Finding cancers early is easy in body parts like breasts, skin and the prostate. In fact, early discovery sometimes leads to unneeded treatment and excisions that go along with the diagnosis.
Liver cancer though often remains hidden until the dread diagnosis: “It has metastasized to the liver.” Go home and get comfortable.
The sooner the liver cancers are found, the more likely surgery or even liver regeneration can be pursued to save lives. Finding a non-invasive method has been difficult. CT scans and MRIs don’t reveal much until the cancer has grown.
Now researchers in synthetic biology at Massachusetts Institute of Technology and University of California in San Diego have devised a clever route in to this amazing organ. Probiotics.
The abstract appears in Science Translational Medicine on May 27 of 2015 as Programmable probiotics for detection of cancer in urine. Bacteria were chosen because previous work revealed that they often thrive in tumor tissue—immune system dialed down– but not always in healthy organs.
- Take probiotic Escherichia coli Nissle 1917.
- Engineer the E. coli to express a gene to make an enzyme called lacZ.
- Inject body (mouse) with a molecule linked to a special protein called luciferin.
- Luciferin is the protein which makes fireflies light up.
- When lacZ splits the molecule, the luciferin exits to the urine.
- Once the twinkling protein hits the outside, there are no secrets. A simple urine test is sufficient to detect.
According to the authors, E. coli Nissle 1917 colonized tumor tissue in rodent models of liver metastasis after oral delivery but did not colonize healthy organs or fibrotic liver tissue.
And according to News Medical online, “the MIT team is now pursuing the idea of using probiotic bacteria to treat cancer, as well as for diagnosing it.”