Figure 7.

Proposed Mechanism of PGV-1 Enhanced S-phase Block and DNA Damage by 5-FU. In a sensitive cancer cell, 5-FU is metabolized into active metabolite 5’-dUMP. It interfere the DNA synthesis and causes apoptosis induced by DNA damage (A). In WiDr cell, 5-FU treatment stimulated NF-κB activation then increased cyclin D1 level. High level of cyclin D1 at S-phase leads to repression of DNA synthesis thus it blocks 5-FU effect (B). In the presence of PGV-1, an inhibitor of NF-κB, cyclin D1 level significantly suppressed and leads to the enhancement of S-phase block by 5-FU (C).