Anti-Tumor Effects of Engineered Pediococcus pentosaceus in a Mouse Tumor Model

Begin with immunodeficient mice bearing subcutaneous xenograft tumors derived from human colorectal cancer cells.

Orally administer Pediococcus pentosaceus, a lactic acid bacterium safe for consumption and engineered to secrete an anticancer protein, to the treated mouse.

Administer saline to the control mouse.

Being acid-tolerant, the bacteria survive the acidic environment of the stomach and reach the intestine.

There, they colonize the intestinal lumen and secrete the anticancer protein.

The secreted protein is taken up by intestinal epithelial cells through endocytosis and released into systemic circulation.

Once in circulation, the protein reaches the tumor site, enters tumor cells, and accumulates in the cytoplasm.

The anticancer protein downregulates genes involved in cell cycle progression while upregulating a protein that promotes cell cycle arrest.

Together, these effects halt tumor cell proliferation.

Sustained exposure to the anticancer protein significantly inhibits tumor growth, compared to the control.