Browsing by Author "Ozdemir Kutbay N."

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    Effects of metformin and pioglitazone combination on apoptosis and AMPK/mTOR signaling pathway in human anaplastic thyroid cancer cells
    (John Wiley and Sons Inc, 2020) Ozdemir Kutbay N.; Biray Avci C.; Sarer Yurekli B.; Caliskan Kurt C.; Shademan B.; Gunduz C.; Erdogan M.
    Anaplastic cancer constitutes 1% of thyroid cancers, and it is one of the most aggressive cancers. Treatment options are external radiation therapy and/or chemotherapy. The success rate with these treatment modalities is not satisfactory. We aimed to evaluate the effects of metformin (MET) and pioglitazone (PIO) combination on apoptosis and AMP-activated protein kinase/mammalian target of rapamycin (mTOR) signaling pathway in human anaplastic thyroid cancer cells. In this study, we evaluated the effects of MET and PIO individually and the combination of the two drugs on the cellular lines SW1736 and C643 ATC. Genes contained in the mTOR signaling pathway were examined using human mTOR Signalization RT2 Profiler PCR Array. In C643 and SW1736 cell lines, IC50 doses of MET and PIO were found out as 17.69 mM, 11.64 mM, 27.12 µM, and 23.17 µM. Also, the combination of MET and PIO was determined as an additive according to isobologram analyses. We have found the downregulation of the expression levels of oncogenic genes: AKT3, CHUK, CDC42, EIF4E, HIF1A, IKBKB, ILK, MTOR, PIK3CA, PIK3CG, PLD1, PRKCA, and RICTOR genes, in the MET and PIO combination-treated cells. In addition, expression levels of tumor suppressor genes, DDIT4, DDIT4L, EIF4EBP1, EIF4EBP2, FKBP1A, FKBP8, GSK3B, MYO1C, PTEN, ULK1, and ULK2, were found to have increased significantly. The MET + PIO combination was first applied to thyroid cancer cells, and significant reductions in the level of oncogenic genes were detected. The decreases, particularly, in AKT3, DEPTOR, EIF4E, ILK, MTOR, PIK3C, and PRKCA expressions indicate that progression can be prevented in thyroid cancer cells and these genes could be selected as therapeutic targets. © 2020 Wiley Periodicals LLC
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    Cardiac phenotype in familial partial lipodystrophy
    (John Wiley and Sons Inc, 2021) Eldin A.J.; Akinci B.; da Rocha A.M.; Meral R.; Simsir I.Y.; Adiyaman S.C.; Ozpelit E.; Bhave N.; Gen R.; Yurekli B.; Ozdemir Kutbay N.; Siklar Z.; Neidert A.H.; Hench R.; Tayeh M.K.; Innis J.W.; Jalife J.; Oral H.; Oral E.A.
