title: Areca quid chewing enhances the expression of salivary matrix metalloproteinase-9.
abstract: OBJECTIVE
  The effects of areca quid (AQ) consumption on salivary matrix metalloproteinases (MMPs) which may participate in tumor invasion and metastasis remains unclear. This study assessed the change in salivary MMP-9 protein levels 2 hours after 5-minute AQ chewing stimulation (AQCS) in non-AQ users and the expression profile of this proteinase in saliva and tumor specimens of oral squamous cell carcinoma (OSCC) patients with a history of AQ use.
  
  
  METHODS
  MMP-9 transcript was analyzed by reverse transcription-polymerase chain reaction. MMP-9 protein level was measured by both Western blot and gelatin zymography.
  
  
  RESULTS
  The protein level of salivary MMP-9 was 3.1- to 8.9-fold enhanced 2 h after AQCS in 3 healthy volunteers as revealed by Western blot and zymography. As a control, gum chewing did not significantly change salivary MMP-9 protein level. Expression of MMP-9 transcript was found in 25 of 28 OSCC specimens and significantly correlated with cervical lymph node metastasis (p = 0.037). All of the 8 tested OSCC tissue homogenate samples available and all 12 saliva samples from 12 oral tumor outpatients were positive for MMP-9 protein.
  
  
  CONCLUSIONS
  Elevation of MMP-9 may be one of the net effects of AQCS in vivo, which may play a role in the pathogenesis of oral mucosal lesions. Furthermore, the association of MMP-9 expression with neck-lymph-node metastasis may imply a significant role of MMP-9 in the progression of OSCC among patients with a history of AQ use in Taiwan.
authors.affiliation: Oral and Maxillofacial Surgery Section, Chi-Mei Medical Center, Tainan, Taiwan.
authors.forename: Shyun-Yeu
authors.initials: SY
authors.lastname: Liu
authors.forename: Mei-Huei
authors.initials: MH
authors.lastname: Lin
authors.forename: Shun-Chun
authors.initials: SC
authors.lastname: Yang
authors.forename: Guan-Cheng
authors.initials: GC
authors.lastname: Huang
authors.forename: Lisa
authors.initials: L
authors.lastname: Chang
authors.forename: Sam
authors.initials: S
authors.lastname: Chang
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Yen
authors.forename: Wei-Fan
authors.initials: WF
authors.lastname: Chiang
authors.forename: Chin-Hai
authors.initials: CH
authors.lastname: Lee
authors.forename: Yung-Yen
authors.initials: YY
authors.lastname: Kuo
authors.forename: Young-Chau
authors.initials: YC
authors.lastname: Liu
mesh_terms: D001114:Areca / Q000009:adverse effects*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology; D006801:Humans; D008409:Mastication; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D009062:Mouth Neoplasms / Q000201:enzymology; D012469:Salivary Glands / Q000201:enzymology*; D013997:Time Factors
chemical_list: D020780:Matrix Metalloproteinase 9