title: Differential ErbB1 signaling in squamous cell versus basal cell carcinoma of the skin.
abstract: In this study, we examined ErbB1 signaling in human basal and squamous cell carcinomas (BCC and SCC) of the skin in vivo. We used enzyme-linked immunosorbent assay, laser capture microdissection-coupled real-time reverse transcriptase-polymerase chain reaction, and immunohistochemistry to assess expression and activation levels of ErbB1 protein, ligands, and potential downstream effectors, in BCC and SCC tumors, stroma, and adjacent epidermis. Although total ErbB1 protein and mRNA were similar in cancerous and normal skin, we found that ErbB1 activation (phospho-Tyr(1068)) was greater in bulk SCC versus BCC or normal skin. In addition, three ErbB1 ligand transcripts (amphiregulin, heparin-binding epidermal growth factor-like growth factor, and transforming growth factor-alpha) were up-regulated in tumor cells of SCC but not BCC. Expression of these ligands was also increased in asymptomatic epidermis adjacent to both SCC and BCC, relative to normal skin. Interestingly, betacellulin transcript levels were inversely regulated compared with the other ligands. Consistently, downstream ErbB1 effectors (Erk1/2 and Akt) were activated in tumor cells of SCC but not of BCC and in adjacent epidermis of both BCC and SCC. These results demonstrate that ErbB1 signaling is hyperactive in tumor cells of SCC but not of BCC and in nearby asymptomatic epidermis of both tumor types. Our results suggest that targeting ErbB1 signaling might be of benefit in the treatment of SCC.
authors.affiliation: Department of Dermatology, University of Michigan Medical Center, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0932, USA.
authors.forename: Laure
authors.initials: L
authors.lastname: Rittié
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kansra
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Stoll
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Johann E
authors.initials: JE
authors.lastname: Gudjonsson
authors.forename: Yuan
authors.initials: Y
authors.lastname: Shao
authors.forename: Lowell E
authors.initials: LE
authors.lastname: Michael
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Fisher
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Johnson
authors.forename: James T
authors.initials: JT
authors.lastname: Elder
mesh_terms: D066258:Amphiregulin; D000818:Animals; D066259:Betacellulin; D002280:Basal Cell Carcinoma / Q000378:metabolism* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D066255:EGF Family of Proteins; D004789:Enzyme Activation; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism; D066260:Epiregulin; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D012867:Skin / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology; D016211:Transforming Growth Factor alpha / Q000235:genetics / Q000378:metabolism
chemical_list: C587848:AREG protein, human; D066258:Amphiregulin; C587851:BTC protein, human; D066259:Betacellulin; D066255:EGF Family of Proteins; C587880:EREG protein, human; D066260:Epiregulin; D006023:Glycoproteins; C587883:HBEGF protein, human; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases