title: Ganglioside GD3 promotes cell growth and invasion through p130Cas and paxillin in malignant melanoma cells.
abstract: Although ganglioside GD3 levels are highly elevated in malignant melanomas, the role of GD3 in melanomas' malignant properties has not been clearly shown. To investigate this problem, we genetically generated GD3-positive (GD3+) transfectant cells from a GD3-negative (GD3-) mutant line SK-MEL-28-N1 and analyzed the phenotypic changes in the transfected cells. GD3+ cells showed markedly increased cell growth and invasive characteristics. Two bands that underwent stronger tyrosine phosphorylation in GD3+ cell lines than in controls after treatment with FCS were found with molecular masses of 130 and 68 kDa. They were identified as p130Cas and paxillin by sequential immunoprecipitation. Their roles in cell growth and invasion were analyzed with a small interfering RNA (siRNA) approach. Cell growth, as analyzed by BrdUrd uptake, was strongly suppressed in GD3+ cells to near the levels of GD3- cells when treated with siRNA for p130Cas but not when treated with siRNA for paxillin. However, treatment with siRNAs of either p130Cas or paxillin resulted in the marked suppression of the invasive activity of GD3+ cells almost to the levels of control cells. These results suggested that these two molecules function as effectors of GD3-mediated signaling, leading to such malignant properties as rapid cell growth and invasion.
authors.affiliation: Departments of Biochemistry II and Oral and Maxillofacial Surgery, Nagoya University School of Medicine, 65 Tsurumai, Showa-ku, Nagoya 466-0065, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Hamamura
authors.forename: Keiko
authors.initials: K
authors.lastname: Furukawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Hayashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hattori
authors.forename: Junji
authors.initials: J
authors.lastname: Nakano
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Nakashima
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Okuda
authors.forename: Hideki
authors.initials: H
authors.lastname: Mizutani
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hattori
authors.forename: Minoru
authors.initials: M
authors.lastname: Ueda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Urano
authors.forename: Kenneth O
authors.initials: KO
authors.lastname: Lloyd
authors.forename: Koichi
authors.initials: K
authors.lastname: Furukawa
mesh_terms: D002455:Cell Division; D045744:Cell Line, Tumor; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005732:Gangliosides / Q000378:metabolism*; D006801:Humans; D008545:Melanoma / Q000209:etiology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009361:Neoplasm Invasiveness; D051419:Paxillin; D010641:Phenotype; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011506:Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D050717:Retinoblastoma-Like Protein p130; D012799:Sialyltransferases / Q000235:genetics; D014162:Transfection; D014443:Tyrosine / Q000737:chemistry
chemical_list: C493841:BCAR1 protein, human; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins; D005732:Gangliosides; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; D034741:RNA, Small Interfering; D050717:Retinoblastoma-Like Protein p130; D014443:Tyrosine; C026226:ganglioside, GD3; D012799:Sialyltransferases; C043662:alpha-N-acetylneuraminate alpha-2,8-sialyltransferase