The PDZ-Binding Motif of HPV16-E6 Oncoprotein Modulates the Keratinization and Stemness Transcriptional Profile In Vivo.

Enoc Mariano Cortés-Malagón,Gloria Fernádez-Tilapa,Odette Verdejo-Torres,Patricio Gariglio,José Bonilla-Delgado,Jaime Escobar-Herrera,José Moreno,Mario Adan Moreno-Eutimio,Alfredo Hidalgo-Miranda,Daniel Mendoza-Villanueva,Carmen Palacios-Reyes,Rubén Gerardo Contreras,Sandra Romero-Cordoba

doi:10.1155/2017/7868645

Abstract

Objective The aim of this work was to compare the early gene expression profiles in the skin of HPV16-E6 transgenic mice regulated by the E6 PDZ-binding motif. Materials and Methods The global transcriptional profiles in dorsal skin biopsies from K14E6 and K14E6Δ146-151 transgenic mice were compared using microarrays. Relevant genes obtained from the most differentially expressed processes were further examined by RT-qPCR, in situ RT-PCR, Western blot, or immunofluorescence. Results The transcriptomic landscape of K14E6 versus K14E6Δ146-151 shows that the most affected expression profiles were those related to keratinocyte differentiation, stem cell maintenance, and keratinization. Additionally, downregulation of epidermal stemness markers such as K15 and CD34, as well as the upregulation of cytokeratin 6b, appeared to be dependent on the E6 PDZ-binding motif. Finally, wound healing, a physiological process linked to stemness, is impaired in the K14E6 mice compared to K14E6Δ146-151. Conclusion The E6 PDZ-binding motif appears to affect stemness and keratinization during early stages of skin carcinogenesis. As E6 plays a significant role in HPV-induced skin carcinogenesis, the K14E6 versus K14E6Δ146-151 transcriptional profile provides a source of valuable data to uncover novel E6 functions in the skin.

Highlights

Human papillomaviruses (HPVs) are small double-stranded DNA viruses that are the main factors for cervical intraepithelial neoplasia, warts, and, less commonly, nonmelanoma skin cancers (NMSCs) [1]
The most frequent NMSCs lesions caused by HPV infections are epidermoid carcinomas, which in the majority of the cases are associated with HPV beta genus, the HPV5 and 8 genotypes [4]
HPV-alpha genus rarely infects the nonmucosal skin, HPV16 infections are found in epidermoid carcinomas in the perianal skin [5], and experimental data on K14E6 transgenic mice suggest that the sole expression of the E6-HPV16 oncoprotein in the basal stratum suffices to generate grade I–III epidermoid carcinomas in the dorsal skin of 1-year-old mice [6]

Summary

Introduction

Human papillomaviruses (HPVs) are small double-stranded DNA viruses that are the main factors for cervical intraepithelial neoplasia, warts, and, less commonly, nonmelanoma skin cancers (NMSCs) [1]. The HPV infects the basal stratum of injured stratified epithelia at a variety of anatomical sites. Most of the HPV oncogenic potential is mediated by E6 and E7 oncogenes, whose protein products block cellular differentiation and induce cell proliferation by mechanisms that are, as yet, not fully understood [3]. Much less is known about NMSCs caused by HPV infections. The most frequent NMSCs lesions caused by HPV infections are epidermoid carcinomas, which in the majority of the cases are associated with HPV beta genus, the HPV5 and 8 genotypes [4]. The HPV16-E6 oncogenic potential in the skin can be virtually ablated in vivo if a truncated version of the E6 oncoprotein, lacking the PDZbinding motif (K14E6Δ146-151 mice), is expressed in the basal stratum [7]

Methods

Results

Conclusion