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A new E6/P63 pathway, together with a strong E7/E2F mitotic pathway, modulates the transcriptome in cervical cancer
Sébastien Teissier1, Youcef Ben Khalifa, Marcella Mori
1Unité Expression Génétique et Maladies, CNRS FRE 2850, Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris cedex 15, France.
Journal of Virology
|June 22, 2007
Summary
Human papillomavirus (HPV) E2's reintroduction in cervical cancer cells activates p53 pathways and represses E2F targets. New research reveals E2 modulates p63 and mitotic pathways, crucial for cervical cancer progression.
Area of Science:
- Oncology
- Virology
- Molecular Biology
Background:
- Cervical carcinoma is linked to human papillomaviruses (HPVs) expressing E6 and E7 oncogenes.
- HPV E6 and E7 oncogenes interact with p53 and pRB pathways, respectively, contributing to carcinogenesis.
- Loss of HPV E2 transcription factor expression, due to viral DNA integration, is a key event in malignant transformation.
Purpose of the Study:
- To identify novel pathways modulated by the HPV E2 transcription factor in cervical carcinoma cells.
- To elucidate the mechanisms by which E2 influences gene expression related to p63 and mitosis.
- To investigate the role of E6 and E7 pathways in cervical cancer progression.
Main Methods:
- Utilized high-density microarrays with over 22,000 human cDNA sequences.
- Employed small interfering RNA (siRNA) to silence specific pathways (E6/E6AP and E7).
- Analyzed gene expression in HeLa cervical carcinoma cell line and stage IV cervical cancer biopsies.
Main Results:
- Identified a novel p63 pathway among E2-activated genes.
- Discovered 38 new mitotic genes repressed by E2.
- Demonstrated that p63 target genes are activated via E6/E6AP silencing, and mitotic genes are repressed via E7 silencing.
- Observed significant induction of a subset of mitotic genes in stage IV cervical cancer biopsies.
Conclusions:
- HPV E2 reintroduction modulates distinct p63 and mitotic gene pathways.
- The E6/E6AP and E7 pathways play critical roles in regulating these E2-modulated genes in cervical cancer.
- The E7 pathway is prominently involved in the progression of advanced cervical carcinoma.
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