PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
Browse
7 results
Search Results
Now showing 1 - 7 of 7
Article Citation - WoS: 6Citation - Scopus: 5Epitranscriptomics M6a Analyses Reveal Distinct M6a Marks Under Tumor Necrosis Factor Α (tnf-Α) Apoptotic Conditions in Hela Cells(Wiley, 2024) Akçaöz Alasar, Azime; Tuncel, Özge; Sağlam, Buket; Gazaloğlu, Yasemin; Atbinek, Melis; Çağıral, Umut; İşcan, Evin; Özhan, Güneş; Akgül, BünyaminTumor necrosis factor-alpha (TNF-alpha) is a ligand that induces both intrinsic and extrinsic apoptotic pathways in HeLa cells by modulating complex gene regulatory mechanisms. However, the full spectrum of TNF-alpha-modulated epitranscriptomic m(6)A marks is unknown. We employed a genomewide approach to examine the extent of m(6)A RNA modifications under TNF-alpha-modulated apoptotic conditions in HeLa cells. miCLIP-seq analyses revealed a plethora of m(6)A marks on 632 target mRNAs with an enrichment on 99 mRNAs associated with apoptosis. Interestingly, the m(6)A RNA modification patterns were quite different under cisplatin- and TNF-alpha-mediated apoptotic conditions. We then examined the abundance and translational efficiencies of several mRNAs under METTL3 knockdown and/or TNF-alpha treatment conditions. Our analyses showed changes in the translational efficiency of TP53INP1 mRNA based on the polysome profile analyses. Additionally, TP53INP1 protein amount was modulated by METTL3 knockdown upon TNF-alpha treatment but not CP treatment, suggesting the existence of a pathway-specific METTL3-TP53INP1 axis. Congruently, METLL3 knockdown sensitized HeLa cells to TNF-alpha-mediated apoptosis, which was also validated in a zebrafish larval xenograft model. These results suggest that apoptotic pathway-specific m(6)A methylation marks exist in cells and TNF-alpha-METTL3-TP53INP1 axis modulates TNF-alpha-mediated apoptosis in HeLa cells.Review Citation - WoS: 8Citation - Scopus: 8Long Noncoding Rnas in Human Cancer and Apoptosis(Bentham Science Publishers, 2023) Erdoğan, İpek; Sweef, Osama; Akgül, BünyaminGenome annotations have uncovered the production of at least one transcript from nearly all loci in the genome at some given time throughout the development. Surprisingly, many of these transcripts do not code for proteins and are relatively long in size, thus called long noncoding RNAs (lncRNAs). Next- and third-generation sequencing technologies have amassed numerous lncRNAs expressed under different phenotypic conditions, yet many remain to be functionally characterized. LncRNAs regulate gene expression by functioning as scaffold, decoy, signaling, and guide molecules both at the transcriptional and post-transcriptional levels, interacting with different types of macromolecules, such as proteins, DNA, and RNA. Here, we review the potential regulatory role of lncRNAs in apoptosis and cancer as some of these lncRNAs may have the diagnostic and therapeutic potential in cancer.Book Part Citation - Scopus: 5Epitranscriptomics Changes the Play: M6a Rna Modifications in Apoptosis(Springer, 2022) Akçaöz, Azime; Akgül, BünyaminApoptosis is a form of programmed cell death that is essential for cellular and organismal homeostasis. Any irregularities that disturb the balance between apoptosis and cell survival have severe implications, such as improper development or life-threatening diseases. Thus, it is highly critical to maintain a proper rate of apoptosis throughout development. In fact, several complex transcriptional and posttranscriptional mechanisms exist in eukaryotes to critically regulate the rate of apoptotic processes. Recent studies suggest that not only RNA sequences but also their modifications, such as m6A methylation, play a fundamental role in these transcriptional and posttranscriptional processes. A specific set of proteins, called writer, eraser, and reader of m6A marks, modulate the rate of apoptosis by determining the m6A repertoire and the fate of certain transcripts associated with apoptosis. In this Review, we will cover the dynamic m6A RNA modifications and their impact on modulation of apoptosis.Article Citation - WoS: 11Citation - Scopus: 10Genomewide M6a Mapping Uncovers Dynamic Changes in the M6a Epitranscriptome of Cisplatin-Treated Apoptotic Hela Cells(MDPI, 2022) Akçaöz, Azime; Tüncel, Özge; Gelmez, Ayşe Bengisu; Sağlam, Buket; Erdoğan Vatansever, İpek; Akgül, BünyaminCisplatin (CP), which is a conventional cancer chemotherapeutic drug, induces apoptosis by modulating a diverse array of gene regulatory mechanisms. However, cisplatin-mediated changes in the m6A methylome are unknown. We employed an m6A miCLIP-seq approach to investigate the effect of m6A methylation marks under cisplatin-mediated apoptotic conditions on HeLa cells. Our high-resolution approach revealed numerous m6A marks on 972 target mRNAs with an enrichment on 132 apoptotic mRNAs. We tracked the fate of differentially methylated candidate mRNAs under METTL3 knockdown and cisplatin treatment conditions. Polysome profile analyses revealed perturbations in the translational efficiency of PMAIP1 and PHLDA1 transcripts. Congruently, PMAIP1 amounts were dependent on METTL3. Additionally, cisplatin-mediated apoptosis was