Growth inhibition by miR-519 via multiple p21-inducing pathways

Mol Cell Biol. 2012 Jul;32(13):2530-48. doi: 10.1128/MCB.00510-12. Epub 2012 Apr 30.

Abstract

The microRNA miR-519 robustly inhibits cell proliferation, in turn triggering senescence and decreasing tumor growth. However, the molecular mediators of miR-519-elicited growth inhibition are unknown. Here, we systematically investigated the influence of miR-519 on gene expression profiles leading to growth cessation in HeLa human cervical carcinoma cells. By analyzing miR-519-triggered changes in protein and mRNA expression patterns and by identifying mRNAs associated with biotinylated miR-519, we uncovered two prominent subsets of miR-519-regulated mRNAs. One subset of miR-519 target mRNAs encoded DNA maintenance proteins (including DUT1, EXO1, RPA2, and POLE4); miR-519 repressed their expression and increased DNA damage, in turn raising the levels of the cyclin-dependent kinase (cdk) inhibitor p21. The other subset of miR-519 target mRNAs encoded proteins that control intracellular calcium levels (notably, ATP2C1 and ORAI1); their downregulation by miR-519 aberrantly elevated levels of cytosolic [Ca(2+)] storage in HeLa cells, similarly increasing p21 levels in a manner dependent on the Ca(2+)-activated kinases CaMKII and GSK3β. The rises in levels of DNA damage, the Ca(2+) concentration, and p21 levels stimulated an autophagic phenotype in HeLa and other human carcinoma cell lines. As a consequence, ATP levels increased, and the level of activity of the AMP-activated protein kinase (AMPK) declined, further contributing to the elevation in the abundance of p21. Our results indicate that miR-519 promotes DNA damage, alters Ca(2+) homeostasis, and enhances energy production; together, these processes elevate the expression level of p21, promoting growth inhibition and cell survival.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Autophagy
  • Base Sequence
  • Calcium / metabolism
  • Calcium Channels / genetics
  • Calcium Signaling
  • Calcium-Transporting ATPases / genetics
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Survival
  • Cyclin-Dependent Kinase Inhibitor p21 / antagonists & inhibitors
  • Cyclin-Dependent Kinase Inhibitor p21 / genetics
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism*
  • DNA Damage
  • DNA Polymerase II / genetics
  • DNA Repair
  • DNA Repair Enzymes / genetics
  • Energy Metabolism
  • Exodeoxyribonucleases / genetics
  • HeLa Cells
  • Humans
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism*
  • Models, Biological
  • ORAI1 Protein
  • Poly-ADP-Ribose Binding Proteins
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / genetics
  • Replication Protein A / genetics
  • Signal Transduction

Substances

  • CDKN1A protein, human
  • Calcium Channels
  • Cyclin-Dependent Kinase Inhibitor p21
  • MIRN519 microRNA, human
  • MicroRNAs
  • ORAI1 Protein
  • ORAI1 protein, human
  • Poly-ADP-Ribose Binding Proteins
  • RNA, Messenger
  • RNA, Small Interfering
  • Replication Protein A
  • DNA Polymerase II
  • POLE protein, human
  • RPA2 protein, human
  • EXO1 protein, human
  • Exodeoxyribonucleases
  • DNA Repair Enzymes
  • ATP2C1 protein, human
  • Calcium-Transporting ATPases
  • Calcium