témavezető: Vizler Csaba
helyszín (magyar oldal): Institute of Biochemistry, BRC of HAS helyszín rövidítés: SzBK
A kutatási téma leírása:
SUMMARY
Malignant tumors are inherently genetically instable and heterogeneous. In advanced carcinoma, circulating tumor cells may appear in the blood. If cancer therapy is successful, the number of circulating tumor cells drops. This phenomenon may help therapeutic decisions. These rare cells (even in advanced cases, a couple of cells/ml blood) might also be used for therapeutic decision, but it is still not clear how they represent the primary tumor and the metastases. Our aims are: A) investigating the viability, genetic variability and metastatic potential of human circulating tumor cells, B) studying the communication between the malignant cells and the tumor connective tissue matrix, C) setting up new animal models for studying agents and interventions targeting circulating tumor cells and metastasis formation.
BACKGROUND
Malignant tumors are inherently genetically instable and heterogeneous. Because of that, within the tumors, cell clones compete for the resources, nutrients and oxygen supply. Sooner or later, a few cells enter the circulation (circulating tumor cells, CTC). The number of circulating tumor cells is very low, even in the case of advanced tumors (a few cells/ml blood), so there are millions of white blood cells for each circulating tumor cell. One of the methods for detecting these rare cells is the CellSearch® platform. The method is based on a selection step relying on the presence of the EpCAM cell surface marker on the carcinoma cell, absent in normal white blood cells. The results are then validated by staining for cytokeratin, another epithelial tumor marker. Changes of the number of circulating tumor cells indicate if chemotherapy was effective. The metastatic cells are an even rarer subpopulation of circulating tumor cells. If research proves that circulating tumor cells obtained in a non-invasive fashion reliably represent the original tumor, they may be used for identifying therapeutic targets, i.e., mutant signal proteins, oncogenes, or cell surface markers, for personalized therapy.
CURRENT RESEaRCH
Our main research topic is application of tissue culture and animal models for tumor biology and tumor therapy. In our animal models we use both immunocompetent and immunodeficient mice. The models are the used for testing drug candidates of mostly Hungarian origin. Recently we described a model equally useful for in vivo imaging of tumors and studying cancer cell – connective tissue tumor matrix interactions. In the present project these approaches will be adapted for studies of circulating tumor cells.
SPECIFIC AIMS
Our consortium partners will regularly provide samples containing circulating tumor cell. The samples will be obtained from patients with apheresis. The circulating tumor cells will be enriched with various techniques, including the CellSearch® platform, an EpCAM based enrichment method in development („cell trap”), or size-based physical filtration, likewise in development by our consortium. The separated cells will then be used for studying the following questions of tumor heterogeneity:
1) What is the percentage of circulating tumor cells with an in vitro growth potential, and what are their growth requirements?
2) How efficiently they form tumors in multiply immunodeficient (NSG) mice?
3) How well the cell lines created from circulating tumor cells represent the primary tumor, e.g., in respect of hormone dependence or cell surface markers?
4) What is the role of host connective tissue matrix in metastasis formation?
5) In an equally important side project, we will set up analogous syngeneic mouse models. We will establish tumor cell lines genetically labeled with fluorescent proteins, then the cell lines will then be used for fluorescent detection of circulating tumor cells or metastases, either by flow cytoflourometry of fluorescent microscopy. The models will also be used for studying the interaction between tumor cells and the connective tissue matrix; furthermore, for testing anti-tumor therapeutical modalities.
MATERIALS AND METHODS
Our studies are based on tissue culture using primary cell culture or malignant cell lines. We will generate reporter cell lines for functional studies. The human cell lines will be tested in immunodeficient mice in vivo. The NSG recipient mice are multiply immunodeficient; as they lack B cells and T cells, and their natural killer cell compartment is also deficient, therefore, they readily accept human tumor xenografts. Importantly, according to literature data, a few dozens of human tumor cells might be sufficient for tumor generation in these mice. We also create fluorescent human tumor cell lines for setting up mouse models for testing anti-cancer compounds and procedures.
SUGGESTED READINGS
Barradas AM, et al. Towards the Biological Understanding of CTC: Capture Technologies, Definitions and Potential to Create Metastasis. Cancers (Basel). 5(4):1619-42 (2013).
de Wit S, et al.: Detection of circulating tumor cells. Scientifica (Cairo). 2014:819362. (2014).
Galluzzi L, et al. Classification of current anticancer immunotherapies. Oncotarget. 5(24):12472-508 (2014).
Jósvay K, et al.: Besides neuro-imaging, the Thy1-YFP mouse could serve for visualizing experimental tumours, inflammation and wound-healing. Sci Rep. 4:6776 (2014).
Marton A, et al.: Melanoma cell-derived exosomes alter macrophage and dendritic cell functions in vitro. Immunol Lett. 148(1):34-38 (2012).
Merlo LM, et al.: Cancer as an evolutionary and ecological process. Nat Rev Cancer 6:924-935 (2006).
Nagy LI, et al.: Lipid droplet binding thalidomide analogs activate endoplasmic reticulum stress and suppress hepatocellular carcinoma in a chemically induced transgenic mouse model. Lipids Health Dis. 12:175 (2013).
Rossi E, at al.: Retaining the long-survive capacity of Circulating Tumor Cells (CTCs) followed by xeno-transplantation: not only from metastatic cancer of the breast but also of prostate cancer patients. Oncoscience. 1(1):49-56 (2013).
Selected publications of the research group
Jósvay K, Winter Z, Katona RL, Pecze L, Marton A, Buhala A, Szakonyi G, Oláh Z, Vizler C. Besides neuro-imaging, the Thy1-YFP mouse could serve for visualizing experimental tumours, inflammation and wound-healing. Scientific Reports, Oct 27;4:6776.
Nagy LI, et al.: Lipid Droplet Binding Thalidomide Analogs Activate Endoplasmic Reticulum Stress and Suppress Hepatocellular Carcinoma in a Chemically Induced Transgenic Mouse Model. Lipids Health Dis. 12(1):175 (2013).
Marton A, at al.: Melanoma cell-derived exosomes alter macrophage and dendritic cell functions in vitro. Immunol Lett. 148(1):34-38 (2012).
Delarasse C, et al: Myelin/oligodendrocyte glycoprotein-deficient (MOG-deficient) mice reveal lack of immune tolerance to MOG in wild-type mice. J Clin Invest. 112(4):544-553 (2003).
Vizler C, at al.: Therapeutic effect of interleukin 12 on mouse haemangiosarcomas is not associated with an increased anti-tumour cytotoxic T-lymphocyte activity. Br J Cancer. 77(4):656-662 (1998).
Recent research grant:
• A novel biotechnology enabling personalized therapy for all cancer patients 2012-2015: 305341 CTCtrap FP7, 109 M Ft
The latest student in the laboratory:
• Marton A, Msc, PhD student, 2011-. Research topic: New anti-cancer- and immunomodulating drugs and procedures
előírt nyelvtudás: angol további elvárások: mammalian tissue culter and/or animal experimentation
felvehető hallgatók száma: 1
Jelentkezési határidő: 2015-10-13
2024. IV. 17. ODT ülés Az ODT következő ülésére 2024. június 14-én, pénteken 10.00 órakor kerül sor a Semmelweis Egyetem Szenátusi termében (Bp. Üllői út 26. I. emelet).
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