Institute for Cancer Research
Department of Medicine I
Medical University of Vienna
A-1090 Vienna, Austria
PI Info: scholar.google.com/citations
The main focus of the Szakacs lab is membrane transport biology, in particular ABC transporters responsible for the multidrug resistance phenotype of cancer cells. In the past years we have developed a new concept to target the Achilles’ heel of resistant cancer cells (ERC Stg 2012-2016). Our current work is based on mouse models of cancer and 3D cell culturing to study clinically relevant mechanisms enabling the survival cancer cells despite toxic chemotherapy.
Targeting Drug-tolerant Persisters: a paradigm shift to conquer therapy resistant breast cancer.
Elucidating the molecular basis of therapy resistance in breast cancer is an unmet clinical need. Based on preliminary results we hypothesize that therapy resistance is linked to a rare population of drug tolerant persister cells (DTPs) that survive treatment through the stabilization of transient drug-induced phenotypes, until mechanisms ensuring stable drug resistance emerge. Profiling the tumor during different stages of therapy is necessary to identify vulnerabilities of this adaptive process.
Our preliminary work has characterized the response of orthotopically transplanted tumor-bearing mice to a series of clinically relevant chemotherapies. While these therapies significantly reduce the tumor size, they are unable to eradicate tumor cells, which give rise to drug-sensitive relapse after the cessation of the treatment (Füredi et al., 2017).
The project will address the following research questions: (1) What is the contribution of phenotypic adaptation vs Darwinian selection? (2) Are cells showing a DTP signature present prior to treatment? (3) Will different clinical protocols induce DTPs with similar signatures? (4) What is the relative contribution of genetic vs non-genetic (epigenetic, transcriptional plasticity) factors, and of the interactions with the microenvironment? (5) What is the relation between the pathways supporting DTPs and the mechanisms underlying resistance to therapy? (6) How can this knowledge be translated to improved patient care?
To address these challenging questions, we will profile individual “tumor histories” at single-cell resolution using in vitro cell lines and organoids derived from genetically engineered mouse models of cancer (GEMMC). We will establish, treat and sample barcoded mammary tumors derived from such organoids to track (epi)genetic and transcriptional alterations along the treatment. Because organoids are engrafted in wild-type mice, scRNA sequencing will also reveal the contribution of immune cells and other niche elements to tumor heterogeneity. To monitor clonal evolution, individual cells in organoids will be transduced with a GFP-positive lentiviral library encoding 20,000 unique barcodes. PDOs will be orthotopically transplanted into the mammary fat pad of wild type FVB mice. Matched samples corresponding to treatment-naïve cells, DTPs and relapse will be collected. In experiments aimed at obtaining therapy resistant tumors, chemotherapy will be continued until the treatment becomes ineffective.
Effective targeting of DTPs will result in a paradigm shift, changing the focus from countering drug resistance mechanisms to preventing or delaying therapy resistance, leading to improved treatments of patients.
Blatter, S., and Rottenberg, S. (2015). Minimal residual disease in cancer therapy – Small things make all the difference. Drug Resistance Updates 21–22, 1–10.
Duarte, A.A., Gogola, E., Sachs, N., Barazas, M., Annunziato, S., Ruiter, J.R. de, Velds, A., Blatter, S., Houthuijzen, J.M., Ven, M. van de, et al. (2018). BRCA-deficient mouse mammary tumor organoids to study cancer-drug resistance. Nature Methods 15, 134–140.
Echeverria, G.V., Ge, Z., Seth, S., Zhang, X., Jeter-Jones, S., Zhou, X., Cai, S., Tu, Y., McCoy, A., Peoples, M., et al. (2019). Resistance to neoadjuvant chemotherapy in triple-negative breast cancer mediated by a reversible drug-tolerant state. Science Translational Medicine 11.
Füredi, A., Szebényi, K., Tóth, S., Cserepes, M., Hámori, L., Nagy, V., Karai, E., Vajdovich, P., Imre, T., Szabó, P., et al. (2017). Pegylated liposomal formulation of doxorubicin overcomes drug resistance in a genetically engineered mouse model of breast cancer. Journal of Controlled Release 261, 287–296.
