Look inside cancer
A group of French scientists proposed a technique for imaging a tumor based only on its physical characteristics. With this method, it is possible to recognize populations of malignant cells, as well as to evaluate the effectiveness of anti-cancer therapy.
Increasingly, scientists are coming to the conclusion that the physical characteristics of the tumor can play an important role in the progression of the tumor and the effectiveness of treatment. For example, it is not difficult to assess the elasticity of the tumor on its surface, but it is much more difficult to assess its rigidity in depth, and it is the internal density of the tumor that determines how permeable it is to therapeutic substances. To evaluate this parameter, the researchers used a non-contact imaging method that does not require the use of contrast agents.
To establish the characteristics of a colorectal tumor in vitro, scientists have created cancer organoids – spheres with a diameter of 0.3 mm, representing aggregates of cancer cells. Then a red laser beam was focused on these organoids. Infinitesimal fluctuations of the sample caused by thermal excitation slightly change the color of the beam at the output. By analyzing the color of the outgoing rays, a map of the mechanical properties of the tumor is formed: the harder the area scanned by the laser, the stronger the vibrations and, accordingly, the color change of the outgoing beam. In the figure, the most rigid area of the tumor is shown in dark red. According to this map, rigidity increases from the surface into the tumor.
The researchers then tested the method on hybrid organoids, which included cells from two different cancerous tumors. The results showed that the technique makes it possible to distinguish two different cell lines by their mechanical properties.
The data obtained may be important for modeling various types of tumors, may help to establish a more accurate diagnosis during biopsy, as well as monitor the effectiveness of therapy and adjust it in accordance with the behavior of the tumor. In addition, this approach may provide new opportunities for personalizing therapy.
Article by Margueritat et al. High-Frequency Mechanical Properties of Tumors Measured by Brillouin Light Scattering is published in PHYSICAL REVIEW LETTERS.
Anastasia Poznyak, portal "Eternal Youth" http://vechnayamolodost.ru / based on CNRS materials: Physics can show us the inside of tumors.