title: Expression of RECK and matrix metalloproteinase-2 in ameloblastoma.
abstract: BACKGROUND
  Ameloblastoma is a frequent odontogenic benign tumor characterized by local invasiveness, high risk of recurrence and occasional metastasis and malignant transformation. Matrix metalloproteinase-2 (MMP-2) promotes tumor invasion and progression by destroying the extracellular matrix (ECM) and basement membrane. For this proteolytic activity, the endogenous inhibitor is reversion-inducing cysteine rich protein with Kazal motifs (RECK). The aim of this study was to characterize the relationship between RECK and MMP-2 expression and the clinical manifestation of ameloblastoma.
  
  
  METHODS
  Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were employed to detect the protein and mRNA expression of RECK and MMP-2 in keratocystic odontogenic tumor (KCOT), ameloblastoma and ameloblastic carcinoma.
  
  
  RESULTS
  RECK protein expression was significantly reduced in KCOT (87.5%), ameloblastoma (56.5%) and ameloblastic carcinoma (0%) (P < 0.01), and was significantly lower in recurrent ameloblastoma compared with primary ameloblastoma (P < 0.01), but did not differ by histological type of ameloblastoma. MMP-2 protein expression was significantly higher in ameloblastoma and ameloblastic carcinoma compared with KCOT (P < 0.01). RECK mRNA expression was significantly lower in ameloblastoma than in KCOT (P < 0.01), lower in recurrent ameloblastoma than in primary ameloblastoma, and was negative in ameloblastic carcinoma. MMP-2 mRNA expression was significantly higher in ameloblastoma compared with KCOT (P < 0.01), but was no different in recurrent ameloblastoma versus primary ameloblastoma. RECK protein expression was negatively associated with MMP-2 protein expression in ameloblastoma (r = -0.431, P < 0.01).
  
  
  CONCLUSIONS
  Low or no RECK expression and increased MMP-2 expression may be associated with negative clinical findings in ameloblastoma. RECK may participate in the invasion, recurrence and malignant transformation of ameloblastoma by regulating MMP-2 at the post-transcriptional level.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Second Affiliated Hospital, Sun Yat-Sen University, 107 Yanjiang Road West, Guangzhou, Guangdong, 510120, PR China. zhangbingz2007@hotmail.com
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.forename: Zhi-Ying
authors.initials: ZY
authors.lastname: Xu
authors.forename: Hong-Liang
authors.initials: HL
authors.lastname: Xie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000564:Ameloblastoma / Q000378:metabolism* / Q000473:pathology; D002648:Child; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D007150:Immunohistochemistry; D007573:Jaw Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis*; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; C115460:RECK protein, human; D012333:RNA, Messenger; D020778:Matrix Metalloproteinase 2