LTF (lactotransferrin, or lactoferrin) plays important role in innate immunity, 
and its anti-tumor function has also been reported in multiple cancers. We 
previously reported that LTF is significantly down-regulated in nasopharyngeal 
carcinoma (NPC) and acts as a tumor suppressor by suppressing AKT signaling. 
However, the exact mechanism of the down-regulation of LTF in NPC has not been 
revealed. In the current study, we screened and identified LTF is a bona fide 
target of miR-214 in NPC cells. miR-214 mimics significantly suppressed LTF mRNA 
and protein expression levels in NPC cells. miR-214 not only can promote NPC 
cell proliferation and invasion abilities in vitro, but also can accelerate 
tumor formation and lung metastasis in a mouse xenograft model. The pro-tumor 
function of miR-214 was depended on LTF suppression since LTF re-expression can 
reverse it. miR-214 can also activate AKT signaling by suppressing LTF 
expression. Furthermore, miR-214 expression level was up-regulated in NPC 
especially in metastasis-prone NPC tumor tissues compared with normal 
nasopharyngeal epithelial tissues, while the LTF expression level was negatively 
correlated with miR-214, suggesting that miR-214 targeting is partly responsible 
for LTF down-regulation in NPC specimens.