sensitized by METTL3 knockdown. These results suggest that apoptotic pathways are modulated by m6A methylation events and that the METTL3–PMAIP1 axis modulates cisplatin-mediated apoptosis in HeLa cells.Article Citation - WoS: 7Citation - Scopus: 8Transcriptomics Profiling Identifies Cisplatin-Inducible Death Receptor 5 Antisense Long Non-Coding Rna as a Modulator of Proliferation and Metastasis in Hela Cells(Frontiers Media S.A., 2021) Gürer, Dilek Cansu; Erdoğan, İpek; Ahmadov, Ulvi; Başol, Merve; Sweef, Osama; Çakan Akdoğan, Gülçin; Akgül, BünyaminCisplatin is a well-known cancer chemotherapeutic agent but how extensively long non-coding RNA (lncRNA) expression is modulated by cisplatin is unknown. It is imperative to employ a comprehensive approach to obtain a better account of cisplatin-mediated changes in the expression of lncRNAs. In this study, we used a transcriptomics approach to profile lncRNAs in cisplatin-treated HeLa cells, which resulted in identification of 10,214 differentially expressed lncRNAs, of which 2,500 were antisense lncRNAs. For functional analyses, we knocked down one of the cisplatin inducible lncRNAs, death receptor 5 antisense (DR5-AS) lncRNA, which resulted in a morphological change in HeLa cell shape without inducing any cell death. A second round of transcriptomics-based profiling revealed differential expression of genes associated with immune system, motility and cell cycle in DR5-AS knockdown HeLa cells. Cellular analyses showed that DR5-AS reduced cell proliferation and caused a cell cycle arrest at S and G2/M phases. Moreover, DR5-AS knockdown reduced the invasive capacity of HeLa cells in zebrafish xenograft model. These results suggest that cisplatin-mediated pleiotropic effects, such as reduction in cell proliferation, metastasis and cell cycle arrest, may be mediated by lncRNAs. © Copyright © 2021 Gurer, Erdogan, Ahmadov, Basol, Sweef, Cakan-Akdogan and Akgül.Article Citation - WoS: 11Citation - Scopus: 13Transcriptomics Analysis of Circular Rnas Differentially Expressed in Apoptotic Hela Cells(Frontiers Media S.A., 2019) Yaylak, Bilge; Erdoğan, İpek; Akgül, BünyaminApoptosis is a form of regulated cell death that plays a critical role in survival and developmental homeostasis. There are numerous reports on regulation of apoptosis by protein-coding genes as well as small non-coding RNAs, such as microRNAs. However, there is no comprehensive investigation of circular RNAs (circRNA) that are differentially expressed under apoptotic conditions. We have performed a transcriptomics study in which we first triggered apoptosis in HeLa cells through treatment with four different agents, namely cisplatin, doxorubicin, TNF-alpha and anti-Fas mAb. Total RNAs isolated from control as well as treated cells were treated with RNAse R to eliminate the linear RNAs. The remaining RNAs were then subjected to deep-sequencing to identify differentially expressed circRNAs. Interestingly, some of the dys-regulated circRNAs were found to originate from protein-coding genes well-documented to regulate apoptosis. A number of candidate circRNAs were validated with qPCR with or without RNAse R treatment as well. We then took advantage of bioinformatics tools to investigate the coding potential of differentially expressed RNAs. Additionally, we examined the candidate circRNAs for the putative miRNA-binding sites and their putative target mRNAs. Our analyses point to a potential for circRNA-mediated sponging of miRNAs known to regulate apoptosis. In conclusion, this is the first transcriptomics study that provides a complete circRNA profile of apoptotic cells that might shed light onto the potential role of circRNAs in apoptosis.Article Citation - WoS: 6Citation - Scopus: 8Deep Sequencing Reveals Two Jurkat Subpopulations With Distinct Mirna Profiles During Camptothecin-Induced Apoptosis(TUBITAK, 2018) Erdoğan, İpek; Coşacak, Mehmet İlyas; Nalbant, Ayten; Akgül, BünyaminMicroRNAs (miRNAs) are small noncoding RNAs of about 19-25 nt that regulate gene expression posttranscriptionally under various cellular conditions, including apoptosis. The miRNAs involved in modulation of apoptotic events in T cells are partially known. However, heterogeneity associated with cell lines makes it difficult to interpret gene expression signatures, especially in cancer-related cell lines. Treatment of the Jurkat T-cell leukemia cell line with the universal apoptotic drug, camptothecin, resulted in identification of two Jurkat subpopulations: one that is sensitive to camptothecin and another that is rather intrinsically resistant. We sorted apoptotic Jurkat cells from nonapoptotic ones prior to profiling miRNAs through deep sequencing. Our data showed that a total of 184 miRNAs were dysregulated. Interestingly, the apoptotic and nonapoptotic subpopulations exhibited distinct miRNA expression profiles. In particular, 6 miRNAs were inversely expressed in these two subpopulations. The pyrosequencing results were validated by real-time qPCR. Altogether, these results suggest that miRNAs modulate apoptotic events in T cells and that cellular heterogeneity requires careful interpretation of miRNA expression profiles obtained from drug-treated cell lines.