Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Book Part Citation - Scopus: 1Automated Analysis of Phase-Contrast Optical Microscopy Time-Lapse Images: Application To Wound Healing and Cell Motility Assays of Breast Cancer(Elsevier, 2023) Erdem, Yusuf Sait; Yalçın Özuysal, Özden; Ayanzadeh, Aydın; Pesen Okvur, Devrim; Mayalı, Berkay; Balıkçı, Muhammed; Belli, Özge Nur; Uçar, Mahmut; Yalçın Özuysal, Özden; Pesen Okvur, Devrim; Önal, Sevgi; Morani, Kenan; Iheme, Leonardo Obinna; Töreyin, Behçet Uğur; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyThis chapter describes a workflow for analyzing phase-contrast microscopy (PCM) data from two fundamental types of biomedical assays: assays for cell motility and assays for wound healing. The workflow of the analysis is composed of the methods for acquiring, restoring, segmenting, and quantifying biomedical data. In the literature, there have been separate methods aimed at specific stages of PCM data analysis. Nonetheless, there has never been a complete workflow for all stages of analysis. This work is an innovation that proposes an end-to-end workflow for image pre-processing, deep learning segmentation, tracking, and quantification stages in cell motility and wound healing assay analyses. The findings indicate that domain knowledge can be used to make simple but significant improvements to the results of cutting-edge methods. Furthermore, even for deep learning-based methods, pre-processing is clearly a necessary step in the workflow. © 2023 Elsevier Inc. All rights reserved.Review Citation - WoS: 14Citation - Scopus: 14Recent Advances in Lab-On Systems for Breast Cancer Metastasis Research(Royal Society of Chemistry, 2023) Fıratlıgil Yıldırır, Burcu; Fıratlıgil Yıldırır, Burcu; Yalçın Özuysal, Özden; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyBreast cancer is the leading cause of cancer-related deaths in women. Multiple molecular subtypes, heterogeneity, and their ability to metastasize from the primary site to distant organs make breast cancer challenging to diagnose, treat, and obtain the desired therapeutic outcome. As the clinical importance of metastasis is dramatically increasing, there is a need to develop sustainable in vitro preclinical platforms to investigate complex cellular processes. Traditional in vitro and in vivo models cannot mimic the highly complex and multistep process of metastasis. Rapid progress in micro- and nanofabrication has contributed to soft lithography or three-dimensional printing-based lab-on-a-chip (LOC) systems. LOC platforms, which mimic in vivo conditions, offer a more profound understanding of cellular events and allow novel preclinical models for personalized treatments. Their low cost, scalability, and efficiency have resulted in on-demand design platforms for cell, tissue, and organ-on-a-chip platforms. Such models can overcome the limitations of two- and three-dimensional cell culture models and the ethical challenges involved in animal models. This review provides an overview of breast cancer subtypes, various steps and factors involved in metastases, existing preclinical models, and representative examples of LOC systems used to study and understand breast cancer metastasis and diagnosis and as a platform to evaluate advanced nanomedicine for breast cancer metastasis.Article Epithelial-Mesenchymal Transition as a Potential Route for Dapt Resistance in Breast Cancer Cells(Walter de Gruyter GmbH, 2023) Tellı, Kubra; Ozuysal, Ozden Yalcın; Yalçın Özuysal, Özden; Yalçın Özuysal, Özden; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyObjectives: Notch is a conserved pathway involved in cell- fate determination and homeostasis. Its dysregulation plays a role in poor prognosis and drug resistance in breast cancer. Targeting Notch signaling via inhibition of the gamma- secretase complex is in the spotlight of modern cancer treat- ments. Gamma-secretase inhibitors (GSI) have shown suc- cessful clinical activity in treating cancers, yet the possible resistance mechanism remains unstudied. Modeling the resistance and understanding culprit molecular mechanisms can improve GSI therapies. Accordingly, the aim of this study is to generate and analyze GSI-resistant breast cancer cells. Methods: Gradually increasing doses of DAPT, a well-known GSI, were applied to MCF-7 breast cancer cell lines to generate resistance. Cell viability, migration and gene expressions were assessed by MTT, wound healing and qRT-PCR analyses. Results: DAPT-resistant MCF-7 cells exhibited abnormal expression of Notch receptors, Notch