Enhancement of malignant properties of human osteosarcoma cells with disialyl gangliosides GD2/GD3.
The expression and implications of gangliosides in human osteosarcomas have not been systematically analyzed. In this study, we showed that gangliosides GD3 and GD2 are highly expressed in the majority of human osteosarcoma cell lines derived from oral cavity regions. Introduction of GD3 synthase cDNA into a GD3/GD2-negative (GD3/GD2-) human osteosarcoma subline resulted in the establishment of GD3/GD2+ transfectant cells. They showed increased cell migration and invasion activities in wound healing and Boyden chamber invasion assays, respectively, compared to the control cells. When treated with serum, GD3/GD2+ cells showed stronger tyrosine phosphorylation of p130Cas, focal adhesion kinase, and paxillin than GD3/GD2- cells. In particular, paxillin underwent much stronger phosphorylation, suggesting its role in cell motility. Furthermore, we tried to dissect the roles of GD3 and GD2 in the malignant properties of the transfectant cells by establishing single ganglioside-expressing cells, that is, either GD3 or GD2. Although GD3/GD2+ cells showed the most malignant properties, GD2+ cells showed almost equivalent levels to GD3/GD2+ cells in invasion and migration activities, and in the intensities of tyrosine phosphorylation of paxillin. Among Src family kinases, Lyn was expressed predominantly, and was involved in the invasion and motility of GD3- and/or GD2-expressing transfectants. Furthermore, it was elucidated by gene silencing that Lyn was located in a different pathway from that of FAK to eventually lead paxillin activation. These results suggested that GD2/GD3 are responsible for the enhancement of the malignant features of osteosarcomas, and might be candidate targets in molecular-targeted therapy.
Department of Biochemistry II, Nagoya University Graduate School of Medicine, Japan.
Hidenobu
H
Shibuya
Kazunori
K
Hamamura
Hiroshi
H
Hotta
Yasuyuki
Y
Matsumoto
Yoshihiro
Y
Nishida
Hisashi
H
Hattori
Keiko
K
Furukawa
Minoru
M
Ueda
Koichi
K
Furukawa
D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D050719:Crk-Associated Substrate Protein / Q000235:genetics / Q000378:metabolism; D051417:Focal Adhesion Kinase 1 / Q000235:genetics / Q000378:metabolism; D005732:Gangliosides / Q000378:metabolism*; D015870:Gene Expression; D020868:Gene Silencing; D006801:Humans; D012516:Osteosarcoma / Q000235:genetics / Q000378:metabolism*; D051419:Paxillin / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism
D050719:Crk-Associated Substrate Protein; D005732:Gangliosides; D051419:Paxillin; D014443:Tyrosine; C026226:ganglioside, GD3; C019403:ganglioside, GD2; D012799:Sialyltransferases; C043662:alpha-N-acetylneuraminate alpha-2,8-sialyltransferase; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases