Markus Schmitt1, Michael Pawlita. 1. Department of Genome Modifications and Carcinogenesis (F020), Research Program Infection and Cancer, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. markus.schmitt@dkfz.de
Abstract
BACKGROUND: Infections with high-risk human papillomaviruses (HPV), mainly HPV type 16, can cause malignant transformation of the human cervical epithelium and cervical cancer (CxCa). Very little is known about the quantitative expression of the various HPV16 transcripts in frequently used cervical cancer cell lines. METHODS: We have quantitatively analysed the viral transcriptome in the HPV16-transformed cell lines SiHa, CaSki, MRI-H196, MRI-H186, HPK-IA and C3. We used a nucleic acid sequence-based amplification (NASBA)-Luminex hybridisation assay quantifying spliced and unspliced HPV16 transcripts. RESULTS: The cell lines differed in their qualitative and quantitative expression of viral transcripts depending on the physical HPV genome status. In SiHa, we found no transcripts containing the splice acceptor at nucleotide 3358 or downstream sequences. In CaSki cells virtually all viral transcripts were detected but with a reduced quantity of late transcripts. We further found that the tumorigenic phenotype of late passage HPK-IA cells may not be mediated through changes in HPV expression. In MRI-H186, HPK-IA and C3 cells very high levels of full-length early transcripts ending at the early polyadenylation signal were found. MRI-H196 expressed L1 full-length (fl) but no E5 fl RNA suggesting the presence of integrated HPV16 genomes with a disrupted E2 region and rearranged L1 DNA sequence. CONCLUSION: Quantitative expression changes of HPV16 transcript markers correlate with the physical state of the HPV genome in HPV16 positive cervical cancer cell lines.
BACKGROUND: Infections with high-risk human papillomaviruses (HPV), mainly HPV type 16, can cause malignant transformation of the human cervical epithelium and cervical cancer (CxCa). Very little is known about the quantitative expression of the various HPV16 transcripts in frequently used cervical cancer cell lines. METHODS: We have quantitatively analysed the viral transcriptome in the HPV16-transformed cell lines SiHa, CaSki, MRI-H196, MRI-H186, HPK-IA and C3. We used a nucleic acid sequence-based amplification (NASBA)-Luminex hybridisation assay quantifying spliced and unspliced HPV16 transcripts. RESULTS: The cell lines differed in their qualitative and quantitative expression of viral transcripts depending on the physical HPV genome status. In SiHa, we found no transcripts containing the splice acceptor at nucleotide 3358 or downstream sequences. In CaSki cells virtually all viral transcripts were detected but with a reduced quantity of late transcripts. We further found that the tumorigenic phenotype of late passage HPK-IA cells may not be mediated through changes in HPV expression. In MRI-H186, HPK-IA and C3 cells very high levels of full-length early transcripts ending at the early polyadenylation signal were found. MRI-H196 expressed L1 full-length (fl) but no E5 fl RNA suggesting the presence of integrated HPV16 genomes with a disrupted E2 region and rearranged L1 DNA sequence. CONCLUSION: Quantitative expression changes of HPV16 transcript markers correlate with the physical state of the HPV genome in HPV16 positive cervical cancer cell lines.
Authors: Gordana Halec; Markus Schmitt; Sam Egger; Christian C Abnet; Chantal Babb; Sanford M Dawsey; Christa Flechtenmacher; Tarik Gheit; Martin Hale; Dana Holzinger; Reza Malekzadeh; Philip R Taylor; Massimo Tommasino; Margaret I Urban; Tim Waterboer; Michael Pawlita; Freddy Sitas Journal: Int J Cancer Date: 2016-01-21 Impact factor: 7.396