The MCM protein family has six highly conserved subunits, MCM2 to 7, and is essential for initiation and elongation of DNA replication in all eukaryotes. Deregulation of the MCM function and expression resulted in cells undergoing tumorigenesis. Therefore, these proteins are potential diagnostic markers for cancer and promising targets for anticancer drug development. To screen lead compounds, which inhibit expression of MCM proteins, several medicinal plants were examined. Among them Pterocarpus santalinus was selected as candidate. Methanolic extract of Pterocarpus santalinus (MEPS) inhibited MCM expression in a dose-dependent manner (40∼60Ռg/ml). MEPS showed cytotoxic and antiproliferative activity against six human cancer cells tested such as HeLa, HT29, T24, HepG2, A549 and Jurkat E6-1. A 35% of abdomen tumor width reduction was observed in vivo experiment using C57BL/6 mouse bearing Sarcoma 180 cells after treatment of MEPS for 16 days. Oligonucleotide microarray analysis identified 69 up-regulated genes and 79 down-regulated genes in HeLa cells after MEPS treatment. The deregulated genes were involved in various biological process including cell cycle regulation and cell proliferation, signal transduction, apoptosis. (Cancer Prev Res 13, 54-61, 2008)

Keywords: Ptercarpus santalinus, Minichromosome maintenance protein, Cytotoxicity, Microarray, In vivo anticancer activity