title: Lysophosphatidic acid (LPA) enhances the metastatic potential of human colon carcinoma DLD1 cells through LPA1.
abstract: Lysophosphatidic acid (LPA) is a lipid mediator with diverse effects on various cells. Here, we investigated the effects of LPA on human colon carcinoma DLD1 cells. Northern blot analysis revealed that DLD1 highly expressed LPA1/Edg-2 but showed only low expression of LPA2/Edg-4 and no expression of LPA3/Edg-7 at the mRNA level. Western blot analysis revealed that DLD1 cells highly expressed LPA1 at the protein level. Using the Boyden chamber assay, LPA markedly increased DLD1 cell migration at concentrations as low as 10 nM, with maximum stimulation at 100 nM (3.6-fold increase). Checkerboard analysis indicated that LPA stimulated both the chemotactic and chemokinetic migration of DLD1 cells. LPA induced a dose-dependent increase in the proliferation of DLD1 cells (3.2-fold increase at 20 microM). Furthermore, LPA stimulated DLD1 cell adhesion to collagen type I (2.0-fold increase at 10 microM) and also stimulated the secretion of both vascular endothelial growth factor (1.4-fold increase at 20 microM) and interleukin 8 (19-fold increase at 20 microM) by ELISA. In contrast, as for matrix metalloproteinase, LPA had no significant effect on pro-matrix metalloproteinase-2 secretion and its activation, as measured by Western blot analysis. Thus, LPA, at concentrations that are present physiologically, enhanced DLD1 cell migration, proliferation, adhesion, and secretion of angiogenic factors, all of which are crucial for cancer metastasis. In comparison, other human colon carcinoma cells (HT29 and WiDR) exclusively expressed LPA2. LPA enhanced their proliferation and secretion of angiogenic factors, whereas LPA did not enhance migration or adhesion. Our results suggest that LPA acts as a potent stimulator of colon cancer progression, although the binding to LPA1 and LPA2 induces slightly different responses.
authors.affiliation: Department of Surgical Oncology, University of Tokyo Graduate School of Medicine, Tokyo 113-8655, Japan. SHIDA-DIS@h.u-tokyo.ac.jp
authors.forename: Dai
authors.initials: D
authors.lastname: Shida
authors.forename: Joji
authors.initials: J
authors.lastname: Kitayama
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Yurai
authors.initials: Y
authors.lastname: Okaji
authors.forename: Nelson Hirokazu
authors.initials: NH
authors.lastname: Tsuno
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yoh
authors.initials: Y
authors.lastname: Takuwa
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nagawa
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D024042:Collagen Type I / Q000378:metabolism; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D016228:Endothelial Growth Factors / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008222:Lymphokines / Q000378:metabolism; D008246:Lysophospholipids / Q000494:pharmacology*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D009362:Neoplasm Metastasis; D009687:Nuclear Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D024042:Collagen Type I; D016228:Endothelial Growth Factors; D020672:I-kappa B Proteins; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8; D008222:Lymphokines; D008246:Lysophospholipids; C000606204:NFKBIA protein, human; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D000072000:NF-KappaB Inhibitor alpha; D020778:Matrix Metalloproteinase 2