P63 drives invasion in keratinocytes expressing HPV16 E6/E7 genes through regulation of Src-FAK signalling.

Kirtiman Srivastava,Dennis J Mccance,Simon Mcdade,Adam Pickard

doi:10.18632/oncotarget.3892

Kirtiman Srivastava, Dennis J Mccance + Show 2 more

Open Access

https://doi.org/10.18632/oncotarget.3892

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Abstract

Using microarray information from oro-pharyngeal data sets and results from primary human foreskin keratinocytes (HFK) expressing Human Papilloma Virus (HPV)-16 E6/E7 proteins, we show that p63 expression regulates signalling molecules which initiate cell migration such as Src and focal adhesion kinase (FAK) and induce invasion in 3D-organotypic rafts; a phenotype that can be reversed by depletion of p63. Knockdown of Src or FAK in the invasive cells restored focal adhesion protein paxillin at cell periphery and impaired the cell migration. In addition, specific inhibition of FAK (PF573228) or Src (dasatinib) activities mitigated invasion and attenuated the expression/activity of matrix metalloproteinase 14 (MMP14), a pivotal MMP in the MMP activation cascade. Expression of constitutively active Src in non-invasive HFK expressing E6/E7 proteins upregulated the activity of c-Jun and MMP14, and induced invasion in rafts. Depletion of Src, FAK or AKT in the invasive cells normalised the expression/activity of c-Jun and MMP14, thus implicating the Src-FAK/AKT/AP-1 signalling in MMP14-mediated extra-cellular matrix remodelling. Up-regulation of Src, AP-1, MMP14 and p63 expression was confirmed in oro-pharyngeal cancer. Since p63 transcriptionally regulated expression of many of the genes in this signalling pathway, it suggests that it has a central role in cancer progression.

Highlights

Cases of head and neck squamous cell carcinomas (HNSCC) are increasing globally by 600,000/annum
Using human foreskin keratinocytes (HFK) expressing HPV16 E6 and E7 genes (E6/E7-HFK) we show that increased expression of p63 promotes migration and invasion in a Src-focal adhesion kinase (FAK)-dependent mechanism
We have previously shown that AKT signalling regulates cell migration and expression of matrix metalloproteinases (MMPs) [21, 22], so we investigated if AKT maybe downstream of the Src-FAK complex

Summary

INTRODUCTION

Cases of head and neck squamous cell carcinomas (HNSCC) are increasing globally by 600,000/annum. Genes from the nonreceptor tyrosine kinase family i.e. protein tyrosine kinase 2 (PTK2; which encodes focal adhesion kinase (FAK)) and Src are known regulators of cell migration [10, 11]. The activated Src-FAK complex is known to mediate the phosphorylation of scaffold proteins like paxillin at Tyr118 to trigger the disassembly of focal contacts, which is prerequisite for cell migration [17]. We show that p63, Src, PTK2, c-Jun (activator protein-1 (AP-1) transcription factor) and MMP14 genes are upregulated in patients with oro-pharyngeal cancers. Using human foreskin keratinocytes (HFK) expressing HPV16 E6 and E7 genes (E6/E7-HFK) we show that increased expression of p63 promotes migration and invasion in a Src-FAK-dependent mechanism. We further identified Src as pivotal regulator of ECM remodelling via AKT/AP-1/MMP14 dependent pathway

RESULTS

DISCUSSION

MATERIALS AND METHODS

Findings

28. Canc Genome Atlas Res N