Scientists have created a hydrogel-based biochip with 3D cells to better help diagnose colorectal cancer - the third most common type of cancer. Colorectal cancer (CRC) develops with minimal clinical symptoms in the early stages. Despite doctors’ efforts, the 5-year survival rate does not exceed 36 per cent. Treatment is effective only if the cancer is detected early.
Diagnostic methods that are currently in use are not sufficient. Analyses carried out in vitro have low specificity and invasive studies such as colonoscopy are not only traumatic, but they are also not always suitable for an early diagnosis, as they do not give a complete picture of the development and distribution of colorectal cancer.
The method proposed by scientists from the Moscow Institute of Physics and Technology (MIPT), the Engelhardt Institute of Molecular Biology (EIMB RAS) and colleagues is based on the simultaneous detection of various substances in patients’ blood.
These substances are autoantibodies against tumour-associated glycans, which can be found in serum at the early stages of cancer, immunoglobulins of different classes, and oncomarkers (molecules produced by tumour cells).
Oncomarkers are already widely used to detect cancer. However, the combination which is used to detect CRC is not sensitive enough and is only able to detect 1 in 2 cases of the disease.
To increase diagnostic sensitivity, researchers turned to glycobiology that is focused on the most important biological molecules - glycans.
Besides acting as nutrients and building materials for cells, glycans are important for the contact between cells, appropriate organ growth and much more.
Tumour cells have special glycans enabling scientists to differentiate them from healthy cells. To detect tumour-associated glycans, scientists use autoantibodies. Autoantibodies against tumour-associated glycans react exclusively with glycans that are only found in CRC cells.
The researchers proposed looking for autoantibodies against tumour-associated glycans in serum. Scientists developed microchips that consist of 3D cells made of a special gel which contains the required reagents - molecular probes.
The structure of the gel provides an optimal environment for conducting tests, and the scientists were able to solve a number of problems to ensure more accurate diagnoses.
The scientists analysed the sera of 33 patients with colorectal cancer, 69 healthy donors and 27 patients with inflammatory bowel disease. Researchers were able to diagnose CRC in 95 per cent of cases, compared to 79 per cent detected by traditional methods. The sensitivity of CRC detection (in patients with Stage II-IV CRC) was 87 per cent versus 21 per cent.