AIM:　To　study　the　effects　of　lysophosphatidic　acid　(LPA)　on　proliferation,　adhesion,　migration,　and　apoptosis　in　the　human　colon　cancer　cell　line,　SW480,　and　its　mechanisms　of　action.　METHODS:　Methyl　tetrazolium　assay　was　used　to　assess　cell　proliferation.　Flow　cytometry　was　employed　to　detect　cell　apoptosis.　Cell　migration　was　measured　by　using　a　Boyden　transwell　migration　chamber.　Cell　adhesion　assay　was　performed　in　96-well　plates　according　to　protocol.　RESULTS:　LPA　significantly　stimulated　SW480　cell　proliferation　in　a　dose-dependent　and　time-dependent　manner　compared　with　the　control　group　(P　＜　0.05)　while　the　mitogen-activated　protein　kinase　(MAPK)　inhibitor,　PD98059,　significantly　blocked　the　LPA　stimulation　effect　on　proliferation.　LPA　also　significantly　stimulated　adhesion　and　migration　of　SW480　cells　in　a　dose-dependent　manner　(P　＜　0.05).　Rho　kinase　inhibitor,　Y-27632,　significantly　inhibited　the　up-regulatory　effect　of　LPA　on　adhesion　and　migration　(P　＜　0.05).　LPA　significantly　protected　cells　from　apoptosis　induced　by　the　chemotherapeutic　drugs,　cisplatin　and　5-FU　(P　＜　0.05),　but　the　phosphoinositide　3-kinase　(PI3K)　inhibitor,　LY294002,　significantly　blocked　the　protective　effect　of　LPA　on　apoptosis.　CONCLUSION:　LPA　stimulated　proliferation,　adhesion,　migration　of　SW480　cells,　and　protected　from　apoptosis.　The　Ras/Raf-MAPK,　G12/13-Rho-RhoA　and　PI3K-AKT/PKB　signal　pathways　may　be　involved.　(C)　2009　The　WJG　Press　and　Baishideng.　All　rights　reserved.