Open AccessGanglioside GD3 promotes cell growth and invasion through p130Cas and paxillin in malignant melanoma cells
Author(s) -
Kazunori Hamamura,
Koichi Furukawa,
Takanori Hayashi,
Takeshi Hattori,
Junji Nakano,
Hideyuki Nakashima,
Takuo Okuda,
Hideki Mizutani,
Hiroyuki Hattori,
Minoru Ueda,
Takeshi Urano,
Kenneth O. Lloyd,
Koichi Furukawa
Publication year - 2005
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0503658102
Subject(s) - paxillin , transfection , small interfering rna , melanoma , cell culture , cell growth , microbiology and biotechnology , tyrosine phosphorylation , cancer research , cell , phosphorylation , chemistry , focal adhesion , biology , biochemistry , genetics
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.