Hámori, L., Kudlik, G., Szebényi, K., Kucsma, N., Szeder, B., Póti, Á., Uher, F., Várady, G., Szüts, D., Tóvári, J., et al. (2020). Establishment and Characterization of a Brca1−/−, p53−/− Mouse Mammary Tumor Cell Line. International Journal of Molecular Sciences 21, 1185.
Hong, S.P., Chan, T.E., Lombardo, Y., Corleone, G., Rotmensz, N., Bravaccini, S., Rocca, A., Pruneri, G., McEwen, K.R., Coombes, R.C., et al. (2019). Single-cell transcriptomics reveals multi-step adaptations to endocrine therapy. Nature Communications 10.
Merino, D., Weber, T.S., Serrano, A., Vaillant, F., Liu, K., Pal, B., Di Stefano, L., Schreuder, J., Lin, D., Chen, Y., et al. (2019). Barcoding reveals complex clonal behavior in patient-derived xenografts of metastatic triple negative breast cancer. Nature Communications 10.
Sharma, S.V., Lee, D.Y., Li, B., Quinlan, M.P., Takahashi, F., Maheswaran, S., McDermott, U., Azizian, N., Zou, L., Fischbach, M.A., et al. (2010). A Chromatin-Mediated Reversible Drug-Tolerant State in Cancer Cell Subpopulations. Cell 141, 69–80.
Szakacs, G., Paterson, J.K., Ludwig, J.A., Booth-Genthe, C., and Gottesman, M.M. (2006). Targeting multidrug resistance in cancer. Nat Rev Drug Discov 5, 219–234.
1. Mihály Cserepes, Dóra Türk, Szilárd Tóth, Veronika F.S. Pape, Anikó Gaál, Melinda Gera, Judit E. Szabó, Nóra Kucsma, György Várady, Beáta G. Vértessy, Christina Streli, Pál T. Szabó, Jozsef Tovari, Norbert Szoboszlai and Gergely Szakács. 2020. Unshielding Multidrug Resistant Cancer through Selective Iron Depletion of P-Glycoprotein-Expressing Cells. Cancer Res. 15;80(4):663-674. doi: 10.1158/0008-5472.
2. Füredi, A., S. Tóth, K. Szebényi, V. F. S. Pape, D. Türk, N. Kucsma, L. Cervenak, J. Tóvári, and G. Szakács. 2017. Identification and Validation of Compounds Selectively Killing Resistant Cancer: Delineating Cell Line–Specific Effects from P-Glycoprotein–Induced Toxicity. Mol. Cancer Ther. 16: 45–56. doi: 10.1158/1535-7163.MCT-16-0333-T.
3. Füredi, A., K. Szebényi, S. Tóth, M. Cserepes, L. Hámori, V. Nagy, E. Karai, P. Vajdovich, T. Imre, P. Szabó, D. Szüts, J. Tóvári, and G. Szakács. 2017. Pegylated liposomal formulation of doxorubicin overcomes drug resistance in a genetically engineered mouse model of breast cancer. J. Controlled Release 261: 287–296. doi.org/10.1016/j.jconrel.2017.07.010
4. Szakács, G., M. D. Hall, M. M. Gottesman, A. Boumendjel, R. Kachadourian, B. J. Day, H. Baubichon-Cortay, and A. Di Pietro. 2014. Targeting the Achilles Heel of Multidrug-Resistant Cancer by Exploiting the Fitness Cost of Resistance. Chem. Rev. 114: 5753–5774. doi: 10.1021/cr4006236
5. Szakacs, G., J. K. Paterson, J. A. Ludwig, C. Booth-Genthe, and M. M. Gottesman. 2006. Targeting multidrug resistance in cancer. Nat Rev Drug Discov 5: 219–34. doi: 10.1158/0008-5472.CAN-09-2422.
6. Szakács, G., J.-P. Annereau, S. Lababidi, U. Shankavaram, A. Arciello, K. J. Bussey, W. Reinhold, Y. Guo, G. D. Kruh, M. Reimers, J. N. Weinstein, and M. M. Gottesman. 2004. Predicting drug sensitivity and resistance: profiling ABC transporter genes in cancer cells. Cancer Cell 6: 129–137. DOI:10.1016/j.ccr.2004.06.026