrangements or point mutations in RAS and c-MET oncogenes are the genetic hallmarks of PTC. Recently, oncogene BRAF has become a subject of great interest. The mutation of BRAF gene is characteristic for PTC and poorly differentiated and/or undifferentiated cancers derived from PTC. The predominant mutation of this gene, reported in PTC, is a single transversion in exon 15 (T1799A), which results in substitution of valine to glutamate at residue 600 (BRAF V600E, formerly position 1796 and residue V599E). It has been proved that the frequency of this mutation in PTC varies within the range of 29% to 69% in different populations. OBJECTIVES: The aim of this study was to estimate the frequency of BRAF (V600E) mutation in PTC in the Polish population, and to evaluate the possible relationships between the presence of BRAF mutation and such parameters, as patient's age, gender, histopathological variant and the clinical staging of PTC. METHODS: Analysis of BRAF (V600E) mutation was performed by single strand conformation polymorphism (SSCP) analysis and real-time allele-specific polymerase chain reaction (ASPCR) in tumour tissues from 25 patients with PTC. We compared the sensitivity of real-time AS-PCR, SSCP method and direct DNA sequencing of PCR products. We used 25 PTC tissues (including the follicular variant of PTC - 8 cases, the classic variant of PTC - 14 cases and the tall-cell variant of PTC - 3 cases). RESULTS: V600E mutation in BRAF gene was detected in 12/25 (48%) cases of PTC. Mutation screening of exon 15 gene BRAF revealed three types of mutations, i.e. V600E, V600M, and overlapping mutations V600E/V600K. No correlation was found between BRAF mutation and patient's age and sex and particular stage in clinical staging systems (TNM Staging, the University of Chicago clinical class, and Ohio State University Staging). Regarding the histopathological variants of PTC, mutation in BRAF gene was more frequent in classic variant of PTC as compared with follicular variant of PTC. CONCLUSION: The real-time AS-PCR method proved to be more sensitive than SSCP and sequencing of PCR products. Our study is the first one in which the frequency of BRAF (V600E) mutation in PTC was reported for the Polish population. Similarly to the results obtained by others, there was no coexistence of BRAF (V600E) mutation and RET/PTC and/or Trk rearrangements or RAS mutation in PTC tissue. Our results do not confirm the relationship between the BRAF (V600E) mutation and the clinical outcome of PTC.

Patterns of cyclin A and B1 immunostaining in papillary thyroid carcinoma.

INTRODUCTION AND OBJECTIVES: Cyclin A, encoded by CCNA (cyclin A) gene with locus in chromosome 4q27, and cyclin B1, encoded by CCNB1 (cyclin B1) gene with locus in chromosome 5q12, are proteins that play a key role in the passage through the restriction point in G2 phase of the cell cycle. The aim of the study was to analyse immunohistochemically the expression of cyclins A and B1 in different variants of papillary thyroid carcinoma (PTC). MATERIAL AND METHODS: The immunostaining patterns of the proteins in question in the tissue of 40 resected PTC (20 cases of classic variant of PTC, 9 cases of PTC follicular variant and 11 cases of other non-classic variants of PTC) were investigated. RESULTS: On analyzing cyclin A and B1 expression, positive staining in 90% cases of PTC were observed. The study revealed a significant difference in expression of cyclins A and B1 between classic and non-classic variants of PTC. The expression of both examined cyclins was weaker in the classic variant of PTC. In the group of follicular variant of PTC, the expression of cyclins was of medium intensity and in the group of other non-classic variants of PTC, the expression was clearly higher. CONCLUSIONS: The results of the presented study suggest that cyclins A and B1 expression may have a characteristic pattern of immunostaining for particular variants of PTC. If the obtained results are confirmed in a larger group of patients, the diagnostic panel constructed of the antibodies against these proteins may increase the diagnostic accuracy in PTC cases.

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

INTRODUCTION: The 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 METHODS: Cytological 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. RESULTS: The 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. CONCLUSIONS: Our 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.

The role of phosphoinositide 3-kinase subunits in chronic thyroiditis.

