Person: ÖZER, SIDIKA AYŞE
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ÖZER
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SIDIKA AYŞE
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Publication Open Access Identification of Differentially Expressed IGFBP5-Related Genes in Breast Cancer Tumor Tissues Using cDNA Microarray Experiments(MDPI AG, 2015-11-10) GÜLLÜ AMURAN, GÖKÇE; Akkiprik, Mustafa; Peker, Irem; Ozmen, Tolga; Amuran, Gokce Gullu; Gulluoglu, Bahadir M.; Kaya, Handan; Ozer, AyseIGFBP5 is an important regulatory protein in breast cancer progression. We tried to identify differentially expressed genes (DEGs) between breast tumor tissues with IGFBP5 overexpression and their adjacent normal tissues. In this study, thirty-eight breast cancer and adjacent normal breast tissue samples were used to determine IGFBP5 expression by qPCR. cDNA microarrays were applied to the highest IGFBP5 overexpressed tumor samples compared to their adjacent normal breast tissue. Microarray analysis revealed that a total of 186 genes were differentially expressed in breast cancer compared with normal breast tissues. Of the 186 genes, 169 genes were downregulated and 17 genes were upregulated in the tumor samples. KEGG pathway analyses showed that protein digestion and absorption, focal adhesion, salivary secretion, drug metabolism-cytochrome P450, and phenylalanine metabolism pathways are involved. Among these DEGs, the prominent top two genes (MMP11 and COL1A1) which potentially correlated with IGFBP5 were selected for validation using real time RT-qPCR. Only COL1A1 expression showed a consistent upregulation with IGFBP5 expression and COL1A1 and MMP11 were significantly positively correlated. We concluded that the discovery of coordinately expressed genes related with IGFBP5 might contribute to understanding of the molecular mechanism of the function of IGFBP5 in breast cancer. Further functional studies on DEGs and association with IGFBP5 may identify novel biomarkers for clinical applications in breast cancer.Publication Metadata only PIK3CA and TP53 MUTATIONS and SALL4, PTEN and PIK3R1 GENE EXPRESSION LEVELS in BREAST CANCER(WALTER DE GRUYTER GMBH, 2020) KAYA, HANDAN; Dirican, Ebubekir; Seven, Ipek Erbarut; Kaya, Handan; Ugurlu, M. Umit; Peker, Irem; Gulluoglu, Bahadir M.; Ozer, Ayse; Akkiprik, MustafaObjective: A high frequency of PI3K signalling pathway abnormalities and TP53 mutations are critical in the development and progression of breast cancer (BCa). We aimed to detect PIK3CA and TP53 mutations via an expression analysis of PIK3R1, PTEN and SALL4 and correlate the expression of these genes with clinical parameters of BCa. Materials and methods: PIK3CA and TP53 mutations in BCa samples were analysed by High-Resolution Melting (HRM) analysis, followed by Sanger sequencing, and the expression levels of PIK3R1, PTEN and SALL4 were evaluated by RT-PCR methods. Results: The frequency of PIK3CA and TP53 mutations was 42% and 38% according to the HRM and Sanger sequencing. There was a significantly high frequency of these mutations in ER(+), N0 and HER2(-) tumour samples. PIK3R1 and PTEN expression levels were high in tumour samples, whereas SALL4 expression was low. In patients with TP53 mutations, PIK3R1 expression was low, and this finding was statistically significant. PIK3R1 and PTEN expression levels showed statistically significant, respectively in G3 grades, ER(+), (PR)(+), HER2(+) and ER(+). Conclusions: We suggest that these candidate genes could be potential prognostic biomarkers of BCa and that they should be considered in the evaluation of clinical parameters of BCa.Publication Open Access Comparison of telomere length and insulin-like growth factor-binding protein 7 promoter methylation between breast cancer tissues and adjacent normal tissues in Turkish women(WILEY, 2017-09) GÜLLÜ AMURAN, GÖKÇE; Kaya, Zehra; Akkiprik, Mustafa; Karabulut, Sevgi; Peker, Irem; Amuran, Gokce Gullu; Ozmen, Tolga; Gulluoglu, Bahadir M.; Kaya, Handan; Ozer, AyseBackgroundBoth insulin-like growth