title: Overexpressed DNA-binding protein inhibitor 2 as an unfavorable prognosis factor promotes cell proliferation in nasopharyngeal carcinoma.
abstract: The aim of the present study was to analyze the expression of DNA-binding protein inhibitor 2 (ID2) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathological features. It was found that the expression of ID2 was significantly increased in NPC cells when compared with that in NP69 cell line. Similar level of ID2 cytoplasmic expression was observed in NPC when compared with that in non-cancerous nasopharynx tissues. However, the level of ID2 in nucleus was increased in NPC when compared with that in normal nasopharynx tissues. Furthermore, the higher expression level of nuclear ID2 was significantly associated with tumor size (T classification), lymph node metastasis (N classification), and clinical stage. Patients with increased ID2 expression level had poorer overall survival rates than those with low ID2 levels. The inhibition of ID2 expression in NPC cell line SUNE1 by lentiviral-mediated short hairpin RNA could suppress cell proliferation and colony formation, but did not disrupt cell migration. Knocking down the expression of ID2 by RNA interference could down-regulate the expression of Snail, suggesting that ID2-promoted cell growth, partially attributing to the regulation of Snail activity in NPC. Our study demonstrated that over-expression of ID2 protein is an unfavorable prognostic factor which promotes cell proliferation in NPC.
authors.affiliation: Department of Pathology,  Basic School of Guangzhou Medical College, Guangzhou 510182,  China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Weiren
authors.initials: W
authors.lastname: Luo
authors.forename: Huiling
authors.initials: H
authors.lastname: Yang
authors.forename: Aibing
authors.initials: A
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhen
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Yu
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Kaitai
authors.initials: K
authors.lastname: Yao
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Weiyi
authors.initials: W
authors.lastname: Fang
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D002277:Carcinoma; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D051797:Inhibitor of Differentiation Protein 2 / Q000096:biosynthesis*; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D009305:Nasopharynx / Q000378:metabolism; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000096:biosynthesis
chemical_list: D014408:Biomarkers, Tumor; C497450:ID2 protein, human; D051797:Inhibitor of Differentiation Protein 2; D012333:RNA, Messenger; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors