Abstract: In vitro growth inhibition tests, cell shape observations, and cell cycle determinations were conducted to evaluate the inhibition effects of wheat germ agglutinin isolectin II (WGAII) on two breast cancer cell lines, MCF-7 and SHZ. WGA demonstrated inhibitive effects on the proliferation of both cell lines showing maximum inhibition at 72h after incubation. SHZ was more sensitive to WGAII treatment, its LD50 being ￣10μg/ml. WGAII treatment crimpled, stretched, clustered, and detached the cancer cells, and worsens their surface reflectivity. The wall of some cells was blebbed, conglutinated, with some of the blebs broken or detached as apoptotic bodies. WGAII blocked the SHZ cell cycle at the G1/S phase, and thus interfered with the normal proliferation of cancer cells.

Key words: wheat germ agglutinin isolectin II (WGA II), rat breast cancer, anti-proliferative effects, apoptosis