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ÖZER, SIDIKA AYŞE

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ÖZER

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SIDIKA AYŞE

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2010 - 20173
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Subject: COLORECTAL-CANCER ×

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Now showing 1 - 3 of 3
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    Mutation distributions and clinical correlations of PIK3CA gene mutations in breast cancer
    (SAGE PUBLICATIONS LTD, 2016) AKKİPRİK, MUSTAFA; Dirican, Ebubekir; Akkiprik, Mustafa; Ozer, Ayse
    Breast cancer (BCa) is the most common cancer and the second cause of death among women. Phosphoinositide 3-kinase (PI3K) signaling pathway has a crucial role in the cellular processes such as cell survival, growth, division, and motility. Moreover, oncogenic mutations in the PI3K pathway generally involve the activation phosphatidylinositol-4,5-bisphosphate 3-kinase-catalytic subunit alpha (PIK3CA) mutation which has been identified in numerous BCa subtypes. In this review, correlations between PIK3CA mutations and their clinicopathological parameters on BCa will be described. It is reported that PIK3CA mutations which have been localized mostly on exon 9 and 20 hot spots are detected 25-40 % in BCa. This relatively high frequency can offer an advantage for choosing the best treatment options for BCa. PIK3CA mutations may be used as biomarkers and have been major focus of drug development in cancer with the first clinical trials of PI3K pathway inhibitors currently in progress. Screening of PIK3CA gene mutations might be useful genetic tests for targeted therapeutics or diagnosis. Increasing data about PIK3CA mutations and its clinical correlations with BCa will help to introduce new clinical applications in the near future.
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    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, Ayse
    BackgroundBoth 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.
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    R72P Polymorphism of TP53 in Ulcerative Colitis Patients is Associated with the Incidence of Colectomy, Use of Steroids and the Presence of a Positive Family History
    (SPRINGER, 2010) ÇELİKEL, ÇİĞDEM; Eren, Fatih; Akkiprik, Mustafa; Atug, Ozlen; Sonmez, Ozgur; Tahan, Gulgun; Ozdemir, Filiz; Hamzaoglu, Hulya Over; Celikel, Cigdem Ataizi; Imeryuz, Nese; Avsar, Erol; Ozer, Ayse
    P53 tumor suppressor protein is one of the pivotal regulators for genome integrity, cell cycle and apoptosis. The most commonly and extensively studied single nucleotide polymorphism (SNP) of p53 is Arg>Pro substitution on codon 72 (R72P). Although we know that the SNP has unique functional effects on the protein, its clinical significance is not clearly identified yet. Aim of the study was to access the relationship between R72P genotype distribution and clinical variables in patients with ulcerative colitis (UC) and colorectal cancer (CRC). Genomic DNA samples were extracted from 95 UC, 50 CRC, and 219 healthy controls. R72P genotype analysis was carried out with polymerase chain reaction following by restriction enzyme digestion. We observed that Pro allele carriage is a strong risk factor for CRC (OR=3.03; 95%CI=1.91-2.40; p=0.003), but only modest association with UC (OR=1.61; 95%CI=0.98-2.65; p =0.059) (Pro/Pro and Pro/Arg genotypes vs. Arg/Arg genotype). We did not find any correlation between genotype distribution of the polymorphism and clinical parameters of CRC, but in UC, Pro/Pro genotype was significantly related to an inflammatory bowel disease family history (OR=8.0; 95%CI=1.68-38.08, p=0.015), and Arg/Pro genotype was significantly associated with the history of disease-related colectomy (OR=17.77; 95%CI=0.98-323.34, p=0.012) and steroid use (OR=10.14; 95%CI=2.63-39.12, p=0.0002). Our data suggest that R72P variant seems to be associated with high risk for development of CRC but carries low risk for development of UC. R72P genotypes might be a useful predictive marker for surgical and medical treatment of UC.