Analysis of c-erbB-2 amplification in salivary gland tumours by differential polymerase chain reaction.
DNA samples extracted from 22 normal salivary glands, 38 salivary pleomorphic adenomas and 20 other salivary gland neoplasms were screened for amplification of the c-erbB-2 oncogene by a differential polymerase chain reaction (PCR). The samples were PCR amplified with primers specific for the c-erbB-2 oncogene and for a reference gene (interferon-gamma). A breast carcinoma cell line SKBR-3 known to contain c-erbB-2 amplification was used as positive control. Following gel electrophoresis, the intensity of the amplified DNA bands was determined by laser densitometry and the level of amplification of the c-erbB-2 oncogene was assessed from the intensity of the c-erbB-2 specific band relative to that of the interferon-gamma band. Of all the tumours detected, only the two poorly differentiated adenocarcinomas, two of the pleomorphic adenomas and one of the Warthin's tumours showed gene amplification at levels comparable to the breast carcinoma cell line. None of the normal salivary gland tissues was found to have amplification. Within the group of pleomorphic adenomas the average level of amplification was not significantly different from that observed in the normal salivary gland, or in total genomic DNA from unrelated tissue (P < or = 0.001, determined by a general linear model of statistical analysis). These results indicate that amplification of the c-erbB-2 oncogene is infrequent in salivary neoplasia. Thus, gene amplification alone cannot account for the high prevalence of c-erbB-2 overexpression demonstrated previously in salivary gland tumours. When present, c-erbB-2 amplification may be associated with a more aggressive behaviour.
Birek
C
C
Faculty of Dentistry, Toronto, Ontario, Canada.
Lui
E
E
Jordan
R C
RC
Dardick
I
I
D000236:Adenoma / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D001943:Breast Neoplasms; D002460:Cell Line; D004247:DNA / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D018734:Genes, erbB-2; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D012016:Reference Values; D012468:Salivary Gland Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D012469:Salivary Glands / Q000166:cytology / Q000473:pathology
D004247:DNA; D004273:DNA, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases