MiR-34a suppresses amphiregulin and tumor metastatic potential of head and neck squamous cell carcinoma (HNSCC)

// Jiali Zhang 1, 2, * , Yu Wang 1, 2 * , Xinming Chen 1, 2 , Yi Zhou 1 , Fangyan Jiang 1 , Jirong Chen 1 , Li Wang 1 , Wen-Feng Zhang 1 1 The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei_MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China 2 Oral Histopathology Department, School and Hospital of Stomatology, Wuhan University, Wuhan, China * These authors have contributed equally to this work Correspondence to: Jiali Zhang, e-mail: jiali_zhang97@163.com Xinming Chen, e-mail: xmchen3011@163.com Wen-Feng Zhang, e-mail: zhangwf59@163.com Keywords: Head and neck squamous cell carcinoma, miR-34a, amphiregulin, metastasis Received: August 11, 2014      Accepted: January 16, 2015      Published: February 05, 2015 ABSTRACT MiR-34a is a well-known tumor metastasis inhibitor, but only a few target genes involved in metastasis have been identified. In HNSCC, the role of miR-34a in metastasis has not been fully elaborated, and the target gene of miR-34a is still blind. Here we addressed that, the relative lower expression of miR-34a is associated with HNSCC lymphatic metastasis. HNSCC metastasis was found to be strongly suppressed in vitro and in vivo by over-expressing miR-34a. In order to screen the possible target genes of miR-34a in HNSCC, a microarray-based differential mRNA profiling mediated by miR-34a over-expression was performed, and AREG was identified as a pivotal target. We demonstrated that the mRNA and protein levels of AREG were greatly reduced when forcing miR-34a expression. The correlation between AREG mRNA levels and HNSCC metastatic phenotype was also significant in HNSCC tissues ( p < 0.01). Moreover, the results of luciferase assay provided the further evidence that miR-34a degraded AREG mRNA through targeting the 3’-UTR site. Restoration of AREG expression partially rescued miR-34a-mediated cell invasion defects in vivo and in vitro . Additionally, Over-expressing miR-34a greatly reduced EGFR and uPA, which were reversed by re-expression of AREG. Taken together, these findings indicate that miR-34a targets AREG, and is essential in inhibition of HNSCC metastasis.