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Differences in Transcriptional Activity of Human Papillomavirus Type 6 Molecular Variants in Recurrent Respiratory Papillomatosis.

Measso do Bonfim C, Simão Sobrinho J, Lacerda Nogueira R, Salgado Kupper D, Cardoso Pereira Valera F, Lacerda Nogueira M, Villa LL, Rahal P, Sichero L - PLoS ONE (2015)

Bottom Line: Furthermore, our results support a crucial role for ELF1 on transcriptional downregulation.We identified TFs implicated in the regulation of HPV-6 early gene expression.Many of these factors are mutated in cancer or are putative cancer biomarkers, and must be further studied.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Genomic Studies, Universidade do Estado de São Paulo, UNESP, São José do Rio Preto, SP, Brazil.

ABSTRACT
A significant proportion of recurrent respiratory papillomatosis (RRP) is caused by human papillomavirus type 6 (HPV-6). The long control region (LCR) contains cis-elements for regulation of transcription. Our aim was to characterize LCR HPV-6 variants in RRP cases, compare promoter activity of these isolates and search for cellular transcription factors (TFs) that could explain the differences observed. The complete LCR from 13 RRP was analyzed. Transcriptional activity of 5 variants was compared using luciferase assays. Differences in putative TFs binding sites among variants were revealed using the TRANSFAC database. Chromatin immunoprecipation (CHIP) and luciferase assays were used to evaluate TF binding and impact upon transcription, respectively. Juvenile-onset RRP cases harbored exclusively HPV-6vc related variants, whereas among adult-onset cases HPV-6a variants were more prevalent. The HPV-6vc reference was more transcriptionally active than the HPV-6a reference. Active FOXA1, ELF1 and GATA1 binding sites overlap variable nucleotide positions among isolates and influenced LCR activity. Furthermore, our results support a crucial role for ELF1 on transcriptional downregulation. We identified TFs implicated in the regulation of HPV-6 early gene expression. Many of these factors are mutated in cancer or are putative cancer biomarkers, and must be further studied.

No MeSH data available.


Related in: MedlinePlus

Binding and activity of ELF1 and FOXA1 to HPV-6vc-ref and HPV-6vc-var1.Luciferase reporter assay for (A) ELF1 and (B) FOXA1. (C) Amplification of LCR fragments following chromatin immunoprecipitation (ChIP) using primers surrounding nucleotide position 7626 that differs among HPV-vc-ref and HPV-6vc-var1 variants. Input-nonimmunoprecipated samples.
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pone.0132325.g003: Binding and activity of ELF1 and FOXA1 to HPV-6vc-ref and HPV-6vc-var1.Luciferase reporter assay for (A) ELF1 and (B) FOXA1. (C) Amplification of LCR fragments following chromatin immunoprecipitation (ChIP) using primers surrounding nucleotide position 7626 that differs among HPV-vc-ref and HPV-6vc-var1 variants. Input-nonimmunoprecipated samples.

Mentions: Divergence in nucleotide position 7626 (T→G) between HPV-6vc-ref and HPV-6vc-var1 results in the replacement of a putative ELF1 for a FOXA1 binding site as suggested by computational analysis (Fig 1B). ELF1 inhibited transcription activity of both isolates in a similar manner (Fig 2A). Although FOXA1 significantly transactivated HPV-6vc-ref, enhancement of transcription was much stronger for the HPV-6vc-var1 isolate. Interestingly, both FOXA1 and ELF1 were shown to bind solely to the HPV-6vc-var1 LCR; no binding of both protein to the HPV-6vc-ref was detected by ChIP (Fig 3B).


Differences in Transcriptional Activity of Human Papillomavirus Type 6 Molecular Variants in Recurrent Respiratory Papillomatosis.

Measso do Bonfim C, Simão Sobrinho J, Lacerda Nogueira R, Salgado Kupper D, Cardoso Pereira Valera F, Lacerda Nogueira M, Villa LL, Rahal P, Sichero L - PLoS ONE (2015)

Binding and activity of ELF1 and FOXA1 to HPV-6vc-ref and HPV-6vc-var1.Luciferase reporter assay for (A) ELF1 and (B) FOXA1. (C) Amplification of LCR fragments following chromatin immunoprecipitation (ChIP) using primers surrounding nucleotide position 7626 that differs among HPV-vc-ref and HPV-6vc-var1 variants. Input-nonimmunoprecipated samples.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494706&req=5

pone.0132325.g003: Binding and activity of ELF1 and FOXA1 to HPV-6vc-ref and HPV-6vc-var1.Luciferase reporter assay for (A) ELF1 and (B) FOXA1. (C) Amplification of LCR fragments following chromatin immunoprecipitation (ChIP) using primers surrounding nucleotide position 7626 that differs among HPV-vc-ref and HPV-6vc-var1 variants. Input-nonimmunoprecipated samples.
Mentions: Divergence in nucleotide position 7626 (T→G) between HPV-6vc-ref and HPV-6vc-var1 results in the replacement of a putative ELF1 for a FOXA1 binding site as suggested by computational analysis (Fig 1B). ELF1 inhibited transcription activity of both isolates in a similar manner (Fig 2A). Although FOXA1 significantly transactivated HPV-6vc-ref, enhancement of transcription was much stronger for the HPV-6vc-var1 isolate. Interestingly, both FOXA1 and ELF1 were shown to bind solely to the HPV-6vc-var1 LCR; no binding of both protein to the HPV-6vc-ref was detected by ChIP (Fig 3B).

Bottom Line: Furthermore, our results support a crucial role for ELF1 on transcriptional downregulation.We identified TFs implicated in the regulation of HPV-6 early gene expression.Many of these factors are mutated in cancer or are putative cancer biomarkers, and must be further studied.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Genomic Studies, Universidade do Estado de São Paulo, UNESP, São José do Rio Preto, SP, Brazil.

ABSTRACT
A significant proportion of recurrent respiratory papillomatosis (RRP) is caused by human papillomavirus type 6 (HPV-6). The long control region (LCR) contains cis-elements for regulation of transcription. Our aim was to characterize LCR HPV-6 variants in RRP cases, compare promoter activity of these isolates and search for cellular transcription factors (TFs) that could explain the differences observed. The complete LCR from 13 RRP was analyzed. Transcriptional activity of 5 variants was compared using luciferase assays. Differences in putative TFs binding sites among variants were revealed using the TRANSFAC database. Chromatin immunoprecipation (CHIP) and luciferase assays were used to evaluate TF binding and impact upon transcription, respectively. Juvenile-onset RRP cases harbored exclusively HPV-6vc related variants, whereas among adult-onset cases HPV-6a variants were more prevalent. The HPV-6vc reference was more transcriptionally active than the HPV-6a reference. Active FOXA1, ELF1 and GATA1 binding sites overlap variable nucleotide positions among isolates and influenced LCR activity. Furthermore, our results support a crucial role for ELF1 on transcriptional downregulation. We identified TFs implicated in the regulation of HPV-6 early gene expression. Many of these factors are mutated in cancer or are putative cancer biomarkers, and must be further studied.

No MeSH data available.


Related in: MedlinePlus