Evidence for at least three alternative mechanisms targeting the p16INK4A/cyclin D/Rb pathway in penile carcinoma, one of which is mediated by high-risk human papillomavirus.
A comprehensive analysis of 53 penile carcinomas was performed to determine which mechanisms might be involved in the disruption of the p16(INK4A)/cyclin D/Rb pathway. To that end, human papillomavirus (HPV) presence, p16(INK4A) expression and promoter methylation, and expression of the BMI-1 polycomb gene product were studied. Sixteen (30%) of the carcinomas were found to harbour high-risk HPV DNA, 15 of which contained HPV 16. HPV 16 E6/E7 oncogene transcripts were detected in 13 (87%) of the carcinomas that contained HPV 16. Strong immunostaining for p16(INK4A) was significantly more frequent in carcinomas that contained high-risk HPV DNA (p < 0.001) and amongst those with HPV 16 DNA, it was more frequent in lesions in which E6/E7 transcripts were detectable (p = 0.029). This supports an active role for HPV E7 in interfering with the p16(INK4A)/cyclin D/Rb pathway. Methylation of the p16(INK4A) promoter or overexpression of the BMI-1 polycomb gene product may provide alternative modes of interference with this pathway. These phenomena were mutually exclusive and found in the absence of HPV in 15% and 10% of the penile carcinomas, respectively. These data indicate that there are at least three plausible mechanisms by which the p16(INK4A)/cyclin D/Rb pathway can become disrupted during penile carcinogenesis.
Ferreux
Emmanuelle
E
Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands.
Lont
Anne P
AP
Horenblas
Simon
S
Gallee
Maarten P W
MP
Raaphorst
Frank M
FM
von Knebel Doeberitz
Magnus
M
Meijer
Chris J L M
CJ
Snijders
Peter J F
PJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D019175:DNA Methylation; D004279:DNA, Viral / Q000032:analysis; D019942:Genes, p16; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D027383:Papillomaviridae / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000150:complications*; D010412:Penile Neoplasms / Q000378:metabolism* / Q000821:virology; D063150:Polycomb Repressive Complex 1; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012367:RNA, Viral / Q000032:analysis; D012097:Repressor Proteins; D014412:Tumor Virus Infections / Q000150:complications*
C069077:BMI1 protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004279:DNA, Viral; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012367:RNA, Viral; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1