title: Molecular characterization of salivary gland malignancy using the Smgb-Tag transgenic mouse model.
abstract: The molecular mechanisms underlying salivary gland tumorigenesis remain unclear. In order to identify genetic changes that occur during the development of invasive adenocarcinoma from normal salivary gland, we used the Smgb-Tag transgenic mouse model. This transgene induces the progressive development of dysplasia to invasive adenocarcinoma in the submandibular salivary gland. Gene expression patterns from 20 submandibular glands (two normal, nine dysplasia and nine adenocarcinoma samples) were assessed using a mouse 15 K cDNA array. Unsupervised hierarchical clustering was used to group gene expression based on 157 differentially expressed genes distinguishing between dysplasias and adenocarcinomas. Further analysis identified 25 significantly overexpressed and 28 underexpressed cDNA sequences in adenocarcinoma as compared to dysplasia. Differential expression of five genes (Lcn2, Ptn, Cd24a, Mapk6 and Rnps1) was validated by quantitative real-time RT-PCR in a total of 48 mouse salivary gland tissues (seven histologically normal, 13 dysplasias and 28 adenocarcinomas), including the 20 samples analyzed by cDNA arrays. Immunohistochemical analysis was used to validate the expression of Ptn and Cd24a at the protein level in a subset of 16 mouse salivary glands (four normal, five dysplasia and seven adenocarcinoma samples), as well as in 23 human submandibular gland tumors (16 pleomorphic adenomas, three adenoid cystic carcinomas, one acinic cell carcinoma, one adenocarcinoma NOS, one myoepithelial and one mucoepidermoid carcinoma). We thus demonstrated that the Smgb-Tag transgenic mouse model is a useful tool for the identification of genes that are deregulated in salivary gland adenocarcinomas. Our data suggest that Ptn and Cd24a may be genetic markers associated with salivary gland tumorigenesis and/or progression.
authors.affiliation: Department of Cellular and Molecular Biology, Ontario Cancer Institute and Princess Margaret Hospital, The University Health Network, Toronto, Ontario, Canada.
authors.forename: Antti A
authors.initials: AA
authors.lastname: Mäkitie
authors.forename: Patricia
authors.initials: P
authors.lastname: Pintor Dos Reis
authors.forename: Shilpi
authors.initials: S
authors.lastname: Arora
authors.forename: Christina
authors.initials: C
authors.lastname: Macmillan
authors.forename: Giles C
authors.initials: GC
authors.lastname: Warner
authors.forename: Mahadeo
authors.initials: M
authors.lastname: Sukhai
authors.forename: Irving
authors.initials: I
authors.lastname: Dardick
authors.forename: Bayardo
authors.initials: B
authors.lastname: Perez-Ordonez
authors.forename: Richard
authors.initials: R
authors.lastname: Wells
authors.forename: Dale
authors.initials: D
authors.lastname: Brown
authors.forename: Ralph
authors.initials: R
authors.lastname: Gilbert
authors.forename: Jeremy
authors.initials: J
authors.lastname: Freeman
authors.forename: Patrick
authors.initials: P
authors.lastname: Gullane
authors.forename: Jonathan
authors.initials: J
authors.lastname: Irish
authors.forename: Suzanne
authors.initials: S
authors.lastname: Kamel-Reid
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000818:Animals; D016000:Cluster Analysis; D004195:Disease Models, Animal; D020869:Gene Expression Profiling; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012468:Salivary Gland Neoplasms / Q000145:classification / Q000235:genetics* / Q000473:pathology