Publications by authors named "Cem Horozoglu"

Background: Indoleamine 2,3-Dioxygenase 1 (IDO1)-mediated tryptophan degradation, which is the rate-limiting enzyme of tryptophan/kynurenine pathway, may cause immune suppression in the tumor microenvironment, while potentiating proliferative and metastatic activity in the tumor focus, Phase studies of IDO1 inhibitors are ongoing, and our study aims to evaluate the potential contribution of IDO1 gene expression to the tryptophan/kynurenine pathway in tumor and tumor microenvironment foci in gastric cancer (GC) on a clinicopathological axis, METHOD: In the case-control study design, the determination of tryptophan and its metabolites in the serum of 51 GC and 49 healthy controls was made using High Pressure Liquid Chromatography-Fluorescence Detector (HPLC-FD). IDO1 expression in a total of 102 tissues with tumor and tumor microenvironment was detected by quantitative PCR (q-PCR).

Results: In gastric tumors, 3,25-fold decreased expression of IDO1 was detected according to the tumor microenvironment (p=0,05), IDO1 expression was found to be more than 2 times higher in signet ring cell carcinoma (SRCC) and poorly differentiated tumors without distant organ metastasis (p<0,05), In GC, tryptophan level was found to be 1,6 times lower than in control (AUC:0889; cut off≤21,57; p<0001), Low tryptophan level was found in advanced tumor stage compared to early stage and in the presence of perineural invasion compared to its absence (p<0,05) The level of kynurenine was found to be approximately 1,8 times lower in SRCC (p=0,04), CONCLUSION: Increased tryptophan accumulation in the gastric tumor and its microenvironment, when catabolized via IDO1, exhibits histological type, tumor differentiation, and metastasis-promoting effects more prominently in aggressive subtypes such as SRCC.

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TRAIL, a member of the TNF family, is expressed in tumor and tumor surrounding tissue in many solid organ cancers. While the induction of tumor-specific apoptosis in correlation with cytokine stimulation may cause anti-tumoral effects, the pro-tumorigenic effects of its expression by tumor surrounding tissue members have been reported in the literature. In our study, it was aimed to evaluate the effect of the gene variant of TRAIL on soluble levels in patients with colorectal cancer (CRC) on the molecular pathological axis.

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Background: Intercellular adhesion molecule-1 (ICAM-1) is a surface glycoprotein important for tumor invasion and angiogenesis. The present research is conducted to investigate whether specific gene polymorphism of ICAM-1 K469E (rs5498) and plasma redox status could be associated with laryngeal cancer (LC) development. Since there is no clear evidence which investigates the relationship between ICAM-1 polymorphism and ROS-mediated plasma protein oxidation in LC, our study is the first significant contribution for investigating the relationship.

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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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Article Synopsis
  • - NORAD is a long non-coding RNA linked to genome stability, showing variable regulation in cancers, and its relationship with ICAM-1 is explored in laryngeal squamous cell carcinoma (LSCC).
  • - A study analyzed NORAD and sICAM1 levels in 105 individuals, finding NORAD was higher in tumor-free tissues and sICAM1 levels were greater in controls compared to LSCC patients.
  • - Both biomarkers displayed potential roles in distinguishing between normal and cancerous tissues, with NORAD showing an Area Under the Curve (AUC) of 0.674 and sICAM1 an AUC of 0.624 in diagnostic sensitivity and specificity.
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This study explores the machine learning-based assessment of predisposition to colorectal cancer based on single nucleotide polymorphisms (SNP). Such a computational approach may be used as a risk indicator and an auxiliary diagnosis method that complements the traditional methods such as biopsy and CT scan. Moreover, it may be used to develop a low-cost screening test for the early detection of colorectal cancers to improve public health.

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Tryptophan metabolism in the tumor microenvironment exerts immunosuppressive effects by affecting the anti-tumor functions of immune cells. The immunosuppressive roles of tryptophan and tryptophan metabolites and their effects on the FOXP3 gene, highly expressed in regulatory T cells (Tregs), are remarkable. Our study aimed to investigate the relation between tryptophan metabolism and the transcription factor FOXP3 gene in colorectal cancer (CRC).

