A synthetic probiotic can treat colorectal cancer

Successful chemoprevention or chemotherapy is achieved by targeted delivery of preventive drugs or therapeutic agents to malignant tumors at the initial stage of canceration
.

Cancer is the main cause of human death, and the global burden is rising
.

Bacteria can be used to treat cancer, and their recognition as anticancer agents can be traced back more than a century ago
.
Potentially harmful or pathogenic strains such as Clostridium, Listeria or Salmonella, whether natural, mutated, or genetically modified, are used in cancer treatment because they can colonize entities under hypoxic conditions Tumor, and cause the tumor to shrink
.
Although efforts have been made to utilize attenuated bacteria, the risk of toxicity or infection hinders their clinical application
.
Lactic acid bacteria (Lab), such as Lactobacillus, Lactococcus, Leuconostoc, or Pediatrics, are generally considered safe and beneficial to the host's health, and are ideal targets for bacterial therapy
.
In addition, they can also be used as living carriers for the delivery of anti-cancer drugs
.

Colorectal cancer (CRC) is a serious cancer that causes nearly 900,000 deaths each year
.
A small protein P8 with a molecular weight of 8 kDa was isolated from Lactobacillus Rhamnosus CBT LR5, which was used to screen new therapeutic proteins against colorectal cancer
.
In order to design and develop a clinically relevant system that can be taken orally and is still stable, the author used a laboratory strain, Micrococcus pentosaceus SL4, as a safe drug delivery vector, which can express and secrete P8, thereby avoiding Its degradation in the gastrointestinal tract
.
The author isolated a strain of Pseudomonas pentosaceus SL4 that can produce bacteriocins and inhibit the growth of Listeria monocytogenes and Staphylococcus aureus from a Korean fermented vegetable food kimchi
.
Pseudomonas pentosaceus is a gram-positive bacteria, facultative anaerobic, acid-tolerant, immobile, and does not form spores
.
It is often separated from fermented foods and used as a starter in the fermentation of dairy products or plants
.
This strain can reduce the toxicity induced by azomethane, inhibit the proliferation of colon cancer cells, and secrete antibacterial peptides that inhibit pathogenic bacteria
.

In this study, the authors used P8 to develop an advanced anti-colorectal cancer probiotic, and through two different mouse models: DLD-1 xenograft and azomethane (AOM) and dextran sodium sulfate (DSS) induced colitis-related tumor formation, proving its powerful curative effect
.
In addition, considering the important relationship between the intestinal microflora and drug response, the authors longitudinally studied the microflora distribution during the administration of P8 synthetic probiotics in the AOM/DSS model to reveal the complexity between individual microbial members Interactions and identify key groups associated with tumorigenesis induced by using our synthetic probiotics and AOM/DSS
.
(Bio Valley)

Note: The original text has been deleted

Reference

Chung et al.
A synthetic probiotic engineered for colorectal cancer therapy modulates gut

Microbiota.
Microbiome (2021) 9: 122 https://doi.
org/10.
1186/s40168-021-01071-4