RGS2-mediated translational control mediates cancer cell dormancy and tumor relapse

J Clin Invest. 2021 Jan 4;131(1):e136779. doi: 10.1172/JCI136779.


Slow-cycling/dormant cancer cells (SCCs) have pivotal roles in driving cancer relapse and drug resistance. A mechanistic explanation for cancer cell dormancy and therapeutic strategies targeting SCCs are necessary to improve patient prognosis, but are limited because of technical challenges to obtaining SCCs. Here, by applying proliferation-sensitive dyes and chemotherapeutics to non-small cell lung cancer (NSCLC) cell lines and patient-derived xenografts, we identified a distinct SCC subpopulation that resembled SCCs in patient tumors. These SCCs displayed major dormancy-like phenotypes and high survival capacity under hostile microenvironments through transcriptional upregulation of regulator of G protein signaling 2 (RGS2). Database analysis revealed RGS2 as a biomarker of retarded proliferation and poor prognosis in NSCLC. We showed that RGS2 caused prolonged translational arrest in SCCs through persistent eukaryotic initiation factor 2 (eIF2α) phosphorylation via proteasome-mediated degradation of activating transcription factor 4 (ATF4). Translational activation through RGS2 antagonism or the use of phosphodiesterase 5 inhibitors, including sildenafil (Viagra), promoted ER stress-induced apoptosis in SCCs in vitro and in vivo under stressed conditions, such as those induced by chemotherapy. Our results suggest that a low-dose chemotherapy and translation-instigating pharmacological intervention in combination is an effective strategy to prevent tumor progression in NSCLC patients after rigorous chemotherapy.

Keywords: Cell Biology; Lung cancer; Oncology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Female
  • Humans
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Neoplasm Proteins / metabolism*
  • Protein Biosynthesis*
  • RGS Proteins / genetics
  • RGS Proteins / metabolism*
  • Recurrence
  • Xenograft Model Antitumor Assays


  • Neoplasm Proteins
  • RGS Proteins
  • RGS2 protein, human