targets (HES1, HES5, HEY1), and epithelial-mesenchymal transition (EMT) markers (E-cadherin, ZO-1, SNAIL2, N-cadherin) to overcome the continuous increase in DAPT toxicity by increased migration through mesenchymal transition. Conclusions: This study prospects into the role of EMT in the potential resistance mechanism against DAPT treatment for breast cancer cells. Complementary targeting of EMT should be investigated further for a possible effect to potentiate DAPT’s anti-cancer effects.Article Citation - WoS: 7Citation - Scopus: 7Connexin 32 Overexpression Increases Proliferation, Reduces Gap Junctional Intercellular Communication, Motility and Epithelial-To Transition in Hs578t Breast Cancer Cells(Springer, 2022) Güngül, Taha Buğra; Meşe Özçivici, Gülistan; Uğur, Deniz; Özçivici, Engin; Yalçın Özuysal, Özden; Yücel, Simge; 03.01. Department of Bioengineering; 01. Izmir Institute of Technology; 04.03. Department of Molecular Biology and Genetics; 03. Faculty of Engineering; 04. Faculty of ScienceConnexins (Cx) are primary components of gap junctions that selectively allow molecules to be exchanged between adjacent cells, regulating multiple cellular functions. Along with their channel forming functions, connexins play a variety of roles in different stages of tumorigenesis and their roles in tumor initiation and progression is isoform- and tissue-specific. While Cx26 and Cx43 were downregulated during breast tumorigenesis, Cx32 was accumulated in the cytoplasm of the cells in lymph node metastasis of breast cancers and Cx32 was further upregulated in metastasis. Cx32's effect on cell proliferation, gap junctional communication, hemichannel activity, cellular motility and epithelial-to-mesenchymal transition (EMT) were investigated by overexpressing Cx32 in Hs578T and MCF7 breast cancer cells. Additionally, the expression and localization of Cx26 and Cx43 upon Cx32 overexpression were examined by Western blot and immunostaining experiments, respectively. We observed that MCF7 cells had endogenous Cx32 while Hs578T cells did not and when Cx32 was overexpressed in these cells, it caused a significant increase in the percentages of Hs578T cells at the S phase in addition to increasing their proliferation. Further, while Cx32 overexpression did not induce hemichannel activity in either cell, it decreased gap junctional communication between Hs578T cells. Additionally, Cx32 was mainly observed in the cytoplasm in both cells, where it did not form gap junction plaques but Cx32 overexpression reduced Cx43 levels without affecting Cx26. Moreover, migration and invasion potentials of Hs578T and migration in MCF7 were reduced upon Cx32 overexpression. Finally, the protein level of mesenchymal marker N-cadherin decreased while epithelial marker ZO-1 and E-cadherin increased in Hs578T cells. We observed that Cx32 overexpression altered cell proliferation, communication, migration and EMT in Hs578T, suggesting a tumor suppressor role in these cells while it had minor effects on MCF7 cells.Article Citation - WoS: 3Citation - Scopus: 6Improved Cell Segmentation Using Deep Learning in Label-Free Optical Microscopy Images(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2021) Ayanzadeh, Aydın; Yalçın Özuysal, Özden; Pesen Okvur, Devrim; Önal, Sevgi; Yalçın Özuysal, Özden; Ünay, Devrim; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyThe recently popular deep neural networks (DNNs) have a significant effect on the improvement of segmentation accuracy from various perspectives, including robustness and completeness in comparison to conventional methods. We determined that the naive U-Net has some lacks in specific perspectives and there is high potential for further enhancements on the model. Therefore, we employed some modifications in different folds of the U-Net to overcome this problem. Based on the probable opportunity for improvement, we develop a novel architecture by using an alternative feature extractor in the encoder of U-Net and replacing the plain blocks with residual blocks in the decoder. This alteration makes the model superconvergent yielding improved performance results on two challenging optical microscopy image series: a phase-contrast dataset of our own (MDA-MB-231) and a brightfield dataset from a well-known challenge (DSB2018). We utilized the U-Net with pretrained ResNet-18 as the encoder for the segmentation task. Hence, following the modifications, we redesign a novel skip-connection to reduce the semantic gap between the encoder and the decoder. The proposed skip-connection increases