TY - JOUR
T1 - Altered in vitro spreading and cytoskeletal organization in human glioma cells by downregulation of urokinase receptor
AU - Chintala, Shravan K.
AU - Mohanam, Sanjeeva
AU - Go, Yoshinori
AU - Venkaiah, Boyapati
AU - Sawaya, Raymond
AU - Gokaslan, Ziya L.
AU - Rao, Jasti S.
PY - 1997/12
Y1 - 1997/12
N2 - The interaction of urokinase-type plasminogen activator (uPA) with its cell-surface receptor (uPAR) is implicated in diverse biological processes such as cell migration, tissue remodeling, and tumor cell invasion. Recent studies indicated that uPAR can act as an extracellular matrix receptor during cell adhesion. Recently, we showed that transfection of the human glioma cell line SNB19 with antisense uPAR resulted in downregulation of uPAR at both the mRNA and protein levels. In this study, we used SNB19 to determine how the presence or absence of uPAR promotes cell spreading and associated changes in cell morphology. Microscopic analysis of cell spreading revealed that antisense uPAR-transfected cells were larger, remained round, and did not spread efficiently over extracellular matrix substrate type IV collagen and fibronectin, unlike parental SNB19 cells, which were smaller and spindle shaped. Biochemical studies showed that antisense uPAR-transfected cells, in addition to not spreading, exhibited increased expression of α3β1 integrin but not α5β1 integrin. However, we could not find a change in the expression of extracellular matrix components or altered growth rate in these cells. Furthermore, despite the increased α3β1 integrin expression, antisense uPAR-transfected cells failed to form an organized actin cytoskeleton when plated on type IV collagen or fibronectin, unlike parental SNB19 cells, which displayed an organized cytoskeleton. These findings show that the absence of uPAR in human glioma cells leads to morphological changes associated with decreased spreading and a disorganized cytoskeleton resulting in altered cell morphology, suggesting that coordinated expression of uPAR and integrin may be involved in spreading of antisense uPAR-transfected glioma cells.
AB - The interaction of urokinase-type plasminogen activator (uPA) with its cell-surface receptor (uPAR) is implicated in diverse biological processes such as cell migration, tissue remodeling, and tumor cell invasion. Recent studies indicated that uPAR can act as an extracellular matrix receptor during cell adhesion. Recently, we showed that transfection of the human glioma cell line SNB19 with antisense uPAR resulted in downregulation of uPAR at both the mRNA and protein levels. In this study, we used SNB19 to determine how the presence or absence of uPAR promotes cell spreading and associated changes in cell morphology. Microscopic analysis of cell spreading revealed that antisense uPAR-transfected cells were larger, remained round, and did not spread efficiently over extracellular matrix substrate type IV collagen and fibronectin, unlike parental SNB19 cells, which were smaller and spindle shaped. Biochemical studies showed that antisense uPAR-transfected cells, in addition to not spreading, exhibited increased expression of α3β1 integrin but not α5β1 integrin. However, we could not find a change in the expression of extracellular matrix components or altered growth rate in these cells. Furthermore, despite the increased α3β1 integrin expression, antisense uPAR-transfected cells failed to form an organized actin cytoskeleton when plated on type IV collagen or fibronectin, unlike parental SNB19 cells, which displayed an organized cytoskeleton. These findings show that the absence of uPAR in human glioma cells leads to morphological changes associated with decreased spreading and a disorganized cytoskeleton resulting in altered cell morphology, suggesting that coordinated expression of uPAR and integrin may be involved in spreading of antisense uPAR-transfected glioma cells.
KW - Adhesion
KW - Glioblastoma
KW - Invasion
KW - Plasminogen activators
KW - Spreading
KW - Urokinase-type plasminogen activator receptor
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U2 - 10.1002/(SICI)1098-2744(199712)20:4<355::AID-MC5>3.0.CO;2-I
DO - 10.1002/(SICI)1098-2744(199712)20:4<355::AID-MC5>3.0.CO;2-I
M3 - Article
C2 - 9433480
AN - SCOPUS:0031425359
SN - 0899-1987
VL - 20
SP - 355
EP - 365
JO - Molecular Carcinogenesis
JF - Molecular Carcinogenesis
IS - 4
ER -