miR156a Mimic Represses the Epithelial-Mesenchymal Transition of Human Nasopharyngeal Cancer Cells by Targeting Junctional Adhesion Molecule A.

MicroRNAs (miRNAs) have been documented as having an important role in the development of cancer. Broccoli is very popular in large groups of the population and has anticancer properties. Junctional adhesion molecule A (JAMA) is preferentially concentrated at tight junctions and influences cell morphology and migration. Epithelial-mesenchymal transition (EMT) is a developmental program associated with cancer progression and metastasis. In this study we aimed to investigate the role of miRNAs from broccoli in human nasopharyngeal cancer (NPC). We demonstrated that a total of 84 conserved miRNAs and 184 putative novel miRNAs were found in broccoli by sequencing technology. Among these, miR156a was expressed the most. In addition, synthetic miR156a mimic inhibited the EMT of NPC cells in vitro. Furthermore, it was confirmed that JAMA was the target of miR156a mimic as validated by 3' UTR luciferase reporter assays and western blotting. Knockdown of JAMA was consistent with the effects of miR156a mimic on the EMT of NPC, and the up-regulation of JAMA could partially restore EMT repressed by miR156a mimic. In conclusion, these results indicate that the miR156a mimic inhibits the EMT of NPC cells by targeting the 3' UTR of JAMA. These miRNA profiles of broccoli provide a fundamental basis for further research. Moreover, the discovery of miR156a may have clinical implications for the treatment of patients with NPC

Broccoli miR156a mimic represses the EMT phenotype of NPC cells <i>in vitro</i>.

<p>Cells are harvested 24 hours after transfection. (A) The invasive properties of the CNE2 (A), HONE1 (B) and C666-1 (C) cells were measured by transwell and Boyden chamber assays. A wound-healing assay of CNE2 (D) and HONE1 (E) cells was performed. The total distance migrated by wounded cells is expressed as a percentage of the initial distance (F). (C) The expressions of epithelial (E-cadherin and α-catenin) and mesenchymal markers (vimentin and Fibronectin) in CNE2 (G) and C666-1 (H) were measured by western blotting. Data are presented as mean ± SD (n = 3). Significant differences between the negative controls and miRNA156a mimics indicated by *<i>P</i> < 0.05 and **<i>P</i> < 0.01.</p

Conserved miRNAs and their read counts in the broccoli library.

<p>Conserved miRNAs and their read counts in the broccoli library.</p

JAMA is essential for miR156a mimic-induced EMT of NPC cells and is involved in the activation of p-Akt <i>in vitro</i>.

<p>(A and B) Analysis of protein expression by western blotting, JAMA and p-Akt protein is reduced by miR156a mimic. (C) JAMA, vimentin and p-Akt are reduced by small interfering RNA (JAMA-siRNA) in CNE2 (C) and HONE1 cells (D). (E) Western blotting assay analyzed CNE2 cells transfected with the JAMA plasmid or vector control, along with miR156a or negative controls.</p