Human papillomavirus E6 and E7 oncoproteins affect the expression of cancer-related microRNAs: additional evidence in HPV-induced tumorigenesis.
OBJECTIVE
Human papillomaviruses (HPVs) are the causative agents of cervical cancer and are also associated with other types of cancers. HPVs can modulate microRNAs (miRNAs) expressed by infected cells. The production of extracellular vesicles is deregulated in cancer, and their cargo delivered to the microenvironment can promote tumorigenesis. The involvement of HPV oncoproteins on miRNA expression in cells and exosomes was analyzed in keratinocytes transduced with E6 and E7 from mucosal HPV-16 or cutaneous HPV-38 (K16 and K38).


METHODS
MiRNAs were investigated through the TaqMan Array Human MicroRNA Cards, followed by real-time RT-PCR assay for specific miRNAs. Selected miRNA targets were analyzed by Western blot and correlated to the HPV oncoproteins by specifically silencing E6 and E7 expression. Exosomes, isolated from K16 and K38 supernatants by differential centrifugations, were quantified through the vesicle-associated acetylcholinesterase activity.


RESULTS
MiRNAs deregulated in K16 and K38 cells were identified. HPV-16 and/or HPV-38 E6 and E7 single proteins can modify the expression of selected miRNAs involved in the tumorigenesis, in particular miR-18a, -19a, -34a and -590-5p. The analysis of the content of exosomes isolated from HPV-positive cells revealed the presence of E6 and E7 mRNAs and few miRNAs. MiR-222, a key miRNA deregulated in many cancers, was identified in exosomes from K16 cells.


CONCLUSIONS
HPV E6 and/or E7 oncoprotein expression can induce the deregulation of some miRNAs. Through the production and function of exosomes, HPV oncogenes as well as HPV-deregulated miRNAs can potentiate the virus oncogenic effects in the tumor cell microenvironment.
Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, 00161, Rome, Italy. mariavincenza.chiantore@iss.it.
Maria Vincenza
MV
Chiantore
Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, 04100, Latina, Italy.
Giorgio
G
Mangino
Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, 04100, Latina, Italy.
Marco
M
Iuliano
Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, 04100, Latina, Italy.
Maria Simona
MS
Zangrillo
Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, 00161, Rome, Italy.
Ilaria
I
De Lillis
Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, 00161, Rome, Italy.
Gabriele
G
Vaccari
Infections and Cancer Biology Group, International Agency for Research on Cancer, 69372, Lyon, France.
Rosita
R
Accardi
Infections and Cancer Biology Group, International Agency for Research on Cancer, 69372, Lyon, France.
Massimo
M
Tommasino
Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Rome, Italy.
Sandra
S
Columba Cabezas
National AIDS Center, Istituto Superiore di Sanità, 00161, Rome, Italy.
Maurizio
M
Federico
Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, 00161, Rome, Italy.|Institute of Molecular Biology and Pathology, Consiglio Nazionale delle Ricerche, 00161, Rome, Italy.
Gianna
G
Fiorucci
Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, 00161, Rome, Italy.|Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, 04100, Latina, Italy.|Institute of Molecular Biology and Pathology, Consiglio Nazionale delle Ricerche, 00161, Rome, Italy.
Giovanna
G
Romeo
D063646:Carcinogenesis; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics* / Q000821:virology; D009856:Oncogene Proteins, Viral / Q000378:metabolism*
D035683:MicroRNAs; D009856:Oncogene Proteins, Viral
Exosomes; Human papillomavirus; Oncoproteins; microRNAs