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Updated: Jun 8, 2026

RNAscope for In situ Detection of Transcriptionally Active Human Papillomavirus in Head and Neck Squamous Cell Carcinoma
Published on: March 11, 2014
The HPV-16 E7 oncoprotein is expressed mainly from the unspliced E6/E7 transcript in cervical carcinoma C33-A cells
Oscar del Moral-Hernández1, Eduardo López-Urrutia, Raúl Bonilla-Moreno
1Unidad Zacatenco, Depto. Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados-IPN (CINVESTAV-IPN), Av. IPN # 2508, Zacatenco, Apdo. Postal 14-740, 07360, Mexico, D.F., Mexico.
Abstract:
The HPV-16 E6/E7 early transcripts are first produced as bicistronic or polycistronic mRNAs, and about 90% of the original pre-mRNA is spliced to produce three new alternative mRNAs. HPV-16 spliced transcripts are expressed heterogeneously in tumors and cell lines. Our results suggest that suboptimal splicing acceptor sites in E6/E7 intron 1 and the differential expression of splicing factors are involved in the production of the heterogeneous splicing profile in cell lines. The unspliced pre-mRNA and the alternative spliced transcripts contribute differentially to the production of E7 in stably transfected C33-A cells. The highest level of E7 was produced from the least prevalent transcript, the unspliced E6/E7(pre-mRNA). The order of relative expression of E7 was unspliced E6/E7(pre-mRNA) > E6*I/E7 > E6*II/E7. Our findings suggest that E6/E7 alternative splicing may be a mechanism for differential expression of the E6 and E7 oncoproteins, which also affects the expression of their targets, the proteins p53 and pRb.
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