"Velcro" for tumor cells

The biochip, developed by researchers at the University of California at Los Angeles, working under the guidance of Dr. Shutao Wang, acts like a Velcro for flies: the surface covered with nanowires allows you to effectively "catch" malignant cells that have separated from the tumor and are circulating in the blood.

Metastases, or secondary tumors, are the most common cause of death in patients with solid tumors. They are formed by so-called circulating tumor cells that have separated from the primary tumor and moved with the blood flow to other parts of the patient's body.

(Solid tumors are a collective designation of tumors that have a specific location and thus differ from various forms of cancer of hematopoietic and lymphoid tissue – leukemia.)

To date, the gold standard for studying the status of a malignant disease is a biopsy of metastases. However, in the early stages of the metastasis process, it is usually quite difficult to determine the localization of the secondary tumor focus. Isolation of circulating tumor cells from the blood of patients will allow doctors to conduct a kind of "liquid" biopsy, the results of which can provide important information about the presence of the metastasis process. This will make it much easier to predict the course of diseases and monitor the effectiveness of treatment.

Several methods for detecting circulating tumor cells already exist, but the Velcro developed by the authors is favorably distinguished not only by its cheapness and speed, but also by the effectiveness of binding malignant cells.

In an article published this month in the journal Angewandte Chemie in the article
«Three-Dimensional Nanostructured Substrates toward Efficient Capture of Circulating Tumor Cells»,
A silicon chip developed by the authors is described, covered with densely arranged nanowires and looking like a carpet.

To test the ability of such a surface to bind cells, scientists incubated them in an environment containing breast cancer cells. As a control, a previously developed cell binding chip with a smooth surface, which has already received approval from the US Food and Drug Administration, was incubated in a similar environment. Both chips were pre-coated with anti-EpCAM antibodies, providing recognition and binding of tumor cells.

The nanostructured chip bound 45-65% of the cancer cells contained in the medium,
whereas for a smooth chip, this indicator was an order of magnitude less: from 4 to 14%.

In addition, it takes at least 3-4 hours to detect malignant cells using a smooth chip. For a new device, the optimal cycle time is only two hours.

For incubation of the nanochip and registration of the cells associated with it, conventional laboratory equipment is necessary – 
standard laboratory incubator and automatic fluorescent microscope.

Here's how it's done:

If further tests of the device using patients' blood, as well as other biological fluids, such as urine and fluid accumulating in the abdominal cavity, prove its effectiveness in detecting circulating tumor cells, oncologists will receive an inexpensive, non-complicated equipment and effective method of early diagnosis of metastasis and monitoring of treatment results.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on UCLA materials: "UCLA researchers create 'fly paper' to capture circulating cancer cells"24.11.2009