PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Integrated Spectroscopic and Morphological Analyses Reveal Cellular Shifts in Gene-Silenced Melanoma CSCs(Nature Portfolio, 2025) Ozdil, Berrin; Guler, Gunnur; Ataman, Evren; Aktug, HuseyinIntratumoral heterogeneity remains a major barrier to durable cancer therapies, largely driven by the persistence of cancer stem cells (CSCs). In this study, we employed an integrated, multi-scale approach to investigate how melanoma CSCs respond to siRNA-mediated silencing of three key regulatory genes: KLF4, SHH, and HIF1 alpha. Using a combination of morphological, molecular, spectroscopic, and elemental analyses, we explored structural and biochemical consequences of gene knockdown. Gene silencing resulted in significant changes in cell shape and size, reduced F-actin organization, and decreased PFN1 expression, indicating a loss of stem-like properties. ATR-FTIR spectroscopy revealed shifts in biomolecular composition, notably a reduction in amide III intensity and an increase in lipid ester content. SEM-EDS point-based elemental analysis revealed SEM-EDS point-based elemental analysis revealed relative differences in carbon and nitrogen levels between selected central and peripheral regions of silenced and control cells, at the micron-scale working depth, reflecting broader elemental distribution trends rather than precise subcellular compartmentalization. XPS analysis further confirmed these differences, providing additional insights into the elemental composition of the cellular surface. The integration of FTIR spectroscopy into this study highlights the potential of infrared spectroscopy as a powerful tool in cancer research. These findings demonstrate that targeting critical regulatory pathways induces cytoskeletal and biochemical remodelling in melanoma CSCs, offering a multi-dimensional perspective on cellular plasticity.Article Citation - WoS: 2Citation - Scopus: 2Vibrational Spectroscopy Unveils Distinct Cell Cycle Features of Cancer Stem Cells in Melanoma(Nature Portfolio, 2025) Uslu, Bensu Ruya; Ozdil, Berrin; Tarhan, Enver; Ozcelik, Serdar; Aktug, Huseyin; Guler, GunnurCancer stem cells (CSCs) play a central role in melanoma growth, resistance to treatment, and relapse, however, their dynamic regulatory behavior remains poorly understood. Vibrational spectroscopy offers a unique, label-free approach to investigate cellular heterogeneity at the molecular level. Here, we explored the biochemical and regulatory dynamics of CSCs identified by using a time-course design, integrating infrared and Raman spectroscopies with cell cycle analysis and immunocytochemistry targeting the checkpoint proteins p16 and p21. CSCs, non-cancer stem cells (NCSCs), and bulk CHL-1 melanoma cells were monitored at 11, 24, 48, and 72 h. CSCs showed a steady S-phase with an early rise in p16 followed by a subsequent increase in p21 expression, indicating a dynamic state of cell cycle checkpoints. In contrast, NCSCs and CHL-1 cells showed more transient p16/p21 expression and CHL-1 exhibited a marked p16 increase at 24 h. Spectroscopic analysis revealed that CSCs exhibited distinct vibrational profiles, predominantly in the nucleic acid-, protein- and lipid-associated regions. These differences were further supported by principal component and hierarchical clustering analyses, which consistently distinguished CSCs from NCSCs. Our findings underline the potential of vibrational spectroscopy to sensitively detect CSC-specific regulatory patterns and support its use in detecting new therapeutic targets in melanoma.Article Time-Dependent Effects of Low-Intensity Pulsed Ultrasound on Apoptosis and Autophagy in Malignant Melanoma Stem Cells(Wiley, 2025) Dikici, Omer; Ozdil, Berrin; Yesin, Taha Kadir; Dikici, Aylin; Adali, Yasemin; Aktug, HuseyinCancer stem cells (CSCs) in malignant melanoma contribute to therapeutic resistance and tumour recurrence. While low-intensity pulsed ultrasound (LIPUS) has been proposed as a non-invasive strategy to induce cell death, its effects on CSC-specific apoptotic and autophagic responses remain unclear. This study aimed to explore the time-dependent effects of LIPUS on apoptosis and autophagy in CD133+ melanoma CSCs and CD133- non-stem melanoma cells. Human melanoma cells (CHL-1) were sorted via FACS into CD133+ and CD133- populations. Cells were exposed to LIPUS (1 MHz, 20% duty cycle, 1 W/cm2) for 1, 5, and 10 min. Protein expression levels of Caspase-3, Caspase-8, mTOR, and LC3 were evaluated via immunofluorescence and quantified by image-based analysis. Both cell populations showed significant increases in Casp3, Casp8, mTOR, and LC3 intensities following LIPUS application. Notably, CD133+ cells exhibited delayed but sustained increases in Casp3 and LC3 expression, while CD133- cells responded more rapidly. mTOR activity demonstrated distinct temporal dynamics between the two groups, suggesting differential modulation of autophagy-related pathways. LIPUS triggers temporally distinct apoptotic and autophagic responses in melanoma CSCs and non-stem cancer cells. These findings suggest a potential therapeutic avenue to selectively disrupt CSC survival mechanisms using mechanical stimulation.Article Citation - WoS: 2Citation - Scopus: 2Modulating Cancer Stem Cell Characteristics in CD133+ Melanoma Cells through Hif1α, KLF4, and SHH Silencing(Amer Chemical Soc, 2025) Ozdil, Berrin; Güler, Günnur; Avci, Cigir Biray; Calik-Kocaturk, Duygu; Gorgulu, Volkan; Uysal, Aysegul; Guler, Gunnur; Aktug, HuseyinMalignant melanoma is a highly aggressive form of skin cancer, partly driven by a subset of cancer stem cells (CSCs) with remarkable capacities for self-renewal, differentiation, and resistance to therapy. In this study, we examined how silencing three key genes-Hif1 alpha, KLF4, and SHH-affects CSC characteristics. Using small interfering RNA (siRNA)-based approaches, we observed significant changes at both the gene and protein levels, shedding light on how these pathways influence melanoma progression. Our results demonstrated that silencing these genes reduces the stem-like features of CSCs. Notably, Hif1 alpha silencing triggered a marked decrease in hypoxia-related gene expression, while targeting SHH led to a reduction in Gli1, a downstream effector of SHH signaling, highlighting its potential as a therapeutic target. We also observed changes in epigenetic markers such as HDAC9 and EP300, which play crucial roles in maintaining stemness and regulating gene expression. Interestingly, these interventions appeared to reprogram CSCs, pushing them toward a phenotype distinct from both traditional CSCs and non-stem cancer cells (NCSCs). Our findings emphasize the importance of targeting key signaling pathways in melanoma CSCs and underscore the value of mimicking the tumor microenvironment in experimental models. By revealing the dynamic plasticity of melanoma CSCs, this study offers fresh insights into potential therapeutic strategies, particularly using siRNA to modulate pathways associated with tumor progression and stem cell behavior.