ANTIPROLIFERATIVE ACTIVITY OF SYNTHETIC TETRAPEPTIDES, ANALOGS OF AS-I PHYTOTOXIN, TOWARDS CANCER CELL-LINES

The in vitro chemosensitivity of three cancer cell lines [HT29 (colon) , HeLa (cervical) and T47D (breast)] to eight synthetic tetrapeptides, analogs of AS-I toxin, with phytotoxic effect on a series of plants w as studied. Mouse fibroblast L929 cell line was also tested for chemos ensitivity to these peptides. All cell lines were especially sensitive to Cys-Val-Gly-Glu tetrapeptide with IC50 values of 0.18, 0.3 and 0.6 3 mM for HT29, HeLa and T47D cells, respectively, whereas the IC50 val ue for th L929 cells was higher than 1 mM. Antiproliferative activity was also observed with peptides Tyr-Val-Gly-Glu and His-Val-Gly-Glu wi th IC50 values higher than those obtained for Cys-Val-Gly-Glu. For the rest of the peptides tested the IC50 values were found close to or hi gher than 3 mM. [(C) 1998 Rapid Science Ltd.].