Identification of cellular targets for the human papillomavirus E6 and E7 oncogenes by RNA interference and transcriptome analyses.
Specific types of human papillomaviruses (HPVs) cause cervical cancer, the second most common tumor in women worldwide. Both cellular transformation and the maintenance of the oncogenic phenotype of HPV-positive tumor cells are linked to the expression of the viral E6 and E7 oncogenes. To identify downstream cellular target genes for the viral oncogenes, we silenced endogenous E6 and E7 expression in HPV-positive HeLa cells by RNA interference (RNAi). Subsequently, we assessed changes of the cellular transcriptome by genome-wide microarray analysis. We identified 648 genes, which were either downregulated (360 genes) or upregulated (288 genes), upon inhibition of E6/E7 expression. A large fraction of these genes is involved in tumor-relevant processes, such as apoptosis control, cell cycle regulation, or spindle formation. Others may represent novel cellular targets for the HPV oncogenes, such as a large group of C-MYC-associated genes involved in RNA processing and splicing. Comparison with published microarray data revealed a substantial concordance between the genes repressed by RNAi-mediated E6/E7 silencing in HeLa cells and genes reported to be upregulated in HPV-positive cervical cancer biopsies.
Kuner
Ruprecht
R
Molecular Genome Analysis, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany.
Vogt
Markus
M
Sultmann
Holger
H
Buness
Andreas
A
Dymalla
Susanne
S
Bulkescher
Julia
J
Fellmann
Mark
M
Butz
Karin
K
Poustka
Annemarie
A
Hoppe-Seyler
Felix
F
D002453:Cell Cycle / Q000187:drug effects; D016000:Cluster Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D015967:Gene Expression Regulation, Viral / Q000187:drug effects; D053263:Gene Regulatory Networks; D006367:HeLa Cells; D052161:Human papillomavirus 18 / Q000235:genetics*; D006801:Humans; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D034622:RNA Interference; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects; D034741:RNA, Small Interfering / Q000494:pharmacology; D012097:Repressor Proteins / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000821:virology
D004268:DNA-Binding Proteins; C052603:E6 protein, Human papillomavirus type 18; C052633:E7 protein, Human papillomavirus type 18; D009856:Oncogene Proteins, Viral; D034741:RNA, Small Interfering; D012097:Repressor Proteins