Faculty of Medicine https://hdl.handle.net/20.500.12294/2572 2026-07-05T08:07:02Z 2026-07-05T08:07:02Z Odemis, Demet Akdeniz Kebudi, Rejin Bayramova, Jamila Erciyas, Seda Kilic Turkcan, Gozde Kuru Tuncer, Seref Bugra Erdogan, Ozge Sukruoglu Celik, Betul Gultaslar, Busra Kurt Bay, Sema Buyukkapu Tuncer, Samuray Yazici, Hulya https://hdl.handle.net/20.500.12294/4140 2024-07-22T15:31:17Z 2024-01-01T00:00:00Z

RB1 gene mutations and genetic spectrum in retinoblastoma cases Odemis, Demet Akdeniz; Kebudi, Rejin; Bayramova, Jamila; Erciyas, Seda Kilic; Turkcan, Gozde Kuru; Tuncer, Seref Bugra; Erdogan, Ozge Sukruoglu; Celik, Betul; Gultaslar, Busra Kurt; Bay, Sema Buyukkapu; Tuncer, Samuray; Yazici, Hulya The aim of the study was to investigate the frequency and types of mutations on the retinoblastoma gene (RB1 gene) in Turkish population. RB1 gene mutation analysis was performed in a total of 219 individuals (122 probands with retinoblastoma, 14 family members with retinoblastoma and 83 clinically healthy family members). All 27 exons and close intronic regions of the RB1 gene were sequenced for small deletions and insertions using both the Sanger sequencing or NGS methods, and the large deletions and duplications were investigated using the MLPA analysis and CNV algorithm. The bilateral/trilateral retinoblastoma rate was 66% in the study population. The general frequency of RB1 gene mutation in the germline of the patients with retinoblastoma was 41.9%. Approximately 51.5% of the patients were diagnosed earlier than 12 months old, and de novo mutation was found in 32.4% of the patients. Germline small genetic rearrangement mutations were detected in 78.9% of patients and LGRs were detected in 21.1% of patients. An association was detected between the eye color of the RB patients and RB1 mutations. 8 of the mutations detected in the RB1 gene were novel in the study.

2024-01-01T00:00:00Z Ozdenoglu, Fazilet Yildiz Odemis, Demet Akdeniz Erciyas, Seda Kilic Tuncer, Seref Bugra Gultaslar, Busra Kurt Salduz, Ahmet Buyukkapu, Sema Olgac, Necat Vakur Kebudi, Rejin Yazici, Hulya https://hdl.handle.net/20.500.12294/4135 2024-07-22T15:31:13Z 2024-01-01T00:00:00Z

High Expression of miR-218-5p in the Peripheral Blood Stream and Tumor Tissues of Pediatric Patients with Sarcomas Ozdenoglu, Fazilet Yildiz; Odemis, Demet Akdeniz; Erciyas, Seda Kilic; Tuncer, Seref Bugra; Gultaslar, Busra Kurt; Salduz, Ahmet; Buyukkapu, Sema; Olgac, Necat Vakur; Kebudi, Rejin; Yazici, Hulya Sarcomas are malignant tumors that may metastasize and the course of the disease is highly aggressive in children and young adults. Because of the rare incidence of sarcomas and the heterogeneity of tumors, there is a need for non-invasive diagnostic and prognostic biomarkers in sarcomas. The aim of the study was to investigate the level of miR-218-5p in peripheral blood and tumor tissue samples of Ewing's sarcoma, osteosarcoma, spindle cell sarcoma patients, and healthy controls, and assessed whether the corresponding molecule was a diagnostic and prognostic biomarker. The study was performed patients (n = 22) diagnosed and treated with Ewing's sarcoma and osteosarcoma and in a control group of 22 healthy children who were matched for age, gender, and ethnicity with the patient group. The expression level of miR-218-5p in RNA samples from peripheral blood and tissue samples were analyzed using the RT-PCR and the expression level of miR-218-5p was evaluated by comparison with the levels in patients and healthy controls. The expression level of miR-218-5p was found to be statistically higher (3.33-fold, p = 0.006) in pediatric patients with sarcomas and when the target genes of miR-218-5p were investigated using the bioinformatics tools, the miR-218-5p was found as an important miRNA in cancer. In this study, the miR-218-5p was shown for the first time to have been highly expressed in the peripheral blood and tumor tissue of sarcoma patients. The results suggest that miR-218-5p can be used as a diagnostic and prognostic biomarker in sarcomas and will be evaluated as an important therapeutic target.

2024-01-01T00:00:00Z Saglam, Nazife Gamze Usta Duz, Mehmet Bugrahan Yilmaz, Seda Salman Ozen, Mustafa Balcioglu, Ibrahim https://hdl.handle.net/20.500.12294/4133 2024-07-22T15:31:10Z 2024-01-01T00:00:00Z

Comparison of microRNA expression levels in patients with schizophrenia before and after electroconvulsive therapy Saglam, Nazife Gamze Usta; Duz, Mehmet Bugrahan; Yilmaz, Seda Salman; Ozen, Mustafa; Balcioglu, Ibrahim ObjectiveExploring the role of microRNAs in the antipsychotic efficacy of electroconvulsive therapy (ECT) will contribute to understanding the underlying mechanism through which ECT exerts its therapeutic effects. The primary objective of this study was to identify microRNA alterations before and after ECT in patients with schizophrenia.MethodsWe compared microarray-based microRNA profiles in peripheral blood from eight patients with schizophrenia before and after ECT and eight healthy controls. Then, we aimed to validate selected differentially expressed microRNAs in 30 patients with schizophrenia following a course of ECT, alongside 30 healthy controls by using quantitative reverse-transcription PCR.ResultsMicroarray-based expression profiling revealed alterations in 681 microRNAs when comparing pre- and post-ECT samples. Subsequent quantitative reverse-transcription PCR analysis of the selected microRNAs (miR-20a-5p and miR-598) did not reveal any statistical differences between pre- and post-ECT samples nor between pre-ECT samples and those of healthy controls.ConclusionAs neuroepigenetic studies on ECT are still in their infancy, the results reported in this study are best interpreted as exploratory outcomes. Additional studies are required to explore the potential epigenetic mechanisms underlying the therapeutic efficacy of ECT.

2024-01-01T00:00:00Z Tanriverdi, Gamze Kaleci, Belisa Yavuz, Furkan Sahin, Hakan Purelku, Merjem Yazici, Zeliha Kokturk, Sibel https://hdl.handle.net/20.500.12294/4131 2024-07-09T07:13:46Z 2024-01-01T00:00:00Z

The effects of the combination of temozolomide and Eribulin on T98G human glioblastoma cell line Tanriverdi, Gamze; Kaleci, Belisa; Yavuz, Furkan; Sahin, Hakan; Purelku, Merjem; Yazici, Zeliha; Kokturk, Sibel Glioblastoma tumors are the most aggressive primary brain tumors that develop resistance to temozolomide (TMZ). Eribulin (ERB) exhibits a unique mechanism of action by inhibiting microtubule dynamics during the G2/M cell cycle phase. We utilized the T98G human glioma cell line to investigate the effects of ERB and TMZ, both individually and in combination. The experimental groups were established as follows: control, E5 (5 nM ERB), T0.75 (0.75 mM TMZ), T1 (1.0 mM TMZ), and combination groups (E5+T0.75 and E5+T1). All groups showed a significant decrease in cell proliferation. Apoptotic markers revealed a time-dependent increase in annexin-V expression, across all treatment groups at the 48-hour time point. Caspase-3, exhibited an increase in the combination treatment groups at the 48-hour mark. Transmission electron microscopy (TEM) revealed normal ultrastructural features in the glioma cells of the control group. However, treatments induced ultrastructural changes within the spheroid glioblastoma model, particularly in the combination groups. These changes included a dose-dependent increase in autophagic vacuoles and apoptotic morphology of the cells. In conclusion, the similarity in the mechanism of action between ERB and TMZ suggests the potential for synergistic effects when combined. Our results highlight that this combination induced severe damage and autophagy in glioma spheroids after 48 hours.

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