Development of preclinical models for studying circulating tumor cells

Circulating tumor cells (CTC) have emerged as an important biomarker in breast cancer, offering indispensable insights into disease progression and therapeutic response. The isolation of CTCs from the complex environment of blood components presents a major challenge due to their low abundance. However, the developed isolation methods enable the enrichment of CTCs from blood samples and facilitate subsequent analysis. The isolation and study of CTCs is becoming an essential research interest of any comprehensive cancer center. At Institute of Oncology Ljubljana, the first steps were made in 2020. We were looking for a simple method for CTC isolation and detection that would allow identification and evaluation of CTCs by cytopathological examination. We evaluated two methods for CTC isolation in breast cancer patients. The Parsortix isolation proved to be a suitable method as it allowed the isolation of higher yields of morphologically preserved CTCs. After the first valuable experiences and the establishment of an interdisciplinary team of researchers, cytopathologists and medical oncologists, the next step is to set up a translational research platform that will be available for the study of CTCs in different types of cancer. The objective of the proposed project is therefore to establish a translational platform for CTC research at the Institute of Oncology Ljubljana. We will focus on breast cancer based on our experience with breast cancer CTCs. In WP1, the in vivo platform will be established. The in vivo platform will enable the evaluation of new treatment strategies and basic research of metastatic process and CTC biology. Furthermore, the fast access to CTCs from mice will enable us to test different culturing conditions to set up a culturing protocol for CTCs. The second objective will therefore be to establish a platform for the ex vivo culturing and expansion of CTCs in WP2. The established platforms in DS1 and DS2 will allow further research in the scope of GALIA clinical study, where we plan to collect, culture and analyze isolated CTCs from 10-15 breast cancer patients. In addition, it will open the possibilities for further preclinical research, in particular the evaluation of the effect of therapies on the metastatic process and basic research on the biology of CTCs.