Galectin-1 expression in human glioma cells: modulation by ionizing radiation and effects on tumor cell proliferation and migration.
Galectins are evolutionarily conserved beta-galactoside-binding lectins which recognize specific glycoconjugates on the cell surface and the extracellular matrix. Accumulating evidence indicates that these proteins are involved in a variety of physiological and pathological processes including tumor growth and metastasis. Up-regulated expression of galectin-1 is a hallmark of a variety of malignant tumors. Here, we examined the expression of galectin-1 in glioma cell lines, the influence of ionizing irradiation and the intracellular and extracellular effects of this protein on tumor cell proliferation and migration. Galectin-1 was detected in both A172 and U118 glioma cells by immunoblot analysis. Ionizing irradiation induced a statistically significant up-regulation in glioma cell lines. RNA-interference-mediated silencing resulted in a significant suppression of the proliferation of the A172 cells, while the addition of recombinant galectin-1 had no effect. On the other hand, the migratory capacity of both cell lines was reduced after galectin-1 down-regulation, and up-regulated by the addition of exogenous galectin-1. Our results provide evidence of a role for galectin-1 in the regulation of glioma cell proliferation and migration. While an intracellular mechanism seemed to prevail in galectin-1-mediated regulation of tumor cell proliferation, the control of cell migration was exerted by both intracellular and extracellular mechanisms. In addition, this protein was up-regulated by ionizing radiation, indicating that the blockade of this protein should be performed before radiotherapy to avoid any undesired stimulating effects. Given the multifactorial role of galectin-1 in the regulation of tumor escape and metastasis, we conclude that targeting galectin-1 may have therapeutic benefits in the treatment of malignant glioma.
Strik
Herwig M
HM
Department of Neurology, University of Göttingen, D-37099 Göttingen, Germany. herwig.strik@med.uni-goettingen.de
Schmidt
Katharina
K
Lingor
Paul
P
Tönges
Lars
L
Kugler
Wilfried
W
Nitsche
Mirko
M
Rabinovich
Gabriel A
GA
Bähr
Mathias
M
D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D037483:Galectin 1 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D015870:Gene Expression; D005910:Glioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D011839:Radiation, Ionizing; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology*; D014162:Transfection; D015854:Up-Regulation / Q000528:radiation effects
D037483:Galectin 1; D034741:RNA, Small Interfering; D011994:Recombinant Proteins