Establishment and Application of 3-Dimensional (3-D) Cell Culture Model of Clinical Circulating Tumor Cells (CTCs)

Circulating tumor cells (CTCs), the rare cell species present in the blood, are considered to mainly contribute to cancer metastasis or relapse. Thus, the detection of CTCs is regarded as an essential clinical tool to detect metastatic cancer. Moreover, CTCs can be the therapeutic target of metastatic cancer care. Therefore, the use of viable CTCs as a biopsy to select therapeutic regimens (e.g. CTCs-based anti-cancer drug testing) opens up a promising route to realize personalized cancer therapy. With the recent advances in cell isolation or detection techniques, various novel approaches have been actively proposed to isolate/detect CTCs. Nevertheless, most of current methods might not be able to obtain the all possible, viable, and label-free CTCs with adequate cell purity and cell number for the subsequent CTCs-based anti-cancer drug testing or other bioassays. To tackle the above technical hurdles, the research project proposes the use of a specific 3-D cell culture technique for the isolation/purification, and cell number expansion of CTCs.

The working principle is based on our preliminary findings showing that the human leukocytes will die away in 3-D cell culture condition, whereas the CTCs will tend to aggregate and proliferate in such environment. Based on this phenomenon, the 3-D CTC cell culture can be used to isolate and purify the viable CTCs from the leukocyte background in a negative selection, and label-free manner, enabling the harvest of the all possible CTCs in a blood sample. Furthermore, the proliferation of CTCs in such 3-D cell culture can adequately expand the cell number of CTCs for the subsequent applications, which is currently impossible using the existing methods.

In the 1st year research project, investigators will further validate and evaluate the clinical feasibility of using a 3-D cell culture model for CTCs isolation/purification and their cell number expansion. In the 2nd and 3rd year research project, investigators will optimize the 3-D cell culture model so as to increase the performances of CTC isolation/purification and proliferation. In the optimization process, investigators will explore the effect of cell culture model (e.g. static or perfusion cell culture, and 3-D cell culture using different 3-D scaffolding materials) or biochemical factors (e.g. glucose concentration, serum concentration, pH, or the supplements of growth factors/cytokines) on the the performances of CTC solation/purification and proliferation. As a whole, investigators hope the proposed research project can find out an efficient and effective approach to isolate/purify/expand clinical CTCs in a viable, label-free, and high-purity manner. These harvested CTCs are valuable for the subsequent analytical tasks.