title: MTA1 Expression in Benign and Malignant Salivary gland Tumors.
abstract: BACKGROUND
  Salivary gland tumors (SGTs) are important parts of human neoplasms. The most common SGT is pleomorphic adenoma and the most common malignant SGTs are mucoepidermoid carcinoma and adenoid cystic carcinoma (ACC). Metastasis-associated genes 1 (MTA1), a member of the nucleosome remodeling and histone deacetylation complex, is one newly discovered gene which recruits histone deacetylation, causing ATP-dependent chromosome remodeling, and regulating transcription. MTA1 had been shown to be overexpressed in malignant tumors with the enhancement of invasion and metastasis.
  
  
  METHODS
  Fifty-six samples of salivary gland tumors from the Khalili Hospital archive, including 20 cases of pleomorphic adenoma, 17 cases of mucoepidermoid carcinoma, 19 cases of ACC, and 23 cases of normal salivary gland tissues were chosen for immunohistochemical analysis of MTA1.
  
  
  RESULTS
  MTA1 expression in the malignant tumors was significantly higher than that in pleomorphic adenoma (P<0.001), and higher in pleomorphic adenoma than the normal salivary glands(P< 0.001). In total, 69.6% of normal salivary gland tissues showed MTA1, but all cases of salivary gland tumors were positive for MTA1. High nuclear expression of MTA1 was detected in 83.3% (30/36) of the malignant salivary gland tumors and 45% (9/20) of pleomorphic adenoma, while low MTA1 expression was seen in all of the normal salivary gland tissues. No statistically significant correlation was found between MTA1 protein expression and any clinicopathological features (P>0.05).
  
  
  CONCLUSIONS
  Our findings demonstrate that MTA1 was significantly overexpressed in malignant salivary gland neoplasm in comparison to a lower level in benign pleomorphic adenoma, suggesting that MTA1 protein might be involved in carcinogenesis.
authors.affiliation: Prevention of Oral and Dental Disease Research Center, Department of Oral and Maxillofacial Pathology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Andisheh-Tadbir
authors.affiliation: Department of Oral and Maxillofacial Pathology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Dehghani-Nazhvani
authors.affiliation: Department of Pathology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Mohammad Javad
authors.initials: MJ
authors.lastname: Ashraf
authors.affiliation: Department of Otorhinolaryngology, Khalili Hospital, Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Bijan
authors.initials: B
authors.lastname: Khademi
authors.affiliation: Department of Endodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Hosein
authors.initials: H
authors.lastname: Mirhadi
authors.affiliation: Department of Oral and Maxillofacial Pathology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Shima
authors.initials: S
authors.lastname: Torabi-Ardekani
keywords: Adenoid cystic carcinoma; MTA; Mucoepidermoid carcinoma; Pleomorphic adenoma.; Salivary gland tumor