TY - JOUR
T1 - miR-218 suppresses nasopharyngeal cancer progression through downregulation of survivin and the SLIT2-ROBO1 pathway
AU - Alajez, Nehad M.
AU - Lenarduzzi, Michelle
AU - Ito, Emma
AU - Hui, Angela B.Y.
AU - Shi, Wei
AU - Bruce, Jeff
AU - Yue, Shijun
AU - Huang, Shao H.
AU - Xu, Wei
AU - Waldron, John
AU - O'Sullivan, Brian
AU - Liu, Fei Fei
PY - 2011/3/15
Y1 - 2011/3/15
N2 - Nasopharayngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignancy most common in East Asia and Africa. Here we report frequent downregulation of the microRNA miR-218 in primary NPC tissues and cell lines where it plays a critical role in NPC progression. Suppression of miR-218 was associated with epigenetic silencing of SLIT2 and SLIT3, ligands of ROBO receptors that have been previously implicated in tumor angiogenesis. Exogenous expression of miR-218 caused significant toxicity in NPC cells in vitro and delayed tumor growth in vivo. We used an integrated trimodality approach to identify targets of miR-218 in NPC, cervical, and breast cell lines. Direct interaction between miR-218 and the 3′-untranslated regions (UTR) of mRNAs encoding ROBO1, survivin (BIRC5), and connexin43 (GJA1) was validated in a luciferase-based transcription reporter assay. Mechanistic investigations revealed a negative feedback loop wherein miR-218 regulates NPC cell migration via the SLIT-ROBO pathway. Pleotropic effects of miR-218 on NPC survival and migration were rescued by enforced expression of miR-218-resistant, engineered isoforms of survivin and ROBO1, respectively. In clinical specimens of NPC (n = 71), ROBO1 overexpression was significantly associated with worse overall (P = 0.04, HR = 2.4) and nodal relapse-free survival (P = 0.008, HR = 6.0). Our findings define an integrative tumor suppressor function for miR-218 in NPC and further suggest that restoring miR-218 expression in NPC might be useful for its clinical management.
AB - Nasopharayngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignancy most common in East Asia and Africa. Here we report frequent downregulation of the microRNA miR-218 in primary NPC tissues and cell lines where it plays a critical role in NPC progression. Suppression of miR-218 was associated with epigenetic silencing of SLIT2 and SLIT3, ligands of ROBO receptors that have been previously implicated in tumor angiogenesis. Exogenous expression of miR-218 caused significant toxicity in NPC cells in vitro and delayed tumor growth in vivo. We used an integrated trimodality approach to identify targets of miR-218 in NPC, cervical, and breast cell lines. Direct interaction between miR-218 and the 3′-untranslated regions (UTR) of mRNAs encoding ROBO1, survivin (BIRC5), and connexin43 (GJA1) was validated in a luciferase-based transcription reporter assay. Mechanistic investigations revealed a negative feedback loop wherein miR-218 regulates NPC cell migration via the SLIT-ROBO pathway. Pleotropic effects of miR-218 on NPC survival and migration were rescued by enforced expression of miR-218-resistant, engineered isoforms of survivin and ROBO1, respectively. In clinical specimens of NPC (n = 71), ROBO1 overexpression was significantly associated with worse overall (P = 0.04, HR = 2.4) and nodal relapse-free survival (P = 0.008, HR = 6.0). Our findings define an integrative tumor suppressor function for miR-218 in NPC and further suggest that restoring miR-218 expression in NPC might be useful for its clinical management.
UR - http://www.scopus.com/inward/record.url?scp=79952751773&partnerID=8YFLogxK
U2 - 10.1158/0008-5472.CAN-10-2754
DO - 10.1158/0008-5472.CAN-10-2754
M3 - Article
C2 - 21385904
AN - SCOPUS:79952751773
SN - 0008-5472
VL - 71
SP - 2381
EP - 2391
JO - Cancer Research
JF - Cancer Research
IS - 6
ER -