What is carcinoma of colon and rectum?
carcinoma of colon and rectum is a common malignant tumor in the gastrointestinal tract
The early symptoms of colorectal cancer are not obvious, and with the increase of cancer, it shows changes in bowel habits, bloody stool, diarrhea, alternating diarrhea and constipation, local abdominal pain and other symptoms, while in the late stage it shows anemia, weight loss and other systemic symptoms.
So how do people usually treat it?
people often use 5-FU
5-FU is a typical treatment for colorectal cancer,
but 5-FU drugs can cause damage to normal cells in addition to killing cancer cells, causing serious side effects.
The goal of our project is to use a specific enzyme to
ameliorate the side effects
of 5-FU.
How does it work?
We used Nissle 1917 as the chassis microbe, the only non-therapeutic E. coli, which is also a probiotic
Patients can took Nissle 1917 engineered probiotics by oral means.
To be more specific:
We pre-introduced the CD enzyme and used cell surface display technology to anchor the HIPA protein on the surface of the strain
Next, the patient takes 5-fluorocytosine (5-FC). 5-FC is a prodrug that does not have a therapeutic effect on its own, but can be converted to 5-fluorouracil (5-FU) under the action of cytosine deaminase.
Once the probiotics entered the body, the designed HIpA protein is then targeted and anchored to the cancer cell surface by binding to HSPG(Heparin sulfate proteoglycan) on the tumor cell surface.
After successful adhesion, the therapeutic part of the engineered bacteria is activated, and the engineered bacteria produce the CD, which converts 5-FC into 5-FU, and finally, 5-FU launches a selective attack on the cancer cells.
