Isolation of rare circulating tumor cell for monitoring and early detection of cancer patients

Mehmet Toner

Dr. Toner’s laboratory recently developed a highly sensitive microfluidic technology called “CTC-chip” to isolate rare circulating tumor cells (CTCs) from peripheral blood. The potential of the CTC-chip is tremendous as it can allow physicians to detect cancers early, follow how well cancers are responding to treatments in ‘real time’ and develop drugs that are aimed at suppressing these metastasizing cells. Although the existence of CTCs has been known for 140 years, they have eluded researchers because they are so rare—as few as 1 CTC in one billion of blood cells. The CTC-chip is about the size of a business card and holds 78,000 microscopic posts coated with an antibody that binds to tumor cells circulating in the blood (Figure 1). The chip can interrogate 1 to 2 million cells per second enabling processing of large volumes of blood to find these extremely rare cells. In clinical studies conducted over the past two years, the CTC-chip was used to identify CTCs in the blood of patients with metastatic cancers of the prostate, lung, pancreas, colon and breast. In some patients with lung cancer, where targeted “smart drugs” can focus on the genetic lesions causing the cancer to grow, the CTC-chip can identify that genetic lesion and help identify which patient is likely to benefit from these novel drugs. The next version of the CT-chip uses carbon nanotube (CNT) based structures to enhance cell-surface interactions for a higher sensitivity and throughput device. The work involves innovation in CNT manufacturing, micro- and nano-fluid dynamics, chemical kinetics, and cancer genomics, and clinical medicine.