Teruyuki Sakai

Agelasphin-9b, (2S,3S,4R)-1-O-(alpha-D-galactopyranosyl)-16-methyl-2- [N-((R)-2- hydroxytetracosanoyl)-amino]- 1,3,4-heptadecanetriol, is a potent antitumor agent isolated from the marine sponge Agelas mauritianus. Various analogues of agelasphin-9b (a lead compound) were synthesized, and the relationship between their structures and biological activities was examined using several assay systems. From the results, KRN7000, (2S,3S,4R)-1-O-(alpha-D- galactopyranosyl)-2-(N-hexacosanoylamino)-1,3,4-octadecanetriol , was selected as a candidate for clinical application.

Autotaxin (ATX) is a tumor cell motility-stimulating factor originally isolated from melanoma cell supernatant that has been implicated in regulation of invasive and metastatic properties of cancer cells. Recently, we showed that ATX is identical to lysophospholipase D, which converts lysophosphatidylcholine to a potent bioactive phospholipid mediator, lysophosphatidic acid (LPA), raising the possibility that autocrine or paracrine production of LPA by ATX contributes to tumor cell motility. Here we demonstrate that LPA and ATX mediate cell motility-stimulating activity through the LPA receptor, LPA1. In fibroblasts isolated from lpa1-/- mice, but not from wild-type or lpa2-/-, cell motility stimulated with LPA and ATX was completely absent. In the lpa1-/- cells, LPA-stimulated lamellipodia formation was markedly diminished with a concomitant decrease in Rac1 activation. LPA stimulated the motility of multiple human cancer cell lines expressing LPA1, and the motility was attenuated by an LPA1-selective antagonist, Ki16425. The present study suggests that ATX and LPA1 represent potential targets for cancer therapy. Autotaxin (ATX) is a tumor cell motility-stimulating factor originally isolated from melanoma cell supernatant that has been implicated in regulation of invasive and metastatic properties of cancer cells. Recently, we showed that ATX is identical to lysophospholipase D, which converts lysophosphatidylcholine to a potent bioactive phospholipid mediator, lysophosphatidic acid (LPA), raising the possibility that autocrine or paracrine production of LPA by ATX contributes to tumor cell motility. Here we demonstrate that LPA and ATX mediate cell motility-stimulating activity through the LPA receptor, LPA1. In fibroblasts isolated from lpa1-/- mice, but not from wild-type or lpa2-/-, cell motility stimulated with LPA and ATX was completely absent. In the lpa1-/- cells, LPA-stimulated lamellipodia formation was markedly diminished with a concomitant decrease in Rac1 activation. LPA stimulated the motility of multiple human cancer cell lines expressing LPA1, and the motility was attenuated by an LPA1-selective antagonist, Ki16425. The present study suggests that ATX and LPA1 represent potential targets for cancer therapy. Cell migration is an important cellular function for many physiological processes, such as embryonic morphogenesis, wound healing, immune-cell trafficking, and brain development (1Singer S.J. Kupfer A. Annu. Rev. Cell Biol. 1986; 2: 337-365Crossref PubMed Scopus (216) Google Scholar). In addition to physiological functions, cancer cells use migration mechanisms that are similar to those that occur in non-neoplastic cells (2Friedl P. Wolf K. Nat. Rev. Cancer. 2003; 3: 362-374Crossref PubMed Scopus (2424) Google Scholar). The principles of cell migration were initially investigated in non-neoplastic fibroblasts, keratinocytes, and myoblasts, and additional studies on tumor cells identified the same basic mechanisms. Understanding more about the cellular and molecular basis of different cell migration/invasion mechanisms will help us to explain how cancer cells disseminate and should lead to new treatment strategies.Lysophosphatidic acid (LPA) 1The abbreviations used are: LPA, lysophosphatidic acid; ATX, autotaxin; OMPT, 1-oleoyl-2-O-methyl-rac-glycerophosphothionate; PTX, pertussis toxin; MSF, mouse skin fibroblast; GAPDH, glyceraldehydephosphate dehydrogenase; Edg, endothelial cell differentiation 1The abbreviations used are: LPA, lysophosphatidic acid; ATX, autotaxin; OMPT, 1-oleoyl-2-O-methyl-rac-glycerophosphothionate; PTX, pertussis toxin; MSF, mouse skin fibroblast; GAPDH, glyceraldehydephosphate dehydrogenase; Edg, endothelial cell differentiation or is a a of and cell Cell PubMed Scopus Google PubMed Scopus Google Scholar). LPA cell migration in many cell in fibroblasts, and cancer cells Cell PubMed Scopus Google PubMed Scopus Google 2003; Google a potential of LPA in cellular migration in physiological and Nat. Rev. Cancer. 2003; 3: PubMed Scopus Google Scholar). for LPA in cancer cell migration from the of a implicated in and PubMed Scopus Google as a for ATX was to identical to lysophospholipase D, an in that converts lysophosphatidylcholine to LPA A. K. K. K. Cell Biol. PubMed Scopus Google A. K. K. K. K. Biol. PubMed Scopus Google Scholar). ATX properties of a which explain has been that and cell motility is attenuated by cells with pertussis Nat. Rev. Cancer. 