miR-145-dependent targeting of junctional adhesion molecule A and modulation of fascin expression are associated with reduced breast cancer cell motility and invasiveness.
Micro RNAs are small non-coding RNAs, which regulate fundamental cellular and developmental processes at the transcriptional and translational level. In breast cancer, miR-145 expression is downregulated compared with healthy control tissue. As several predicted targets of miR-145 potentially regulate cell motility, we aimed at investigating a potential role for miR-145 in breast cancer cell motility and invasiveness. Assisted by Affymetrix array technology, we demonstrate that overexpression of miR-145 in MDA-MB-231, MCF-7, MDA-MB-468 and SK-BR-3 breast cancer cells and in Ishikawa endometrial carcinoma cells leads to a downregulation of the cell-cell adhesion protein JAM-A and of the actin bundling protein fascin. Moreover, podocalyxin and Serpin E1 mRNA levels were downregulated, and gamma-actin, transgelin and MYL9 were upregulated upon miR-145 overexpression. These miR-145-dependent expression changes drastically decreased cancer cell motility, as revealed by time-lapse video microscopy, scratch wound closure assays and matrigel invasion assays. Immunofluorescence microscopy demonstrated restructuring of the actin cytoskeleton and a change in cell morphology by miR-145 overexpression, resulting in a more cortical actin distribution, and reduced actin stress fiber and filopodia formation. Nuclear rotation was observed in 10% of the pre-miR-145 transfected MDA-MB-231 cells, accompanied by a reduction of perinuclear actin. Luciferase activation assays confirmed direct miR-145-dependent regulation of the 3'UTR of JAM-A, whereas siRNA-mediated knockdown of JAM-A expression resulted in decreased motility and invasiveness of MDA-MB-231 and MCF-7 breast cancer cells. Our data identify JAM-A and fascin as novel targets of miR-145, firmly establishing a role for miR-145 in modulating breast cancer cell motility. Our data provide a rationale for future miR-145-targeted approaches of antimetastatic cancer therapy.
Götte
M
M
Department of Gynecology and Obstetrics, Münster University Hospital, Münster, Germany. mgotte@uni-muenster.de
Mohr
C
C
Koo
C-Y
CY
Stock
C
C
Vaske
A-K
AK
Viola
M
M
Ibrahim
S A
SA
Peddibhotla
S
S
Teng
Y H-F
YH
Low
J-Y
JY
Ebnet
K
K
Kiesel
L
L
Yip
G W
GW
D000199:Actins / Q000032:analysis; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D002352:Carrier Proteins / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D003599:Cytoskeleton; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism*; D035683:MicroRNAs / Q000378:metabolism*; D008840:Microfilament Proteins / Q000032:analysis / Q000378:metabolism*; D009124:Muscle Proteins / Q000032:analysis; D009361:Neoplasm Invasiveness; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis; D011956:Receptors, Cell Surface; D012795:Sialoglycoproteins / Q000032:analysis
D000199:Actins; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; C407243:F11R protein, human; D007136:Immunoglobulins; C541010:MIRN145 microRNA, human; D035683:MicroRNAs; D008840:Microfilament Proteins; D009124:Muscle Proteins; D017395:Plasminogen Activator Inhibitor 1; D011956:Receptors, Cell Surface; D012795:Sialoglycoproteins; C001643:podocalyxin; C051615:transgelin; C020324:fascin