"

From 2013.igem.org

Goals & Challenges

a.)Our bacteria should express our proteins precisely

b.)Expressed proteins should be isolated and purified effectively

c.)Proteins should penetrate cell membranes

d.)Once entered our proteins should induce apoptotic pathway on cancer cell spesifically.

Challenges:

a.) Apoptosis was our method of terminating cancer cells living. Cells may be eliminated by a number of alternative mechanisms including necrosis. Necrosis is typically described as a “nonspecific” form of cell death, characterized by rupture of the plasma membrane with a consequent localized inflammatory response and damage to surrounding cells and tissues. In contrast, apoptosis is associated with the rapid engulfment and removal of cell corpses by phagocytic cells that recognize “eat-me” signals displayed on the outer surface of the apoptotic cell . Furthermore, apoptotic cell death is the consequence of a series of precisely regulated events that are frequently altered in tumor cells. This provides the opportunity for selective clinical intervention to bring about the death of the tumor cell without damage to normal cells.These basic differences between these two processes of cell death underscore the reason why apoptosis, and not necrosis, represents the most desirable target mechanism for the induction of cell death in tumor cells.

b.)Chosen apoptotic proteins should be tumor specific. Despite the success of modern cancer therapies,the three major therapeutic interventions surgery,radiation, and chemotherapy still typically result in considerable damage to healthy tissue.We need new cancer treatments that precisely distinguish between diseased and healthy cells. To this end, synthetic biologists have engineered bacteria to target and invade cancer cells. Engineering bacteria in order to express tumor specific killer proteins enables . We aimed protective healthly cell untill thearapy. Thus we chosen apoptin.

c.) Also we cogitated about alternative proteins to apoptin and found e4of4. It behaves similar to apoptin.In this way we supported more data.

d.) Our constructs cannot cross the membrane of cancer cells due to being a large molecule. Therefore we used TAT peptide.It acts as a membrane shuttle; the structural determinants of transport and the manner by which the peptide crosses the lipid bilayer.

e.)We also offered disjunctive penetrating peptide instead of TAT in order to improve our data. Also we selected MPG peptide.

</div>