Overexpression of c-erbB-3 in various stages of human squamous cell carcinomas.
Amplification of the c-erbB-3 gene and the expression of its mRNA and protein in human squamous cell carcinomas (SCC) were analyzed. Although no amplification of the c-erbB-3 gene was observed, overexpression of its mRNA was observed in SCC by RT-PCR. The expression of this gene in SCC was 15-50 times higher than in normal fibroblasts. Overexpression of the secreted type of erbB-3 mRNA was also observed in all SCC. Moreover, overproduction of the c-erbB-3 protein was also detected in SCC by dot blot analysis using anti-c-erbB-3 monoclonal antibodies. In nude mice, the expression of c-erbB-3 mRNA was higher in metastatic tumors compared with primary tumors. These results suggest that both the transmembrane and secreted types of c-erbB-3 play a significant role in the formation and development of SCC.
Funayama
T
T
Department of Oral and Maxillofacial Surgery II, Okayama University Dental School, Japan.
Nakanishi
T
T
Takahashi
K
K
Taniguchi
S
S
Takigawa
M
M
Matsumura
T
T
D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D015342:DNA Probes; D004591:Electrophoresis, Polyacrylamide Gel; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction / Q000379:methods; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D020893:Receptor, ErbB-3; D015854:Up-Regulation
D015342:DNA Probes; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D066246:ErbB Receptors; D020893:Receptor, ErbB-3