Δnp63α regulates keratinocyte proliferation by controlling PTEN expression and localization

M. K. Leonard, R. Kommagani, V. Payal, L. D. Mayo, H. N. Shamma, M. P. Kadakia

Research output: Contribution to journalArticle

38 Scopus citations

Abstract

ΔNp63α, implicated as an oncogene, is upregulated by activated Akt, part of a well-known cell survival pathway. Inhibition of Akt activation by phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and the presence of putative p63-binding sites in the pten promoter led us to investigate whether ΔNp63α regulates PTEN expression. Knockdown of ΔNp63α led to increases in PTEN levels and loss of activated Akt, while overexpression of ΔNp63α decreased PTEN levels and elevated active Akt. The repression of PTEN by ΔNp63α occurs independently of p53 status, as loss of ΔNp63α increases PTEN expression in cell lines with and without functional p53. In addition, decreased levels of ΔNp63α resulted in an increase in nuclear PTEN. Conversely, in vivo nuclear PTEN was absent in the proliferative basal layer of the epidermis where ΔNp63α expression is highest. Additionally, we show that in keratinocytes a balance between ΔNp63α and PTEN regulates Akt activation and maintains normal proliferation rates. This balance is disrupted in non-melanoma skin cancers through increased ΔNp63α levels, and could enhance proliferation and subsequent neoplastic development. Our studies show that ΔNp63α negatively regulates PTEN, thereby providing a feedback loop between PTEN, Akt and ΔNp63α, which has an integral role in skin cancer development.

Original languageEnglish (US)
Pages (from-to)1924-1933
Number of pages10
JournalCell Death and Differentiation
Volume18
Issue number12
DOIs
StatePublished - Dec 2011

Keywords

  • Akt
  • keratinocytes
  • p63
  • PTEN
  • skin cancer

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology

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