Slug silencing inhibited perineural invasion through regulation of EMMPRIN expression in human salivary adenoid cystic carcinoma.
Salivary adenoid cystic carcinoma (SACC) is the most frequent salivary gland malignancy with a unique characteristic that has been named perineural invasion (PNI). EMMPRIN is a transmembrane glycoprotein that has been demonstrated to promote PNI in SACC. Slug, one of the most effective promoters of the epithelial-to-mesenchymal transition (EMT), has been found to be associated with PNI in SACC. The aim of the present study was to investigate the roles and relationships of Slug, EMMPRIN, and E-cadherin in the PNI process of SACC. The expression levels of Slug, EMMPRIN, and E-cadherin in 115 primary SACC cases were statistically analyzed by immunohistochemistry. Simultaneously, the SACC cell line SACC-83 was transfected with recombinant plasmids of silencing Slug (si-Slug) and/or silencing EMMPRIN (si-EMMPRIN). The functions of Slug and EMMPRIN in the EMT and PNI process were assessed by reverse transcription PCR (RT-PCR), western blotting, morphological observation, scratch test, migration assay, and in vitro perineural invasion assay. The immunohistochemical statistics revealed that the high expression of Slug and EMMPRIN and the low expression of E-cadherin were significantly associated with the PNI of SACC (P < 0.05). Slug expression was significantly associated with EMMPRIN expression (P < 0.05), and Slug expression and EMMPRIN expression were both significantly negatively associated with E-cadherin expression (P < 0.05). Slug and EMMPRIN silencing both significantly inhibited EMMPRIN expression but promoted E-cadherin expression in SACC-83 cells (P < 0.01). The series of in vitro assays revealed that silencing of Slug, EMMPRIN, or both induced cell morphology changes and inhibited tumor cell motility and PNI ability in SACC-83 cells (P < 0.01). These results suggested that Slug silencing could inhibit the EMT process by downregulating EMMPRIN and then upregulating E-cadherin in the PNI process of SACC. The present study indicated that Slug and EMMPRIN are potential biomarkers and therapeutic targets for the diagnosis and treatment of PNI in human SACC.
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, 710032, China.
Baolei
B
Wu
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, 710032, China.
Jianhua
J
Wei
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, 710032, China.
Zhiqiang
Z
Hu
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, 710032, China.
Chun
C
Shan
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, 710032, China.
Lei
L
Wang
Shanghai Key Laboratory of Stomatology, Department of Oral & Maxillofacial-Head & Neck Oncology, School of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200011, China.
Chenping
C
Zhang
Shanghai Key Laboratory of Stomatology, Department of Oral & Maxillofacial-Head & Neck Oncology, School of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200011, China.
Xi
X
Yang
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, 710032, China. yangxinjie@fmmu.edu.cn.
Xinjie
X
Yang
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, No.145 West Changle road, Xi'an, 710032, China. leidelin@fmmu.edu.cn.
Delin
D
Lei
D000328:Adult; D000368:Aged; D015703:Antigens, CD; D051926:Basigin / Q000378:metabolism*; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D003528:Carcinoma, Adenoid Cystic / Q000378:metabolism / Q000473:pathology*; D058750:Epithelial-Mesenchymal Transition / Q000502:physiology; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012468:Salivary Gland Neoplasms / Q000378:metabolism / Q000473:pathology*; D000071250:Snail Family Transcription Factors / Q000378:metabolism*
D015703:Antigens, CD; C497886:BSG protein, human; C513384:CDH1 protein, human; D015820:Cadherins; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D051926:Basigin
EMMPRIN; EMT; Perineural invasion; Salivary adenoid cystic carcinoma; Slug