Human U87 astrocytoma cell invasion induced by interaction of βig-h3 with integrin α5β1 involves calpain-2.
It is known that βig-h3 is involved in the invasive process of many types of tumors, but its mechanism in glioma cells has not been fully clarified. Using immunofluorescent double-staining and confocal imaging analysis, and co-immunoprecipitation assays, we found that βig-h3 co-localized with integrin α5β1 in U87 cells. We sought to elucidate the function of this interaction by performing cell invasion assays and gelatin zymography experiments. We found that siRNA knockdowns of βig-h3 and calpain-2 impaired cell invasion and MMP secretion. Moreover, βig-h3, integrins and calpain-2 are known to be regulated by Ca(2+), and they are also involved in tumor cell invasion. Therefore, we further investigated if calpain-2 was relevant to βig-h3-integrin α5β1 interaction to affect U87 cell invasion. Our data showed that βig-h3 co-localized with integrin α5β1 to enhance the invasion of U87 cells, and that calpain-2, is involved in this process, acting as a downstream molecule.
Department of Neurosurgery, Tangdu Hospital, Forth Military Medical University, Xi'an, China.
Jie
J
Ma
Wei
W
Cui
Shi-ming
SM
He
Yong-hong
YH
Duan
Li-Jun
LJ
Heng
Liang
L
Wang
Guo-dong
GD
Gao
D001253:Astrocytes / Q000378:metabolism*; D001254:Astrocytoma / Q000378:metabolism*; D002154:Calpain / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D039081:Integrin alpha5beta1 / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D000099222:betaIG-H3 Protein
D002154:Calpain; D016326:Extracellular Matrix Proteins; D039081:Integrin alpha5beta1; D034741:RNA, Small Interfering; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein; C569870:CAPN2 protein, human