HPV16 E6 regulates annexin 1 (ANXA1) protein expression in cervical carcinoma cell lines

Marilia Freitas Calmon; Laura Sichero; Enrique Boccardo; Luisa Lina Villa; Paula Rahal

doi:10.1016/j.virol.2016.05.016

HPV16 E6 regulates annexin 1 (ANXA1) protein expression in cervical carcinoma cell lines

Virology. 2016 Sep:496:35-41. doi: 10.1016/j.virol.2016.05.016. Epub 2016 May 28.

Authors

Marilia Freitas Calmon¹, Laura Sichero², Enrique Boccardo³, Luisa Lina Villa⁴, Paula Rahal⁵

Affiliations

¹ Department of Biology, Institute of Bioscience, Language and Exact Science, São Paulo State University, São Jose do Rio Preto, Brazil.
² Molecular Biology Laboratory, Centre for Translational Research in Oncology, Instituto do Câncer do Estado de São Paulo (ICESP), São Paulo, Brazil.
³ Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo., São Paulo, Brazil.
⁴ Department of Radiology and Oncology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
⁵ Department of Biology, Institute of Bioscience, Language and Exact Science, São Paulo State University, São Jose do Rio Preto, Brazil. Electronic address: rahalp@yahoo.com.br.

PMID: 27240147
DOI: 10.1016/j.virol.2016.05.016

Abstract

Annexin 1 (ANXA1) is a substrate for E6AP mediated ubiquitylation. It has been hypothesized that HPV 16 E6 protein redirects E6AP away from ANXA1, increasing its stability and possibly contributing to viral pathogenesis. We analyzed ANXA1 expression in HPV-positive and negative cervical carcinoma-derived cells, in cells expressing HPV-16 oncogenes and in cells transduced with shRNA targeting E6AP. We observed that ANXA1 protein expression increased in HPV-16-positive tumor cells, in keratinocytes expressing HPV-16 E6wt (wild-type) or E6/E7 and C33 cells expressing HPV-16 E6wt. ANXA1 protein expression decreased in cells transfected with E6 Dicer-substrate RNAs (DsiRNA) and C33 cells cotransduced with HPV-16 E6wt and E6AP shRNA. Moreover, colony number and proliferation rate decreased in HPV16-positive cells transduced with ANXA1 shRNA. We observed that in cells infected with HPV16, the E6 binds to E6AP to degrade p53 and upregulate ANXA1. We suggest that ANXA1 may play a role in HPV-mediated carcinogenesis.

Keywords: ANXA1; Cervical cell lines; E6; HPV16; Keratinocytes; P53.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Annexin A1 / genetics
Annexin A1 / metabolism*
Cell Line, Tumor
Female
Gene Expression
Gene Knockdown Techniques
Human papillomavirus 16 / physiology
Humans
Oncogene Proteins, Viral / genetics
Oncogene Proteins, Viral / metabolism*
Papillomavirus Infections / complications
Papillomavirus Infections / virology
Proteolysis
RNA Interference
RNA, Messenger / genetics
RNA, Messenger / metabolism
RNA, Small Interfering / genetics
Repressor Proteins / genetics
Repressor Proteins / metabolism*
Tumor Suppressor Protein p53 / genetics
Tumor Suppressor Protein p53 / metabolism
Uterine Cervical Neoplasms / etiology*
Uterine Cervical Neoplasms / metabolism*

Substances

Annexin A1
E6 protein, Human papillomavirus type 16
Oncogene Proteins, Viral
RNA, Messenger
RNA, Small Interfering
Repressor Proteins
Tumor Suppressor Protein p53