The CRTC1-NEDD9 signaling axis mediates lung cancer progression caused by LKB1 loss

Cancer Res. 2012 Dec 15;72(24):6502-11. doi: 10.1158/0008-5472.CAN-12-1909. Epub 2012 Oct 16.

Abstract

Somatic mutation of the tumor suppressor gene LKB1 occurs frequently in lung cancer where it causes tumor progression and metastasis, but the underlying mechanisms remain mainly unknown. Here, we show that the oncogene NEDD9 is an important downstream mediator of lung cancer progression evoked by LKB1 loss. In de novo mouse models, RNAi-mediated silencing of Nedd9 inhibited lung tumor progression, whereas ectopic NEDD9 expression accelerated this process. Mechanistically, LKB1 negatively regulated NEDD9 transcription by promoting cytosolic translocation of CRTC1 from the nucleus. Notably, ectopic expression of either NEDD9 or CRTC1 partially reversed the inhibitory function of LKB1 on metastasis of lung cancer cells. In clinical specimens, elevated expression of NEDD9 was associated with malignant progression and metastasis. Collectively, our results decipher the mechanism through which LKB1 deficiency promotes lung cancer progression and metastasis, and provide a mechanistic rationale for therapeutic attack of these processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinase Kinases
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Adaptor Proteins, Signal Transducing / physiology*
  • Animals
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism
  • Carcinoma, Non-Small-Cell Lung / pathology*
  • Cell Line, Tumor
  • Disease Progression
  • Gene Deletion
  • Gene Expression Regulation, Neoplastic
  • HEK293 Cells
  • Humans
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology*
  • Male
  • Mice
  • Mice, Nude
  • Mice, Transgenic
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism
  • Phosphoproteins / physiology*
  • Protein Serine-Threonine Kinases / genetics*
  • Signal Transduction / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription Factors / physiology*

Substances

  • Adaptor Proteins, Signal Transducing
  • CRTC1 protein, human
  • NEDD9 protein, human
  • Phosphoproteins
  • Transcription Factors
  • Protein Serine-Threonine Kinases
  • STK11 protein, human
  • AMP-Activated Protein Kinase Kinases