Alongside cardiovascular disease, cancer has become the top cause of death in industrialised countries (France, Germany, Italy, the United Kingdom, Japan, the United States, Canada, and Russia). Many people affected are diagnosed only after the tumour has developed extensively. This often reduces the chance of recovery significantly: the cure rate for prostate cancer is 32 percent and only 11 percent for colon cancer. The ability to detect such tumours reliably and early would not only save lives, but also reduce the need for expensive, stressful treatment.
Researchers working with Martin Fussenegger, Professor at the Department of Biosystems Science and Engineering at ETH Zurich in Basel, have now presented a possible solution for this problem: a synthetic gene network that serves as an early warning system. It recognises the four most common types of cancer — prostate, lung, colon and breast cancer — at a very early stage, namely when the level of calcium in the blood is elevated due to the developing tumour.
This early warning system comprises a genetic network that biotechnologists integrate into human body cells, which in turn are inserted into an implant. This encapsulated gene network is then implanted under the skin where it constantly monitors the blood calcium level.
As soon as the calcium level exceeds a particular threshold value over a longer period of time, a signal cascade is triggered that initiates production of the body’s tanning pigment melanin in the genetically modified cells. The skin then forms a brown mole that is visible to the naked eye.
The mole appears long before the cancer becomes detectable through conventional diagnosis. The person with the implant should see a Physician for further evaluation without panicking.
Calcium was used as the indicator of the development of the four types of cancer, as it is regulated strongly in the body. Bones serve as a buffer that can balance out concentration differences. However, when too much calcium is detected in the blood, this may serve as a sign for one of the four cancers.
The disadvantage of the implant is the service life is limited and the encapsulated living cells will last for about a year, so after a year they must be inactivated and replaced.
Aizhan Tastanova, Marc Folcher, Marius Müller, Gieri Camenisch, Aaron Ponti, Thomas Horn, Maria S. Tikhomirova, Martin Fussenegger. Synthetic biology-based cellular biomedical tattoo for detection of hypercalcemia associated with cancer. Science Translational Medicine, 2018; 10 (437): eaap8562 DOI: 10.1126/scitranslmed.aap8562