Type 1 and type 2 iodothyronine 5' deiodinases (D1 and D2, respectively) catalyze the conversion of thyroxine (T₄) to triiodothyronine (T₃). Similar to other genes crucial for T₃ generation, D1 and D2 expression might be disturbed in papillary thyroid cancer (PTC) possible as a result of impairments in thyroid transcription factors Titf1/Nkx2-1 and Pax-8. The aim of the study was to investigate changes in the expression of D1 and D2 in PTC compared to changes in the expression of Titf1/Nkx2-1 and Pax-8. Although D1 and D2 activities were decreased in tumor samples (PTC) compared to control C samples (tissues from a nontumorous part of the gland), the differences were not statistically significant. Contrary to that, their mRNA levels were significantly decreased in PTC samples compared to C samples (p = 0.017 and p = 0.012, respectively). Interestingly there was clear discrepancy between enzymatic activity and mRNA level of both deiodinases. There was a statistically significant correlation between D1 and Pax-8 (r = 0.464, p = 0.039), D2 and Pax-8 (r = 0.461, p = 0.041), D2 and Titf1/Nkx2-1 mRNA levels (r = 0.526, p = 0.017). Our results show that changes in D1 and D2 expression in PTC, including the discrepancy between deiodinases activity and mRNA level, might possibly related to impaired Titf1/Nkx2-1 and Pax-8 action.

Type 1 5'-deiodinase is one of two isoenzymes that participate in conversion of prohormone thyroxine into triiodothyronine (T3). A decrease in type 1 5'-deiodinase expression was observed in renal clear cell carcinoma, thyroid cancer, and lung cancer. The aim of this study was to evaluate type 1 5'-deiodinase activity and mRNA level in breast cancer tissue and non-cancerous surrounding breast tissue. Material was collected from 36 patients undergoing radical mastectomy or local tumor resection. In all non-cancerous breast tissues, type 1 50-deiodinase activity was found to be at a very low or immeasurable level, and type 1 5'-deiodinase mRNA was detected only in 2 out of the 36 samples. By contrast, 20 out of the 36 breast cancer tissues, mainly grades G1 and G2, expressed abundant type 1 5'-deiodinase activity and/or a high mRNA level. Our data demonstrated the presence of type 1 5'-deiodinase in well-differentiated breast cancer tissue. High enzymatic activity of type 1 50-deiodinase can potentially lead to an increase in the production of T3, which may affect target gene transcription, including genes responsible for energy expenditure, growth, differentiation, and proliferation.

Background: Premature coronary artery disease is one of the most pressing global issues in modern cardiology. The aim of the study was to investigate the role of family history of premature cardiovascular disease (CVD) in patients aged < 50 years with myocardial infarction (MI) compared to that in patients aged ≥50 years with MI and to that in young people without MI (no-MI < 50). Methods: The studied group (MI < 50) consisted of 240 patients aged 26–49 years with MI. The control groups consisted of 240 patients (MI ≥ 50) with MI aged 50–92 years and 240 healthy people aged 30–49 years without a history of MI (no-MI < 50). Results: There were statistically significant differences between the MI < 50 and MI ≥ 50 and no-MI < 50 groups regarding the family history of premature MI/ischaemic stroke and the percentage of patients with ≥2 relatives affected (10.8, 2.9, and 3.7%, respectively; p < 0.0001). There was a statistically significant difference in the patient age at the first MI occurrence among patients without a family history of premature CVD, those with 1 affected relative, and those with ≥2 affected first-degree relatives (56.6, 48.6 and 41.8 years, respectively) as well as those with affected first- and second-degree relatives (56.5, 50.7 and 47.0 years, respectively). Conclusions: A younger age of patients with myocardial infarction is associated with a higher number of relatives with a history of premature MI/ischaemic stroke. Thus, the family history of premature atherosclerosis involving not only first- but also second-degree relatives seems to be a valuable factor in CVD risk evaluation in young people. Graphical

Sialylation of cell components is an important immunomodulating mechanism affecting cell response to hormones and adhesion molecules. To study alterations in sialic acid metabolism in Graves' disease (GD) we measured the following parameters in various human thyroid tissues: lipid-bound sialic acid (LBSA) content, ganglioside profile, total sialyltransferase activity, and the two major sialyltransferase mRNAs for sialyltransferase-1 (ST6Gal I) and for sialyltransferase-4A (ST3Gal I). Fragments of toxic thyroid nodules (TN), nontoxic thyroid nodules (NN) and nontumorous tissue from patients with nodular goiter or thyroid cancer were used as a control (C). The LBSA content and sialyltransferase activity were the highest in the GD group (164 ± 4.44 versus 120 ± 2.00 nmoL/g, p = 0.005 and 1625 ± 283.5 versus 324 ± 54.2 cpm/mg of protein, p < 0.005 compared to control group C). Ganglioside profile in the GD group was similar to that in control tissues. Sialyltransferase- 1 mRNA and sialyltransferase-4A mRNA levels were significantly higher in the GD group than in the control group (12.52 ± 6.90 versus 2.54 ± 1.24 arbitrary units, p < 0.005 and 2,49 ± 1.16 versus 1.23 ± 0.46 arbitrary units, p < 0.05, respectively). There was a positive correlation between the increased sialyltransferase-1 mRNA level and the TSH-receptor antibody titer determined by the TRAK test. These results indicate that sialyltransferases expression and activity are increased in GD. Exact mechanism of this upregulation remains unknown, though one of possible explanations is the activation of the thyrotropin (TSH) receptor.