WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 4Citation - Scopus: 3An Investigation of Rna Methylations With Biophysical Approaches in a Cervical Cancer Cell Model(Mdpi, 2024) Saglam, Buket; Akkus, Onur; Akcaoz-Alasar, Azime; Ceylan, Cagatay; Guler, Gunnur; Akgul, BunyaminRNA methylation adds a second layer of genetic information that dictates the post-transcriptional fate of RNAs. Although various methods exist that enable the analysis of RNA methylation in a site-specific or transcriptome-wide manner, whether biophysical approaches can be employed to such analyses is unexplored. In this study, Fourier-transform infrared (FT-IR) and circular dichroism (CD) spectroscopy are employed to examine the methylation status of both synthetic and cellular RNAs. The results show that FT-IR spectroscopy is perfectly capable of quantitatively distinguishing synthetic m(6)A-methylated RNAs from un-methylated ones. Subsequently, FT-IR spectroscopy is successfully employed to assess the changes in the extent of total RNA methylation upon the knockdown of the m(6)A writer, METTL3, in HeLa cells. In addition, the same approach is shown to accurately detect reduction in total RNA methylation upon the treatment of HeLa cells with tumor necrosis factor alpha (TNF-alpha). It is also demonstrated that m(1)A and m(6)A methylation induce quite a distinct secondary structure on RNAs, as evident from CD spectra. These results strongly suggest that both FT-IR and CD spectroscopy methods can be exploited to uncover biophysical properties impinged on RNAs by methyl moieties, providing a fast, convenient and cheap alternative to the existing methods.Article Citation - WoS: 4Citation - Scopus: 3Expression Patterns of M6a Rna Methylation Regulators Under Apoptotic Conditions in Various Human Cancer Cell Lines(TUBITAK, 2024) Alasar, Azime Akçaöz; Sağlam, Buket; Vatansever, İpek Erdoğan; Akgül, BünyaminBackground/aim: Cancer is a complex disease that involves both genetic and epigenetic factors. While emerging evidence clearly suggests that changes in epitranscriptomics play a crucial role in cancer pathogenesis, a comprehensive understanding of the writers, erasers, and readers of epitranscriptomic processes, particularly under apoptotic conditions remains lacking. The aim of this study was to uncover the changes in the expression of m6A RNA modifiers under apoptotic conditions across various cancer cell lines. Materials and methods: Initially, we quantified the abundance of m6A RNA modifiers in cervical (HeLa and ME180), breast (MCF7 and MDA-MB-231), lung (A549 and H1299), and colon (Caco-2 and HCT116) cancer cell lines using qPCR. Subsequently, we induced apoptosis using cisplatin and tumor necrosis factor-alpha (TNF-α) to activate intrinsic and extrinsic pathways, respectively, and assessed apoptosis rates via flow cytometry. Further, we examined the transcript abundance of m6A RNA modifiers under apoptotic conditions in cervical, breast, and lung cancer cell lines using qPCR. Results: Overall, treatment with cisplatin increased the abundance of m 6A modifiers, whereas TNF-α treatment decreased their expression in cervical, breast, and lung cancer cell lines. Specifically, cisplatin-induced apoptosis, but not TNF-α-mediated apoptosis, resulted in decreased abundance of METTL14 and FTO transcripts. Additionally, cisplatin treatment drastically reduced the abundance of IGF2BP2 and IGF2BP3 readers. Conclusion: These results suggest that the differential response of cancer cells to apoptotic inducers may be partially attributed to the expression of m6A RNA modifiers.Article Citation - WoS: 6Epitranscriptomics M<sup>6</Sup>a Analyses Reveal Distinct M<sup>6</Sup>a Marks Under Tumor Necrosis Factor Α (tnf-Α) Apoptotic Conditions in Hela Cells(Wiley, 2024) Akçaöz Alasar, Azime; Tüncel, Özge; Sağlam, Buket; Gazaloğlu, Yasemin; Atbinek, Melis; Çağıral, Umut; 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.