    Objectives: LMNA variants have been previously associated with cardiac abnormalities independent of lipodystrophy. We aimed to assess cardiac impact of familial partial lipodystrophy (FPLD) to understand the role of laminopathy in cardiac manifestations. Study design: Retrospective cohort study. Methods: Clinical data from 122 patients (age range: 13–77, 101 females) with FPLD were analysed. Mature human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from a patient with an LMNA variant were studied as proof-of-concept for future studies. Results: Subjects with LMNA variants had a higher prevalence of overall cardiac events than others. The likelihood of having an arrhythmia was significantly higher in patients with LMNA variants (OR: 3.77, 95% CI: 1.45–9.83). These patients were at higher risk for atrial fibrillation or flutter (OR: 5.78, 95% CI: 1.04–32.16). The time to the first arrhythmia was significantly shorter in the LMNA group, with a higher HR of 3.52 (95% CI: 1.34–9.27). Non-codon 482 LMNA variants were more likely to be associated with cardiac events (vs. 482 LMNA: OR: 4.74, 95% CI: 1.41–15.98 for arrhythmia; OR: 17.67, 95% CI: 2.45–127.68 for atrial fibrillation or flutter; OR: 5.71, 95% CI: 1.37–23.76 for conduction disease). LMNA mutant hiPSC-CMs showed a higher frequency of spontaneous activity and shorter action potential duration. Functional syncytia of hiPSC-CMs displayed several rhythm alterations such as early afterdepolarizations, spontaneous quiescence and spontaneous tachyarrhythmia, and significantly slower recovery in chronotropic changes induced by isoproterenol exposure. Conclusions: Our results highlight the need for vigilant cardiac monitoring in FPLD, especially in patients with LMNA variants who have an increased risk of developing cardiac arrhythmias. In addition, hiPSC-CMs can be studied to understand the basic mechanisms for the arrhythmias in patients with lipodystrophy to understand the impact of specific mutations. © 2021 John Wiley & Sons Ltd
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    Identifying Clinical Characteristics of Hypoparathyroidism in Turkey: HIPOPARATURK-NET Study
    (Springer, 2022) Konca Degertekin C.; Gogas Yavuz D.; Pekkolay Z.; Saygili E.; Ugur K.; Or Koca A.; Unubol M.; Topaloglu O.; Aydogan B.I.; Ozdemir Kutbay N.; Hekimsoy Z.; Yilmaz N.; Balci M.K.; Tanrikulu S.; Aydogan Unsal Y.; Ersoy C.; Omma T.; Keskin M.; Yalcin M.M.; Yetkin I.; Soylu H.; Karakose M.; Yilmaz M.; Karakilic E.; Piskinpasa H.; Batman A.; Akbaba G.; Elbuken G.; Tura Bahadir C.; Kilinc F.; Bilginer M.C.; Turhan Iyidir O.; Canturk Z.; Aktas Yilmaz B.; Sayiner Z.A.; Eroglu M.
    Hypoparathyroidism is an orphan disease with ill-defined epidemiology that is subject to geographic variability. We conducted this study to assess the demographics, etiologic distribution, treatment patterns and complication frequency of patients with chronic hypoparathyroidism in Turkey. This is a retrospective, cross-sectional database study, with collaboration of 30 endocrinology centers located in 20 cities across seven geographical regions of Turkey. A total of 830 adults (mean age 49.6 ± 13.5 years; female 81.2%) with hypoparathyroidism (mean duration 9.7 ± 9.0 years) were included in the final analysis. Hypoparathyroidism was predominantly surgery-induced (n = 686, 82.6%). The insulting surgeries was carried out mostly due to benign causes in postsurgical group (SG) (n = 504, 73.5%) while patients in nonsurgical group (NSG) was most frequently classified as idiopathic (n = 103, 71.5%). The treatment was highly dependent on calcium salts (n = 771, 92.9%), calcitriol (n = 786, 94.7%) and to a lower extent cholecalciferol use (n = 635, 76.5%) while the rate of parathyroid hormone (n = 2, 0.2%) use was low. Serum calcium levels were most frequently kept in the normal range (sCa 8.5–10.5 mg/dL, n = 383, 46.1%) which might be higher than desired for this patient group. NSG had a lower mean plasma PTH concentration (6.42 ± 5.53 vs. 9.09 ± 7.08 ng/l, p < 0.0001), higher daily intake of elementary calcium (2038 ± 1214 vs. 1846 ± 1355 mg/day, p = 0.0193) and calcitriol (0.78 ± 0.39 vs. 0.69 ± 0.38 mcg/day, p = 0.0057), a higher rate of chronic renal disease (9.7% vs. 3.6%, p = 0.0017), epilepsy (6.3% vs. 1.6%, p = 0.0009), intracranial calcifications (11.8% vs. 7.3%, p < 0.0001) and cataracts (22.2% vs. 13.7%, p = 0.0096) compared to SG. In conclusion, postsurgical hypoparathyroidism is the dominant etiology of hypoparathyroidism in Turkey while the nonsurgical patients have a higher disease burden with greater need for medications and increased risk of complications than the postsurgical patients. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.