2003; 3: PubMed Scopus Google Biol. 2003; PubMed Scopus Google A. Biol. PubMed Google that with are LPA of the cellular of which to the cell differentiation and a LPA PubMed Scopus Google Cell Biol. PubMed Scopus Google Biol. PubMed Scopus Google K. K. Biol. PubMed Scopus Google K. Biol. 2003; PubMed Scopus Google Scholar). been A. K. A. 2003; PubMed Scopus Google Biol. PubMed Scopus Google Scholar). that mediate and through and and PubMed Scopus Google Scholar). the LPA in cell motility to we the of LPA in and cell that and cell motility is by LPA1 activation. a of Rac1 in cell was from were from was as A. K. K. K. Cell Biol. PubMed Scopus Google skin cells were from skin of by wild-type or and as Biol. PubMed Scopus Google Scholar). cells were in with and cells from the to the were used for cancer cell lines used in study were in with as A. K. A. K. K. Google migration was in a as A. K. K. K. Cell Biol. PubMed Scopus Google Scholar). 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PubMed Scopus Google Google and that the is to the invasive and metastatic of cancer cells PubMed Scopus Google Scholar). that ATX and LPA1 are the potential targets for cancer therapy. Cell migration is an important cellular function for many physiological processes, such as embryonic morphogenesis, wound healing, immune-cell trafficking, and brain development (1Singer S.J. Kupfer A. Annu. Rev. Cell Biol. 1986; 2: 337-365Crossref PubMed Scopus (216) Google Scholar). In addition to physiological functions, cancer cells use migration mechanisms that are similar to those that occur in non-neoplastic cells (2Friedl P. Wolf K. Nat. Rev. Cancer. 2003; 3: 362-374Crossref PubMed Scopus (2424) Google Scholar). The principles of cell migration were initially investigated in non-neoplastic fibroblasts, keratinocytes, and myoblasts, and additional studies on tumor cells identified the same basic mechanisms. Understanding more about the cellular and molecular basis of different cell migration/invasion mechanisms will help us to explain how cancer cells disseminate and should lead to new treatment acid (LPA) 1The abbreviations used are: LPA, lysophosphatidic acid; ATX, autotaxin; OMPT, 1-oleoyl-2-O-methyl-rac-glycerophosphothionate; PTX, pertussis toxin; MSF, mouse skin fibroblast; GAPDH, glyceraldehydephosphate dehydrogenase; Edg, endothelial cell differentiation 1The abbreviations used are: LPA, lysophosphatidic acid; ATX, autotaxin; OMPT, 1-oleoyl-2-O-methyl-rac-glycerophosphothionate; PTX, pertussis toxin; MSF, mouse skin fibroblast; GAPDH, glyceraldehydephosphate dehydrogenase; Edg, endothelial cell differentiation or is a a of and cell Cell PubMed Scopus Google PubMed Scopus Google Scholar). LPA cell migration in many cell in fibroblasts, and cancer cells Cell PubMed Scopus Google PubMed Scopus Google 2003; Google a potential of LPA in cellular migration in physiological and Nat. Rev. Cancer. 2003; 3: PubMed Scopus Google Scholar). for LPA in cancer cell migration from the of a implicated in and PubMed Scopus Google as a for ATX was to identical to lysophospholipase D, an in that converts lysophosphatidylcholine to LPA A. K. K. K. Cell Biol. PubMed Scopus Google A. K. K. K. K. Biol. PubMed Scopus Google Scholar). ATX properties of a which explain has been that and cell motility is attenuated by cells with pertussis Nat. Rev. Cancer. 2003; 3: PubMed Scopus Google Biol. 2003; PubMed Scopus Google A. Biol. PubMed Google that with are LPA of the cellular of which to the cell differentiation and a LPA PubMed Scopus Google Cell Biol. PubMed Scopus Google Biol. PubMed Scopus Google K. K. Biol. PubMed Scopus Google K. Biol. 2003; PubMed Scopus Google Scholar). been A. K. A. 2003; PubMed Scopus Google Biol. 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PubMed Scopus Google Google and that the is to the invasive and metastatic of cancer cells PubMed Scopus Google Scholar). that ATX and LPA1 are the potential targets for cancer therapy. for on and for the of and and and of for the of

We have purified soluble mouse and human CD1d molecules to assess the structural requirements for lipid antigen presentation by CD1. Plate-bound CD1d molecules from either species can present the glycolipid alpha-galactosyl ceramide (alpha-GalCer) to mouse natural killer T cells, formally demonstrating both the in vitro formation of antigenic complexes, and the presentation of alpha-GalCer by these two CD1d molecules. Using surface plasmon resonance, we show that at neutral pH, mouse CD1 and human CD1d bind to immobilized alpha-GalCer, unlike human CD1b, which requires acidic pH for lipid antigen binding. The CD1d molecules can also bind both to the nonantigenic beta-GalCer and to phosphatidylethanolamine, indicating that diverse lipids can bind to CD1d. These studies provide the first quantitative analysis of monomeric lipid antigen-CD1 interactions, and they demonstrate that the orientation of the galactose, or even the nature of the polar head group, are likely to be more important for T cell receptor contact than CD1d binding.