Targeted disruption of TC-PTP in the proliferative compartment augments STAT3 and AKT signaling and skin tumor development

Sci Rep. 2017 Mar 21:7:45077. doi: 10.1038/srep45077.

Abstract

Tyrosine phosphorylation is a vital mechanism that contributes to skin carcinogenesis. It is regulated by the counter-activities of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Here, we report the critical role of T-cell protein tyrosine phosphatase (TC-PTP), encoded by Ptpn2, in chemically-induced skin carcinogenesis via the negative regulation of STAT3 and AKT signaling. Using epidermal specific TC-PTP knockout (K14Cre.Ptpn2fl/fl) mice, we demonstrate loss of TC-PTP led to a desensitization to tumor initiator 7,12-dimethylbenz[a]anthracene (DMBA)-induced apoptosis both in vivo epidermis and in vitro keratinocytes. TC-PTP deficiency also resulted in a significant increase in epidermal thickness and hyperproliferation following exposure to the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Western blot analysis showed that both phosphorylated STAT3 and phosphorylated AKT expressions were significantly increased in epidermis of TC-PTP-deficient mice compared to control mice following TPA treatment. Inhibition of STAT3 or AKT reversed the effects of TC-PTP deficiency on apoptosis and proliferation. Finally, TC-PTP knockout mice showed a shortened latency of tumorigenesis and significantly increased numbers of tumors during two-stage skin carcinogenesis. Our findings reveal that TC-PTP has potential as a novel target for the prevention of skin cancer through its role in the regulation of STAT3 and AKT signaling.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alleles
  • Animals
  • Apoptosis / genetics
  • Cell Proliferation
  • Cell Transformation, Neoplastic / genetics*
  • Cell Transformation, Neoplastic / metabolism*
  • Disease Models, Animal
  • Epidermis / metabolism
  • Epidermis / pathology
  • Gene Knockout Techniques
  • Gene Targeting
  • Hyperplasia
  • Keratinocytes / drug effects
  • Keratinocytes / metabolism
  • Keratinocytes / pathology
  • Mice
  • Mice, Knockout
  • Organ Specificity
  • Phosphorylation
  • Protein Tyrosine Phosphatase, Non-Receptor Type 2 / genetics*
  • Protein Tyrosine Phosphatase, Non-Receptor Type 2 / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism*
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction*
  • Skin Neoplasms / genetics*
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / pathology
  • Tetradecanoylphorbol Acetate / pharmacology

Substances

  • STAT3 Transcription Factor
  • Proto-Oncogene Proteins c-akt
  • Protein Tyrosine Phosphatase, Non-Receptor Type 2
  • Tetradecanoylphorbol Acetate