부산대학교 도서관

The hedgehog (Hh)/GLI signaling pathway has been implicated not only in a variety of developmental processes in wide range of organisms, but also in the formation and development of different tumors including skin, brain, prostate, upper gastrointestinal tract, pancreas and lung. Targeting Hh/GLI signaling has been expected as an effective cancer therapeutic strategy. To find the specific inhibitors of Hh/GLI signaling pathway from natural resources, a cell-based screening assay system targeting transcriptional activator GLI1, which constitutes the final step in the Hh signaling pathway, was constructed. A pGL4-Luc reporter vector inserted with 12×GLI binding sites was stably transfected into HaCaT cell line expressing GLI1 under tetracycline repressor control. A suitable protocol for the screening was then established. The screening of our natural products library with the above constructed system identified six active compounds; staurosporinone (1), 6-hydroxystaurosporinone (2), arcyriaflavin C (3), 5,6-dihydroxyarcyriaflavin A (4), zerumbone (5), and zerumbone epoxide (6). Their IC_<50> values of GLI1 transcriptional inhibitory activity were 1.8, 3.6, 11.3, 6.9, 3.0 and 55μM, respectively. The next screening of our natural plants extracts library gave 15 hit plants. Repeated chromatography separations of the MeOH extracts of Physalis minima and Zizyphus cambodiana gave active compounds. P minima gave two compounds; physalin F (10) and physalin B (11), and Z. combodiana a compound; colubrinic acid (13). Their IC_<50> values were 0.66, 0.62 and 29μM, respectively. It was reported that glil, ptchl, bcl2 are the Hh/GLI-mediated transcriptional targets. The influences of these inhibitors (1, 5, 10 and 11) on these protein expressions were investigated with western blotting analysis. These inhibitors decreased the expression of GLI1 and PTCH1, which are related Hh signaling pathway. Moreover, BCL2, which is related with apoptosis, was also decreased.