the accuracy of the model on both datasets. The proposed segmentation approach results in Jaccard Index values of 85.0% and 89.2% on the DSB2018 and MDA-MB-231 datasets, respectively. The results reveal that our method achieves competitive results compared to the state-of-the-art approaches and surpasses the performance of baseline approaches.Article Citation - WoS: 16Citation - Scopus: 18Connexin 32 Induces Pro-Tumorigenic Features in Mcf10a Normal Breast Cells and Mda-Mb Metastatic Breast Cancer Cells(Elsevier, 2020) Meşe Özçivici, Gülistan; Ünal, Yağmur Ceren; Yücel, Simge; Yalçın Özuysal, Özden; Vural, Zehra; Turan, Fatma Başak; Meşe, Gülistan; 01. Izmir Institute of Technology; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of ScienceConnexins (Cx), the basic subunit of gap junctions, play important roles in cell homeostasis, and their abnormal expression and function are associated with human hereditary diseases and cancers. In tumorigenesis, connexins were observed to have both anti-tumorigenic and pro-tumorigenic roles in a context- and stage-dependent manner. Initially, Cx26 and Cx43 were thought to be the only connexins involved in normal breast homeostasis and breast cancer. Later on, association of Cx32 expression with lymph node metastasis of breast cancer and subsequent demonstration of its expression in normal breast tissue suggested that Cx32 contributes to breast tissue homeostasis. Here, we aimed to determine the effects of Cx32 on normal breast cells, MCF10A, and on breast cancer cells, MDA-MB-231. Cx32 overexpression had profound effects on MCF10A cells, decreasing cell proliferation by increasing the doubling time of MCF10A. Furthermore, MCF10A cells acquired mesenchymal-like appearance upon Cx32 expression and had increased migration capacity and expression of both E-cadherin and vimentin. In contrast, Cx32 overexpression altered the EMT markers of MDA-MB-231 by increasing the expression of mesenchymal markers, such as slug and vimentin, and decreasing E-cadherin expression without affecting their proliferation and morphology. Our results indicate, for the first time in the literature, that Cx32 has tumor-promoting roles in MCF10A and MDA-MB-231 cells.Article Citation - WoS: 9Citation - Scopus: 10Effects of Notch Signalling on the Expression of Sema3c, Hmga2, Cxcl14, Cxcr7, and Ccl20 in Breast Cancer(TÜBİTAK, 2019) Küçükköse, Cansu; Yalçın Özuysal, Özden; Yalçın Özuysal, Özden; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyMetastasis is the main reason for death in breast cancer. Understanding the molecular players in metastasis is crucial for diagnostic and therapeutic purposes. Notch signalling plays an oncogenic role in breast tumorigenesis and is involved in metastasis. Downstream mediators of Notch signalling in prometastatic processes are not yet fully discovered. Here we aimed to investigate whether Notch signalling regulates the expression of SEMA3C, HMGA2, CXCL14, CXCR7, and CCL20, which are involved in prometastatic processes, in breast cell lines. To this end, expression of the selected genes was analysed following Notch activation by overexpression of the Notch1 intracellular domain in the normal breast epithelial cell line MCF10A, and inhibition by silencing of the Notch transcriptional mediator RBPj kappa in the breast cancer cell line MDA MB 231. SEMA3C and HMGA2 mRNA were decreased, while CXCL14 and CXCR7 mRNA were increased significantly in response to Notch activation in MCF10A cells. Notch inhibition in MDA MB 231 cells significantly decreased HMGA2 and CCL20 mRNA. Protein levels were not significantly altered by Notch modulation. In conclusion, we showed that Notch signalling regulates expression of SEMA3C, CXCL14, CCL20, CXCR7, and HMGA2, which are prominent candidate genes that might function downstream of Notch to induce prometastatic processes.Article Citation - WoS: 17Citation - Scopus: 19Pro-Metastatic Functions of Notch Signaling Is Mediated by Cyr61 in Breast Cells(Elsevier, 2020) Küçükköse, Cansu; Yalçın Özuysal, Özden; Efe, Eda; Doğan, Hülya; Günyüz, Zehra Elif; Fıratlıgil Yıldırır, Burcu; Fıratlıgil, Burcu; Efe, Eda; Doğan, Hülya; Yalçın Özuysal, Özden; İlhan, Mustafa; 01. Izmir Institute of Technology; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of ScienceMetastasis is the main cause of cancer related deaths, and unfolding the molecular mechanisms underlying metastatic progression is critical for the development of novel therapeutic approaches. Notch is one of the key signaling pathways involved in breast tumorigenesis and