1. Genome-wide CRISPR screen identifies LGALS2 as an oxidative stress-responsive gene with an inhibitory function on colon tumor growth
- Author
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Haiwen Li, Renzhi Han, Yeh Siang Lau, Chen Zhang, and Lixia Zhao
- Subjects
Male ,STAT3 Transcription Factor ,0301 basic medicine ,Cancer Research ,Cell Survival ,Galectin 2 ,Colorectal cancer ,Azoxymethane ,medicine.disease_cause ,Article ,Stress signalling ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Genetics ,medicine ,Animals ,Humans ,Phosphorylation ,Colitis ,STAT3 ,Molecular Biology ,Acute colitis ,Whole Genome Sequencing ,biology ,Dextran Sulfate ,High-throughput screening ,High-Throughput Nucleotide Sequencing ,Cancer ,Hydrogen Peroxide ,medicine.disease ,Disease Models, Animal ,Oxidative Stress ,HEK293 Cells ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,biology.protein ,Cancer research ,Female ,CRISPR-Cas Systems ,Colorectal Neoplasms ,Reactive Oxygen Species ,Carcinogenesis ,Oxidative stress - Abstract
Colorectal cancer is the third leading cause of cancer-related deaths in the United States and the third most common cancer in men and women. Around 20% colon cancer cases are closely linked with colitis. Both environmental and genetic factors are thought to contribute to colon inflammation and tumor development. However, the genetic factors regulating colitis and colon tumorigenesis remain elusive. Since reactive oxygen species (ROS) is vitally involved in tissue inflammation and tumorigenesis, here we employed a genome-wide CRISPR knockout screening approach to systemically identify the genetic factors involved in the regulation of oxidative stress. Next generation sequencing (NGS) showed that over 600 gRNAs including the ones targeting LGALS2 were highly enriched in cells survived after sublethal H2O2 challenge. LGALS2 encodes the glycan-binding protein Galectin 2 (Gal2), which is predominantly expressed in the gastrointestinal tract and downregulated in human colon tumors. To examine the role of Gal2 in colitis, we employed the dextran sodium sulfate (DSS)-induced acute colitis model in mice with (WT) or without Lgals2 (Gal2-KO) and showed that Gal2 deficiency ameliorated DSS-induced colitis. We further demonstrated that Gal2-KO mice developed significantly larger tumors than WT mice using Azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colorectal cancer model. We found that STAT3 phosphorylation was significantly increased in Gal2-deficient tumors as compared to those in WT mice. Gal2 overexpression decreased the proliferation of human colon tumor epithelial cells and blunted H2O2-induced STAT3 phosphorylation. Overall, our results demonstrate that Gal2 plays a suppressive role in colon tumor growth and highlights the therapeutic potential of Gal2 in colon cancer.
- Published
- 2020