MicroRNA-203 inhibits tumour growth and metastasis through PDPN.

OBJECTIVE: MicroRNAs play an important role in regulating hypopharyngeal cancer development. miR-203 has been previously shown to possess antitumour capabilities in many cancers, but not in hypopharyngeal cancer.

DESIGN: Using human normal and hypopharyngeal cancer specimens, we explored the expression levels of miR-203 in the two groups and further correlated them with different stages of cancer and lymph node metastasis.

SETTING AND PARTICIPANTS: Applying human pharynx FaDu cancer cells and lentiviral transduction technique, we investigated the effects of miR-203 on cancer cell viability, migration and invasion. Moreover, we studied the novel relationship between miR-203 and podoplanin (PDPN) in hypopharyngeal cancer.

RESULTS: The downregulated levels of miR-203 in human hypopharyngeal cancer tissues were associated with advanced cancer stages and lymph node metastasis. High levels of miR-203 inhibited cell viability, migration and invasion of hypopharyngeal cancer cells. Further studies suggested miR-203 directly targeted and inhibited PDPN expression. PDPN silencing suppresses hypopharyngeal cancer cell abilities. In addition, PDPN overexpression was able to reverse miR-203 inhibitory effects on cell viability, migration and invasion.

CONCLUSION: PDPN acts as an oncogene to promote hypopharyngeal cancer cell viability, migration and invasion. miR-203 directly targets PDPN to suppress its expression, thus exerting inhibitory effects on cancer metastasis.