BACKGROUND: The 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. METHODS: Following 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. RESULTS: The 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). CONCLUSION: The 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.

Evaluation of efficacy of iodine prophylaxis in Poland based on the examination of schoolchildren living in Opoczno Town (Lodz Voivodship).

BACKGROUND: In 1997 a currently obligatory model of iodine prophylaxis, based on mandatory iodization of household salt with 30 mg KI/kg, was introduced. The aim of our study was to assess the iodine intake among school-age children living in Opoczno in 3 subsequent time points - in 1994, before establishment of currently operating model of iodine prophylaxis, in 1999 - 2 years after implementation of iodine prophylaxis and in 2010, - 14 years after its implementation. METHODS: We assessed goitre incidence and urine iodine concentration (UIC) in 104 children in 1994, 207 children in 1999 and 174 children in 2012. Age of examined children ranged from 6 to 15 years. The thyroid volumes evaluated by ultrasound were compared to reference values for thyroid volume proposed by Zimmermann at al. Moreover, we have introduced a new index - V/BSA ratio (comparison of thyroid volume to the body surface area), which to our belief allows for more accurate assessment of thyroid volume. RESULTS: The median of UICs was 45.5 µg/L (1994), 101.1 µg/L (1999) and 100.6 µg/L (2010). The distribution of obtained results has changed as well - iodine concentrations below 50 µg/L were present in 59.1% children in 1994, in 12.6% children - in 1999 and in 7.1% children - in 2010.Although a significant decrease in goitre incidence with regard to age - 92.6% (1994) vs 18.5% (1999) and 15.8% (2010), as well as with regard to BSA - 95.4% (1994) vs 15.2% (1999) and 11.6% (2010) was observed, it still points to the iodine deficiency, which is in contradiction with UICs as they are within normal limits. V/BSA ratio avoids such discrepancy. The values of ratio V/BSA were higher in 1994 (7.079 ± 2.775) than in 1999 (2.935 ± 1.112) (p<0.05) and in 2010 (2.846 ± 1.029) (p<0.05). CONCLUSIONS: Hitherto model of iodine prophylaxis has proved to be effective in eliminating the iodine deficiency. The iodine intake is now more even, homogenous, which translates into smaller scatter of UICs and less percentage of children, in whom UIC is less than 50 µg/L. However, the iodine intake only slightly exceeds the recommended values, so median of UICs oscillates around the lower limit of references values.

Increased expression of PIN1 gene in papillary thyroid carcinoma.

BACKGROUND: Peptidyl-prolyl cis/trans isomerase (Pin1), encoded by PIN1 gene with locus in chromosome 19p13, is an enzyme that catalytically induces conformational changes in proteins after phosphorylation on serine or threonine residues preceding proline (pSer/Thr-Pro motifs); in this way, it has an influence on protein interactions and intracellular localizations of proteins. The aim of the study were: 1) an assessment of PIN1 gene expression level in benign and malignant thyroid lesions; 2) the evaluation of possible correlations between gene expression and histopathological variants of papillary thyroid carcinoma (PTC) or tumour size, classified according to TNM classification of primary tumours (in case of PTC only); 3) the estimation of possible relationships between expression of the gene in question and patients' sex or age. METHODS: Seventy (70) tissue samples were analyzed: 32 cases of PTC, 7 cases of medullary thyroid carcinoma (MTC), 7 cases of follicular adenoma (FA), and 24 cases of nodular goitre (NG). In real-time polymerase chain reaction (real-time PCR), two-step RT-PCR (reverse transcriptase-polymerase chain reaction) in an ABI PRISM 7500 Sequence Detection System was employed. The PIN1 gene expression level was assessed, calculating the mean relative quantification rate (RQ rate) increase for each sample. RESULTS: The level of PIN1 gene expression (compared to that in macroscopically unchanged thyroid tissue) was higher in PTC group than those in FA, MTC and/or NG groups, but the statistical significance was noted for difference between PTC and NG groups only. On the other hand, the differences of RQ rate value between different PTC variants were statistically insignificant. No correlations were found between RQ values and tumour size, as well as between RQ values and patients' sex or age in PTC group. CONCLUSIONS: The PIN1 gene expression may have - in future - an important meaning in the diagnostics of PTC and in understanding its pathogenesis. However, our results - mostly due to the small number of cases - do not yet allow considering PIN1 gene as a prognostic molecular PTC marker.

