PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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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 Citation - WoS: 12Citation - Scopus: 12Sema6d Differentially Regulates Proliferation, Migration, and Invasion of Breast Cell Lines(American Chemical Society, 2022) Meşe Özçivici, Gülistan; Yalçın Özuysal, Özden; Özçivici, Engin; İpekgil, Doğaç; Tok, Güneş; Meşe, Gülistan; Özçivici, Engin; Yalçın Özuysal, Özden; 03.01. Department of Bioengineering; 04.03. Department of Molecular Biology and Genetics; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologySemaphorin 6D (SEMA6D), a member of the class 6 semaphorin family, is a membrane-associated protein that plays a key role in the development of cardiac and neural tissues. A growing body of evidence suggests that SEMA6D is also involved in tumorigenesis. In breast cancer, high SEMA6D levels are correlated with better survival rates. However, very little is known about the functional significance of SEMA6D in breast tumorigenesis. In the present study, we aimed to investigate the effects of SEMA6D expression on the normal breast cell line MCF10A and the breast cancer cell lines MCF7 and MDA MB 231. We demonstrated that SEMA6D expression increases the proliferation of MCF10A cells, whereas the opposite effect was observed in MCF7 cells. SEMA6D expression induced anchorage-independent growth in both cancer cell lines. Furthermore, migration of MCF10A and MCF7 cells and invasion of MDA MB 231 cells were elevated in response to SEMA6D overexpression. Accordingly, the genes related to epithelial-mesenchymal transition (EMT) were altered by SEMA6D expression in MCF10A and MCF7 cell lines. Finally, we provided evidence that SEMA6D levels were associated with the expression of the cell cycle, EMT, and Notch signaling pathway-related genes in breast cancer patients' data. We showed for the first time that SEMA6D overexpression has cell-specific effects on the proliferation, migration, and invasion of normal and cancer breast cell lines, which agrees with the gene expression data of clinical samples. This study lays the groundwork for future research into understanding the functional importance of SEMA6D in breast cancerArticle Citation - WoS: 20Citation - Scopus: 22Refractive Index Sensing for Measuring Single Cell Growth(American Chemical Society, 2021) Çetin, Arif E.; Yalçın Özuysal, Özden; Yalçın Özuysal, Özden; Khademhosseini, Ali; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyAccessing cell growth on adhesive substrates is critical for identifying biophysical properties of cells and their therapeutic response to drug therapies. However, optical techniques have low sensitivity, and their reliability varies with cell type, whereas microfluidic technologies rely on cell suspension. In this paper, we introduced a plasmonic functional assay platform that can precisely measure cell weight and the dynamic change in real-time for adherent cells. Possessing this ability, our platform can determine growth rates of individual cells within only 10 mm to map the growth profile of populations in short time intervals. The platform could successfully determine heterogeneity within the growth profile of populations and assess subpopulations exhibiting distinct growth profiles. As a proof of principle, we investigated the growth profile of MCF-7 cells and the effect of two intracellular metabolisms critical for their proliferation. We first investigated the negative effect of serum starvation on cell growth. We then studied ornithine decarboxylase (ODC) activity, a key enzyme which is involved in proliferation, and degraded under low osmolarity that inhibits cell growth. We successfully determined the significant distinction between growth profiles of MCF-7 cells and their ODC-overproducing variants that possess strong resistance to the negative effects of low osmolarity. We also demonstrated that an exogenous parameter, putrescine, could rescue cells from ODC inhibition under hypoosmotic conditions. In addition to the ability of accessing intracellular activities through ex vivo measurements, our platform could also determine therapeutic behaviors of cancer cells in response to drug treatments. Here, we investigated difluoromethylornithine (DFMO), which has antitumor effects on MCF-7 cells by inhibiting ODC activity. We successfully demonstrated the susceptibility of MCF-7 cells to such drug treatment, while its DFMO-resistant subpopulation could survive in the presence of this antigrowth agent. By rapidly determining cell growth kinetics in small samples, our plasmonic platform may be of broad use to basic research and clinical applications.Article Citation - WoS: 24Citation - Scopus: 30Hologlev: a Hybrid Magnetic Levitation Platform Integrated With Lensless Holographic Microscopy for Density-Based Cell Analysis(American Chemical Society, 2021) Delikoyun, Kerem; Anıl İnevi, Müge; Yaman, Sena; Yalçın Özuysal, Özden; Sarıgil, Öykü; Telli, Kübra; Yalçın Özuysal, Özden; 01. Izmir Institute of Technology; 03.01. Department of Bioengineering; 04.03. Department of Molecular Biology and Genetics; 03. Faculty of Engineering; 04. Faculty of ScienceIn clinical practice, a variety of diagnostic applications require the identification of target cells. Density has been used as a physical marker to distinguish cell populations since metabolic activities could alter the cell densities. Magnetic levitation offers great promise for separating cells at the single cell level within heterogeneous populations with respect to cell densities. Traditional magnetic levitation platforms need bulky and precise optical microscopes to visualize levitated cells. Moreover, the evaluation process of cell densities is cumbersome, which also requires trained personnel for operation. In this work, we introduce a device (HologLev) as a fusion of the magnetic levitation principle and lensless digital inline holographic microscopy (LDIHM). LDIHM provides ease of use by getting rid of bulky and expensive optics. By placing an imaging sensor just beneath the microcapillary channel without any lenses, recorded holograms are processed for determining cell densities through a fully automated digital image processing scheme. The device costs less than $100 and has a compact design that can fit into a pocket. We perform viability tests on the device by levitating three different cell lines (MDA-MB-231, U937, D1 ORL UVA) and comparing them against their dead correspondents. We also tested the differentiation of mouse osteoblastic (7F2) cells by monitoring characteristic variations in their density. Last, the response of MDA-MB-231 cancer cells to a chemotherapy drug was demonstrated in our platform. HologLev provides cost-effective, label-free, fully automated cell analysis in a compact design that could be highly desirable for laboratory and point-of-care testing applications.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.Article Citation - WoS: 79Citation - Scopus: 94Biofabrication of in Situ Self Assembled 3d Cell Cultures in a Weightlessness Environment Generated Using Magnetic Levitation(Nature Publishing Group, 2018) Yalçın Özuysal, Özden; Tekin, Hüseyin Cumhur; Özçivici, Engin; Arslan Yıldız, Ahu; Meşe Özçivici, Gülistan; Yaman, Sena; Anıl İnevi, Müge; 03.01. Department of Bioengineering; 04.03. Department of Molecular Biology and Genetics; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyMagnetic levitation though negative magnetophoresis is a novel technology to simulate weightlessness and has recently found applications in material and biological sciences. Yet little is known about the ability of the magnetic levitation system to facilitate biofabrication of in situ three dimensional (3D) cellular structures. Here, we optimized a magnetic levitation though negative magnetophoresis protocol appropriate for long term levitated cell culture and developed an in situ 3D cellular assembly model with controlled cluster size and cellular pattern under simulated weightlessness. The developed strategy outlines a potential basis for the study of weightlessness on 3D living structures and with the opportunity for real-time imaging that is not possible with current ground-based simulated weightlessness techniques. The low-cost technique presented here may offer a wide range of biomedical applications in several research fields, including mechanobiology, drug discovery and developmental biology.Article Citation - WoS: 90Citation - Scopus: 94Progesterone and Wnt4 Control Mammary Stem Cells Via Myoepithelial Crosstalk(John Wiley and Sons Inc., 2015) Rajaram, Renuga Devi; Yalçın Özuysal, Özden; Caikovski, Marian; Ayyanan, Ayyakkannu; Rougemont, Jacques; Shan, Jingdong; Vainio, Seppo J.; Yalçın Özuysal, Özden; Brisken, Cathrin; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyOvarian hormones increase breast cancer risk by poorly understood mechanisms. We assess the role of progesterone on global stem cell function by serially transplanting mouse mammary epithelia. Progesterone receptor (PR) deletion severely reduces the regeneration capacity of the mammary epithelium. The PR target, receptor activator of Nf-κB ligand (RANKL), is not required for this function, and the deletion of Wnt4 reduces the mammary regeneration capacity even more than PR ablation. A fluorescent reporter reveals so far undetected perinatal Wnt4 expression that is independent of hormone signaling. Pubertal and adult Wnt4 expression is specific to PR+ luminal cells and requires intact PR signaling. Conditional deletion of Wnt4 reveals that this early, previously unappreciated, Wnt4 expression is functionally important. We provide genetic evidence that canonical Wnt signaling in the myoepithelium required PR and Wnt4, whereas the canonical Wnt signaling activities observed in the embryonic mammary bud and in the stroma around terminal end buds are independent of Wnt4. Thus, progesterone and Wnt4 control stem cell function through a luminal-myoepithelial crosstalk with Wnt4 acting independent of PR perinatally. Synopsis This paper ascribes a new role for Wnt4 in pre-pubertal mammary gland development while revealing luminal cells to respond to Wnt activation. During regeneration, Wnt4 interacts with progesterone receptor signaling, correcting previous notions on RANKL signaling in this context. Wnt4 is an essential control factor for mammary epithelial stem cell function. RANKL is not required for mammary gland regeneration potential. Wnt4 activates canonical Wnt signaling in the basal/myoepithelial compartment. Progesterone receptor signaling is required for mammary epithelial Wnt4 expression already during puberty. This paper ascribes a new role for Wnt4 in pre-pubertal mammary gland development while revealing luminal cells to respond to Wnt activation. During regeneration, Wnt4 interacts with progesterone receptor signaling, correcting previous notions on RANKL signaling in this context.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.