NOVEL ANTITUMOR AGENT AND METHOD FOR SCREENING SAME
The present invention provides a novel antitumor agent with a novel action mechanism. The novel antitumor agent comprises, as the active ingredient, a substance capable of inhibiting a cell cycle-dependent Rho GTPase activating protein (RhoGAP). The RhoGAP, which depends on the cell cycle, plays an important role in the course of the acquisition of metastatic ability and/or invasive ability by cancer cells. By targeting the RhoGAP, the invasion and/or metastasis of cancer cells can be controlled. As the substance capable of inhibiting the cell cycle-dependent RhoGAP, an antisense oligonucleotide against an RhoGAP-encoding gene, an oligonucleotide inducing RNA interference, etc. can be cited. An oligonucleotide containing a synthetic nucleic acid such as BNA is preferred because of the high stability thereof. The present invention also provides a screening method for selecting an antitumor agent which is capable of suppressing the invasion and/or metastasis of cancer cells by a novel mechanism. This method for screening a novel antitumor agent is characterized in that a substance capable of inhibiting a cell cycle-dependent Rho GTPase activating protein is selected thereby.