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Background/aim: Functional and bioinformatic studies provide strong evidence that long non-coding RNAs (lncRNAs) can alter the molecular mechanisms of cancer through their interactions with DNA, RNAs, and proteins. This study aimed to evaluate the role of H19 and LINC00675 lncRNAs in colorectal cancers (CRCs) in terms of clinicopathological features.

Materials And Methods: Tumor and tumor-free surrounding tissue samples were obtained from 51 CRC cases.

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Immunomodulatory signals regulate the self-tolerance, activation, priming and survival processes of T cells. Programmed cell death protein 1 (PD1), Programmed death-ligand 1 (PD-L1) inhibitory signals and CD27, CD28 costimulators have been detected for many solid organ cancers in tumor-infiltrating T cells. It was aimed to investigate the immune cell-based regulatory genetic variants in laryngeal squamous cell carcinoma (LSCC) in terms of clinicopathological features.

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Background: The aim of this study was to investigate the possible relationship between galectin-3 gene variants, serum level, gene expression level, and the risks and survivals of resectable non-small cell lung cancer patients.

Methods: The rs4644 and rs4652 variants of galectin-3 were genotyped by TaqMan single nucleotide polymorphism assay using genomic deoxyribonucleic acid isolated from the peripheral blood of 65 (54 males, 11 females; mean age: 60.1±11.

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Rapidly accumulating preclinical and clinical studies have helped us to unveil underlying mechanisms of colorectal cancer development and progression. Deregulated signaling pathways play instrumental role in carcinogenesis, drug resistance and metastasis. Wnt signaling cascade has attracted considerable attention in colorectal cancer as many ground-breaking researches have highlighted central role of Wnt pathway in pathogenesis of colorectal cancer.

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It is known that disorders in apoptosis function play an important role in the pathogenesis of many types of cancer, including lung cancer. Tumor necrosis factor related apoptosis inducing ligand (TRAIL), a type II transmembrane protein, is a death ligand capable of inducing apoptosis by activating distinctive death receptor. Our purpose in this study is to investigate the gene polymorphisms in TRAIL molecular pathway and TRAIL gene expression levels in non-small cell lung cancer (NSCLC) patients in terms of pathogenesis and prognosis of the disease.

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Article Synopsis
  • This study looked at how certain gene changes and levels in lung cancer patients might affect their survival chances and disease spread.
  • The researchers tested blood and tumor samples from 36 patients to find out about mutations in the epidermal growth factor receptor gene and levels of programmed death ligand 1.
  • Results showed that some mutations were linked to worse disease spread, but patients with lower levels of one type of protein in their blood lived longer than those with higher levels.
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Background/aim: Adipocyte gene expression is altered in obese individuals through multiple metabolic and biochemical pathways. In this study, we aimed to examine the expression of resistin (Retn), amylin (Iapp), and dopamine receptor domain 5 (Drd5) genes previously suggested to contribute to the pathogenesis of obesity, albeit controversially. We also aimed to determine the effects on short and long-term mRNA levels of these genes in obese mice, induced with high-fat diet (HFD).

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Osteosarcoma (OSA) is the most common adolescence cancer among all primary bone tumors next only to multiplemyeloma. It has a substantially worse prognosis and ability to metastasize to lung. MMPs (matrix metalloproteinases) are among the major proteases that take part in regulation of ECM (extracellular matrix).

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The Wnt pathway alterations have been identified in colorectal and many other cancer types. It has been reported that galectin-3 (which is encoded by the LGALS3 gene) alters the signaling mechanism in the Wnt/ β-catenin pathway by binding to β-catenin in colon and other cancers. AXIN1 is mainly responsible for the assembly of the β-catenin destruction complex in the Wnt pathway.

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Aim: There are two different types of diabetes mellitus, type 1 and type 2, with still unclear molecular mechanisms. In the present study, we aimed to investigate the role of small ubiquitin-like modifier 4 (SUMO4) M55V and nuclear factor kappa B1 (NFKB1)-94del/ins in type-2 diabetes mellitus.

Materials And Methods: We analyzed SUMO4 M55V and NFKB1-94del/ins variants in 104 patients with type-2 diabetes and 124 healthy controls using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques.

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