CRISPR Knockout of the HuR Gene Causes a Xenograft Lethal Phenotype

Mol Cancer Res. 2017 Jun;15(6):696-707. doi: 10.1158/1541-7786.MCR-16-0361. Epub 2017 Feb 27.


Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related deaths in the United States, whereas colorectal cancer is the third most common cancer. The RNA-binding protein HuR (ELAVL1) supports a pro-oncogenic network in gastrointestinal (GI) cancer cells through enhanced HuR expression. Using a publically available database, HuR expression levels were determined to be increased in primary PDA and colorectal cancer tumor cohorts as compared with normal pancreas and colon tissues, respectively. CRISPR/Cas9 technology was successfully used to delete the HuR gene in both PDA (MIA PaCa-2 and Hs 766T) and colorectal cancer (HCT116) cell lines. HuR deficiency has a mild phenotype, in vitro, as HuR-deficient MIA PaCa-2 (MIA.HuR-KO(-/-)) cells had increased apoptosis when compared with isogenic wild-type (MIA.HuR-WT(+/+)) cells. Using this isogenic system, mRNAs were identified that specifically bound to HuR and were required for transforming a two-dimensional culture into three dimensional (i.e., organoids). Importantly, HuR-deficient MIA PaCa-2 and Hs 766T cells were unable to engraft tumors in vivo compared with control HuR-proficient cells, demonstrating a unique xenograft lethal phenotype. Although not as a dramatic phenotype, CRISPR knockout HuR HCT116 colon cancer cells (HCT.HuR-KO(-/-)) showed significantly reduced in vivo tumor growth compared with controls (HCT.HuR-WT(+/+)). Finally, HuR deletion affects KRAS activity and controls a subset of pro-oncogenic genes.Implications: The work reported here supports the notion that targeting HuR is a promising therapeutic strategy to treat GI malignancies. Mol Cancer Res; 15(6); 696-707. ©2017 AACR.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / genetics*
  • Adenocarcinoma / pathology
  • Animals
  • Carcinoma, Pancreatic Ductal / genetics*
  • Carcinoma, Pancreatic Ductal / pathology
  • Cell Line, Tumor
  • Clustered Regularly Interspaced Short Palindromic Repeats
  • Colonic Neoplasms / genetics*
  • Colonic Neoplasms / pathology
  • ELAV-Like Protein 1 / genetics*
  • ELAV-Like Protein 1 / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic
  • Gene Knockout Techniques
  • Humans
  • Mice, Nude
  • Neoplasms, Experimental / genetics
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology
  • Phenotype
  • Xenograft Model Antitumor Assays


  • ELAV-Like Protein 1
  • ELAVL1 protein, human