Resistance to the induction of apoptosis is a possible me- chanism by which tumor cells can survive anti-neoplastic treatments. Melanoma is notoriously resistant to anti-neop- lastic therapy. Previous studies have demonstrated focal adhesion kinase (FAK) overexpression in melanoma cell lines. Given its probable role in mediating resistance to apo- ptosis, many researchers have sought to determine whether the downregulation of FAK in melanoma cells would confer a greater sensitivity to anti-neoplastic agents. Genistein is a known inhibitor of protein-tyrosine kinase (PTK), which may attenuate the growth of cancer cells by inhibiting the PTK- mediated signaling pathway. This present study was under- taken to investigate the effect of genistein on the expression of FAK and cell cycle related proteins in the G361 me- lanoma cell line. Genistein was found to have a preferential cyto- toxic effect on G361 melanoma cells over HaCaT normal ke- ratinocytes. Genistein decreased the expression of 125 kDa phosphotyrosine kinase and the FAK protein in particular. Genistein treatment did not affect the expression of p53 in G361 cells in which p21 is upregulated. The expression of cy- clin B and cdc2 was downregulated by genistein treatment. Taken together, our data indicate that genistein induces the decreased proliferation of G361 melanoma cells via the in-hibition of FAK expression and regulation of cell cycle genes. This suggests that the use of genistein may be a via- ble approach to future melanoma treatments.

• Gyoo Cheon Kim(Department of Oral Anatomy, School of Dentistry, Pusan National University) Correspondence to
• Sang Rye Park(Department of Oral Anatomy, School of Dentistry, Pusan National University)
• Hyun-Ho Kwak(Department of Oral Anatomy, School of Dentistry, Pusan National University)
• Bong-Soo Park(Department of Oral Anatomy, School of Dentistry, Pusan National University)