miR-214 Regulates Lactoferrin Expression and Pro-Apoptotic Function in Mammary Epithelial Cells ,

Abstract

Lactoferrin (Lf) is an abundantly expressed protein in human milk. Lactoferrin exhibits several important biological functions, and its expression is regulated by multiple environmental factors. Cellular endogenous factors, however, have not been extensively studied with regard to lactoferrin gene expression. In this study, we showed that lactoferrin gene expression and function are directly targeted by miR-214 in HC11 and MCF7 cells. In the lactoferrin mRNA 3 prime untranslated region (UTR) of human, mouse, rat, pig, bovine, camel, and goat species, there is a conserved region that perfectly matches the seed region of miR-214. Transfection of miR-214 mimic in HEK293 cells dose-dependently inhibited the activity of pGL3-control vector containing lactoferrin mRNA 3 prime UTR downstream of the luciferase gene. In HC11 cells, miR-214 overexpression inhibited the induction of lactoferrin expression by beta -estradiol (E2) and dexamethasone-prolactin-insulin (DPI). Furthermore, in MCF7 cells, overexpression of miR-214 markedly decreased lactoferrin expression (P lt 0.05), and inhibition of endogenous miR-214 expression increased lactoferrin expression and cellular apoptotic activities (P lt 0.05). In summary, our data showed that miR-214 is directly involved in lactoferrin expression and lactoferrin mediated cancer susceptibility (proapoptotic activities) in mammary epithelial cells.

Ovarian tumor-associated microRNA-20a decreases natural killer cell cytotoxicity by downregulating MICA/B expression

“…19 The orientation of the inserts was confirmed by sequencing. The SKOV3 and ES-2 cells were transfected with the pGL3 control vector or the PGL3 reconstructed vector containing either the wild type or mutant 39-UTR in combination with 40 nM miR-20a mimics and 20 ng of the pGL-Renilla luciferase vector as a transfection control.…”

Milk Protein Synthesis in the Lactating Mammary Gland: Insights from Transcriptomics Analyses

“…For instance lactoferrin expression is known to be induced during mastitis (e.g., [140]) and lactoferrin expression increases dramatically after treatment of mammary epithelial cells with bacteria lipopolysaccharides or double stranded RNA through PKC, NF-kappaB, and MAPK pathways [141]. Transcript abundance of LTF is also under control of a specific miRNA (miR-214) [142]. Beta-lactoglobulin in sheep is regulated by the milk protein binding factor (MPBF/Stat5) [143].…”

miR-214: a potential biomarker and therapeutic for different cancers

“…They also noted that downregulation of miR-214 may lead to the development of breast tumors and metastases as the overexpression of miR-214 inhibited both the proliferation and invasion of both MCF7 and MDA-MB-231 cells [34]. Liao et al found that downregulation of endogenous miR-214 activated cellular apoptosis activity in nonmetastatic MCF7 cells [58]. It was also reported that at least one copy of the miR-214 allele was found to be deleted in 24% of all primary breast tumors [34].…”

“…Transfection of HC11 cells with miR-214 mimic downregulated lactoferrin protein expression that reduced the inhibitory action of lactoferrin on tumor progression [58]. miR-214 also inhibited the expression of inhibitor of growth protein 4 (ING4) which is involved in apoptosis, DNA repair and cell cycle arrest through p53 [14,78].…”