Overexpression of the human homologue of Drosophila patched (PTCH) in skin tumours: specificity for basal cell carcinoma.
The human homologue of the Drosophila segment polarity gene patched (PTCH) has been identified as the gene for the naevoid basal cell carcinoma (BCC) syndrome and has also been shown to be mutated in sporadic BCC. In order to elucidate the specificity of the PTCH abnormality in BCC, we examined normal skin and 12 BCC and 24 other types of tumour from Japanese patients for expression of the PTCH transcript by competitive reverse transcription-polymerase chain reaction, as mutational inactivation of PTCH leads to overexpression of the mutant transcript owing to failure of a negative feedback mechanism. We found a high level of PTCH expression in all 12 BCCs, while 23 of the other tumours and four specimens of normal skin showed no or weak expression of the gene, with the exception of one specimen from a patient with Bowen's disease which had high expression. These results indicate that the PTCH abnormality plays a critical role in the pathogenesis of BCC.
Nagano
T
T
Department of Dermatology, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Bito
T
T
Kallassy
M
M
Nakazawa
H
H
Ichihashi
M
M
Ueda
M
M
D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000235:genetics / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D029721:Drosophila Proteins; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics; D011956:Receptors, Cell Surface; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism
D029721:Drosophila Proteins; D019476:Insect Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011956:Receptors, Cell Surface; C070844:ptc protein, Drosophila