Master Degree / Yüksek Lisans Tezleri

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Author: search.filters.author.Akgül, BünyaminSubject: search.filters.subject.Apoptosis

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Now showing 1 - 7 of 7
  • Master Thesis
    Investigation of the Effects of Gtf2a1-Antisense Long Non-Coding Rna on Cell Fate
    (01. Izmir Institute of Technology, 2022) Çiftçi, Yusuf Cem; Akgül, Bünyamin; Akgül, Bünyamin; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Apoptosis is a distinct mode of programmed cell death whereby cellular contents are broken down and accumulated in the apoptotic bodies. The vast majority of the genome consists of non-coding RNAs (ncRNA). NcRNAs can be divided into groups depending on their length, for example, long non-coding RNA (lncRNA) longer than 200 nucleotides. It has been demonstrated that these have important roles in the development, and treatment of cancer and in other diseases that critically affect human life. Considering the lncRNAs’ mechanisms of action on apoptosis, they modulate activity of transcription factors, regulate miRNAs, and interact with proteins related to histone mechanisms such as chromatin modifier. In this perspective, GTF2A1-AS which is an uncharacterized and novel lncRNA was found as one of highly expressed lncRNA in transcriptomic data obtained from HeLa cells treated with cisplatin. The potential role of GTF2A1-AS within the cell was investigated through the transcriptomic data provided by GTF2A1-AS knockdown. It has been found that specific gene clusters mainly enriched in the pathway which is Defective Homology directed Repair through Homologous Recombination. In this process, double-strand breaks are repaired with the help of BRCA1/2, RAD50, RAD51, PALB2 proteins which are known as DNA damage response proteins. Thus, the genes related with DNA damage response were selected to validate the transcriptomic data. In light of this information, GTF2A1-AS knockdown has resulted in an increase in the early apoptosis in HeLa cells. Additionally, when GTF2A1-AS knockdown was combined with cisplatin, it sensitized HeLa cells against cisplatin by affecting late apoptosis, specifically. Consequently, GTF2A1-AS as a cisplatin inducible lncRNA modulates apoptosis and chemosensitivity in HeLa cells.
  • Master Thesis
    Examination of Stable Intronic Sequence Rna Profile Under Apoptotic Conditions
    (Izmir Institute of Technology, 2022) Akgül, Bünyamin; Akgül, Bünyamin; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Apoptosis is a process of programmed cell death. Cisplatin, a chemotherapeutic drug, activates intrinsic pathway of apoptosis while TNF-alpha, a death ligand, activates the extrinsic pathway of apoptosis. Noncoding RNAs involve in regulation of apoptotic pathways at post-transcriptional level. Stable intronic sequence RNAs (sisRNAs) are the novel class of non-coding RNAs which can be generated by splicing- dependent and independent mechanisms. sisRNAs transcribed from their intronic promoter may contain 5’ cap and polyA tail. Despite the reports of several studies about sisRNAs in Xenopus and Drosophila, a genome-wide profile of sisRNAs in human is lacking. Therefore, we aimed to identify sisRNAs profile that are transcribed from their intronic promoter under cisplatin- and TNF-alpha- mediated apoptosis conditions. In this thesis study, the deep sequencing of total RNA, polyA + and polyA eliminated fractions from cisplatin-, TNFalpha-, DMSO-treated cells were performed. Differentially expressed intronic transcripts were analysed by DE-kupl algorithm. The intronic transcripts both in total RNA and polyA + RNA fractions but not in polyA eliminated fractions were screened visually on Integrated Genome Viewer (IGV) and selected as sisRNA candidateS. 48 sisRNA candidates were detected in cisplatin-treated data while 33 sisRNA candidates were detected in TNF-alpha- treated data. 5’ and 3’ RACE PCRs were performed for determination of transcriptional units of sisRNA candidates. Overexpression of sisRDOCK7-IT1 caused 8.09% increase in total apoptosis of HeLa cells in 48 hours. sisRDOCK7-IT1 triggers the activation of apoptosis but the mechanism of its induction of apoptosis is still unknown.
  • Master Thesis
    Transcriptomics Profiling of M6a Rna Modifications in Tnf-Alpha Induced Apoptosis
    (01. Izmir Institute of Technology, 2021) Akçaöz, Azime; Akgül, Bünyamin; Akgül, Bünyamin; 01. Izmir Institute of Technology; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science
    Apoptosis is a form of programmed cell death that occurs as a result of physiological or pathological causes. TNF-alpha, which has a regulatory role in immune system cells, stimulates apoptosis through the external pathway. For this reason, it can be used for the treatment of various diseases. Although there are many studies on the regulatory mechanisms of TNF-alpha mediated apoptosis, the contribution of RNA modifications has not been fully elucidated. Regarding the potential role of m6A RNA modification in apoptosis, studies have focused on the effects of regulatory proteins and there is no genome-wide m6A methylation profile yet. In the present thesis, firstly, the gene expression patterns of m6A writer, eraser, and reader were examined in HeLa cells and 632 genes with differential m6A methylation pattern were identified by the miCLIP method. 99 genes involved in apoptotic pathways were determined by GO analysis. Candidates were selected based on m6A methylation fold change, intracellular expression level and apoptotic role of the relevant gene. Methylation points in IGV were confirmed and specific validation experiments were performed on these m6A points. SELECT based validation studies showed 1-2 cycle increase in the TNF-alpha group compared to the control group. This confirms the miCLIP data, which also pointed to an increase in m6A methylation. To elucidate the fate of candidate RNAs, the gene expression levels, and translational status of candidate genes were analyzed. METTL3 KD HeLa cells exposed to TNF-alpha exhibited an increase in the expression of PHLDA1, IFI6 and HRK by almost 2-fold. Polysome fractionation assay showed that translation level decreased in TNF-alpha treated METTL3 KD HeLa cells. As a conclusion, global m6A level affected RNA abundance as well as translation.
  • Master Thesis
    Indentification of Circular Ribonucleic Acids Differentially Expressed in Apoptotic Hela Cells
    (Izmir Institute of Technology, 2018) Yaylak, Bilge; Akgül, Bünyamin; Akgül, Bünyamin; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Apoptosis is a mechanism of programmed cell death that is essential for survival, homeostatis and development. Various protein coding genes and non-coding RNAs were reported as apoptosis regulators. However, the potential roles of circular RNA in the regulation of apoptosis are still unknown. In this study, we have performed transcriptomics study to reveal differentially expressed, pathway-drug specific and/or global circRNAs in apoptotic HeLa cells. Cisplatin (CP), doxorubicin (DOX), Fas mAb(FAS) and TNF-alpha (TNF-a) were used to trigger apoptosis in HeLa cells. Apoptosis rates of three replicates of treatment and control cells were measured by flow cytometry and differentially expressed circular RNAs were identified by deep RNA sequencing. Circular RNA candidates were firstly sorted based on their significance according to pad j value, further classified based on fold change, pathway-drug specificity and source genes. Then, circular RNA candidates were analysed bioinformatically to obtain their coding potential, potential miRNA binding sites and involvement in possible apoptotic pathways. Furthermore, divergent primers were designed to validate backsplicing junction sequence of circular RNA candidates. RNAse R treatment was used to eliminate linear transcripts and enrich circular RNAs. The expression of candidate circular RNAs was analysed RNAse R treated samples. Backsplicing junctions of positive circular control circ-HIPK3 was validated by TA cloning and sequencing. Differential expression of positive control (circ-HIPK3), candidate-8 and candidate-6 were validated by quantitative PCR.
  • Master Thesis
    Molecular Characterization of the Gtf2a-1 Antisense Long Non-Coding Rna
    (Izmir Institute of Technology, 2017) Yarımçam, Murat Caner; Akgül, Bünyamin; Akgül, Bünyamin; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
    One of the essential events in cell regulation and normal development of an organism is apoptosis. The dysregulation of apoptosis is associated with diseases such as cancer. Apoptosis induction can kill cancer cells without harming the individual. For this purpose, new methods are developed to fight the cancer cells. One of the novel approaches is based on long non-coding RNAs (lncRNAs). LncRNAs are differentially expressed in cancer cells and they regulate and interact essential pathways. The ones related to apoptosis are the targets. In this study, target lncRNA was determined based on RNA-Seq data. Then apoptosis was induced in HeLa cells with cisplatin and qRT-PCR was performed with isolated RNAs from the cells to validate the data with regard to upregulation of GTF2A-1 anti-sense lncRNA in apoptosis. Then GapmeR specific to target lncRNA was designed and transfected into HeLa cells in order to induce apoptosis. After induction of apoptosis, total RNA and protein were isolated from the cells. qRTPCR was performed to validate the RNA-Seq data. Western blotting was performed in order to characterize the target lncRNA by controlling its effects on different apoptosis pathways. Western blotting results are showing resemblance between GTF2A-1 antisense lncRNA silencing-induced apoptosis and cisplatin-induced apoptosis. The western blotting result of Cytochrome c is interesting because its amount is decreased in GTF2A- 1 anti-sense lncRNA silencing-induced apoptosis. The candidate, GTF2A-1 anti-sense lncRNA, is directly regulating the apoptosis in HeLa cells and in this study, some of the pathways that are regulated with this lncRNA were shown.
  • Master Thesis
    Identification of Long Non-Coding Rnas That Regulate Apoptosis in Human
    (Izmir Institute of Technology, 2015) Ahmadov, Ulvi; Akgül, Bünyamin; Akgül, Bünyamin; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Apoptosis is essential for cellular homeostasis and normal development. Aberrant apoptosis (too much or too less) is associated with many important diseases such as autoimmune diseases and cancer. Studies have led to the identification of a number of proteins and microRNAs involved in the regulation of apoptosis. However, the role of long non-coding RNAs (lncRNAs) is still unclear. In this study, two cancer therapeutics drugs, cisplatin and doxorubicin, and two ligands, Fas mAb and TNF-alpha, were used in identification of differentially expressed pathway-drug specific and/or global lncRNAs in apoptotic HeLa cells. Following dose-kinetics experiments the level of apoptosis was measured by Flow Cytometry and was further verified by Fluorescence Microscopy and Western Blotting via measurement of Caspase 3, 8 and 9 protein levels. Three replicates of total RNAs (control and drug/ligand-treated cells) were sent to deepsequencing using the Illumina platform. The resulting reads matched to the human genome greater than 95%. Under our experimental setting, treatments with cisplatin, doxorubicin, Fas mAb and TNF-alpha led to the differential expression of 1644, 506, 584 and 807 lncRNAs, respectively (2-fold or higher, P < 0.01). Two of identified lncRNAs common for all inducers was in antisense position to TRAIL-R2 receptor and FasR associated factor which play directly in apoptosis. Results suggest that many lncRNAs are differentially expressed upon treatment with the indicated agents. Functional characterization of candidates might provide an interesting insight into regulation of apoptosis.
  • Master Thesis
    Investigation of the Functions of Candidate Mirnas in Camptothecin-Induced Apoptosis in Human Cells
    (Izmir Institute of Technology, 2012) Demir, Şeyda; Akgül, Bünyamin; Akgül, Bünyamin; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
    MicroRNAs are non-coding 19-25nt long, small RNAs that regulate expression of about 30% of human genes by inhibiting mRNA translation or inducing its degradation. MicroRNAs play important role in cell growth, differentiation, apoptosis. miRNAs regulate apoptosis by targeting genes involved in apoptotic pathway as a pro or anti-apoptotic genes. This study has aimed to identify whether candidate miRNAs ( miR-17* and miR-425) have a regulatory role in camptothecin induced apoptosis or not in Human cells and Hela cells that derived from cervical cancer were used as a model cell line. These candidates were selected based on deep sequencing data that showed some miRNAs differentially expressed after camptothecin treatment as compared with non-treated control group. To show candidate miRNAs whether have a role or not in regulation of camptothecin induced apoptosis, first Hela cells were transfected with candidate miRNAs then candidate miRNA over-expressed cells were treated with camptothecin eventually level of apoptosis was measured by flow cytometry and the results were evaluated by comparing miRNA over-expressed cell group with un-transfected control group. Active caspase-3 level also was measured by using flow cytometry and the data showed miR-17* and miR-425 function as pro-apoptotic regulator in camptothecin induced apoptosis in Hela cells.