Ganglioside GD3 promotes cell growth and invasion through p130Cas and paxillin in malignant melanoma cells
Ganglioside GD3 promotes cell growth and invasion through p130Cas and paxillin in malignant melanoma cells
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DOI：
10.1073/pnas.0503658102
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发表时间：
2005-08-02
影响因子：
11.1
通讯作者：
Furukawa, K
中科院分区：
文献类型：
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作者：
Hamamura, K;Furukawa, K;Furukawa, K
尽管神经节苷脂GD3水平在恶性黑色素瘤中显著升高，但GD3在黑色素瘤恶性特性中的作用尚未明确阐明。为了研究这一问题，我们从GD3阴性（GD3(-)）突变细胞系SK - MEL - 28 - N1基因构建了GD3阳性（GD3(+)）转染细胞，并分析了转染细胞的表型变化。GD3 +细胞显示出细胞生长和侵袭特性显著增强。在用胎牛血清（FCS）处理后，在GD3(+)细胞系中发现有两条带比对照组发生更强的酪氨酸磷酸化，其分子量分别为130和68 kDa。通过连续免疫沉淀鉴定它们为p130Cas和桩蛋白（paxillin）。用小干扰RNA（siRNA）方法分析了它们在细胞生长和侵袭中的作用。通过BrdUrd摄取分析细胞生长情况，当用针对p130Cas的siRNA处理时，GD3(+)细胞的生长被强烈抑制到接近GD3 -细胞的水平，而用针对桩蛋白的siRNA处理时则没有这种效果。然而，用针对p130Cas或桩蛋白的siRNA处理都导致GD3(+)细胞的侵袭活性显著抑制，几乎达到对照细胞的水平。这些结果表明这两种分子作为GD3介导的信号传导的效应分子发挥作用，导致诸如细胞快速生长和侵袭等恶性特性。
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 siRNIA 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.