Publications by authors named "Ugur Gezer"

Epigenetic dysregulation is a hallmark of many human malignancies, with DNA methylation being a primary mechanism influencing gene expression and maintaining genomic stability. Genome-wide hypomethylation, characteristic of many cancers, is partly attributed to the demethylation of repetitive elements, including LINE-1, a prevalent non-LTR retrotransposon. The methylation status of LINE-1 is closely associated with overall genomic methylation levels in tumors.

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Article Synopsis
  • Liquid biopsies are changing the way we detect and manage cancer by analyzing cell-free DNA (cfDNA) for potential biomarkers, like human satellite 2 (HSATII), which shows elevated levels in cancer patients.
  • This study focused on comparing HSATII levels in the plasma of breast cancer patients to healthy individuals using targeted sequencing and copy number variation (CNV) analysis.
  • Results indicated significant CNVs in HSATII sequences linked to breast cancer, while challenges with cfDNA fragmentation complicate data interpretation, highlighting the need for improved sequencing methods for cancer screening.
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Background/aim: Colorectal cancer (CRC) is one of leading cancers in terms of incidence and mortality. Interaction of tumor cells with the surrounding microenvironment plays a crucial role in the development and progression of CRC. Many pathways such as the kynurenine pathway, OX40/OX40L-mediated signaling and microRNAs targeting PD-L1 may be involved in CRC development by affecting T cell activation, thus creating an immune-deficient microenvironment.

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Breast cancer is the most common cancer affecting women worldwide. It is a malignant and heterogeneous disease with distinct molecular subtypes, which has prognostic and predictive implications. Circulating tumor DNA (ctDNA), cell-free fragmented tumor-derived DNA in blood plasma, is an invaluable source of specific cancer-associated mutations and holds great promise for the development of minimally invasive diagnostic tests.

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Prostate cancer (PCa) is a common malignant disease with high mortality rates that develops and progresses in an androgen-dependent way. In recent years, RNA sequencing enabled identification of many PCa-related long noncoding RNAs including androgen receptor-regulated long non-coding RNA 1 () and prostate cancer-associated transcript 1 (). In the present study, our goal was to illuminate expression changes of and in the context of androgen stimulation or androgen receptor (AR) blockade with respect to AR expression status.

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Liquid biopsy is a broad term that refers to the testing of body fluids for biomarkers that correlate with a pathological condition. While a variety of body-fluid components (e.g.

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Background: Gastric cancer (GC) is a common cause of cancer-related deaths. The poor clinical outcome in GC patients is partially associated with a lack of appropriate diagnostic and prognostic biomarkers. In the present study, we evaluated the diagnostic and prognostic values of cell-free DNA (cfDNA) integrity and the concentration of circulating nucleosomes (cNUCs).

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Background And Aim: Currently, cancer biomarkers are associated with low diagnostic performance, and the notion of using cell-free DNA (cfDNA) as a surrogate cancer biomarker is a subject of ongoing research efforts. Pericentromeric satellite repeats were shown to expand in tumor cells. Here, we hypothesized that the increased release of satellite DNA into the circulation might be a basis for developing a biomarker for the detection of cancer.

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Breast cancer is the most common type of cancer in women worldwide. Triple methylation of H4 lysine 20 (H4K20me3), a key component of epigenetic regulation of genomic integrity, is catalyzed by the methyltransferase, SUV420H2. Data on the expression status of SUV420H2 in breast cancer are limited.

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Background: Novel biomarkers are needed to predict the effectiveness of the treatment of presurgical neoadjuvant chemotherapy (NAC) in breast cancer (BC).

Objective: This is an exploratory study to assess the impact of 3 cancer-related long non-coding RNAs (lncRNAs) (H19, MALAT1 and GA5) in blood plasma of patients with BC in predicting the response to NAC.

Methods: The plasma levels of RNAs were relatively measured by quantitative PCR at baseline, and at the end of the fourth cycle of NAC in patients with locally advanced BC.

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Background/aim: No blood-based biomarkers are available to differentiate between colonic tumors and precancerous polyps. Previously we demonstrated levels of trimethylated H4K20 (H4K20me3) to be lower in blood plasma from patients with colon cancer than those from cancer-free individuals. Herein, we added individuals with precancerous polyps for the first time in order to analyze and investigate the usefulness of plasma H4K20me3 and histone H4 to discriminate colon tumors from precancerous polyps.

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Background: Reseptor tyrosine kinases (cMET and EGFR) are important in lung cancer targeted therapy. We believe if we can use them as markers for clinicians to help decide the diagnosis of lung cancer. This parameter will be important in serum samples of patients with lung cancer diagnosis and treatment.

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Gastric cancer (GC) is among the most frequent malignant diseases. Despite advances in treatment, the clinical outcome of patients with GC remains poor. The establishment of novel biomarkers is urgently required for early detection, treatment evaluation and prognostic assessment.

