title: Proteome-wide analysis of head and neck squamous cell carcinomas using laser-capture microdissection and tandem mass spectrometry.
abstract: Remarkable progress has been made to identify genes expressed in squamous cell carcinomas of the head and neck (HNSCC). However, limited information is available on their corresponding protein products, whose expression, post-translational modifications, and activity are ultimately responsible for the malignant behavior of this tumor type. We have combined laser-capture microdissection (LCM) with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify proteins expressed in histologically normal squamous epithelium and matching SCC. The protein fraction from approximately 10,000-15,000 normal and tumor cells was solubilized, digested with trypsin, and the resulting peptides were analyzed by LC-MS/MS. Database searching of the resulting sequence information identified 30-55 proteins per sample. Keratins were the most abundant proteins in both normal and tumor tissues. Among the proteins differentially expressed, keratin 13 was much lower in tumors, whereas heat-shock (Hsp) family members were highly expressed in neoplastic cells. Wnt-6 and Wnt-14 were identified in both normal and tumor tissues, respectively, and placental growth factor (PIGF) was detected only in tumors. Immunohistochemical analysis of HNSCC tissues revealed lack of keratin 13 in tumor tissues, and strong staining in normal epithelia, and high expression of Hsp90 in tumors. Our study, by combining LCM and proteomic technologies, underscores the advantages of this approach to investigate complex changes at the protein level in HNSCC, thus complementing existing and emerging genomic technologies. These efforts may likely result in the identification of new biomarkers for HNSCC that can be used to diagnose disease, predict susceptibility, and monitor progression in individual patients.
authors.affiliation: Chemistry and Chemical Biology Department, Barnett Institute, Northeastern University, 341 Mugar Building, 360 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: Haven
authors.initials: H
authors.lastname: Baker
authors.forename: Vyomesh
authors.initials: V
authors.lastname: Patel
authors.forename: Alfredo A
authors.initials: AA
authors.lastname: Molinolo
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Shillitoe
authors.forename: John F
authors.initials: JF
authors.lastname: Ensley
authors.forename: George H
authors.initials: GH
authors.lastname: Yoo
authors.forename: Abelardo
authors.initials: A
authors.lastname: Meneses-García
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Myers
authors.forename: Adel K
authors.initials: AK
authors.lastname: El-Naggar
authors.forename: J S
authors.initials: JS
authors.lastname: Gutkind
authors.forename: William S
authors.initials: WS
authors.lastname: Hancock
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002853:Chromatography, Liquid / Q000379:methods; D006258:Head and Neck Neoplasms / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007834:Lasers; D008297:Male; D042282:Microdissection / Q000379:methods; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D040081:Protein Array Analysis / Q000379:methods; D020543:Proteome / Q000032:analysis / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D009363:Neoplasm Proteins; D020543:Proteome