factor-binding protein 7 (IGFBP7) and telomere length (TL) are associated with proliferation and senescence of human breast cancer. This study assessed the clinical significance of both TL and IGFBP7 methylation status in breast cancer tissues compared with adjacent normal tissues. We also investigated whether IGFBP7 methylation status could be affecting TL. MethodsTelomere length was measured by quantitative PCR to compare tumors with their adjacent normal tissues. The IGFBP7 promoter methylation status was evaluated by methylation-specific PCR and its expression levels were determined by western blotting. ResultsTelomeres were shorter in tumor tissues compared to controls (P<.0001). The mean TL was higher in breast cancer with invasive ductal carcinoma (IDC; n=72; P=.014) compared with other histological type (n=29), and TL in IDC with HER2 negative (n=53; P=.017) was higher than TL in IDC with HER2 positive (n=19). However, telomeres were shortened in advanced stages and growing tumors. IGFBP7 methylation was observed in 90% of tumor tissues and 59% of controls (P=.0002). Its frequency was significantly higher in IDC compared with invasive mixed carcinoma (IMC; P=.002) and it was not correlated either with protein expression or the other clinicopathological parameters. ConclusionThese results suggest that IGFBP7 promoter methylation and shorter TL in tumor compared with adjacent tissues may be predictive biomarkers for breast cancer. Telomere maintenance may be indicative of IDC and IDC with HER2 (-) of breast cancer. Further studies with larger number of cases are necessary to verify this association.Publication Open Access A novel approach for rapid screening of mitochondrial D310 polymorphism(BMC, 2006-12) GÜLLÜOĞLU, MAHMUT BAHADIR; Aral, C; Kaya, H; Ataizi-Celikel, C; Akkiprik, M; Sonmez, O; Gulluoglu, BM; Ozer, ABackground: Mutations in the mitochondrial DNA ( mtDNA) have been reported in a wide variety of human neoplasms. A polynucleotide tract extending from 303 to 315 nucleotide positions (D310) within the non-coding region of mtDNA has been identified as a mutational hotspot of primary tumors. This region consists of two polycytosine stretches interrupted by a thymidine nucleotide. The number of cytosines at the first and second stretches are 7 and 5 respectively, according to the GeneBank sequence. The first stretch exhibits a polymorphic length variation (6-C to 9-C) among individuals and has been investigated in many cancer types. Large-scale studies are needed to clarify the relationship between cytosine number and cancer development/progression. However, time and money consuming methods such as radioactivity-based gel electrophoresis and sequencing, are not appropriate for the determination of this polymorphism for large case-control studies. In this study, we conducted a rapid RFLP analysis using a restriction enzyme, BsaXI, for the single step simple determination of 7-C carriers at the first stretch in D310 region. Methods: 25 colorectal cancer patients, 25 breast cancer patients and 41 healthy individuals were enrolled into the study. PCR amplification followed by restriction enzyme digestion of D310 region was performed for RFLP analysis. Digestion products were analysed by agarose gel electrophoresis. Sequencing was also applied to samples in order to confirm the RFLP data. Results: Samples containing 7-C at first stretch of D310 region were successfully determined by the BsaXI RFLP method. Heteroplasmy and homoplasmy for 7-C content was also determined as evidenced by direct sequencing. Forty-one percent of the studied samples were found to be BsaXI positive. Furthermore, BsaXI status of colorectal cancer samples were significantly different from that of healthy individuals. Conclusion: In conclusion, BsaXI RFLP analysis is a simple and rapid approach for the single step determination of D310 polymorphism of mitochondrial DNA. This method allows the evaluation of a significant proportion of samples without the need for sequencing- and/or radioactivity-based techniques.