metastasis. Notch activation induces pro-metastatic processes such as migration, invasion and epithelial to mesenchymal transition (EMT). However, molecular mediators working downstream of Notch in these processes are not fully elucidated. CYR61 is a secreted protein implicated in metastasis, and its inhibition by a monoclonal antibody suppresses metastasis in xenograft breast tumors, indicating the clinical importance of CYR61 targeting. Here, we aimed to investigate whether CYR61 works downstream of Notch in inducing pro-metastatic phenotypes in breast cells. We showed that CYR61 expression is positively regulated by Notch activity in breast cells. Notch1-induced migration, invasion and anchorage independent growth of a normal breast cell line, MCF10A, were abrogated by CYR61 silencing. Furthermore, upregulation of core EMT markers upon Notch1-activation was impaired in the absence of CYR61. However, reduced migration and invasion of highly metastatic cell line, MDA MB 231, cells upon Notch inhibition was not dependent on CYR61 downregulation. In conclusion, we showed that in normal breast cell line MCF10A, CYR61 is a mediator of Notch1-induced pro-metastatic phenotypes partly via induction of EMT. Our results imply CYR61 as a prominent therapeutic candidate for a subpopulation of breast tumors with high Notch activity.Book Part Citation - Scopus: 4Epigenetics of Breast Cancer: Dna Methylome and Global Histone Modifications(Springer, 2016) Meşe Özçivici, Gülistan; Yalçın Özuysal, Özden; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyBreast cancer, a heterogeneous disease comprised of tumors with different histological characteristics and clinical outcomes, is the leading cause of cancer deaths in women. Heterogeneous nature of the breast cancer demands delicate approaches to diagnose and follow the most appropriate strategy for clinical management. Based on microarray analysis of mRNA expression, four main molecular subtypes were identified: (a) luminal A, (b) luminal B, (c) basal-like, and (d) ERBB2(+). Even though molecular subtypes provided novel insights into our understanding of breast cancer heterogeneity, there is still room for improvement for better diagnostic, prognostic and therapeutic approaches. In this sense, epigenetics, specifically DNA methylation and histone modifications, have emerged as prominent candidates since several epigenetic factors were observed to be recurrently mutated in cancers including breast cancer. Recent advances in the field implicated that DNA methylation profiles and histone modifications are strongly associated with breast tumor subtypes and patient prognosis. Therefore, understanding contributions of epigenetics to breast cancer biology will lead to better diagnostic and prognostic strategies and will enable development of novel therapeutic approaches. © Springer International Publishing Switzerland 2016.Article Citation - WoS: 19Citation - Scopus: 19Irf6 Is Involved in the Regulation of Cell Proliferation and Transformation in Mcf10a Cells Downstream of Notch Signaling(Public Library of Science, 2015) Zengin, Talip; Ekinci, Burcu; Yalçın Özuysal, Özden; Yalçın Özuysal, Özden; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyIRF6, a member of Interferon Regulatory Factors (IRF) family, is involved in orofacial and epidermal development. In breast cancer cell lines ectopic expression of IRF6 reduces cell numbers suggesting a role as negative regulator of cell cycle. IRF6 is a direct target of canonical Notch signaling in keratinocyte differentiation. Notch is involved in luminal cell fate determination and stem cell regulation in the normal breast and is implicated as an oncogene in breast cancer. Notch activation is sufficient to induce proliferation and transformation in non-tumorigenic breast epithelial cell line, MCF10A. ΔNp63, which is downregulated by Notch activation in the breast, regulates IRF6 expression in keratinocytes. In this report, we investigate Notch-IRF6 and ΔNp63-IRF6 interactions in MCF10A and MDA MB 231 cells. We observed that in these cells, IRF6 expression is partially regulated by canonical Notch signaling and ΔNp63 downregulation. Furthermore, we demonstrate that IRF6 abrogation impairs Notch-induced proliferation and transformation in MCF10A cells. Thus, we confirm the previous findings by showing a tissue independent regulation of IRF6 by Notch signaling, and extend them by proposing a context dependent role for IRF6, which acts as a positive regulator of proliferation and transformation in MCF10A cells downstream of Notch signaling.