Loss of CDKN2A at chromosome 9 has a poor clinical prognosis and promotes lung cancer progression

Mol Genet Genomic Med. 2020 Dec;8(12):e1521. doi: 10.1002/mgg3.1521. Epub 2020 Nov 6.

Abstract

Objective: This study aimed to identify critical genes involved in the tumor biology of lung cancer via datamining of The Cancer Genome Atlas (TCGA) with special focus on gene copy number variation.

Methods: Genomic deletion and amplification were analyzed with cBioportal online tools. Relative expression of Cyclin Dependent Kinase Inhibitor 2A (CDKN2A) was analyzed by both real-time polymerase chain reaction (PCR) and Western blot. The abundance of methylthioadenosine phosphorylase (MTAP) and epithelial-mesenchymal transition markers were analyzed by real-time PCR. Cell proliferation was determined by cell counting kit-8 method and cell viability was measured with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cell migration and invasion were measured with transwell chamber assay, and migrative capacity was further evaluated by wound healing assay.

Results: We found the frequent loss of CDKN2A was associated with its downregulation in lung cancer, and siRNA-mediated CDNKN2A knockdown significantly stimulated cell proliferation, invasion, and migration. Mechanistically, we unraveled that MTAP, which was positively correlated with CDKN2A, predominantly mediated the antitumoral function of CDKN2A in lung cancer.

Conclusion: Our study consolidated the involvement of CDKN2A-MTAP signaling in the context of lung cancer.

Keywords: CDKN2A; MTAP; copy number variation; lung cancer.

MeSH terms

  • A549 Cells
  • Biomarkers, Tumor / deficiency
  • Biomarkers, Tumor / genetics*
  • Biomarkers, Tumor / metabolism
  • Cell Movement
  • Cell Proliferation
  • Chromosomes, Human, Pair 9 / genetics
  • Cyclin-Dependent Kinase Inhibitor p16 / deficiency
  • Cyclin-Dependent Kinase Inhibitor p16 / genetics*
  • Cyclin-Dependent Kinase Inhibitor p16 / metabolism
  • Epithelial-Mesenchymal Transition
  • Humans
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Purine-Nucleoside Phosphorylase / metabolism

Substances

  • Biomarkers, Tumor
  • CDKN2A protein, human
  • Cyclin-Dependent Kinase Inhibitor p16
  • Purine-Nucleoside Phosphorylase
  • 5'-methylthioadenosine phosphorylase