Dr. Onur Çizmecioḡlu graduated from the Department of Molecular Biology and Genetics at Bilkent University in 2002. He received his Ph.D. degree in 2009 from the German Cancer Research Center (DKFZ) and Heidelberg University in cell biology. During his PhD and a subsequent concise post-doctoral training in the laboratory of Prof. Ingrid Hoffmann, he conducted research in the fields of cell cycle and centrosome duplication. His efforts in the Hoffmann lab culminated in publication of key first and/or second author research articles in prestigious journals including The Journal of Cell Biology, The EMBO Journal, Journal of Biological Chemistry, Journal of Cell Science and Cell Cycle. In order to gain expertise in signal transduction and cancer biology, he joined the lab of Prof. Thomas M. Roberts at Dana-Farber Cancer Institute (DFCI), Harvard Medical School as a research fellow in 2011. His research at DFCI elucidated unique and redundant features of phosphoinositide 3-kinase (PI 3-kinase) isoforms in regulation of signal transduction and carcinogenesis and resulted in two additional publications in Oncogene and eLIFE (and one other under revision).
In September 2016, Dr. Çizmecioḡlu returned to his Alma mater and joined the ranks of the Department of Molecular Biology and Genetics as an assistant professor. His current research is centered on how different members of PI 3-kinases are involved in signaling and cancer.
The regulatory modules inside a cell are informed about the environmental conditions through the process of signal transduction. This process in part is facilitated by kinases, which help activate specific transcriptional programs in the nucleus in response to mitogenic stimuli. In principle, a deregulated kinase can lead to an overactive signaling module and ultimately, to cancer. The discoveries in the field have become the basis for development of new drugs that inhibit actions of specific kinases. This class of drugs, called kinase inhibitors, offers extraordinary hope for the future of cancer therapy. Phosphoinositide 3-kinase (PI3K) pathway is activated in a plethora of human cancers. Several hundred inhibitors targeting different components of the pathway are currently in clinical trials. Therefore it is of utmost importance to understand if and how tumors could circumvent PI3K inhibition to sustain survival and proliferation.
In order to obtain a more comprehensive understanding of the PI3K pathway in signaling and cancer;
- We develop cellular models that utilize molecular genetic tools and the CRISPR-Cas9 technology to study gain of function of pathway related oncogenes and loss of tumor suppressor functions in the pathway, e.g. PTEN loss.
- We use retro/lentiviral expression libraries to study mechanisms of functional compensation and drug resistance.
- We utilize quantitative high throughput phosphoproteomics/metabolomics approaches to define functional redundancies and signature features of the PI3K pathway components.
After the establishment and initial characterization of these cellular models, we would like to put these cell biological findings to test utilizing xenograft transplantations in immunocompromised mice. Cells can either be treated in culture with stable RNAi or expression vectors or in host animals with systemic administration of small molecule inhibitors/drugs of interest. In these experiments, tumor burden would be monitored and quantified; any regression or spontaneous remission will be further analyzed by means of immunohistochemistry, immunoblotting and gene expression microarrays.
Cizmecioglu, O., Ni, J., Xie, S., Zhao, J. J., & Roberts, T. M. (2016). Rac1-mediated membrane raft localization of PI3K/p110β is required for its activation by GPCRs or PTEN loss. eLife, 5, e17635.
Tumurbaatar, I., Cizmecioglu, O., Hoffmann, I., Grummt, I., & Voit, R. (2011). Human Cdc14B promotes progression through mitosis by dephosphorylating Cdc25 and regulating Cdk1/cyclin B activity. PloS one, 6(2), e14711.
Cizmecioglu, O., Arnold, M., Bahtz, R., Settele, F., Ehret, L., Haselmann-Weiss, U., Antony, C., & Hoffmann, I. (2010). Cep152 acts as a scaffold for recruitment of Plk4 and CPAP to the centrosome. The Journal of cell biology, 191(4), 731–739.