Assessment of RET/PTC1 and RET/PTC3 rearrangements in fine-needle aspiration biopsy specimens collected from patients with Hashimoto's thyroiditis.

BACKGROUND: RET/PTC rearrangements are the most frequent molecular changes in papillary thyroid carcinoma (PTC). So far, 15 main RET/PTC rearrangements have been described, among which RET/PTC1 and RET/PTC3 are the most common in PTC - especially in radiation-induced tumours. RET/PTC1 and RET/PTC3 are the result of intrachromosomal paracentric inversions in chromosome 10, where RET and the activating genes (H4 and ELE1, respectively) are located. Recently, RET/PTC rearrangements have been shown not only in PTC but also in benign thyroid lesions, including Hashimoto's thyroiditis (HT). The aim of study was an assessment of RET/PTC1 and RET/PTC3 rearrangements in patients with Hashimoto's thyroiditis. MATERIALS AND METHODS: Thyroid aspirates, eligible for the study, were obtained from 26 patients with Hashimoto's thyroiditis by fine-needle aspiration biopsy (FNAB). Each aspirate was smeared for conventional cytology, while its remaining part was immediately washed out of the needle. The cells, obtained from the needle, were used in further investigation. Total RNA from FNAB was extracted by use of an RNeasy Micro Kit, based on modified Chomczynski and Sacchi's method and reverse transcription (RT-PCR) was done. Quantitative evaluation of RET/PTC1 and RET/PTC3 rearrangements by real-time PCR was performed by an ABI PRISM® 7500 Sequence Detection System. In the study, PTC tissues with known RET/PTC1 and RET/PTC3 rearrangements served as a reference standard (calibrator), while ß-actin gene was used as endogenous control. RESULTS: Amplification reactions were done in triplicate for each examined sample. No RET/PTC1 and RET/PTC3 rearrangements were found in the examined samples. CONCLUSIONS: Our results indicate that RET/PTC1 and RET/PTC3 rearrangements in Hashimoto's thyroiditis, if any, are rather rare events and further investigations should be conducted in order to determine molecular changes, connecting Hashimoto's thyroiditis with PTC.

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

BACKGROUND: COX-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. METHODS: Twenty 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. ß-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. RESULTS: COX-2 gene expression was higher in patients with PTC, when compared to specimens from patients with non-toxic nodular goitre (NTG). CONCLUSIONS: The 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.

Relative quantification of PIK3CA gene expression level in fine-needle aspiration biopsy thyroid specimens collected from patients with papillary thyroid carcinoma and non-toxic goitre by real-time RT-PCR.

BACKGROUND: Recent studies have shown that the phosphatidylinositol 3-kinase (PI3K) signaling pathway is important regulator of many cellular events, including apoptosis, proliferation and motility. PI3K pathway alterations (PIK3CA gene mutations and/or amplification) have been observed in various human tumours. In the majority of diagnosed cases, mutations are localized in one of the three "hot spots" in the gene, responsible for coding catalytic subunit α of class I PI3K (PIK3CA). Mutations and amplification of PIK3CA gene are characteristic for thyroid cancer, as well. METHODS: The aim of our study was to examine a gene expression level of PIK3CA in fine-needle aspiration biopsy (FNAB) thyroid specimens in two types of thyroid lesions, papillary thyroid carcinoma (PTC) and non-toxic goitre (NTG). Following conventional cytological examination, 42 thyroid FNAB specimens, received from patients with PTC (n = 20) and NTG (n = 22), were quantitatively evaluated regarding PIK3CA expression level by real-time PCR in the ABI PRISM® 7500 Sequence Detection System. RESULTS: Significantly higher expression level (RQ) of PIK3CA in PTC group has been noted in comparison with NTG group (p < 0.05). CONCLUSION: These observations may suggest role of PIK3CA alterations in PTC carcinogenesis.