miR-200b suppresses invasiveness and modulates the cytoskeletal and adhesive machinery in esophageal squamous cell carcinoma cells via targeting Kindlin-2.
To further our understanding of the pathobiology of esophageal squamous cell carcinoma (ESCC), we previously performed microRNA profiling that revealed downregulation of miR-200b in ESCC. Using quantitative real-time PCR applied to 88 patient samples, we confirmed that ESCC tumors expressed significantly lower levels of miR-200b compared with the respective adjacent benign tissues (P = 0.003). Importantly, downregulation of miR-200b significantly correlated with shortened survival (P = 0.025), lymph node metastasis (P = 0.002) and advanced clinical stage (P = 0.020) in ESCC patients. Quantitative mass spectrometry identified 57 putative miR-200b targets, including Kindlin-2, previously implicated in the regulation of tumor invasiveness and actin cytoskeleton in other cell types. Enforced expression of miR-200b mimic in ESCC cells led to a decrease of Kindlin-2 expression, whereas transfection of miR-200b inhibitor induced Kindlin-2 expression. Furthermore, transfection of miR-200b mimic or knockdown of Kindlin-2 in ESCC cells decreased cell protrusion and focal adhesion (FA) formation, reduced cell spreading and invasiveness/migration. Enforced expression of Kindlin-2 largely abrogated the inhibitory effects of miR-200b on ESCC cell invasiveness. Mechanistic studies revealed that Rho-family guanosine triphosphatases and FA kinase mediated the biological effects of the miR-200b-Kindlin-2 axis in ESCC cells. To conclude, loss of miR-200b, a frequent biochemical defect in ESCC, correlates with aggressive clinical features. The tumor suppressor effects of miR-200b may be due to its suppression of Kindlin-2, a novel target of miR-200b that modulates actin cytoskeleton, FA formation and the migratory/invasiveness properties of ESCC.
Department of Biochemistry and Molecular Biology, The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong 515041, China.
Hai-Feng
HF
Zhang
Kai
K
Zhang
Lian-Di
LD
Liao
Li-Yan
LY
Li
Ze-Peng
ZP
Du
Bing-Li
BL
Wu
Jian-Yi
JY
Wu
Xiu-E
XE
Xu
Fa-Min
FM
Zeng
Bo
B
Chen
Hui-Hui
HH
Cao
Meng-Xiao
MX
Zhu
Li-Hua
LH
Dai
Lin
L
Long
Zhi-Yong
ZY
Wu
Raymond
R
Lai
Li-Yan
LY
Xu
En-Min
EM
Li
D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D003599:Cytoskeleton / Q000378:metabolism*; D004938:Esophageal Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D005260:Female; D022001:Focal Adhesions / Q000502:physiology*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000235:genetics*; D010766:Phosphorylation; D011379:Prognosis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015996:Survival Rate; D014407:Tumor Cells, Cultured
C477322:FERMT3 protein, human; C533896:MIRN200 microRNA, human; D008565:Membrane Proteins; D035683:MicroRNAs; D009363:Neoplasm Proteins