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Purpose: In this prospective observational study, we aimed to report the applicability and tolerability of neoadjuvant volumetric modulated arc therapy with simultaneous integrated boost (SIB-VMAT) and concurrent chemotherapy in patients with locally advanced rectal cancer (LARC), and to evaluate the correlation of pathological response with apparent diffusion coefficient (ADC) measurements on diffusion-weighted magnetic resonance imaging (DW-MRI) and apoptotic markers.

Methods: The study enrolled 30 patients with T3 to T4 and/or N+ rectal cancer who preoperatively received SIB-VMAT and concurrent chemotherapy. Before and after the neoadjuvant treatment, apoptotic markers including the nucleosomes and cell-free DNA fragments in the serum samples were examined; DNA integrity was assessed by amplifying the ACTB gene; and the ADC measurements on the DW-MRI were analyzed.

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Background/aim: Prostate cancer (PCa) is an androgen-dependent disease. Novel anti-androgens (i.e.

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Long non-coding RNAs (lncRNAs) are key regulatory molecules in many fundamental cellular processes and their deregulation is assumed to contribute to carcinogenesis. Exosomal lncRNAs are thought to be involved in the dissemination of cell signals to control local cellular microenvironments. In the current study, exosomal expression of growth arrest specific 5 (), an inhibitor of cell proliferation and promoter of apoptosis, was evaluated in apoptotic processes initiated by different mechanisms.

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MicroRNAs (miRNAs) represent a class of short endogenous non-coding RNAs that negatively regulate gene expression at the post-transcriptional level in many biological processes, including proliferation, differentiation, stress response and apoptosis. In this study we analyzed a set of seven miRNA molecules in sera of patients with papillary thyroid cancer, multinodular goiter and healthy controls to identify miRNA molecules that may have utility as markers for PTC. MiR-21 serum levels in the preoperative PTC and MG groups were significantly higher than the control group.

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The global burden of colorectal cancer (CRC)-associated morbidity and mortality is increasing, in part due to a lack of early detection. Direct structural examination techniques, such as colonoscopy, are invasive and can therefore affect the willingness of patients to participate in screening. Recently, the use of "liquid biopsy" has gained considerable attention as a novel source of biomarkers.

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Article Synopsis
  • Circulating nucleic acids (CNAs) are being studied as non-invasive biomarkers for cancer detection, particularly focusing on histone methylation in colorectal cancer (CRC).
  • Previous research analyzed specific histone trimethylation marks (H3K9me3 and H4K20me3) in blood samples, and this study expands on that by measuring additional marks (H3K27me3) in CRC patients and healthy controls.
  • Results showed that levels of H3K27me3 and H4K20me3 were significantly lower in CRC patients, indicating that these histone modifications could be useful biomarkers for CRC detection, especially when combined.
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Long non-coding RNAs (lncRNAs) have been shown to be aberrantly expressed in head and neck cancer (HNC). The aim of the present study was to evaluate plasma levels of three lncRNA molecules (lincRNA-p21, GAS5, and HOTAIR) in the treatment response in HNC patients treated with radical chemoradiotherapy (CRT). Forty-one patients with HNC were enrolled in the study.

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Breast cancer is a complex disease displaying different profiles involving genetic as well as epigenetic factors. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression. Recent studies demonstrated that miRNAs may display great potential for the development of novel biomarkers and therapeutic targets.

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Histone modifications are involved in the DNA damage response (DDR). Here, by utilizing an ELISA immunoassay we assessed the methylation at H3K9 (H3K9me2 and H3K9me3) in two cell lines with differential sensitivity to radiation-induced apoptosis, HeLa (sensitive) and MCF-7 (resistant). We found that DNA damage induction by γ-irradiation leads to considerable accumulation (up to 5-fold) of H3K9me2 and H3K9me3, but not of H4K20me3 (control modification) in MCF-7 cells (p<0.

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Exosomes are membranous vesicles containing various biomolecules including lncRNAs which are involved in cellular communication and are secreted from many cells including cancer cells. In our study, investigated the exosomal GAS5 and lincRNA-p21 lncRNA levels in urine samples from 30 patients with prostate cancer (PCa) and 49 patients with benign prostatic hyperplasia. Quantification of lncRNA molecules was performed by real-time PCR.

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Unlabelled: Background /Aim: Studies evaluating the integrity of cell-fee DNA (cfDNA) in colorectal cancer (CRC) have led to inconsistent results. Herein, we analyzed the utility of two different DNA integrity indexes (ACTB(384)/ACTB(106) and ALU(247)/ALU(115)) to assess cfDNA fragmentation in Turkish CRC patients. The correlation of circulating nucleosomes (cNUC) with the fragment sizes was also evaluated.

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