ZNF185 is a p63 target gene critical for epidermal differentiation and squamous cell carcinoma development

Abstract

Development and maintenance of healthy stratified epithelia require the coordination of complex transcriptional programmes. The transcription factor p63, a member of the p53 family, plays a crucial role in epithelial development and homeostasis. Analysis of the p63-dependent transcriptome indicated that one important aspect of p63 functions in epithelial development is the regulation of cell–cell and cell–matrix adhesion programmes. However, limited knowledge exists on the relevant cell–cell adhesion molecules involved in physiological epithelial formation. Similarly, limited data are available to understand if deregulation of the cell–cell adhesion programme is important in tumour formation. Here, using the epidermis as an experimental model with the RNA sequencing approach, we identify a novel p63-regulated gene induced during differentiation, ZNF185. ZNF185 is an actin-cytoskeleton-associated Lin-l 1, Isl-1 and Mec-3 (LIM) domain-containing protein, whose function is poorly known. We found that p63 binds to a specific enhancer region, promoting its expression to sustain epithelial differentiation. ZNF185 silencing strongly impaired keratinocyte differentiation according to gene array analysis. ZNF185 is detected at the cell–cell periphery where it physically interacts with E-cadherin, indicating that it is important to maintain epithelial integrity beyond its pro-differentiation role. Interestingly, poorly differentiated, including head and neck, cervical and oesophageal, squamous cell carcinomas display loss of ZNF185 expression. Together, these studies reinforce that p63 is a crucial gene for maintaining epithelial tissue integrity and support the deregulation of the cell-cell adhesion programme,which plays a critical role in carcinoma development.

ZNF185 is a p53 target gene following DNA damage

“…We have previously shown that the p53 family member p63, using a novel promoter region and a specific enhancer, directly regulated ZNF185 expression in keratinocytes [33]. To investigate whether also p53 could regulate ZNF185 expression and expand the p53 target genes involved in cytoskeleton regulation and cell polarity, we further analysed ZNF185 promoter region using UCSC genome browser (Fig 1A).…”

ΔNp63 promotes IGF1 signalling through IRS1 in squamous cell carcinoma

“…RNA sequencing was performed as previously described [95]. Briefly, total RNA was extracted using a mirVana miRNA isolation kit (Thermo Fisher).…”

TP63 links chromatin remodeling and enhancer reprogramming to epidermal differentiation and squamous cell carcinoma development

“…The p63 protein also binds to the enhancer region of ZNF185 and promotes its expression in keratinocyte during epithelial differentiation. However, ZNF185 is downregulated in HNSCC, esophageal and cervical SCC even though p63 is commonly amplified in these cancers [ 27 ]. It is not clear why ZNF185 is decreased in SCC, and may be due to loss of function mutations on coactivators bound to p63, which results in a decrease of enhancer activity of ZNF185 in SCC cells.…”

“…ΔNp63α is the prominent isoform of the TP63 gene expressed in keratinocytes and basal cells of diverse epithelia [ 19 – 21 ] and various SCCs [ 2 ]. ΔNp63α promotes SCC development through regulating different target genes, including cell growth and proliferation [ 22 , 23 ], extracellular matrix (ECM)–receptor interaction [ 24 ], cell adhesion [ 25 – 27 ], glucose metabolism [ 28 , 29 ], anti-oxidant defense [ 30 , 31 ], DNA damage repair [ 32 , 33 ], terminal differentiation [ 34 , 35 ], and inflammation and angiogenesis [ 36 – 41 ] (Fig. 2 ).…”