title: Parathyroid hormone-related protein serves as a prognostic indicator in oral squamous cell carcinoma.
abstract: BACKGROUND
  In our previous study, parathyroid hormone-like hormone (PTHLH) which encodes parathyroid hormone-related protein (PTHrP) was revealed to be up-regulated in oral squamous cell carcinoma (OSCC) compared with paired apparently normal surgical margins using microarray method. However, the function and prognostic indicators of PTHLH/PTHrP in OSCC remain obscure.
  
  
  METHODS
  The mRNA levels of PTHLH and its protein levels were investigated in 9 OSCC cell lines and in 36 paired OSCC specimens by real-time PCR and western blotting. The biological function of PTHLH/PTHrP was investigated using small interfering RNA (siRNA) in 3 OSCC cell lines, and immunohistochemistry was used to estimate the prognostic value of PTHrP in 101 patients with head and neck squamous cell carcinoma (HNSCC), including OSCC and oropharyngeal squamous cell carcinoma. Cell cycle was tested by flow cytometry and cell cycle related genes were investigated by western blotting and immunocytochemistry assay.
  
  
  RESULTS
  This study showed that the mRNA and protein levels of PTHLH in 9 OSCC cell lines were much higher than that in normal epithelial cells (P < 0.0001). In 36 paired OSCC tissues, PTHLH mRNA expressions were found higher in 32 OSCC tissues than that of paired apparently normal surgical margins (P = 0.0001). The results revealed that the down-regulation of PTHLH/PTHrP by siRNAs could reduce cell proliferation and inhibit plate and soft agar colony formation as well as affect the cell cycle of OSCC cells. The key proteins related to the cell cycle were changed by anti-PTHLH siRNA. The results showed that cyclin D1 and CDK4 expressions were significantly reduced in the cells transfected with anti-PTHLH siRNA. On the other hand, the expression of p21 was increased. The results also showed that high PTHrP level was associated with poor pathologic differentiation (P = 0.0001) and poor prognosis (P = 0.0003) in patients with HNSCC.
  
  
  CONCLUSIONS
  This study suggests that PTHLH/PTHrP is up-regulated in OSCCs. Therefore, PTHLH/PTHrP could play a role in the pathogenesis of OSCC by affecting cell proliferation and cell cycle, and the protein levels of PTHrP might serve as a prognostic indicator for evaluating patients with HNSCCs.
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. zhongjing_lv2012@163.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. zhongjing_lv2012@163.com.
authors.forename: Zhongjing
authors.initials: Z
authors.lastname: Lv
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. wuxiangbing2007@163.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. wuxiangbing2007@163.com.
authors.forename: Xiangbing
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. caowei561521@hotmail.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. caowei561521@hotmail.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Cao
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. johnnyshen7603@163.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. johnnyshen7603@163.com.
authors.forename: ZongZe
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. lizhenwang535@hotmail.com.|Department of Oral Pathology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. lizhenwang535@hotmail.com.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. xfr1988@163.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. xfr1988@163.com.
authors.forename: FuRong
authors.initials: F
authors.lastname: Xie
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. zjjshuobo@163.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. zjjshuobo@163.com.
authors.forename: JianJun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. jitong70@hotmail.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. jitong70@hotmail.com.
authors.forename: Tong
authors.initials: T
authors.lastname: Ji
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. yanming8012@126.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. yanming8012@126.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. chenwantao2002@hotmail.com.|Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China. chenwantao2002@hotmail.com.
authors.forename: WanTao
authors.initials: W
authors.lastname: Chen
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D009959:Oropharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D044162:Parathyroid Hormone-Related Protein / Q000235:genetics / Q000378:metabolism*; D011379:Prognosis; D016016:Proportional Hazards Models; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D000077195:Squamous Cell Carcinoma of Head and Neck; D013997:Time Factors; D014162:Transfection
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; C470121:PTHLH protein, human; D044162:Parathyroid Hormone-Related Protein; D012333:RNA, Messenger