Application of High-Throughput Microfluidic 3-Dimensional Cell Culture System on Clinical Circulating Tumor Cells (Ctcs) Detection and Cell Number Expansion- Feasibility Study of Using the Number Expanded CTCs for Clinical Anti-Cancer Drug Testing

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. To tackle the above technical hurdles, the research project proposes the use of a microfluidic-based 3-D CTC cell culture technique for the detection (initial screening), isolation, 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, such a micro-scale 3-D cell culture model can be used to qualitatively or quantitatively detect CTCs through the microscopic observation of the formation of CTC aggregates. Such a simple and economical CTC detection scheme is found clinically useful for the initial screening of metastatic cancer. Based on the findings, moreover, the 3-D CTC cell culture can also 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 CTCs-based anti-cancer drug testing. This is currently impossible using the existing methods. In the 1st year research project, a high-throughput microfluidic 3-D cell culture system will be used as a cell culture platform for 3-D CTC culture. We will explore the clinical feasibility of utilizing the proposed 3-D CTC culture system for the initial screening of metastatic Head and Neck cancer. In the 2nd year research project, we will use the microfluidic 3-D cell culture system for CTC isolation and its cell number expansion. Our ultimate goal is to use the isolated and cell number-expanded CTCs for cell-based anti-cancer drug testing. Before we can achieve this, the verification works will be performed to compare the native CTCs5 (namely the original CTCs isolated from a blood sample) response to anti-cancer drugs with that of CTCs obtained after in vitro proliferation process. In the 3rd year research project, the high throughput microfluidic 3-D CTC cell culture system will be used to evaluate the response of cell number-expanded CTCs to anti-cancer drugs. The clinical studies will be carried out to evaluate the effectiveness of CTCs-based anti-cancer drug testing in guiding clinical chemotherapy, by which the correlation of the results of the CTCs-based anti-cancer drug testing and the clinical outcomes of the cancer patients treated with the same anti-cancer drugs and comparable conditions will be established. As a whole, we hope the proposed research project can benefit future cancer care particularly on initial screening of metastatic cancer, and personalized chemotherapy.

Project ID:PB10501-3714
External Project ID:MOST104-2628-E182-002-MY3