Team:JNFLS/Description
JNFLS
Description
Colon cancer is the second most common cancer in China. It happens when tumorous growths develop in the large intestine. The mortality rate of early stage is lower than 5%. Unfortunately, the clinical manifestation of early stage is not obvious and lacks specificity which makes colon cancer easily treated as appendicitis or enteritis. As a result, most patients are diagnosed with advanced tumor, whose mortality rate is over 95%. What’s worse, low success rate and unbearable pain discourage a large proportion of sufferers to receive conventional treatments including surgeries, radiotherapy and chemotherapy, which further lowers the possibility of survival. Consequently, the major reason why we concern particularly colon cancer is that colon cancer is considered as one of the most fatal assassin of health as well as life quality, especially to middle-aged people in China and the world.
As a daily beverage and inexpensive healthy product, yogurt is bought and drunk extensively in our daily life, which makes it a desirable medium to carry the designed probiotics across the digestive system to where the colon tumor locates.
Theoretically, the biggest characteristic of cancer cells is rapid cell division, resulting in the hypoxia microenvironment of solid tumor. Our project is to construct three plasmids, which are transported to the solid tumor using the probiotics Nissle 1917 as gene delivery carrier. To be more specific, when the extracellular environment lacks oxygen, a plasmid in Nissle 1917 can express invasion protein and HylA protein, allowing the Nisssle 1917 to invade into tumor cells and avoid cell lysosomes endocytosis. After the Nissle 1917 enters solid tumor cells, the second plasmid will express TAT protein, inducing cell apoptosis. The specialty of our project is that if the Nissle 1917 enters the nontumorous cells by mistake, the third plasmid will initiate suicide program, which will not pose a threat to normal cells, achieving the security of gene therapy.
