PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 13Citation - Scopus: 13Her2-Targeted, Degradable Core Cross-Linked Micelles for Specific and Dual Ph-Sensitive Dox Release(John Wiley and Sons Inc., 2021) Bayram, Nazende Nur; Ulu, Gizem Tuğçe; Topuzoğulları, Murat; Baran, Yusuf; Dinçer İşoğlu, SevilHere, a targeted, dual-pH responsive, and stable micelle nanocarrier is designed, which specifically selects an HER2 receptor on breast cancer cells. Intracellularly degradable and stabilized micelles are prepared by core cross-linking via reversible addition-fragmentation chain-transfer (RAFT) polymerization with an acid-sensitive cross-linker followed by the conjugation of maleimide-doxorubicin to the pyridyl disulfide-modified micelles. Multifunctional nanocarriers are obtained by coupling HER2-specific peptide. Formation of micelles, addition of peptide and doxorubicin (DOX) are confirmed structurally by spectroscopical techniques. Size and morphological characterization are performed by Zetasizer and transmission electron microscope (TEM). For the physicochemical verification of the synergistic acid-triggered degradation induced by acetal and hydrazone bond degradation, Infrared spectroscopy and particle size measurements are used. Drug release studies show that DOX release is accelerated at acidic pH. DOX-conjugated HER2-specific peptide-carrying nanocarriers significantly enhance cytotoxicity toward SKBR-3 cells. More importantly, no selectivity toward MCF-10A cells is observed compared to HER2(+) SKBR-3 cells. Formulations cause apoptosis depending on Bax and Caspase-3 and cell cycle arrest in G2 phase. This study shows a novel system for HER2-targeted therapy of breast cancer with a multifunctional nanocarrier, which has higher stability, dual pH-sensitivity, selectivity, and it can be an efficient way of targeted anticancer drug delivery.Article Citation - WoS: 5Citation - Scopus: 7The Roles of Antiapoptotic Sphingosine Kinase-1 and Glucosylceramide Genes in Drug Induced Cell Death of Mcf-7 Breast Cancer Cells(Zerbinis Medical Publications, 2011) Güçlüler, Gözde; Pişkin, Özden; Baran, YusufPurpose: Sphingolipids are important signaling molecules mediating cell survival, proliferation, cell cycle regulation and apoptosis. Ceramide is the most vital sphingolipid which induces growth arrest, senescence, and apoptosis. In this study, we aimed to determine the roles of sphingosine kinase- 1 (SK-1) and glucosylceramide synthase (GCS) genes in paclitaxel, doxorubicin, tamoxifen, cyclophosphamide and docetaxel induced apoptosis in human MCF-7 breast cancer cells. Methods: IC50 values (drug concentration inhibiting cell growth by 50%) of the anticancer agents were calculated using XTT cell proliferation assay. Changes in mitochondrial membrane potential (MMP) were determined using JC-1 assay kit. Changes in the mRNA levels of SK-1 and GCS genes were measured by using RT-PCR technique. Results: The results demonstrated significant decrease in cellular proliferation and increase in loss of MMP in a dose-dependent manner. Paclitaxel, doxorubicin, tamoxifen, cyclophosphamide and docetaxel application downregulated SK-1 expression while paclitaxel, tamoxifen, cyclophosphamide and docetaxel but not doxorubicin downregulated GCS comparing to untreated control cells. Conclusion: These results show for the first time that these agents induce apoptosis in MCF-7 cells by downregulating the antiapoptotic SK-1 and GCS genes that may result in accumulation of apoptotic ceramides. © 2011 Zerbinis Medical Publications.Article Citation - WoS: 16Citation - Scopus: 16Multidrug Resistance Mediated by Mrp1 Gene Overexpression in Breast Cancer Patients(Taylor and Francis Ltd., 2009) Abaan, Ogan Demir; Mutlu, Pelin Kaya; Baran, Yusuf; Atalay, Can; Gündüz, UfukMultidrug resistance (MDR) is a serious handicap towards the effective treatment of breast cancer patients. One of the most prevalent MDR mechanisms is through the overexpression of genes coding the proteins called Multidrug Resistance-associated Proteins (MRPs). The aim of this study was to investigate the expression of MRP1 in tumor tissues from breast cancer patients. In this study, a semi-quantitative RT-PCR approach was utilized. Our results suggest that MRP1 overexpression can mediate MDR in patients. Pre-evaluation of the level of such MDR mediators before chemotherapy can increase the efficacy of the treatment.Article Citation - WoS: 11Citation - Scopus: 16Bisphosphonate Treatment and Radiotherapy in Metastatic Breast Cancer(Humana Press, 2008) Ural, Ali Uğur; Avcu, Ferit; Baran, YusufPatients with advanced breast cancer frequently develop metastasis to bone. Bone metastasis results in intractable pain and high risk of pathologic fractures due to osteolysis. The treatment of breast cancer patients with bone metastases requires a multidisciplinary approach. Radiotherapy is an established treatment for metastatic bone pain. It may be delivered either as a localized low dose treatment for localized bone pain or systemically for more widespread symptoms. Bisphosphonates have been shown to reduce morbidity and bone pain from bone metastases when given to patients with metastatic bone disease. In vivo studies indicate that early bisphosphonates administration in combination with radiotherapy improves remineralization and restabilization of osteolytic bone metastases in animal tumor models. This review focused on a brief discussion about biology of bone metastases, the effects of radiotherapy and bisphosphonate therapy, and possible mechanisms of combination therapy in metastatic breast cancer patients.Letter Citation - WoS: 2Citation - Scopus: 3Rates of Myocardial Infarction and Coronary Artery Disease and Risk Factors in Patients Treated With Radiation Therapy for Early-Stage Breast Cancer(John Wiley and Sons Inc., 2007) Ural, Ali Uğur; Avcu, Ferit; Baran, YusufWe read the interesting article by Jagsi et al on the increased rates of coronary artery disease in patients treated with radiation therapy for early-stage breast cancer.1 In their study, those authors concluded that the findings support further assessment of clinical outcomes when newer techniques of chemotherapy planning are employed as well as investigation of the potential role of innovative techniques. However, there was no mention of the novel radiosensitizing and chemosensitizing effects of bisphosphonates (BPs), which inhibit tumor cell adhesion to bone, and tumor growth in breast cancer.