New system for detecting cancer-related markers on CTCs

New system for detecting cancer-related markers on CTCs

Taking biopsies and running endless tests is no one's idea of ​​a good time, even if it's necessary to monitor your health. Now researchers in Japan report developing a new technique that could make cancer testing much less invasive.

In a study published in September in the Journal of the American Chemical Society, researchers at Tokyo Medical and Dental University (TMDU) presented a new technique for evaluating the cancer-related marker using breast cancer cell lines.

Detection of cancer-related markers is a powerful method for determining diagnosis, prognosis and treatment outcome. Modern techniques are able to detect these markers in patient samples such as blood and urine, providing a non-invasive way to monitor and evaluate patients.

Circulating tumor cells (CTCs), cancer cells found in the blood, are one of the main targets used to evaluate blood samples from cancer patients. However, it can be difficult to isolate these cells from the blood, and current approaches do not adequately detect both epithelial cell and mesenchymal cell markers that are important in determining cancer stage.”

Miyuki Tabata, lead author of the study

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To create a system that can quickly and easily detect cancer-related markers on CTCs (and possibly other factors in the blood), the researchers used a device called an ion-sensitive field-effect transistor (ISFET), which is a tiny electrical circuit that is activated by a change in pH. They coated these transistors with breast cancer cells and then added an antibody linked to a chemical reporter that causes a change in pH when the antibody recognizes the cells.

“We found that the chemical reporter glucose oxidase successfully detected the expression of epidermal growth factor receptor (EGFR), a marker of poor cancer prognosis, on CTC membranes,” says Yuji Miyahara, senior author of the study. “In addition, the strength of the chemical signal correlated with the amount of EGFR expressed by the cells.”

Importantly, these results corresponded to EGFR levels detected using other techniques, indicating that the ISFET approach accurately identifies cancer-related marker expression on cells.

“These results represent proof of concept that an ISFET-based system can be used to efficiently assess the cancer status of patients using liquid biopsy samples,” explains Tabata.

Because ISFETs can be fabricated to be the size of a single cell and assembled into giant arrays, this technique has the potential to enable high-throughput analysis of cancer cells at single-cell resolution. Furthermore, the use of multiple antibodies for the chemical enzyme detection step could enable the simultaneous analysis of multiple cancer-related markers.

Source:

Tokyo University of Medicine and Dentistry

Reference:

Tabata, M., et al. (2022) Detection of epidermal growth factor receptor expression in breast cancer cell lines using an ion-sensitive field-effect transistor in combination with enzymatic chemical signal amplification. Journal of the American Chemical Society. doi.org/10.1021/jacs.2c06122.

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