title: MicroRNA-144 promotes cell proliferation, migration and invasion in nasopharyngeal carcinoma through repression of PTEN.
abstract: Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer with significantly high prevalence in Southern China. Unlike other head and neck cancers, mutations or deletions of tumor suppressor genes in NPC are not common. Recently, downregulation of tumor suppressor genes expression by microRNA (miRNA) is increasingly recognized as an important mechanism of nasopharyngeal tumorigenesis. In this study, we reported that microRNA-144 (miR-144) was frequently upregulated in NPC specimens and cell lines. Repression of miR-144 significantly decreased cell proliferation, clonogenicity, migration, invasion and tumor formation in nude mice, while restoring miR-144 in miR-144-attenuated NPC cells exhibited a strong tumorigenic role. Further, we found that miR-144 was inversely correlated with the tumor suppressor gene phosphatase and tensin homolog (PTEN) in NPC specimens and cell lines, and then we identified PTEN as a direct target of miR-144 in NPC cell lines. PTEN downregulation in miR-144-attenuated cells could increase cell growth, migration and invasion. Mechanistic investigations revealed that miR-144 suppressed the expression of PTEN to increase the expression of pAkt and cyclin D1 to promote G(1)-phase transition and decrease E-cadherin to promote migration and invasion. Taken together, we provide compelling evidence that miR-144 functions as an onco-miRNA in NPC, and its oncoeffects are mediated chiefly by repressing PTEN expression to activate the PI3K/Akt pathway.
authors.affiliation: Department of Clinical Oncology, The University of Hong Kong,  Pokfulam, Hong Kong, China.
authors.forename: Li-Yi
authors.initials: LY
authors.lastname: Zhang
authors.forename: Victor
authors.initials: V
authors.lastname: Ho-Fun Lee
authors.forename: Alissa Michelle Go
authors.initials: AM
authors.lastname: Wong
authors.forename: Dora Lai-Wan
authors.initials: DL
authors.lastname: Kwong
authors.forename: Ying-Hui
authors.initials: YH
authors.lastname: Zhu
authors.forename: Sui-Sui
authors.initials: SS
authors.lastname: Dong
authors.forename: Kar-Lok
authors.initials: KL
authors.lastname: Kong
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.forename: Sai-Wah
authors.initials: SW
authors.lastname: Tsao
authors.forename: Xin-Yuan
authors.initials: XY
authors.lastname: Guan
authors.forename: Li
authors.initials: L
authors.lastname: Fu
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D002277:Carcinoma; D016022:Case-Control Studies; D002448:Cell Adhesion; D002453:Cell Cycle; D002465:Cell Movement; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000473:pathology*; D009305:Nasopharynx / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D051059:PTEN Phosphohydrolase / Q000037:antagonists & inhibitors* / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: C554293:MIRN144 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human